WO2016159538A1

WO2016159538A1 - System and method for pin authentication

Info

Publication number: WO2016159538A1
Application number: PCT/KR2016/002548
Authority: WO
Inventors: 이정엽
Original assignee: 주식회사 키페어
Priority date: 2015-04-03
Filing date: 2016-03-15
Publication date: 2016-10-06
Also published as: KR20160118841A

Abstract

The present invention relates to a system and a method for PIN authentication. The system for PIN authentication according to one embodiment of the present invention comprises: a terminal for generating a first session key on the basis of an inputted PIN and encrypting the inputted PIN using the first session key so as to generate an encrypted PIN; and a smart card chip for performing PIN authentication after decrypting the encrypted PIN using a second session key generated on the basis of a pre-stored PIN when receiving the encrypted PIN from the terminal.

Description

PIN authentication system and method

The present invention relates to a PIN authentication system and method, and more particularly, to a PIN authentication system and method for performing a PIN authentication between the terminal and the smart card chip.

PIN stands for "Personal Identification Number" and means a personal identification number, and is information used to authenticate a user (person) in a digital environment such as the Internet, a computer, a smartphone, a smart card chip, and the like.

1 is a schematic diagram of a PIN authentication system according to an embodiment of the prior art, which shows a PIN authentication scheme without encryption between a terminal and a smart card chip.

Referring to FIG. 1, when a user _{inputs a} PIN (PIN _Input ) to the terminal 11 for user authentication, the terminal 11 connects to the smart card chip 21 through a NFC (Near Field Communication) communication. PIN _Input ). Then, the smart card chip 21 compares the PIN (PIN _Input ) received from the terminal 11 and the PIN (PIN _Saved ) previously stored to determine whether or not. If it does not match, the terminal 11 responds to the PIN authentication failure, and if it matches, the terminal 11 responds to the PIN authentication success.

However, the above-described PIN authentication scheme according to an embodiment of the prior art had a weak security problem because the PIN can be exposed as it is in communication between the terminal and the smart card chip.

On the other hand, Figure 2 is a schematic diagram of a PIN authentication system according to another embodiment of the prior art, showing an encryption PIN authentication method using a symmetric key (Symmetric Key) between the terminal and the smart card chip.

Referring to FIG. 2, when a user _{inputs a} PIN (PIN _Input ) to the terminal 12 for user authentication, the terminal 12 encrypts the PIN (PIN _Input ) using a secret key and then NFC. The encrypted PIN E_PIN is transmitted to the smart card chip 22 through communication or the like. Then, the smart card chip 22 decrypts the encrypted PIN (E_PIN) received from the terminal 12 using the secret key, and then decrypts the decrypted PIN (PIN _Input ) and the previously stored PIN (PIN _Saved ). Compare and determine whether they match. If it does not match, the terminal 12 responds to the PIN authentication failure, and if it does match, the terminal 12 responds to the PIN authentication success.

However, since the PIN authentication method according to another embodiment of the prior art described above stores a secret key shared between the terminal and the smart card chip, the user may use two or more terminals (eg, a computer or a smartphone). If there is a need to store the secret key for each terminal, and there is still a security vulnerability because there is a risk that the secret key is exposed through the terminal.

3 is a schematic diagram of a PIN authentication system according to another embodiment of the prior art, showing an encryption PIN authentication method using a public key between a terminal and a smart card chip.

Referring to FIG. 3, when a user _{inputs a} PIN (PIN _Input ) to the terminal 13 for user authentication, the terminal 13 receives a public key from the smart card chip 23 through NFC communication or the like. After the PIN _input ) is encrypted, the encrypted PIN (E_PIN) is transmitted to the smart card chip 23 through NFC communication. Then, the smart card chip 23 decrypts the encrypted PIN (E_PIN) received from the terminal 13 by using a private key and then decrypts the PIN (PIN _Input ) and the PIN (previously stored). PIN _Saved ) is compared to determine whether they match. If it does not match, the terminal 13 responds to the PIN authentication failure, and if it matches, the terminal 13 responds to the PIN authentication success.

However, the above-described PIN authentication scheme according to another embodiment of the prior art has a problem that a large amount of computation is required in the process of decrypting the smart card chip due to the RSA algorithm for processing public and private keys. In particular, in a wireless environment such as NFC communication, there is a problem that an error may occur because the smart card chip is reset (reset) due to lack of power.

Therefore, there is no risk of exposing the secret key through the terminal, and the encryption PIN authentication method that can be used stably even in NFC communication by reducing the amount of calculation with a fast encryption algorithm is required.

[Preceding technical literature]

Republic of Korea Patent Publication No. 10-2005-0119751

Republic of Korea Patent Application Publication No. 10-2014-0143130

The present invention was devised to meet the above-described needs, and an object of the present invention is to provide a PIN authentication system and method for performing stable PIN encryption between a terminal and a smart card chip.

Another object of the present invention is to provide a PIN authentication system and method that can be used stably even in NFC communication by reducing the amount of calculation with a fast encryption algorithm without the risk of exposing the secret key through the terminal.

It is still another object of the present invention to provide a PIN authentication system and method for performing encrypted PIN authentication using a session key generated based on a PIN.

For this purpose, a PIN authentication system of one embodiment of the present invention generates a first session key based on an input PIN, encrypts the input PIN using the first session key, and A terminal for generating an encrypted PIN; And a smart card chip that, upon receiving the encrypted PIN from the terminal, decrypts the encrypted PIN using a second session key generated based on a pre-stored PIN and performs PIN authentication. .

The smart card chip for PIN authentication according to one embodiment of the present invention includes a communication unit configured to perform at least one of contact communication and contactless communication with a terminal; A memory unit for storing a PIN; And a controller configured to communicate with the terminal through the communication unit to perform PIN authentication, wherein the controller receives an encrypted PIN from the terminal, based on a PIN stored in the memory unit. Generate a PIN, decrypt the encrypted PIN using the session key, and perform PIN authentication.

On the other hand, a PIN authentication method of one embodiment of the present invention includes the steps of: generating, by a terminal, a first session key based on an input PIN; Generating, by the terminal, an encrypted PIN by encrypting the input PIN using the first session key; Generating, by the smart card chip, a second session key based on a pre-stored PIN; And performing, by the smart card chip, PIN authentication by decrypting the encrypted PIN transmitted from the terminal by using the second session key.

According to the present invention, since encrypted PIN authentication is performed using a session key generated based on a PIN, it is possible to perform stable and encrypted PIN authentication between a terminal and a smart card chip.

Specifically, while the encryption PIN authentication method using a symmetric key according to the prior art requires a method for securely managing a separate key for encrypting a PIN in the terminal, the PIN authentication method according to the present invention encrypts the PIN in the terminal. No key management is required because it does not store a separate key to do this.

In addition, the encryption PIN authentication method using a public key according to the prior art should use a high computational algorithm, such as the Rivest Shamir Adleman (RSA) algorithm for processing the public key and the private key, the PIN authentication method according to the present invention is AES ( Since algorithms such as Advanced Encryption Standard) can be used with low computational complexity, they can be operated on smart card chips through NFC communication.

2 is a schematic diagram of a PIN authentication system according to another embodiment of the prior art, showing an encryption PIN authentication method using a symmetric key between a terminal and a smart card chip.

FIG. 4 is a schematic diagram of a PIN authentication system according to an embodiment of the present invention, which illustrates a method of generating a session key between a terminal and a smart card chip to perform encryption PIN authentication.

5 is a configuration diagram of a smart card chip according to an embodiment of the present invention.

6 is a flowchart of a PIN authentication method according to an embodiment of the present invention.

7 illustrates an encryption process using the AES 128 CBC algorithm according to a preferred embodiment of the present invention.

8 illustrates a decoding process using an AES 128 CBC algorithm according to a preferred embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted in the following description.

4, the PIN authentication system according to an embodiment of the present invention may be composed of a terminal 100, a smart card chip 200, and the like.

The terminal 100 is equipped with a universal serial bus (USB) port such as a personal computer (PC), a laptop, etc., and enables short-range wireless communication such as all types of wired terminals capable of USB communication (contact communication), smartphones, and tablet PCs. It is meant to include all types of wireless terminals capable of (contactless communication).

The smart card chip 200 may be implemented and used as a security token (HSM) in the form of a USB device or a plastic card, for example, and performs PIN authentication through contact and / or contactless communication with the terminal 100. do.

In this regard, Figure 5 shows the configuration of a smart card chip 200 according to an embodiment of the present invention.

Referring to FIG. 5, the smart card chip 200 according to an embodiment of the present invention includes a control unit 210, a memory unit 220, a communication unit 230, and the like.

The control unit 210 may be implemented as, for example, a microprocessor (CPU), a cryptographic accelerator (Crypto Accelerator), etc., and controls the memory unit 220 and the communication unit 230 to perform PIN authentication and to execute a terminal ( Provide information required by 100).

The memory unit 220 may be implemented as, for example, an electrically erasable programmable read only memory (EEPROM), and stores an operating system (OS) for driving a smart card chip, an encryption / decryption program for PIN authentication, a PIN, and the like.

In addition, the communication unit 230 is provided with a built-in antenna to receive power induced from the terminal 100 to perform short-range wireless communication (contactless communication) with the terminal 100, and optionally via a smart card reader or USB terminal ( It may also be implemented to enable contact communication with 100).

Hereinafter, a PIN authentication system and method according to an embodiment of the present invention will be described in detail with reference to FIGS. 4 to 8.

4 to 6, in step S610, when the terminal 100 receives a PIN (PIN _Input ) from a user or the like, in step S620, the terminal 100 generates a one-time random number (RND) for PIN encryption. Transmits a Get Challenge command to the smart card chip 200 to receive

Then, in step S625, the smart card chip 200 generates a one-time random number (RND) for PIN encryption and transmits to the terminal 100.

In step S630, the terminal 100 generates a first session key SES_KEY ₁ based on a PIN (PIN _Input ) input from a user or the like. In step S640, the terminal 100 generates a first session key SES_KEY _1. ) And the one-time random number (RND) to encrypt the _input PIN (PIN _Input ) to generate an encrypted PIN (E_PIN). In operation S650, the terminal 100 transmits the generated encrypted PIN E_PIN to the smart card chip 200.

In this case, according to a preferred embodiment of the present invention, the terminal 100 uses a symmetric key algorithm with a small amount of calculation, for example, a Data Encryption Standard (DES) algorithm, an Advanced Encryption Standard (AES) algorithm, and more preferably a 128-bit key. Session key generation and encryption are performed using the AES 128 Cipher Block Chaining (CBC) algorithm.

Referring to FIG. 7, the terminal 100 generates a 16-byte first padding PIN (PIN_PAD ₁ ) by padding a null character to an _input PIN. A first session key SES_KEY ₁ is generated by performing an AES 128 CBC encryption (AES128_CBC_ENC) algorithm based on the 1 padding PIN (PIN_PAD ₁ ) and an initial vector (IV) used for CBC mode encryption / decryption.

In addition, the terminal 100 performs an AES 128 CBC encryption (AES128_CBC_ENC) algorithm based on a one-time random number RND, a first padding PIN PIN_PAD ₁ , a first session key SES_KEY ₁ , and an initial vector IV. Generate an encrypted PIN (E_PIN).

Referring back to FIG. 6, in step S635, the smart card chip 200 generates a second session key SES_KEY ₂ based on a PIN (PIN _Saved ) previously stored. For reference, in FIG. 6, step S635 is shown to be performed before step S650, but may be performed after step S650.

In operation S655, the smart card chip 200 decrypts the encrypted PIN E_PIN using a second session key SES_KEY _{2. In} operation S665, the smart card chip 200 decrypts the decrypted PIN ( A PIN authentication is performed by comparing the PIN _Input ) and the previously saved PIN (PIN _Saved ) to determine whether they match.

In this case, as described above, according to the preferred embodiment of the present invention, the smart card chip 200 uses a symmetric key algorithm with a small amount of calculation, for example, a Data Encryption Standard (DES) algorithm, an Advanced Encryption Standard (AES) algorithm, More preferably, session key generation and decryption are performed using an AES 128 Cipher Block Chaining (CBC) algorithm using a 128-bit key.

Referring to Figure 8 above it, creating a smart card chip (200) channel (Null) to the character padding (padding) of a 16-byte second padding PIN (PIN_PAD ₂₎ to the pre-stored PIN (PIN _Saved), and A second session key (SES_KEY ₂ ) is generated by performing an AES 128 CBC encryption (AES128_CBC_ENC) algorithm based on the second padding PIN (PIN_PAD ₂ ) and an initial vector (IV) used for CBC mode encryption / decryption. do.

The smart card chip 200 performs the AES 128 CBC decryption (AES128_CBC_DEC) algorithm based on the encrypted PIN E_PIN, the second session key SES_KEY ₂ , and the initial vector IV to decrypt the one-time random number D_RND. ) And the decrypted padding PIN (D_PIN_PAD).

Thereafter, the smart card chip 200 determines whether the one-time random number RND transmitted to the terminal 100 and the decrypted one-time random number D_RND are the same, and the second padding PIN PIN_PAD ₂ is decoded. PIN authentication is performed by determining whether the padding PIN D_PIN_PAD is the same.

Referring back to FIG. 6, in step S675, the smart card chip 200 responds to the terminal 100 with a PIN authentication result. For example, if the determination result in step S655 does not match (for example, RND and D_RND are not the same or PIN_PAD ₂ and D_PIN_PAD are not the same), the terminal 100 responds with a PIN authentication failure, and terminates the procedure. If the determination result is the same (for example, if RND and D_RND are the same and PIN_PAD ₂ and D_PIN_PAD are the same), the terminal 100 responds to the PIN authentication success and proceeds to the following procedure.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains may be embodied in other specific various forms without changing the technical spirit or essential features of the present invention. The examples are to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. Should be interpreted as

Claims

In a personal identification number (PIN) authentication system,

A terminal for generating a first session key based on the input PIN, and encrypting the input PIN using the first session key to generate an encrypted PIN; And

And a smart card chip that receives the encrypted PIN from the terminal, decrypts the encrypted PIN using a second session key generated based on a pre-stored PIN, and then performs PIN authentication. Authentication system.
The method of claim 1,

And the terminal generates the encrypted PIN based on a one-time random number received from the smart card chip.
The method of claim 2,

The terminal generates a first padding PIN by padding a null character on the input PIN, and generates the first session key based on the first padding PIN and an initial vector. And then generate the encrypted PIN based on the one-time random number, the first padding PIN, the first session key, and the initial vector.
The method of claim 3,

The smart card chip generates a second padding PIN by padding a null character on the previously stored PIN, and generates the second session key based on the second padding PIN and the initial vector. And decrypting the encrypted PIN based on the second session key and the initial vector to generate a decrypted one-time random number and a decrypted padding PIN.
The method of claim 4, wherein

The smart card chip performs PIN authentication based on at least one of whether the one-time random number transmitted to the terminal is identical to the decrypted one-time random number and whether the second padding PIN and the decrypted padding PIN are the same. PIN authentication system.
The method according to any one of claims 1 to 5,

The encryption and decryption is performed using a symmetric key algorithm.
The method according to any one of claims 1 to 5,

The communication between the terminal and the smart card chip PIN authentication system, characterized in that using the NFC (Near Field Communication) communication.
In the smart card chip for PIN (Personal Identification Number) authentication,

A communication unit configured to perform at least one of contact communication and contactless communication with the terminal;

A memory unit for storing a PIN; And

And a controller for communicating with the terminal through the communication unit to perform PIN authentication.

When the controller receives the encrypted PIN from the terminal, the controller generates a session key based on the PIN stored in the memory unit, decrypts the encrypted PIN using the session key, and then authenticates the PIN. Smart card chip, characterized in that to perform.
The method of claim 8,

The controller determines whether the one-time random number transmitted to the terminal is identical to the one-time random number generated by decrypting the encrypted PIN, and a PIN generated by decrypting the PIN stored in the memory unit and the encrypted PIN. Smart card chip, characterized in that to perform a PIN authentication based on at least one of the same.
The method according to claim 8 or 9,

The controller generates a padding PIN by padding a null character on the PIN stored in the memory unit, and generates the session key based on the padding PIN and an initial vector. And decrypting the encrypted PIN based on the session key and the initial vector.
A security token comprising a smart card chip according to any one of claims 8 to 10.
In the PIN (Personal Identification Number) authentication method,

Generating, by the terminal, a first session key based on the input PIN;

Generating, by the terminal, an encrypted PIN by encrypting the input PIN using the first session key;

Generating, by the smart card chip, a second session key based on a pre-stored PIN; And

And the smart card chip decrypting the encrypted PIN transmitted from the terminal by using the second session key to perform PIN authentication.
The method of claim 12,

Before generating the first session key,

The terminal further comprises the step of receiving a one-time (random number) from the smart card chip.
The method of claim 13,

Generating the first session key,

Generating, by the terminal, a first padding PIN by padding a null character on the input PIN; And

Generating, by the terminal, the first session key based on the first padding PIN and an initial vector;

Generating the encrypted PIN,

And generating, by the terminal, the encrypted PIN based on the one-time random number, the first padding PIN, the first session key, and the initial vector.
The method of claim 14,

Generating the second session key,

Generating, by the smart card chip, a second padding PIN by padding a null character on the pre-stored PIN; And

Generating, by the smart card chip, a second session key based on the second padding PIN and the initial vector;

Performing the PIN authentication,

And decrypting, by the smart card chip, the encrypted PIN based on the second session key and the initial vector.
The method according to any one of claims 12 to 15,

The encryption and decryption is performed using a symmetric key algorithm.