WO2021103772A1

WO2021103772A1 - Data transmission method and apparatus

Info

Publication number: WO2021103772A1
Application number: PCT/CN2020/116374
Authority: WO
Inventors: 欧锻灏
Original assignee: 华为技术有限公司
Priority date: 2019-11-30
Filing date: 2020-09-21
Publication date: 2021-06-03
Also published as: CN112887971B; CN112887971A

Abstract

Embodiments of the present application provide a data transmission method and apparatus. The method comprises: a core network device may transmit, to a base station, a base station private key corresponding to a base station public key; and when transmitting a broadcast message to a UE, the base station obtains signature information by means of a base station private key signature, and carries the signature information and the base station public key in the broadcast message and transmits to the UE. By carrying, in the broadcast message, the signature information, which uses the base station private key signature, and the base station public key, the UE can verify, according to the signature information and the base station public key, whether the message is from a legitimate base station, so as to refuse the operation of a pseudo base station, and the base station public key is carried in the broadcast message and transmitted to the UE, and thus, the prevent invention can avoid the problem that the UE is unavailable caused because the pseudo base station intentionally transmits a large number of waste public keys to deplete the storage resource of the UE.

Description

Data transmission method and device

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office, the application number is 201911208412.3, and the application name is "Data Transmission Method and Device" on November 30, 2019, the entire content of which is incorporated into this application by reference.

Technical field

This application relates to communication technology, and in particular to a data transmission method and device.

Background technique

The base station and user equipment (User equipment, UE) communicate through the air interface. On the one hand, the information sent by the UE to the base station through the air interface includes pre-authentication information encrypted with the core network (Core network, CN) public key. The routing information that needs to be sensed by the base station (such as slice information or UE capability information, etc.). The routing information that needs to be sensed by the base station is currently not encrypted. It is transmitted in plain text on the air interface. The routing information that needs to be sensed by the base station may be tampered with, thereby threatening the UE. Or the safety of the operator. On the other hand, the UE cannot identify whether the broadcast message is from a pseudo base station or a legitimate base station, and may be attacked by the pseudo base station. Therefore, a security mechanism is needed to ensure the security of the air interface communication between the UE and the base station.

Summary of the invention

The embodiments of the present application provide a data transmission method and device, so that a UE can identify a pseudo base station and avoid illegal operations of the pseudo base station on the UE.

The first aspect of the present application provides a data transmission method, including: a base station requests a base station private key corresponding to a base station public key from a core network device, the base station sends a broadcast message to the UE, and the broadcast message includes signature information and the base station The public key, and the signature information is obtained by the base station through the base station's private key signature.

On the one hand, in this application, the PKG function is integrated into existing core network equipment, such as UDM network elements. The core network equipment will generate a pair of master public key MPK and master private key MSK, and the master private key is securely stored in In the core network equipment, the master public key is securely issued to the UE. The core network device issues the corresponding base station private key to the legal base station that has passed the authentication according to its identity. The base station and the core network device can reuse the existing authentication method between the base station and the core network for mutual authentication, avoiding repeated construction .

On the other hand, the base station carries the signature information signed with the base station private key and the base station public key in the broadcast message, so that the UE can verify whether the message comes from a legitimate base station based on the signature information and the base station public key, thereby rejecting the operation of the pseudo base station, The base station public key is carried in a broadcast message and sent to the UE, which can prevent the pseudo base station from deliberately sending massive garbage public keys to exhaust the storage resources of the UE and cause the UE to be unavailable.

In an exemplary manner, the broadcast message includes a first replay parameter, and the first replay parameter is used by the UE to verify whether the broadcast message is a replay message.

The base station carries replay parameters in the broadcast message, so that the UE can identify whether the received broadcast message is sent by a legitimate base station or a replay message sent by a pseudo base station, thereby avoiding replay attacks.

In an exemplary manner, the method further includes:

The base station receives the response message of the broadcast message sent by the UE, and the response message of the broadcast message includes first encryption information, and the first encryption information is the UE according to the base station public key and the stored master public key. The key is obtained by encrypting the first information;

The base station uses the base station private key to decrypt the first encrypted information. The base station private key is generated by the core network device according to the base station public key and the master private key. The master private key is a pair of secret keys generated by the core network device;

If the base station fails to decrypt the first encrypted information using the base station private key, the base station discards the response message of the broadcast message.

The UE can use the base station public key and the master public key to encrypt the information that needs to be sensed by the base station in the response message of the broadcast message, which can ensure the security of the information that needs to be sensed by the base station, thereby avoiding the leakage of the information that needs to be sensed by the base station. Cause losses to users or operators. After receiving the response message of the broadcast message, the base station decrypts the encrypted information according to the base station private key to obtain the information that needs to be sensed.

In an exemplary manner, the response message of the broadcast message includes the second replay parameter, and the method further includes:

Verifying, by the base station, whether the response message of the broadcast message is a replay message according to the second replay parameter;

The decryption of the first encrypted information by the base station using the base station private key includes:

When verifying that the response message of the broadcast message is not a replay message, the base station uses the base station private key to decrypt the first encrypted information.

The method further includes: when verifying that the response message of the broadcast message is a replay message, the base station discards the response message of the broadcast message.

The UE carries replay parameters in the response message of the broadcast message, so that the base station can identify whether the response message of the received broadcast message is sent by a legitimate UE or a replay message sent by other devices, thereby avoiding replay attacks.

In an exemplary manner, after the base station obtains the base station private key from the core network device, the base station private key is not stored.

As the base station has limited resources compared with PKG, the base station private key stored in the base station may have the risk of leakage. In this method, the base station does not need to save the base station private key, but dynamically requests the base station private key every time, which reduces the leakage of the base station private key. It also saves the storage resources of the base station.

In an exemplary manner, the base station requesting the base station private key corresponding to the base station public key from the core network device includes:

Sending, by the base station, a first request message to the core network device, where the first request message includes the base station public key;

The base station receives a response message of the first request message sent by the core network device, and the response message of the first request includes the base station private key.

In an exemplary manner, the base station public key includes a base station identity and a validity period of the base station public key.

In an exemplary manner, the base station public key includes a base station identity identifier.

In an exemplary manner, when the base station public key includes a base station identity, the first encryption information is obtained by the UE encrypted according to the base station public key, the master public key, and first time information The first time information is related to the current timestamp and the first time interval when the UE is encrypted; the base station private key is the core network device according to the base station public key, the master private key, and the second time interval. When time information is generated, the second time information is related to the current timestamp when the core network device generates the base station private key and the first time interval.

In an exemplary manner, the core network device is a unified data management UDM network element.

In an exemplary manner, the base station and the core network device perform identity authentication based on the Internet security protocol IPsec.

The second aspect of the present application provides a data transmission method, including: a UE receives a broadcast message sent by a base station, the broadcast message includes signature information and a base station public key, and the signature information is obtained by the base station through the base station private key signature The base station private key is sent to the base station by the core network equipment; the UE verifies whether the broadcast message comes from a legitimate base station according to the stored master public key, the base station public key, and the signature information. The public key is generated by the core network equipment for the UE; when the broadcast message comes from a legal base station, the UE processes the broadcast message; when the broadcast message does not come from a legal base station, the UE The broadcast message is discarded.

In an exemplary manner, the broadcast message includes the first playback parameter, and the UE verifies whether the broadcast message comes from a legitimate base station according to the saved master public key, the base station public key, and the signature information, include:

Verifying, by the UE, whether the broadcast message is a replay message according to the first replay parameter;

The UE verifies the signature information according to the master public key and the base station public key;

When it is verified that the broadcast message is not a replay message, and the signature information is successfully verified according to the master public key and the base station public key, it is determined that the broadcast message comes from a legitimate base station.

In an exemplary manner, it further includes:

When the broadcast message comes from a legitimate base station, the UE sends a response message of the broadcast message to the base station. The response message of the broadcast message includes first encryption information, and the first encryption information is the UE Obtained by encrypting the first information according to the base station public key and the master public key.

In an exemplary manner, the response message of the broadcast message further includes a second replay parameter, and the second replay parameter is used by the base station to verify whether the response message of the broadcast message is a replay message.

In an exemplary manner, the base station public key includes a base station identity and the validity period of the base station public key; the UE verifies the broadcast according to the stored master public key, the base station public key, and the signature information. Whether the message comes from a legitimate base station, including:

The UE verifies whether the validity period of the base station public key is valid;

When the validity period of the base station public key is valid, the UE verifies the signature information according to the master public key and the base station public key;

Determine whether the broadcast message comes from a legal base station according to the verification result of the signature information.

In an exemplary manner, the base station public key includes a base station identity, and the UE verifies whether the broadcast message comes from a legitimate base station according to the stored master public key, the base station public key, and the signature information, including:

The UE verifies the signature information according to the master public key, the base station public key, and third time information, where the third time information is related to the current timestamp and the first time interval of the UE;

When the base station public key includes a base station identity, the first encryption information may be obtained by the UE encrypting the first information according to the base station public key, the master public key, and first time information, The first time information is related to the current timestamp when the UE is encrypted and the first time interval.

In an exemplary manner, the core network device is a UDM network element.

For the beneficial effects of the method provided in the second aspect of the present application, refer to the description of the beneficial effects of the corresponding content in the first aspect, which will not be repeated here.

A third aspect of the present application provides a data transmission method, further comprising: a core network device receives a request message sent by a base station, the request message includes the base station public key of the base station; the core network device according to the base station public key The base station private key corresponding to the base station public key is generated with the master private key; the core network device sends the base station private key to the base station.

In an exemplary manner, the method further includes: the core network device generates a secret key pair, the secret key pair includes a master public key and the master private key; the core network device stores the master private key Key, the master public key is securely issued to the user equipment UE.

In an exemplary manner, the core network device is a UDM network element, and only after the UDM network element performs identity authentication with the base station, the UDM network element issues a base station private key to the base station.

In this application, the PKG function is integrated into existing core network equipment, such as UDM network elements. The core network equipment will generate a pair of master public key MPK and master private key MSK, and the master private key is securely stored in the core network. In the device, the master public key is securely issued to the UE. The core network device issues the corresponding base station private key to the legal base station that has passed the authentication according to its identity. The base station and the core network device can reuse the existing authentication method between the base station and the core network for mutual authentication, avoiding repeated construction .

A fourth aspect of the present application provides a base station, including:

An obtaining module, configured to request the base station private key corresponding to the base station public key from the core network device, and the base station and the core network device have passed identity authentication;

The signature module is used to sign according to the private key of the base station to obtain signature information;

The sending module is also used to send a broadcast message to the UE, and the broadcast message includes the signature information and the base station public key.

In an exemplary manner, it further includes a receiving module and a decrypting module;

The receiving module is configured to receive a response message of the broadcast message sent by the UE, the response message of the broadcast message includes first encryption information, and the first encryption information is the UE according to the base station public key and The stored master public key is obtained by encrypting the first information;

The decryption module is configured to decrypt the first encrypted information using the base station private key, the base station private key is generated by the core network device according to the base station public key and the master private key, and the master The public key and the master private key are a pair of secret keys generated by the core network device; when the base station fails to decrypt the first encrypted information using the base station private key, the response message of the broadcast message is discarded .

In an exemplary manner, the response message of the broadcast message includes a second replay parameter, and further includes a verification module configured to: verify the response of the broadcast message according to the second replay parameter Whether the message is a replay message;

The decryption module is specifically configured to use the base station private key to decrypt the first encrypted information when the verification module verifies that the response message of the broadcast message is not a replay message.

In an exemplary manner, the decryption module is further configured to: when the verification module verifies that the response message of the broadcast message is a replay message, discard the response message of the broadcast message.

In an exemplary manner, after the obtaining module obtains the base station private key from the core network device, the base station private key is not stored.

In an exemplary manner, the acquiring module is specifically configured to: send a first request message to the core network device, where the first request message includes the base station public key; and receive a message sent by the core network device The response message of the first request message, and the response message of the first request includes the base station private key.

In an exemplary manner, the base station public key includes a base station identity identifier. Correspondingly, the first encryption information is obtained by the UE encrypted according to the base station public key, the master public key, and first time information, and the first time information is the same as the current timestamp when the UE was encrypted And the first time interval; the base station private key is generated by the core network device according to the base station public key, the master private key, and second time information, and the second time information is related to the core network device The current timestamp when the base station private key is generated is related to the first time interval.

In an exemplary manner, the core network device is a UDM network element.

A fifth aspect of the present application provides a UE, including:

The receiving module is used to receive a broadcast message sent by a base station, the broadcast message includes signature information and a base station public key, the signature information is obtained by the base station through the base station private key signature, and the base station private key is a core network device Sent to the base station;

The verification module is used for the UE to verify whether the broadcast message comes from a legitimate base station according to the saved master public key, the base station public key, and the signature information, and the master public key is that the core network device is the UE Generated; when the broadcast message is not from a legitimate base station, discard the broadcast message.

In an exemplary manner, the broadcast message includes the first replay parameter, and the verification module is specifically configured to:

Verifying whether the broadcast message is a replay message according to the first replay parameter;

Verify the signature information according to the master public key and the base station public key;

In an exemplary manner, it further includes:

An encryption module, configured to encrypt first information according to the base station public key and the master public key to obtain first encrypted information when the broadcast message comes from a legal base station;

The sending module is configured to send a response message of the broadcast message to the base station, and the response message of the broadcast message includes the first encryption information.

In an exemplary manner, the base station public key includes a base station identity and the validity period of the base station public key; the verification module is specifically configured to verify whether the validity period of the base station public key is valid, when the base station public key When the validity period of the key is valid, the signature information is verified according to the master public key and the base station public key, and it is determined whether the broadcast message comes from a legitimate base station according to the verification result of the signature information.

In an exemplary manner, the base station public key includes a base station identity; the verification module is specifically configured to: verify the signature information according to the master public key, the base station public key, and third time information The third time information is related to the current time stamp of the UE and the first time interval, and it is determined whether the broadcast message comes from a legitimate base station according to a verification result of the signature information.

When the base station public key includes a base station identity, the first encryption information may be obtained by the UE encrypting the first information according to the base station public key, the master public key, and first time information Yes, the first time information is related to the current timestamp when the UE was encrypted and the first time interval.

In an exemplary manner, the core network device is a UDM network element.

A sixth aspect of this application provides a core network device, including:

A receiving module to receive a request message sent by a base station, where the request message includes the base station public key of the base station;

A generating module, configured to generate a base station private key corresponding to the base station public key according to the base station public key and the master private key;

The sending module is used to send the base station private key to the base station.

In an exemplary manner, it further includes a storage module;

The generating module is also used to generate a secret key pair, the secret key pair including a master public key and the master private key;

The storage module is used to store the master private key, and the master public key is securely issued to the user equipment UE.

A seventh aspect of the present application provides a base station, including a processor, a memory, and a transceiver. The memory is used to store instructions, the transceiver is used to communicate with other devices, and the processor is used to execute storage in the memory. , So that the base station executes the method provided in the first aspect of the present application and any possible implementation manner of the first aspect.

An eighth aspect of the present application provides a UE, including a processor, a memory, and a transceiver. The memory is used to store instructions, the transceiver is used to communicate with other devices, and the processor is used to execute instructions stored in the memory. , So that the UE executes the method provided in the second aspect of the present application and any possible implementation manner of the second aspect.

A ninth aspect of the present application provides a core network device, including a processor, a memory, and a transceiver. The memory is used to store instructions, the transceiver is used to communicate with other devices, and the processor is used to execute storage in the memory. , So that the core network device executes the method provided in the third aspect and any possible implementation manner of the third aspect of the present application.

The tenth aspect of the present application provides a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed, the computer executes the first aspect and any one of the first aspect of the present application. The method provided by the implementation method.

The eleventh aspect of the present application provides a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed, the computer executes any one of the second aspect and the second aspect of the present application. It is possible to implement the method provided by the method.

A twelfth aspect of the present application provides a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed, the computer executes any one of the third aspect and the third aspect of the present application. It is possible to implement the method provided by the method.

A thirteenth aspect of the present application provides a computer program product. The computer program product includes instructions. When the instructions are executed, the computer executes the first aspect of the present application and any one of the possible implementation manners of the first aspect. method.

The fourteenth aspect of the present application provides a computer program product. The computer program product includes instructions. When the instructions are executed, the computer executes the second aspect of the present application and any possible implementation of the second aspect. method.

The fifteenth aspect of the present application provides a computer program product. The computer program product includes instructions. When the instructions are executed, the computer executes the third aspect of the present application and any possible implementation manner of the third aspect. method.

The sixteenth aspect of the present application provides a system-on-chip or system-on-chip, which can be applied to a base station, and the system-on-chip or system-on-chip includes: at least one communication interface, at least one processor, and at least A memory, the communication interface, the memory, and the processor are interconnected by a bus, and the processor executes the instructions stored in the memory so that the base station can execute any one of the first aspect and the first aspect of the application The method provided by the implementation method.

The seventeenth aspect of the present application provides a system-on-chip or system-on-chip, the system-on-chip or system-on-chip can be applied to UE, and the system-on-chip or system-on-chip includes: at least one communication interface, at least one processor, and at least A memory, the communication interface, the memory, and the processor are interconnected by a bus, and the processor executes the instructions stored in the memory to enable the UE to execute any possible implementation of the second aspect and the second aspect of the present application The method provided by the method.

An eighteenth aspect of the present application provides a system on a chip or a system chip, which can be applied to a core network device, and the system on a chip or a system chip includes: at least one communication interface and at least one processor , At least one memory, the communication interface, the memory, and the processor are interconnected through a bus, and the processor executes the instructions stored in the memory to make the core network execute any of the third and third aspects of the present application. A method provided by a possible implementation.

The data transmission method and device provided by the embodiments of this application integrate the PKG function into the core network equipment, for example, in the UDM network element, the base station and the core network equipment can reuse the existing authentication mechanism between the two for identity authentication After passing the identity authentication, the core network device can send the base station private key corresponding to the base station public key to the base station. When the base station sends a broadcast message to the UE, it obtains the signature information through the base station private key signature, and carries the signature information and the base station public key in The broadcast message is sent to the UE. By carrying the signature information signed with the base station private key and the base station public key in the broadcast message, the UE can verify whether the message comes from a legitimate base station based on the signature information and the base station public key, thereby rejecting the operation of the pseudo base station and carrying the base station public key in The broadcast message is sent to the UE, which can prevent the pseudo base station from deliberately sending massive garbage public keys to exhaust the storage resources of the UE, causing the UE to be unavailable, and the core network equipment in this embodiment has the PKG function, so that the base station can reuse the core network The identity authentication method between devices does not require a separate design for authentication with PKG.

Description of the drawings

Figure 1 is a schematic diagram of a 5G network architecture;

FIG. 2 is a flowchart of a data transmission method provided in Embodiment 1 of this application;

FIG. 3 is a flowchart of the data transmission method provided in the second embodiment of this application;

4 is a signaling flowchart of the data transmission method provided in Embodiment 3 of this application;

FIG. 5 is a schematic structural diagram of a base station provided in Embodiment 4 of this application;

FIG. 6 is a schematic structural diagram of a UE provided in Embodiment 5 of this application;

FIG. 7 is a schematic diagram of a structure of a core network device provided by implementation six of this application;

FIG. 8 is a schematic structural diagram of a base station provided in Embodiment 7 of this application;

FIG. 9 is a schematic structural diagram of a UE provided in Embodiment 8 of this application;

FIG. 10 is a schematic structural diagram of a core network device provided in Embodiment 9 of this application.

Detailed ways

The embodiment of the application provides a data transmission method. The method of the embodiment of the application can be applied to a 5G network, but is not limited to a 5G network. With the evolution of communication systems, the method of this application may also be applied to future communication systems Or in the next generation mobile communication system.

The 5G network is also called a new wireless communication system and a new access technology (New Radio, NR for short). The 5G network includes an access network (AN for short) and a core network.

Figure 1 is a schematic diagram of the 5G network architecture. As shown in Figure 1, the access network in the 5G system can be a radio access network (radio access network, (R)AN for short), and (R)AN in the 5G system The device can be composed of multiple 5G-(R)AN nodes. The 5G-(R)AN nodes can include: new air interface base station (NR nodeB, gNB for short), next-generation evolved base station (NG-eNB), and central unit ( Central unit (CU) and distributed unit (DU) separated form gNB, etc.), transmission receiving point (TRP), transmission point (TP), wireless fidelity (WIreless) -Fidelity, WiFi for short) access point (AP for short) or other nodes of the network.

The core network of the 5G network includes Access and Mobility Management Function (AMF) network elements, Session Management Function (SMF) network elements, and User Plane Function (UPF) ) Network element, Policy Control Function (PCF) network element, Application Function (AF) network element, Unified data management (UDM) network element, Authentication server function (Authentication) Server Function, abbreviated as AUSF) network element, network slice selection function (Network Slice Selection Function, process NSSF) network element and other functional units.

AMF is mainly responsible for services such as mobility management and access management. SMF network elements are mainly responsible for session management, address management and allocation of terminal devices, dynamic host configuration protocol functions, selection and control of user plane functions, etc. The UPF network element is mainly responsible for externally connecting to a data network (data network, DN for short) and user plane data packet routing and forwarding, message filtering, and performing QoS control related functions. The PCF network element is mainly responsible for providing a unified policy framework for network behavior management, providing policy rules for control plane functions, and obtaining registration information related to policy decisions. AUSF is mainly responsible for the authentication function of terminal equipment. UDM network elements are mainly responsible for the management of resources, users and services in the network. UDM can automatically discover the storage, network, security, and server equipment deployed in the data center and disaster recovery center in a variety of ways; and automatically perform these equipment Identify and classify, synchronize the relevant configuration and status information of the device to UDM for unified management and monitoring.

It should be noted that these functional units can work independently, or they can be combined to achieve certain control functions, such as access control and mobility management functions such as access authentication, security encryption, location registration for terminal equipment, and user Session management functions such as the establishment, release, and modification of the surface transmission path.

The functional units in the 5G network can communicate through the next generation network (NG) interface. For example, the terminal device can transmit control plane messages with the AMF through the NG interface 1 (N1), (R)AN The device can establish a user plane data transmission channel with UPF network element through NG interface 3 (abbreviated as N3), (R)AN device can establish control plane signaling connection with AMF via NG interface 2 (abbreviated as N2), and UPF network element can use NG Interface 4 (N4 for short) exchanges information with SMF network elements. AMF can exchange information with SMF network elements through NG interface 11 (N11 for short). SMF network elements can exchange information with PCF network elements through NG interface 7 (N7 for short). For interaction, UDM interacts with AMF through interface 8 (abbreviated as N8), and UDM interacts with SMF network element through interface 10 (abbreviated as N10).

It should be noted that, in addition to the functional units shown in FIG. 1, the network elements of the core network of the 5G network may also include other functional units.

The embodiments of this application involve UEs, which are also called terminal devices, which can be mobile phones, computers, cellular phones, cordless phones, session initiation protocol (SIP) phones, smart phones, and personal digital assistants (personal digital assistants). digital assistant, PDA for short), computers, laptop computers, handheld communication devices, handheld computing devices, satellite wireless devices, wireless modem cards, TV set top boxes (STB for short), in-vehicle devices, wearable devices ( Such as smart watches, smart bracelets, smart glasses), smart home devices, other devices used to communicate on wireless systems, etc.

The air interface communication between the UE and the base station needs to be secure. On the one hand, the UE needs to identify whether the message sent by the base station is from a legitimate base station or a pseudo base station. In the prior art, the UE cannot identify whether the base station is from a legitimate base station or a pseudo base station. When spoofing messages are broadcast, the UE can only accept requests. For example, the pseudo base station can continuously send an identity request (Identity Request) to the UE, and the UE continuously responds to the user's subscription concealed identifier (SUCI) or globally unique temporary identity (GUTI), which causes the mobile phone power consumption. The pseudo base station can also initiate a denial of service (Denial of Service, DoS) attack or a distributed denial of service attack (DDoS) to the UE, causing the UE to fail to respond to normal services.

On the other hand, when the UE sends a message to the base station, it is transmitted in plain text over the air interface, and the information transmitted over the air interface may be tampered with or stolen. The information sent by the UE to the base station via the air interface includes not only the pre-authentication information encrypted with the core network public key, but also routing information that needs to be sensed by the base station, such as slice information and UE capability information. The slice information is used by the base station to select AMF For network elements, UE capability information is used by the base station to identify the UE capability. This part of the routing information that needs to be sensed by the base station is currently not encrypted, and is transmitted in clear text over the air interface. During the air interface transmission, if the slice information is tampered with, DDoS may be initiated to the AMF network element, and if the UE capability information is leaked, the privacy of the UE may be threatened.

The UE needs to identify whether the broadcast message comes from a legal base station. The legal base station can sign the broadcast message with a private key and then send it to the UE. The UE uses the base station's public key to verify the broadcast message. If the verification is passed, it means that the broadcast message is from a legitimate base station. If the verification is not passed, it means that the broadcast message is from a pseudo base station. The premise of this method is to ensure that the public and private key pairs are legal. If traditional asymmetric cryptographic algorithms, such as the RSA key generation algorithm, are used, since the RSA key generation algorithm is public, anyone can generate a pair The public key and private key pair that passed the signature verification can be signed. In order to ensure the legitimacy of the RSA public-private key pair, one method is to preset the pair of public and private keys on the UE and the base station respectively by the manufacturer before leaving the factory. However, the UE cannot determine which base station it will communicate with before use. Even if it knows the public keys of all base stations, the UE has to spend storage resources to store and manage a large number of public keys that may be connected to the base station.

The Identity-Based Encryption (IBE) solution can solve the above problems. In the IBE solution, the base station needs to pass the identity authentication of the PKG when applying for the private key to get the legal private key, and not everyone can pass it. Generated by public algorithms. Therefore, only one master public key needs to be preset in the UE, and the master public key and the master private key are preset in the PKG, and the PKG is responsible for generating legal private keys for all base stations.

An IBE method is as follows: the base station carries its own public key in a broadcast message and sends it to the UE, and the base station public key is generated by the base station according to the base station ID and the validity period. After receiving the base station public key, the UE stores the base station public key. After the base station passes the identity authentication by the PKG, it requests the PKG for the private key corresponding to the base station public key. The private key corresponding to the base station public key is generated by the PKG based on the base station public key and the master private key. The PKG generates a pair of a master public key and a master private key. The master private key is saved by the PKG, and the master public key is securely issued to the UE. After the base station uses a valid private key to sign the broadcast message, it sends the broadcast message to the UE. After the UE receives the broadcast message, it verifies whether the signature information in the broadcast message comes from a legitimate base station according to the stored base station public key and the master public key generated by the PKG. If the signature information comes from a legitimate base station, the UE receives the broadcast message and replies to the base station with a response to the broadcast message through the air interface.

However, the following problems still exist in the above-mentioned IBE method: (1) PKG and 5G network are deployed independently, which requires pseudo base stations and PKG to redesign the authentication mechanism. (2) Before broadcasting the message, the base station needs to send the base station public key to the UE for storage. The pseudo base station may initiate a large number of useless base station public keys to the UE to exhaust the storage resources of the UE and make the UE unavailable. (3) The base station needs to store the corresponding base station private key during the validity period of the public key. Since the base station has limited resources compared with the PKG, the base station private key cannot be well protected, and the base station private key stored in the base station may be leaked. (4) The air interface communication between the UE and the base station lacks an anti-replay mechanism, and the broadcast message signed by the base station may be reused by illegal base stations. (5) The information sent by the UE to the base station that needs to be sensed by the base station cannot be encrypted and transmitted with the core network public key because it needs to be sensed by the base station. The information that needs to be sensed by the base station is transmitted in plain text, which may lead to information leakage or tampering.

In order to solve the problems of the prior art, an embodiment of the present application provides a data transmission method between a base station and a UE. The base station signs a broadcast message sent to the UE so that the UE can verify whether the broadcast message comes from a legitimate base station according to the signature. Encrypt the message sent to the base station to prevent the information contained in the message from being tampered with.

In the embodiment of this application, the base station private key used by the base station for signing is issued by the core network device, which has IBE capability and can realize the PKG function. The core network device may be a UDM network element in a 5G core network. It may also be other network elements in the 5G core network, which is not limited in this application. Of course, the core network equipment is not limited to the core network element of the 5G network, but may also be the core network element of other networks, for example, the element of the Long Term Evolution (LTE) core network.

In the embodiment of this application, the core network device with PKG function generates a pair of master public key MPK and master private key MSK. The master private key is securely stored in the core network device, and the master public key is securely issued to the UE. For example, the master public key is preset in the UE before the UE leaves the factory. The core network device issues the corresponding base station private key to the legal base station that has passed the authentication according to its identity. The base station and the core network device can reuse the existing authentication method between the base station and the core network for mutual authentication, avoiding repeated construction . In the 5G network based on the 3rd Generation Partnership Project (3rd Generation Partnership Project, 3GPP), base stations and core network devices in the 5G core network can perform identity authentication based on Internet Protocol Security (IPsec) and identity based on IPsec Authentication is mutual authentication. It can be understood that as the network evolves or is different, the identity authentication methods of base stations and core network equipment will change accordingly.

FIG. 2 is a flowchart of the data transmission method provided in Embodiment 1 of this application. As shown in FIG. 1, the method in this embodiment includes the following steps:

S101: The base station requests the base station private key corresponding to the base station public key from the core network device.

The base station and the core network device perform identity authentication first, and after mutual confirmation of the identities, the base station can request the base station private key from the core network device. Normally, when the base station or the core network equipment is initialized, the identity authentication between the two is required.

The base station may send a first request message to the core network device, where the first request message is used to request a private key corresponding to the base station public key, and the first request message includes the base station public key, and the base station public key is generated by the base station. The first request message may be an existing message or a newly defined message.

In an optional manner, the base station public key consists of the base station identity and the validity period of the base station public key. The validity period of the base station public key can be a period of time. During the validity period, the base station or UE uses the base station public key to sign or encrypt . In another optional manner, the base station public key is composed of a base station identity, and the base station public key does not include the validity period of the base station public key.

After receiving the first request message, the core network device generates the base station private key according to the base station public key included in the first request and the locally stored master private key, and carries the base station private key in the response message of the first request message and sends it to Base station.

When the base station public key is composed of the base station identity and the validity period of the base station public key, the core network device generates the base station private key according to the base station public key and the master private key stored locally. When the base station public key is the identity of the base station, the core network device generates it according to the base station public key, the master public key stored locally, and the second time information.

The second time information is related to the current timestamp of the core network device and the first time interval. The first time interval may be determined by the core network device itself and notified to the UE and the base station. The first time interval may also be specified by the system and preset in the base station, UE, and core network equipment. In this solution, the core network equipment generates the base station private key similar to the time-based one-time password algorithm (TOTP). TOTP is an example of hash-based message authentication code (HMAC). Use a cryptographic hash function to combine the key with the current timestamp to generate a one-time password. Since network delays and unsynchronized clocks may cause the password recipient to have to try a series of possible times for authentication, the timestamp is usually increased at 30-second intervals, thereby reducing the potential search space.

The core network device can calculate the second time information through the following formula: TC=floor(timestamp/T), where TC represents the second time information, floor represents the round-down operation, and timestamp represents the current timestamp of the core network device, T represents the first time interval. Timestamp is a variable. The core network device calculates the base station private key according to the current timestamp. The value of T can be set according to the actual situation, for example, it can be 30ms, 60ms, 30 minutes, 1 hour, and so on.

It can be understood that the above formula is only an example, and the second time information can also be calculated in other ways, for example, the second time information can be obtained by rounding timestamp/T up, or the integer TC can be obtained by performing other operations on timestamp/T. The method is not limited in this embodiment.

After generating the base station private key corresponding to the base station public key, the core network device may carry the base station private key in the response message of the first request message and send it to the base station.

In this embodiment, the base station may request the base station private key from the core network device in the following situations:

(1) In the case where the base station public key consists of the base station identity and the validity period of the base station public key, before the base station needs to send a broadcast message to the UE, the base station first judges whether the validity period of the base station public key is valid. Exemplarily, the base station judges whether the current time is within the validity period of the base station public key, if the current time is within the validity period of the base station public key, then the validity period of the base station public key is determined to be valid, and if the current time is not within the validity period of the base station public key, it is determined The validity period of the base station public key is invalid.

When the validity period of the base station public key is invalid, the base station requests a new base station private key from the core network equipment. Specifically, the base station generates a new validity period for the base station public key, and the base station identity and the new validity period for the base station public key form a new The base station public key, the core network device generates a corresponding new base station private key for the base station according to the new base station public key, and returns it to the base station.

When the validity period of the base station public key is valid, the base station reads the base station private key from the memory, and the base station private key stored in the base station memory may be replaced due to the memory replacement algorithm. If the base station can read the base station private key from the memory The base station private key is used to sign the broadcast message. If the base station cannot read the base station private key from the memory, the base station requests a new base station private key from the core network device.

(2) In the case that the base station public key is composed of the base station identity, before the base station needs to send a broadcast message to the UE, the base station calculates the fourth time information according to the current timestamp and the first time interval, and compares the fourth time information with The fifth time information stored locally is compared, where the fifth time information is calculated according to the current timestamp and the first time interval when the base station receives the base station private key sent by the core network device. When the fourth time information is compared with the first time interval 5. When the time information is the same, it indicates that the base station private key is valid. When the fourth time information and the fifth time information are not the same, it indicates that the base station private key is invalid, and the base station requests a new base station private key from the core network device. Wherein, the manner of generating the fourth time information and the fifth time information refers to the manner of generating the second time information, which will not be repeated here.

(3) The base station periodically requests the base station private key from the core network equipment.

(4) When the base station sends a broadcast message, it dynamically requests the base station private key from the core network device. In this manner, the base station does not need to store the base station private key every time it obtains the base station private key from the core network device. In the foregoing three methods, after the base station obtains the base station private key from the core network device, it needs to store the base station private key. As the base station has limited resources compared with PKG, the base station private key stored in the base station may have the risk of leakage. In this method, the base station does not need to save the base station private key, but dynamically requests the base station private key every time, which reduces the leakage of the base station private key. It also saves the storage resources of the base station.

S102. The base station sends a broadcast message to the UE. The broadcast message includes signature information and the base station public key. The signature information is obtained by the base station through the base station private key signature.

It can be understood that the base station private key used by the base station during the validity period of the base station public key is the same. Similarly, the base station private key used by the base station in the first time interval is also the same, and the first time interval can also be understood as the base station public key The validity period of is only the first time interval does not need to be carried when the base station requests the base station private key from the core network device.

The base station signs the broadcast information sent according to the base station private key, carries both the signature information and the base station public key in the broadcast message and sends it to the UE. The signature information is used for the UE to verify the legitimacy of the base station, and the base station public key is used for the UE to pair The response message sent to the base station is encrypted. It can be understood that in addition to the signature information and the base station public key, the broadcast message also carries service information. The service information varies with the type of the broadcast message. In this embodiment, the broadcast message can be any existing information between the base station and the UE. Messages that need to be sent by broadcast.

In this embodiment, the base station carries the base station public key in a broadcast message and sends it to the UE. The UE does not need to spend resources to store the base station public key, which prevents the pseudo base station from deliberately sending a large number of illegal base station public keys to the UE to exhaust the storage resources of the UE. , Causing the UE to be unavailable.

Optionally, the broadcast message includes a first replay parameter, and the first replay parameter is used by the UE to verify whether the broadcast message is a replay message, where the first replay parameter may be a timestamp, a random number, or a sequence number. Each time the base station sends a broadcast message, it carries replay parameters, and the replay parameters carried each time are different. The UE determines whether a replay attack (Replay Attacks) occurs through the replay parameters.

Replay attack, also known as replay attack or playback attack, refers to the attacker sending a packet that the destination host has received to achieve the purpose of deceiving the system. It is mainly used in the identity authentication process to destroy the correctness of the authentication. The replay attack can be carried out by the initiator or the enemy who intercepts and retransmits the data. The attacker uses network monitoring or other methods to steal the authentication credential, and then resend it to the authentication server. In this embodiment, the pseudo base station can intercept the broadcast message signed by the legitimate base station, and then repeatedly send it to the UE to exhaust the UE resources. The base station carries replay parameters in the broadcast message so that the UE can identify whether the received broadcast message is What is sent by the legitimate base station is the replay message sent by the pseudo base station.

S103. The base station receives a response message of the broadcast message sent by the UE, where the response message of the broadcast message includes first encryption information, and the first encryption information is obtained by the UE encrypting the first information according to the base station public key and the stored master public key .

Step S103 is an optional step. After the UE receives the broadcast message, it may not return the response message of the broadcast message to the base station. After receiving the broadcast message, the UE determines whether it needs to return the broadcast message to the base station according to the type of the broadcast message or the included service content. The response message of the message.

The base station public key used by the UE to encrypt the first information is the base station public key sent by the base station through a broadcast message, and the master public key is generated and issued to the UE by a core network device with a PKG function.

S104. The base station uses the base station private key to decrypt the first encrypted information.

When the base station public key consists of the base station identity and the validity period, the UE uses the base station public key and the master public key to encrypt the first information in the response message of the broadcast message to obtain the first encrypted information. The first information may be information that needs to be sensed by the base station For example, slice information and UE capability information, by encrypting the first information, the security of the first information can be guaranteed. After receiving the response message of the broadcast message, the base station decrypts the first encrypted information according to the base station private key.

When the base station public key is the base station identity, the UE uses the base station public key, the master public key, and the first time information to encrypt the first information to obtain the first encrypted information, where the first time information is the current timestamp when the UE was encrypted As for the first time interval, the UE can calculate the first time information in the same manner as the second time information, which will not be repeated here.

After receiving the response message of the broadcast message, the base station calculates the sixth time information according to the current timestamp and the first time interval, and compares the sixth time information with the fifth time information stored locally, where the fifth time information is When the base station receives the base station private key sent by the core network equipment, it is calculated based on the current timestamp and the first time interval. When the sixth time information is the same as the fifth time information, it means that the base station private key is valid and the base station private key is used. The key decodes the first encrypted information. When the sixth time information and the fifth time information are not the same, it means that the base station private key is invalid. The base station requests a new base station private key from the core network device, and uses the new base station private key to decrypt the first encrypted information. Wherein, the manner of generating the sixth time information and the fifth time information refers to the manner of generating the second time information described above, which will not be repeated here.

If the base station fails to decrypt the first encrypted information using the base station private key, the base station discards the response message of the broadcast message. If the base station uses the base station private key to successfully decrypt the first encrypted information, the response message of the broadcast message is processed.

Optionally, the response message of the broadcast message includes a second replay parameter, and the base station verifies whether the response message of the broadcast message is a replay message according to the second replay parameter, where the second replay parameter may be a timestamp or random Number or serial number. The second replay parameter and the first replay parameter may be the same or different. For example, the first replay parameter is a timestamp, and the second replay parameter is a random number, that is, the base station and the UE use different replay parameters to verify the pair Whether the message sent by the terminal is a replay message. Alternatively, the first replay parameter and the second replay parameter are both timestamps, that is, the base station and the UE use the same replay parameter to verify whether the message sent by the opposite end is a replay message.

When verifying that the response message of the broadcast message is a replay message, the base station discards the response message of the broadcast message. When verifying that the response message of the broadcast message is not a replay message, the base station uses the base station private key to decrypt the first encrypted information.

In this embodiment, the base station may first verify whether the response message of the broadcast message is a replay message, and when it is confirmed that the response message of the broadcast message is not a replay message, the base station private key is further used to decrypt the first encrypted information. If it is confirmed that the response message of the broadcast message is a replay message, the response message of the broadcast message is discarded, and the first encrypted information does not need to be decrypted.

Optionally, the base station may also decrypt the first encrypted information first. If the decryption is successful, it further verifies whether the response message of the broadcast message is a replay message according to the second replay parameter. If the decryption fails, the information of the broadcast message is lost. The response message does not verify whether the response message of the broadcast message is a replay message.

Or, the base station performs the following operations at the same time: verifying whether the response message of the broadcast message is a replay message, and decrypting the first encrypted information, if it is verified that the response message of the broadcast message is not a replay message, and the first encrypted information is successfully decrypted, The response message of the broadcast message is processed, otherwise the response message of the broadcast message is lost.

In this embodiment, the base station requests the base station private key corresponding to the base station public key from the core network device, and the base station sends a broadcast message to the UE. The broadcast message includes signature information and the base station public key. The signature information is obtained by the base station through the base station private key signature. By carrying the signature information signed with the base station private key and the base station public key in the broadcast message, the UE can verify whether the message comes from a legitimate base station based on the signature information and the base station public key, thereby rejecting the operation of the pseudo base station and carrying the base station public key in The broadcast message is sent to the UE, which can prevent the pseudo base station from deliberately sending massive garbage public keys to exhaust the storage resources of the UE, causing the UE to be unavailable, and the core network equipment in this embodiment has the PKG function, so that the base station can reuse the core network The identity authentication method between devices does not require a separate design for authentication with PKG.

FIG. 3 is a flowchart of the data transmission method provided in the second embodiment of the application. The first embodiment mainly describes the data transmission method from the perspective of the base station, and this embodiment describes the data transmission method from the UE perspective. As shown in FIG. 3, this embodiment The example method includes the following steps:

Step S201: The UE receives a broadcast message sent by a base station. The broadcast message includes signature information and a base station public key. The signature information is obtained by the base station through the base station private key signature, and the base station private key is sent to the base station by the core network device.

Step S202: The UE verifies whether the broadcast message comes from a legitimate base station according to the stored master public key, the base station public key included in the broadcast message, and the signature information.

The master public key is generated by the core network device for the UE, and can be preset in the UE when the UE leaves the factory. Since the signature information is signed by the base station using the base station private key, and the base station private key is generated based on the base station public key and the master private key, if the broadcast message has not been tampered with, the signature information in the broadcast message and the UE pass the master public key and the base station. The signature information obtained by the public key signature is consistent. If the broadcast message is tampered with, the signature information obtained by the UE through the master public key and the base station public key is inconsistent with the signature information contained in the broadcast message.

Optionally, the base station public key consists of the base station identity and the validity period, or the base station public key consists of the base station identity.

When the base station public key consists of the base station identity and the validity period, after the base station receives the broadcast message, it first obtains the validity period of the base station public key from the base station public key, and judges whether the validity period of the base station public key is valid according to the current time and the validity period of the base station public key If the validity period of the base station public key is valid, the base station public key and the master public key are used to verify the signature information, and it is determined whether the broadcast message comes from a legitimate base station according to the verification result of the signature information. If the verification of the signature information is successful, it is determined that the broadcast message comes from a legitimate base station. If the verification of the signature information fails, it is determined that the broadcast message does not come from a legitimate base station. If the validity period of the base station public key is invalid, there is no need to verify the signature information, and it is determined that the broadcast message is not from a legitimate base station.

When the base station public key is the base station identity, after receiving the broadcast message, the base station generates third time information according to the current timestamp and the first time interval, and verifies the signature information according to the master public key, base station public key, and third time information . If the verification of the signature information is successful, it is determined that the broadcast message comes from a legitimate base station. If the verification of the signature information fails, it is determined that the broadcast message does not come from a legitimate base station.

When the broadcast message comes from a legal base station, step S203 is executed. When the broadcast message is not from a legal base station, the UE loses the broadcast message.

Optionally, the broadcast message includes a first replay parameter, and the first replay parameter is used to verify whether the broadcast message is a replay message. Correspondingly, the UE verifies whether the broadcast message comes from a legal base station according to the master public key, the base station public key, the first playback parameter, and the signature information. The UE verifies whether the broadcast message is a replay message according to the first replay parameter, and verifies the signature information according to the master public key and the base station public key. When it is verified that the broadcast message is not a replay message, it signs according to the master public key and the base station public key When the information verification is successful, it is determined that the broadcast message comes from a legal base station; otherwise, it is determined that the broadcast message does not come from a legal base station.

In one method, the UE first verifies whether the broadcast message is a replay message according to the first replay parameter. When the broadcast message is not a replay message, the UE further verifies the signature information according to the master public key and the base station public key. When the verification is successful, it is determined that the broadcast message comes from a legitimate base station. When the verification of the signature information fails, or when the broadcast message is a replay message, it is determined that the broadcast message does not come from a legitimate base station. When the broadcast message is a replay message, the UE does not need to verify the signature information to determine that the broadcast message does not come from a legitimate base station.

In another method, the UE first verifies the signature information according to the master public key and the base station public key. When the signature information is successfully verified, it further verifies whether the broadcast message is a replay message according to the first replay parameter. When the broadcast message is not a replay message, When broadcasting a message, make sure that the broadcast message comes from a legitimate base station. When the broadcast message is a replay message, or when the verification of the signature information fails, it is determined that the broadcast message does not come from a legitimate base station. When the verification of the signature information fails, the UE does not need to further determine whether the broadcast message is a replay message, and can determine that the broadcast message does not come from a legitimate base station.

In another way, the UE performs the following operations at the same time: verify whether the broadcast message is a replay message according to the first replay parameter, verify the signature information according to the base station public key and the master public key, when the broadcast message is not a replay message, and When the signature information is successfully verified, it is determined that the broadcast message comes from a legitimate base station.

S203: When the broadcast message comes from a legal base station, the UE encrypts the first information according to the base station public key and the master public key to obtain the first encrypted information.

The first information may be information that needs to be sensed by the base station, such as slice information and UE capability information. The UE can use the base station public key and the master public key to encrypt the information that needs to be sensed by the base station in the broadcast message to prevent the information that needs to be sensed by the base station from being tampered with, causing damage to the operator and/or endangering the privacy of the UE.

In the case that the base station public key consists of the base station identity and the validity period of the base station public key, the UE uses the master public key and the base station public key included in the broadcast message to encrypt the first information to obtain the first encrypted information. In the case that the base station public key includes the base station identity, the UE determines the first time information according to the current timestamp and the first time interval, and encrypts the first information according to the base station public key, the master public key, and the first time information to obtain the first time information. One encrypted information.

Step S203 is an optional step. After the UE receives the broadcast message, if it needs to return the response message of the broadcast message to the base station, encrypt the first information, and if it does not need to return the response message of the broadcast message to the base station, perform the broadcast message. Normal processing flow.

S204. The UE sends a response message of the broadcast message to the base station, where the response message of the broadcast message includes the first encryption information.

It can be understood that in this embodiment, the UE only uses the base station public key and the master public key to encrypt the first information that needs to be sensed by the base station, and other information in the response message of the broadcast message can still be processed in the existing manner, for example, , UE uses the core network public key to encrypt the pre-authentication information.

Optionally, the response message of the broadcast message includes a second replay parameter, and the second replay parameter is used by the base station to verify whether the response message of the broadcast message is a replay message. Wherein, the second playback parameter may be a timestamp, a random number, or a sequence number.

In this embodiment, the UE receives the broadcast message sent by the base station. The broadcast message includes signature information and the base station public key. The signature information is obtained by the base station through the base station private key signature. The base station private key is sent by the core network device to the base station. The saved master public key, base station public key included in the broadcast message, and signature information verify whether the broadcast message comes from a legal base station. The master public key is generated by the core network device for the UE. When the broadcast message does not come from a legal base station, the UE discards the broadcast message . The base station carries the signature information and the base station public key in the broadcast message, so that the UE can verify whether the broadcast message comes from a legitimate base station based on the signature information and the base station public key, thereby rejecting the operation of the pseudo base station, and carrying the base station public key in the broadcast message to send For the UE, it is possible to prevent the pseudo base station from deliberately sending massive garbage public keys to exhaust the storage resources of the UE and cause the UE to be unavailable.

Figure 4 is a signaling flow chart of the data transmission method provided in the third embodiment of the application. This embodiment takes the core network equipment as an UDM network element as an example for description. The base station public key consists of the base station identity and the validity period, as shown in Figure 4 As shown, the method of this embodiment includes the following steps:

S301. The UDM network element generates a master public key and a master private key, saves the master private key, and issues the master public key to the UE.

In S302, the base station and the UDM network element perform identity authentication based on Ipsec.

Wherein, steps S301 and S302 are executed in no order. The UDM network element can generate the master public key and the master private key in any existing manner, which is not limited in this embodiment.

S303. The base station sends a first request message to the UDM network element, where the first request message includes the base station public key.

The first request message is used to request the base station private key corresponding to the base station public key, and the base station public key is composed of the base station identity and the validity period. After receiving the first request message, the UDM network element generates a base station private key for the base station according to the base station public key and the locally stored master private key, carries the base station private key in the response message of the first request message and sends it to the base station.

It can be understood that the base station does not directly exchange information with the UDM network element. The message sent by the base station to the UDM network element will be transparently transmitted to the UDM network element through the AMF network element. Similarly, the message sent by the UDM network element to the base station will also pass through the AMF network element. Penetrate.

S304. The UDM network element sends a response message of the first request message to the base station, where the response message of the first request message includes the base station private key.

After the base station receives the base station private key, it can store the base station private key in the memory.

S305: The base station judges whether the validity period of the base station public key is valid.

When the base station needs to broadcast the service message, it first determines whether the validity period of the base station public key is valid. If the validity period of the base station public key is valid, execute S306; if the validity period of the base station public key is invalid, execute S307.

S306. The base station generates a new base station public key, and requests the UDM network element for the base station private key corresponding to the new base station public key according to the new base station public key.

Specifically, the base station first generates a new validity period, generates a new base station public key according to the base station identity and the new validity period, and sends the base station private key corresponding to the new base station public key to the UDM network element through the above S303 and S304 methods. Step S307 is executed after step S306.

S307: The base station uses the base station private key to generate signature information.

S308. The base station sends a broadcast message to the UE. The broadcast message includes signature information, the base station public key, and the first playback parameter.

The base station uses the base station private key to sign the broadcast message, carries the signature information, the base station public key, and the first playback parameter in the broadcast message and sends it.

S309. The UE verifies whether the broadcast message comes from a legal base station according to the stored master public key, base station public key, signature information, and first playback parameter.

When the broadcast message comes from a legal base station, the UE executes step S310. When the broadcast message is not from a legal base station, the UE discards the broadcast message.

S310. First encrypted information obtained by the UE encrypting the first information according to the base station public key and the master public key.

S311. The UE sends a response message of the broadcast message to the base station, where the response message of the broadcast message includes the first encryption information and the second playback parameter.

S312: The base station judges whether the response message of the broadcast message is a replay message according to the second replay parameter, and when the response message of the broadcast message is not a replay message, the base station private key is used to decrypt the first encrypted information.

For the specific implementation of this embodiment, refer to the related descriptions of Embodiment 1 and Embodiment 2, which will not be repeated here.

FIG. 5 is a schematic structural diagram of a base station provided in Embodiment 4 of this application. As shown in FIG. 5, the base station provided in this embodiment includes:

The obtaining module 11 is used to request the base station private key corresponding to the base station public key from the core network device;

The signature module 12 is used for signing according to the private key of the base station to obtain signature information;

The sending module 13 is configured to send a broadcast message to the UE, and the broadcast message includes the signature information and the base station public key.

In an exemplary manner, a receiving module 14 and a decrypting module 15 are further included.

The receiving module 14 is configured to receive a response message of the broadcast message sent by the UE. The response message of the broadcast message includes first encryption information, and the first encryption information is the UE according to the base station public key. It is obtained by encrypting the first information with the stored master public key.

The decryption module 15 is configured to decrypt the first encrypted information using the base station private key, the base station private key is generated by the core network device according to the base station public key and the master private key, The master public key and the master private key are a pair of secret keys generated by the core network device; when the base station private key is used to decrypt the first encrypted information, the response message of the broadcast message is discarded.

In an exemplary manner, the response message of the broadcast message includes the second replay parameter. The base station may further include a verification module configured to verify whether the response message of the broadcast message is a replay message according to the second replay parameter. The decryption module 15 is specifically configured to use the base station private key to decrypt the first encrypted information when the verification module verifies that the response message of the broadcast message is not a replay message.

The decryption module 15 is further configured to: when the verification module verifies that the response message of the broadcast message is a replay message, discard the response message of the broadcast message.

In an exemplary manner, after obtaining the base station private key from the core network device, the obtaining module 11 does not store the base station private key.

In an exemplary manner, the acquiring module 11 is specifically configured to: send a first request message to the core network device, where the first request message includes the base station public key; and receive a message sent by the core network device The response message of the first request message includes the private key of the base station.

In an exemplary manner, the base station public key includes a base station identity; correspondingly, the first encryption information is obtained by the UE encrypted according to the base station public key, the master public key, and first time information , The first time information is related to the current timestamp and the first time interval when the UE was encrypted; the base station private key is the core network device according to the base station public key, the master private key, and the first time interval; 2. Time information generated, the second time information is related to the current timestamp when the core network device generates the base station private key and the first time interval.

In an exemplary manner, the core network device is a UDM network element.

The base station in this embodiment can be used to execute the method steps performed by the base station in any one of the foregoing method embodiments 1 to 3. The specific implementation manner and technical effect are similar, and details are not described herein again.

FIG. 6 is a schematic structural diagram of a UE provided in Embodiment 5 of this application. As shown in FIG. 6, the UE provided in this embodiment includes:

The receiving module 21 is configured to receive a broadcast message sent by a base station. The broadcast message includes signature information and a base station public key. The signature information is obtained by the base station by signing the base station private key, and the base station private key is the core network. Sent by the device to the base station;

The verification module 22 is used for the UE to verify whether the broadcast message comes from a legal base station according to the stored master public key, the base station public key, and the signature information, and the master public key is that the core network device is the Generated by the UE; when the broadcast message is not from a legitimate base station, the broadcast message is discarded.

In an exemplary manner, the broadcast message includes a first replay parameter, and the verification module 22 is specifically configured to: verify whether the broadcast message is a replay message according to the first replay parameter; The master public key and the base station public key verify the signature information, when it is verified that the broadcast message is not a replay message, and the signature information is successfully verified according to the master public key and the base station public key To determine that the broadcast message comes from a legitimate base station.

In an exemplary manner, optionally, it further includes: an encryption module 23 and a sending module 24.

The encryption module 23 is configured to encrypt the first information according to the base station public key and the master public key to obtain the first encrypted information when the broadcast message comes from a legal base station;

The sending module 24 is configured to send a response message of the broadcast message to the base station, and the response message of the broadcast message includes the first encryption information.

In an exemplary manner, the base station public key includes a base station identity and the validity period of the base station public key; the verification module 22 is specifically configured to: verify whether the validity period of the base station public key is valid; when the base station When the validity period of the public key is valid, the signature information is verified according to the master public key and the base station public key; and it is determined whether the broadcast message comes from a legitimate base station according to the verification result of the signature information.

In an exemplary manner, the base station public key includes a base station identity; the verification module 22 is specifically configured to: perform the signature information on the signature information according to the master public key, the base station public key, and third time information. It is verified that the third time information is related to the current timestamp of the UE and the first time interval; it is determined whether the broadcast message comes from a legitimate base station according to the verification result of the signature information.

When the base station public key includes a base station identity, optionally, the first encryption information is that the UE encrypts the first information according to the base station public key, the master public key, and first time information Obtained, the first time information is related to the current timestamp when the UE was encrypted and the first time interval.

In an exemplary manner, the core network device is a UDM network element.

The UE in this embodiment can be used to execute the method steps performed by the UE in the foregoing method embodiment. The specific implementation manner and technical effect are similar, and details are not described herein again.

Fig. 7 is a schematic structural diagram of the core network device provided in the sixth embodiment of the application. The core network device may be, for example, a UDM network element. As shown in Fig. 7, the core network device provided in this embodiment includes:

The receiving module 31 is configured to receive a request message sent by a base station, where the request message includes the base station public key of the base station;

The generating module 32 is configured to generate a base station private key corresponding to the base station public key according to the base station public key and the master private key;

The sending module 33 is configured to send the base station private key to the base station.

Optionally, the core network device further includes a storage module. The generating module is also used to generate a secret key pair, the secret key pair includes a master public key and the master private key; the storage module is used to store the master private key, and the master public key is secured To the user equipment UE.

The core network device of this embodiment can be used to execute the method steps performed by the core network device in the foregoing method embodiment. The specific implementation manner and technical effect are similar, and details are not described herein again.

Each of the above modules or units may be implemented by software, hardware, or a combination of software and hardware. For example, the verification module 22 and the encryption module 23 in FIG. 6 may be implemented based on software.

In this application, "implemented by software" means that the processor reads and executes the program instructions stored in the memory to implement the functions corresponding to the above-mentioned modules or units, where the processor refers to a processing circuit that has the function of executing program instructions, Including but not limited to at least one of the following: central processing unit (CPU), microprocessor, digital signal processing (DSP), microcontroller (microcontroller unit, MCU), or artificial intelligence processing Various types of processing circuits capable of running program instructions. In other embodiments, the processor may also include circuits for other processing functions (such as hardware circuits for hardware acceleration, buses, and interface circuits, etc.). The processor can be presented in the form of an integrated chip, for example, in the form of an integrated chip whose processing function only includes the function of executing software instructions, or it can also be presented in the form of SoC (system on a chip, system on chip), that is, on a chip Above, in addition to the processing circuit (usually called "core") that can run program instructions, it also includes other hardware circuits for implementing specific functions (which can be based on ASIC or FPGA). Correspondingly, the processing functions include In addition to the function of executing software instructions, various hardware acceleration functions (such as AI calculation, encoding and decoding, compression and decompression, etc.) can also be included.

In this application, "implemented by hardware" means that the functions of the above-mentioned modules or units are realized by a hardware processing circuit that does not have program instruction processing functions. The hardware processing circuit can be composed of discrete hardware components or integrated circuits. In order to reduce power consumption and size, it is usually implemented in the form of integrated circuits. The hardware processing circuit can include ASIC (application-specific integrated circuit), or PLD (programmable logic device, programmable logic device); among them, PLD can also include FPGA (field programmable gate array, field programmable gate array) , CPLD (complex programmable logic device, complex programmable logic device) and so on. These hardware processing circuits can be a separately packaged semiconductor chip, or can be integrated with other circuits (such as CPU, DSP) and packaged into a semiconductor chip. For example, ASIC and CPU can be integrated together to form a SoC and packaged separately into a chip, or FPGA and CPU can also be integrated together to form SoPC (system on a programmable chip, programmable system on chip).

It should be noted that when this application is implemented through software, hardware, or a combination of software and hardware, different software and hardware can be used, and it is not limited to use only one type of software or hardware. For example, one of the modules or units can be implemented by using a CPU, and the other module or unit can be implemented by using a DSP. Similarly, when using hardware implementation, one of the modules or units can be implemented using ASIC, and the other module or unit can be implemented using FPGA. Of course, part or all of the modules or units are not limited to use the same kind of software (for example, all through a CPU) or the same kind of hardware (for example, all through an ASIC). In addition, for those skilled in the art, it can be known that software is generally more flexible, but its performance is not as good as hardware, and hardware is just the opposite. Therefore, those skilled in the art can choose software or hardware or a combination of both according to actual needs. Form to achieve.

FIG. 8 is a schematic structural diagram of a base station provided in Embodiment 7 of the application. As shown in FIG. 8, the base station 400 includes a processor 41, a memory 42 and a transceiver 43. The memory 42 is used to store instructions. The transceiver 43 is used to communicate with other devices, and the processor 41 is used to execute instructions stored in the memory, so that the base station 400 executes the method performed by the base station in the foregoing method embodiment.

FIG. 9 is a schematic structural diagram of a UE provided in Embodiment 8 of this application. As shown in FIG. 9, the UE 500 includes: a processor 51, a memory 52, and a transceiver 53, the memory 52 is used to store instructions, and the transceiver 53 is used to communicate with other devices, and the processor 51 is used to execute instructions stored in the memory, so that the UE 500 executes the method executed by the UE in the foregoing method embodiment.

FIG. 10 is a schematic structural diagram of a core network device provided by Embodiment 9 of this application. As shown in FIG. 10, the core network device 600 includes a processor 61, a memory 62, and a transceiver 63. The memory 62 is used to store instructions. The transceiver 63 is used to communicate with other devices, and the processor 61 is used to execute instructions stored in the memory, so that the core network device 600 executes the method performed by the core network device in the foregoing method embodiment.

The tenth embodiment of the present application provides a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed, the computer executes the method executed by the base station in the foregoing method embodiment.

The eleventh embodiment of the present application provides a computer-readable storage medium, the computer-readable storage medium stores instructions, and when the instructions are executed, the computer executes the method performed by the UE in the foregoing method embodiment.

The twelfth embodiment of the present application provides a computer-readable storage medium that stores instructions, and when the instructions are executed, the computer executes the method performed by the core network device in the foregoing method embodiment.

Those skilled in the art can understand that the functions described in combination with the various illustrative logical blocks, modules, and algorithm steps described in the disclosure of this application can be implemented by hardware, software, firmware, or any combination thereof. If implemented in software, the functions described by various illustrative logical blocks, modules, and steps can be stored or transmitted as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may include a computer-readable storage medium, which corresponds to a tangible medium, such as a data storage medium, or a communication medium that includes any medium that facilitates the transfer of a computer program from one place to another (for example, according to a communication protocol) . In this manner, a computer-readable medium may generally correspond to (1) a non-transitory tangible computer-readable storage medium, or (2) a communication medium, such as a signal or carrier wave. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, codes, and/or data structures for implementing the techniques described in this application. The computer program product may include a computer-readable medium.

By way of example and not limitation, such computer-readable storage media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, magnetic disk storage devices or other magnetic storage devices, flash memory, or structures that can be used to store instructions or data Any other media that can be accessed by the computer in the form of desired program code. And, any connection is properly termed a computer-readable medium. For example, if you use coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave to transmit instructions from a website, server, or other remote source, then the coaxial cable Wire, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. However, it should be understood that the computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other temporary media, but are actually directed to non-transitory tangible storage media. As used herein, magnetic disks and optical discs include compact discs (CD), laser discs, optical discs, digital versatile discs (DVD), and blu-ray discs. Disks usually reproduce data magnetically, while optical discs use lasers to reproduce data optically. data. Combinations of the above should also be included in the scope of computer-readable media.

It can be processed by, for example, one or more digital signal processors (DSP), general-purpose microprocessors, application-specific integrated circuits (ASIC), field programmable logic arrays (FPGA) or other equivalent integrated or discrete logic circuits. To execute instructions. Therefore, the term "processor" as used herein may refer to any of the foregoing structure or any other structure suitable for implementing the techniques described herein. In addition, in some aspects, the functions described by the various illustrative logical blocks, modules, and steps described herein may be provided in dedicated hardware and/or software modules configured for encoding and decoding, or combined Into the combined codec. Moreover, the technology may be fully implemented in one or more circuits or logic elements.

The technology of this application can be implemented in a variety of devices or devices, including wireless handsets, integrated circuits (ICs), or a set of ICs (for example, chipsets). Various components, modules, or units are described in this application to emphasize the functional aspects of the device for implementing the disclosed technology, but they do not necessarily need to be implemented by different hardware units. In fact, as described above, various units can be combined with appropriate software and/or firmware in the codec hardware unit, or by interoperating hardware units (including one or more processors as described above). provide.

The above are only exemplary specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or changes within the technical scope disclosed in this application. Replacement shall be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

A data transmission method, characterized in that it comprises:

The base station requests the core network device for the base station private key corresponding to the base station public key;

The base station sends a broadcast message to the user equipment UE, the broadcast message includes signature information and the base station public key, and the signature information is obtained by the base station by signing the base station private key.
The method according to claim 1, wherein the broadcast message includes a first replay parameter, and the first replay parameter is used by the UE to verify whether the broadcast message is a replay message.
The method according to claim 1 or 2, further comprising:

The base station receives the response message of the broadcast message sent by the UE, and the response message of the broadcast message includes first encryption information, and the first encryption information is the UE according to the base station public key and the stored master public key. The key is obtained by encrypting the first information;

The base station uses the base station private key to decrypt the first encrypted information. The base station private key is generated by the core network device according to the base station public key and the master private key. The master private key is a pair of secret keys generated by the core network device;

If the base station fails to decrypt the first encrypted information using the base station private key, the base station discards the response message of the broadcast message.
The method according to claim 3, wherein the response message of the broadcast message includes a second playback parameter, and the method further comprises:

Verifying, by the base station, whether the response message of the broadcast message is a replay message according to the second replay parameter;

The decryption of the first encrypted information by the base station using the base station private key includes:

When verifying that the response message of the broadcast message is not a replay message, the base station uses the base station private key to decrypt the first encrypted information.
The method according to claim 4, wherein when verifying that the response message of the broadcast message is a replay message, the base station discards the response message of the broadcast message.
The method according to any one of claims 1-5, wherein the request by the base station from the core network device for the base station private key corresponding to the base station public key comprises:

Sending, by the base station, a first request message to the core network device, where the first request message includes the base station public key;

The base station receives a response message of the first request message sent by the core network device, and the response message of the first request includes the base station private key.
The method according to any one of claims 1-6, wherein the base station public key includes a base station identity and a validity period of the base station public key.
A data transmission method, characterized in that it comprises:

The user equipment UE receives the broadcast message sent by the base station. The broadcast message includes signature information and the base station public key. The signature information is obtained by the base station by signing the base station private key, and the base station private key is sent to the core network equipment. Of the base station;

The UE verifies whether the broadcast message comes from a legal base station according to the stored master public key, the base station public key, and the signature information, and the master public key is generated by the core network device for the UE;

When the broadcast message is not from a legitimate base station, the UE discards the broadcast message.
The method according to claim 8, wherein the broadcast message includes a first playback parameter, and the UE verifies the broadcast message according to the stored master public key, the base station public key, and the signature information Whether from a legitimate base station, including:

Verifying, by the UE, whether the broadcast message is a replay message according to the first replay parameter;

The UE verifies the signature information according to the master public key and the base station public key;

When the UE verifies that the broadcast message is not a replay message, and successfully verifies the signature information according to the master public key and the base station public key, it is determined that the broadcast message comes from a legitimate base station.
The method according to claim 8 or 9, wherein the method further comprises:

When the broadcast message comes from a legitimate base station, the UE sends a response message of the broadcast message to the base station. The response message of the broadcast message includes first encryption information, and the first encryption information is the UE Obtained by encrypting the first information according to the base station public key and the master public key.
The method according to claim 10, wherein the response message of the broadcast message further includes a second replay parameter, and the second replay parameter is used by the base station to verify whether the response message of the broadcast message is To replay the message.
The method according to any one of claims 8-11, wherein the base station public key includes a base station identity and the validity period of the base station public key;

The UE verifying whether the broadcast message comes from a legal base station according to the stored master public key, the base station public key, and the signature information includes:

The UE verifies whether the validity period of the base station public key is valid;

When the validity period of the base station public key is valid, the UE verifies the signature information according to the master public key and the base station public key;

Determine whether the broadcast message comes from a legal base station according to the verification result of the signature information.
A data transmission method is characterized in that it further includes:

The core network device receives a request message sent by the base station, where the request message includes the base station public key of the base station;

Generating, by the core network device, the base station private key corresponding to the base station public key according to the base station public key and the master private key;

The core network device sends the base station private key to the base station.
The method according to claim 12, further comprising:

Generating a secret key pair by the core network device, the secret key pair including a master public key and the master private key;

The core network device stores the master private key, and the master public key is securely issued to the user equipment UE.
A base station, characterized in that it comprises:

The obtaining module is used to request the base station private key corresponding to the base station public key from the core network device;

The signature module is used to sign according to the private key of the base station to obtain signature information;

The sending module is configured to send a broadcast message to the user equipment UE, the broadcast message including the signature information and the base station public key.
The base station according to claim 15, wherein the broadcast message includes a first replay parameter, and the first replay parameter is used by the UE to verify whether the broadcast message is a replay message.
The base station according to claim 15 or 16, further comprising:

The receiving module is configured to receive a response message of the broadcast message sent by the UE. The response message of the broadcast message includes first encryption information, and the first encryption information is stored by the UE according to the base station public key and Obtained by encrypting the first information with the master public key;

The decryption module is configured to decrypt the first encrypted information using the base station private key, the base station private key is generated by the core network device according to the base station public key and the master private key, and the master public key And the master private key are a pair of secret keys generated by the core network device; when the base station private key is used to decrypt the first encrypted information, the response message of the broadcast message is discarded.
The base station according to claim 17, wherein the response message of the broadcast message includes the second replay parameter, and further includes:

A verification module, configured to verify whether the response message of the broadcast message is a replay message according to the second replay parameter;

The decryption module is specifically used for:

When the verification module verifies that the response message of the broadcast message is not a replay message, the base station private key is used to decrypt the first encrypted information.
The base station according to claim 18, wherein the decryption module is further configured to: when the verification module verifies that the response message of the broadcast message is a replay message, discard the response message of the broadcast message.
The base station according to any one of claims 15-19, wherein the acquiring module is specifically configured to:

Sending a first request message to the core network device, where the first request message includes the base station public key;

Receiving a response message of the first request message sent by the core network device, where the response message of the first request includes the base station private key.
The base station according to any one of claims 15-20, wherein the base station public key includes a base station identity and a validity period of the base station public key.
A user equipment UE is characterized in that it includes:

The receiving module is used to receive a broadcast message sent by a base station, the broadcast message includes signature information and a base station public key, the signature information is obtained by the base station through the base station private key signature, and the base station private key is a core network device Sent to the base station;

A verification module, configured to verify whether the broadcast message comes from a legal base station according to the saved master public key, the base station public key, and the signature information, and the master public key is generated by the core network device for the UE; When the broadcast message is not from a legitimate base station, the broadcast message is discarded.
The UE according to claim 22, wherein the broadcast message includes a first playback parameter, and the verification module is specifically configured to:

Verifying whether the broadcast message is a replay message according to the first replay parameter;

Verify the signature information according to the master public key and the base station public key;

When it is verified that the broadcast message is not a replay message, and the signature information is successfully verified according to the master public key and the base station public key, it is determined that the broadcast message comes from a legitimate base station.
The UE according to claim 22 or 23, further comprising:

An encryption module, configured to encrypt first information according to the base station public key and the master public key to obtain first encrypted information when the broadcast message comes from a legal base station;

The sending module is configured to send a response message of the broadcast message to the base station, and the response message of the broadcast message includes the first encryption information.
The UE according to claim 24, wherein the response message of the broadcast message further includes a second replay parameter, and the second replay parameter is used by the base station to verify whether the response message of the broadcast message is To replay the message.
The UE according to any one of claims 22-25, wherein the base station public key includes a base station identity and a validity period of the base station public key, and the verification module is specifically configured to:

Verifying whether the validity period of the base station public key is valid;

When the validity period of the base station public key is valid, verify the signature information according to the master public key and the base station public key;

Determine whether the broadcast message comes from a legal base station according to the verification result of the signature information.
A core network device is characterized in that it further includes:

A receiving module, configured to receive a request message sent by a base station, where the request message includes the base station public key of the base station;

A generating module, configured to generate a base station private key corresponding to the base station public key according to the base station public key and the master private key;

The sending module is used to send the base station private key to the base station.
The device according to claim 27, further comprising a storage module;

The generating module is also used to generate a secret key pair, the secret key pair including a master public key and the master private key;

The storage module is used to store the master private key, and the master public key is securely issued to the user equipment UE.