WO2022143798A1 - Method for verifying cross-chain transaction, and terminal device and readable storage medium - Google Patents

Abstract

The present application is applicable to the technical field of computer applications. Provided are a method for verifying a cross-chain transaction, and a terminal device and a readable storage medium. The method comprises: acquiring a cross-chain event submitted by a source chain; generating a cross-chain transaction on the basis of the cross-chain event, wherein the cross-chain transaction comprises a verification protocol; and sending the cross-chain transaction to a relay chain, and instructing the relay chain to verify the verification protocol and then send the cross-chain transaction to a cross-chain gateway of a destination chain after the verification is passed. By means of the embodiments of the present application, a cross-chain transaction is sent to a relay chain, and the relay chain is instructed to only verify a verification protocol in the cross-chain transaction, such that insofar as privacy is ensured, the problem of increasing the processing burden on a cross-chain gateway due to verifying a cross-chain transaction by means of a cross-chain gateway of a destination chain at present can be solved.

Description

Verification method, terminal device and readable storage medium for cross-chain transaction

This application claims the priority of the Chinese patent application with the application number 202011630475.0 and the application name "Verification method, terminal device and readable storage medium for cross-chain transactions" submitted to the State Intellectual Property Office on December 30, 2020, all of which are The contents are incorporated herein by reference.

technical field

The present application belongs to the field of computer technology, and in particular relates to a verification method for cross-chain transactions, a terminal device and a readable storage medium.

Background technique

With the development of blockchain application technology, different blockchains can communicate with each other through cross-chain technology, which mainly includes notary-based mechanisms, hash locking, and relay chains. Among them, the cross-chain transaction based on the relay chain is that different application chains access the relay chain through the cross-chain gateway, and perform cross-chain operations through the relay chain.

Since the business sensitive information of the institutions on both sides of the transaction is involved in the cross-chain transaction, and the cross-chain transaction stored through the relay chain can be obtained by other institutions, it is easy to cause the privacy of both parties to be leaked. At present, in order to avoid privacy leakage during the cross-chain transaction, the information in the cross-chain transaction is sent to the relay chain in the form of ciphertext. Cross-chain gateway verification increases the processing burden of cross-chain gateway.

technical problem

One of the purposes of the embodiments of the present application is to provide a cross-chain transaction verification method, terminal device and readable storage medium, which can solve the problem that the cross-chain transaction is currently verified by the cross-chain gateway of the destination chain, and the cross-chain transaction is increased. The problem of the processing burden of the gateway.

technical solutions

In order to solve the above-mentioned technical problems, the technical solutions adopted in the embodiments of the present application are:

In the first aspect, an embodiment of the present application provides a cross-chain transaction verification method, which is applied to a source chain cross-chain gateway, and the method includes:

Obtain the cross-chain event submitted by the source chain; generate a cross-chain transaction based on the cross-chain event, and the cross-chain transaction includes a verification protocol; send the cross-chain transaction to the relay chain, instructing the relay chain to After the verification protocol is verified, the cross-chain transaction is sent to the target-chain cross-chain gateway.

In the second aspect, the embodiments of the present application provide a cross-chain transaction verification method, which is applied to the relay chain, and the method includes:

Receive the cross-chain transaction sent by the source-chain cross-chain gateway, where the cross-chain transaction includes a verification protocol; verify the verification protocol according to preset verification rules; if the verification is passed, send the cross-chain transaction to the destination chain cross-chain gateway. chain transactions.

Exemplarily, the running the verification code to verify the zero-knowledge proof includes:

Taking the transaction ciphertext as input, decrypt the transaction ciphertext through the symmetric key in the zero-knowledge proof to obtain the transaction plaintext to be verified; The transaction plaintexts are compared; if they are consistent, the cross-chain transaction validity certificate and cross-chain call information in the transaction plaintext are verified; if the cross-chain transaction is verified to be valid and the cross-chain call information is verified to be correct, the verification is passed.

Exemplarily, the method further includes:

If the verification is passed, send the transaction ciphertext and the encrypted symmetric key to the destination chain cross-chain gateway; wherein the encrypted symmetric key is used to instruct the destination chain cross-chain gateway to use the The second private key of the second asymmetric key decrypts the encrypted symmetric key to obtain the symmetric key; the transaction ciphertext is used to instruct the destination chain cross-chain gateway to decrypt the encrypted symmetric key using the symmetric key The transaction ciphertext is obtained to obtain the transaction plaintext; the transaction plaintext is used to instruct the destination chain cross-chain gateway to initiate a call to the destination chain according to the cross-chain call information in the transaction plaintext.

In a third aspect, the embodiments of the present application provide a cross-chain transaction verification method, which is applied to a destination chain cross-chain gateway, and the method includes:

Receive the cross-chain transaction sent by the relay chain, where the cross-chain transaction includes the transaction ciphertext and the encrypted symmetric key; decrypt the encrypted symmetric key by using the second private key of the second asymmetric key to obtain Symmetric key; decrypt the transaction ciphertext using the symmetric key to obtain the transaction plaintext of the cross-chain transaction; initiate a call to the destination chain according to the cross-chain call information in the transaction plaintext.

In a fourth aspect, the embodiments of the present application provide a verification system for cross-chain transactions, including:

The source chain cross-chain gateway is used to generate cross-chain transactions according to the cross-chain events of the source chain, and send the cross-chain transactions to the relay chain;

The relay chain is used to receive the cross-chain transaction sent by the cross-chain gateway of the source chain, and verify the verification protocol of the cross-chain transaction through the verification rules. After the verification is passed, send the cross-chain transaction to the cross-chain gateway of the destination chain. trade;

The destination chain cross-chain gateway is used to receive the cross-chain transaction sent by the relay chain, parse the cross-chain transaction, obtain the transaction plaintext, and call the destination chain according to the transaction plaintext.

In a fifth aspect, an embodiment of the present application provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, when the processor executes the computer program implement the method described.

In a sixth aspect, an embodiment of the present application provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and the computer program implements the method when executed by a processor.

In a seventh aspect, an embodiment of the present application provides a computer program product, which enables the terminal device to execute the above-mentioned method when the computer program product is run on a terminal device.

It can be understood that, for the beneficial effects of the foregoing second aspect to the seventh aspect, reference may be made to the relevant descriptions in the foregoing first aspect, which will not be repeated here.

beneficial effect

The beneficial effects of the embodiment of the present application compared with the prior art are: through the embodiment of the present application, the source chain cross-chain gateway obtains the cross-chain event submitted by the source chain; based on the cross-chain event, a cross-chain transaction is generated, and the cross-chain transaction includes verification. protocol; send the cross-chain transaction to the relay chain, and instruct the relay chain to send the cross-chain transaction to the destination chain cross-chain gateway after passing the verification protocol; the cross-chain transaction generated by the cross-chain gateway, the cross-chain transaction includes Verification protocol, the relay chain can send the cross-chain transaction to the cross-chain gateway of the destination chain only after the verification protocol is passed, without the need for the cross-chain gateway of the destination chain to verify again, so that the cross-chain gateway remains lightweight; At the same time, the verification of cross-chain transactions by the relay chain is more reliable; it has strong ease of use and practicability.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present application more clearly, the following briefly introduces the accompanying drawings that are used in the description of the embodiments or exemplary technologies. Obviously, the drawings in the following description are only for the present application. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic diagram of a system architecture of an application scenario provided by an embodiment of the present application;

2 is a schematic flowchart of a verification method for a cross-chain transaction provided by an embodiment of the present application;

3 is a schematic flowchart of a verification method for a cross-chain transaction provided by another embodiment of the present application;

4 is a schematic flowchart of a verification method for a cross-chain transaction provided by another embodiment of the present application;

5 is a schematic diagram of an interaction flow provided by an embodiment of the present application;

6 is a schematic structural diagram of a cross-chain gateway of a source chain provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a relay chain provided by an embodiment of the present application;

FIG. 8 is a structural example diagram of a cross-chain gateway of a destination chain provided by an embodiment of the present application;

9 is a schematic structural diagram of a verification system for cross-chain transactions provided by an embodiment of the present application;

FIG. 10 is a schematic structural diagram of a terminal device provided by an embodiment of the present application.

Embodiments of the present invention

In the following description, for the purpose of illustration rather than limitation, specific details such as a specific system structure and technology are set forth in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

With the development and innovation of blockchain technology, a large number of blockchain networks with different characteristics and adapting to the needs of different scenarios have emerged in different fields, and many value islands have been formed between each blockchain network. Chain technology realizes the interconnection and value transfer between different blockchains.

One of the cross-chain technologies is the cross-chain based on the relay chain. As shown in FIG. 1 , which is a schematic diagram of a system architecture of an application scenario provided by an embodiment of the present application, blockchain A and blockchain B conduct cross-chain transactions through relay chain R. Blockchain A consists of institution a1, institution a2, institution a3, etc., and blockchain B consists of institution b1, institution b2, institution b3, etc. When the institution a1 of blockchain A and the institution b1 of blockchain B conduct business cooperation through cross-chain, the institution a1 at the node of blockchain A is connected to the relay chain R through the cross-chain gateway Pa, and the institution b1 is in the blockchain. The nodes of the block chain B access the relay chain R through the cross-chain gateway Pb. Both the cross-chain gateway Pa and the cross-chain gateway Pb register the information of the application chain (blockchain) A and the application chain (blockchain) B with the relay chain R in advance, and register the verification rules of their respective application chains.

Institution a1 throws a cross-chain event from blockchain A, and the cross-chain gateway Pa listens to the cross-chain event, converts it to generate a cross-chain transaction T, and submits it to the relay chain R; among them, the cross-chain transaction T contains Source chain A (blockchain A) and destination chain B (blockchain B) address information, source chain A (blockchain A) call information (contract, method, parameters, etc.), and the cross-chain transaction validity proof of source chain A (blockchain A). After the relay chain R passes through the consensus mechanism, the cross-chain transaction is packaged into a block, and the built-in cross-chain transaction verification engine invokes the pre-registered verification rules of blockchain A to verify the cross-chain transaction T of blockchain A. After verification, the cross-chain transaction can be routed to the destination chain B (blockchain B). After the cross-chain gateway Pb of the destination chain B (blockchain B) synchronizes to the cross-chain transaction T, it converts the invocation information into the transaction of blockchain B, and calls the contract of blockchain B. The cross-chain gateway Pb After receiving the receipt from blockchain B, the receipt is submitted to the relay chain R in the form of a cross-chain transaction. The relay chain R produces blocks, performs the verification process and routes to the source chain A (blockchain A ).

Since the information in the cross-chain transaction involves the business-sensitive information of the institutions a1 and b1 on both sides of the cross-chain, it is not expected to be seen by other institutions, and the cross-chain transaction stored on the relay chain can be obtained by other institutions, resulting in The privacy of both parties to the transaction is leaked.

In order to avoid the problem of privacy leakage of cross-chain transactions, the call information and proof information in cross-chain transactions are sent to the relay chain in the form of cipher text. The intercommunication method of the cross-chain gateway of the chain for verification. For example: AppChain A's cross-chain gateway Pa registers AppChain with AppChain B's cross-chain gateway Pb, and deploys a verification rule for cross-chain transaction verification; AppChain A's cross-chain gateway Pa and AppChain B The cross-chain gateway Pb performs key negotiation to obtain a symmetric key key; when application chain A initiates a cross-chain transaction to application chain B, the cross-chain gateway Pa uses the symmetric key key to encrypt the cross-chain transaction call information and certification information , and then send it to the relay chain. Since the relay chain receives the transaction ciphertext, the transaction information cannot be disclosed. The relay chain routes the transaction ciphertext to the destination chain B. After receiving the cross-chain transaction, the cross-chain gateway Pb of the destination chain B decrypts the transaction ciphertext with the key; The transaction is validated for validity. After verification, the cross-chain gateway Pb converts the call information in the cross-chain transaction into the transaction of the destination application chain B, and submits it to the application chain B (destination chain B).

Through the above embodiments, the burden of the cross-chain gateway is increased. A cross-chain gateway is essentially an interactive component that connects different blockchain systems and is a lightweight node. After the verification of transaction validity is transferred to the cross-chain gateway, the burden of the cross-chain gateway will increase with the increase of cross-chain transactions with different application chains. Second, transaction verification is less reliable. The cross-chain gateway is a single-point component architecture, and the single-point architecture is prone to errors, so the reliability of transaction verification performed by the cross-chain gateway is poor. Then, transaction verification via cross-chain gateways is less scalable. Every time an application chain conducts a cross-chain transaction with another application chain, the cross-chain gateway needs to register with the other side's cross-chain gateway and deploy a verification rule of the other side's application chain, which makes the transaction less scalable.

This application hides business-sensitive information in cross-chain transactions by means of zero-knowledge proof, and the validity of cross-chain transactions can still be verified through the relay chain, while protecting the privacy information of both parties in cross-chain transactions from being leaked.

The verification process in the cross-chain transaction process is described below through each unilateral node in the interaction process.

Referring to FIG. 2 , it is a schematic flowchart of a verification method for a cross-chain transaction provided by an embodiment of the present application. This method is applied to the cross-chain gateway of the source chain, and the execution subject is the cross-chain gateway Pa as shown in FIG. 1 . The method includes the following steps:

Step S201, acquiring the cross-chain event submitted by the source chain.

In some embodiments, taking the architecture of the application scenario shown in FIG. 1 as an example, blockchain A and blockchain B conduct cross-chain transactions through relay chain R, and blockchain A is composed of institutions a1, a2, a3, etc. The blockchain B consists of institutions b1, b2, b3, etc. Blockchain A is the source chain, and Blockchain B is the destination chain. The organization a1 of blockchain A and the organization b1 of blockchain B conduct business cooperation through cross-chain.

Among them, institution a1 deploys the node of blockchain A, the cross-chain gateway Pa and the node of relay chain R, and the institution b1 deploys the node of blockchain B, the cross-chain gateway Pb and the node of relay chain R, each The cross-chain gateway has a pair of asymmetric keys, namely a public key and a private key pair.

Exemplarily, the institution a1 throws a cross-chain event from the blockchain A by calling the business contract of the blockchain A. The action of the cross-chain gateway Pa monitoring mechanism a1 throwing cross-chain events. The cross-chain gateway Pa listens to the cross-chain event and obtains the cross-chain event.

Among them, the cross-chain event includes the address information and transaction plaintext of source chain A (blockchain A) and destination chain B (blockchain B). The transaction plaintext includes source chain A (blockchain A) to destination chain B (blockchain B). The cross-chain call information (contracts, methods, parameters, etc.) of blockchain B), and the validity proof of cross-chain transactions of source chain A (blockchain A).

In some embodiments, the method further includes:

Generate the first asymmetric key and the symmetric key; register the first public key of the first asymmetric key, the address information of the source chain, and the verification rules of the source chain with the relay chain, and obtain the purpose of storage in the relay chain The second public key of the second asymmetric key of the cross-chain gateway; wherein the symmetric key is used to encrypt the transaction plaintext of the cross-chain event, and the verification rule is the verification code for verifying the verification protocol.

Exemplarily, the first asymmetric key is generated by the cross-chain gateway Pa, and the first asymmetric key includes a first public key and a first private key. The cross-chain gateway Pa registers the information and the first public key of the institution a1 of the blockchain A with the relay chain R, and registers the verification rules of the blockchain A with the relay chain R. The source chain cross-chain gateway uses the generated symmetric key to encrypt the transaction plaintext of the cross-chain event. Among them, the transaction plaintext of the cross-chain event includes the cross-chain call information and the validity proof of the cross-chain transaction; the cross-chain call information includes the destination chain contract address, destination chain contract method and parameters.

Step S202, generating a cross-chain transaction based on the cross-chain event, where the cross-chain transaction includes a verification protocol.

In some embodiments, after the cross-chain gateway Pa monitors the cross-chain event, it generates a cross-chain transaction based on the cross-chain event. The verification protocol can be a zero-knowledge proof, and the verification rule is a verification code of a zero-knowledge proof. The verification engine of the relay chain R can call the verification code to verify the cross-chain transaction issued by the blockchain A.

Exemplarily, cross-chain transactions include transaction ciphertext, encrypted symmetric keys, and zero-knowledge proofs.

In some embodiments, generating cross-chain transactions based on cross-chain events includes:

Encrypt the transaction plaintext of the cross-chain event with the symmetric key to obtain the transaction ciphertext; take the transaction ciphertext as the public input, and use the transaction plaintext and the symmetric key as the private input, run the preset zero-knowledge proof generation code, and generate zero The knowledge proof uses zero-knowledge proof as the verification protocol; encrypts the symmetric key with the second public key of the second asymmetric key of the destination chain cross-chain gateway to obtain the encrypted symmetric key.

Among them, the transaction plaintext is the transaction information in the cross-chain event, including the cross-chain call information Payload and the cross-chain transaction validity proof Proof. The transaction ciphertext is obtained by encrypting the transaction plaintext with a symmetric key; the encrypted symmetric key is to encrypt the symmetric key of the cross-chain gateway Pa through the second public key of the second asymmetric key of the cross-chain gateway Pb. Obtained; the verification protocol is a zero-knowledge proof generated based on the transaction plaintext, transaction ciphertext and symmetric key.

Exemplarily, the cross-chain gateway Pa uses the symmetric key K to encrypt the transaction plaintext in the cross-chain event (including cross-chain call information and cross-chain transaction validity proof); wherein, the cross-chain call information includes the destination chain contract address, destination chain Contract methods and parameters. The cross-chain call information is encrypted and denoted as E(Payload, K), and the encrypted cross-chain call information E(Payload, K) is used as the public input for generating the verification protocol. The cross-chain gateway Pa uses the symmetric key K to encrypt the cross-chain transaction validity proof, the encrypted cross-chain transaction validity proof is recorded as E(Proof, K), and the encrypted cross-chain transaction validity proof E(Proof, K) as public input to generate the verification protocol. The symmetric key K and the transaction plaintext (cross-chain call information and cross-chain transaction validity proof) are used as privacy inputs to generate the verification protocol.

In some embodiments, after the cross-chain gateway Pa monitors the cross-chain event, it generates a zero-knowledge proof by running a preset zero-knowledge proof generation code, and uses the above E(Payload, K) and E(Proof, K) as the Public input, symmetric key K, cross-chain call information Payload and cross-chain transaction validity proof Proof are used as privacy input to generate zero-knowledge proof. Among them, the preset zero-knowledge proof generation code can be zkSNARK.

In addition, the cross-chain gateway Pa also uses the second public key of the second asymmetric key of the target-chain cross-chain gateway to encrypt the symmetric key. The cross-chain gateway Pb randomly generates a second asymmetric key, and the second asymmetric key includes a second public key and a second private key. The cross-chain gateway Pb registers the information and the second public key of the organization b1 of the blockchain B with the relay chain R, and registers the verification rules of the blockchain B with the relay chain. Among them, the verification rule can be a verification code of a zero-knowledge proof, and the verification engine of the relay chain R can call the verification code to verify the cross-chain transaction issued by the blockchain B.

Step S203, sending the cross-chain transaction to the relay chain, instructing the relay chain to send the cross-chain transaction to the target chain cross-chain gateway after passing the verification of the verification protocol.

In some embodiments, the cross-chain gateway Pa submits the cross-chain transaction to the relay chain R, and the relay chain R packages the cross-chain transaction into a block, and sends the cross-chain transaction to the destination chain cross-chain gateway. Cross-chain transactions include transaction ciphertext, encrypted symmetric keys, and zero-knowledge proofs.

In some embodiments, the method includes: sending the transaction ciphertext, the encrypted symmetric key and the zero-knowledge proof to the relay chain, and instructing the relay chain to run the verification code corresponding to the verification rule to verify the zero-knowledge proof. Since the relay chain receives the transaction ciphertext, the transaction information cannot be disclosed.

In some embodiments, the method includes:

Send a cross-chain transaction to the relay chain, instructing the relay chain to send the transaction ciphertext and encrypted symmetric key to the destination chain cross-chain gateway through the relay chain after passing the verification protocol.

The encrypted symmetric key is used to instruct the destination chain cross-chain gateway to decrypt the encrypted symmetric key using the second private key of the second asymmetric key to obtain a symmetric key; the transaction ciphertext is used to instruct the destination chain cross-chain gateway Decrypt the transaction ciphertext using the symmetric key to obtain the transaction plaintext; the transaction plaintext is used to instruct the destination chain cross-chain gateway to initiate a call to the destination chain according to the calling information in the transaction plaintext.

Through the embodiments of the present application, during the cross-chain transaction process, the cross-chain gateway encrypts the transaction plaintext of the cross-chain event and uses the transaction plaintext as the privacy input for generating the zero-knowledge proof, and instructs the relay chain to verify the zero-knowledge of the cross-chain transaction. Knowledge proof is used for verification. The logic of zero-knowledge proof verification includes the verification of the validity of cross-chain transactions and the correctness of cross-chain call information, and the relay chain receives the transaction ciphertext, so the transaction cannot be disclosed. It protects the privacy of cross-chain transactions; at the same time, it is verified by the relay chain, which reduces the load of data processing by the cross-chain gateway and ensures the reliability of cross-chain transaction verification.

Referring to FIG. 3 , it is a schematic flowchart of a verification method for a cross-chain transaction provided by another embodiment of the present application. This method is applied to the relay chain, and the execution subject is the relay chain R as shown in FIG. 1 . The method includes the following steps:

Step S301: Receive a cross-chain transaction sent by the source-chain cross-chain gateway, where the cross-chain transaction includes a verification protocol.

In some embodiments, taking the architecture shown in FIG. 1 as an example, the cross-chain gateway Pa is the source-chain cross-chain gateway, and the relay chain R receives the cross-chain transaction submitted by the cross-chain gateway Pa.

Among them, the verification protocol can be a zero-knowledge proof, and the verification rule is a piece of zero-knowledge proof verification code, and the verification engine of the relay chain R can call the verification code to verify the cross-chain transaction issued by the blockchain A. Cross-chain transactions can include transaction ciphertext, encrypted symmetric keys, and zero-knowledge proofs. The encrypted symmetric key is obtained by the source-chain cross-chain gateway encrypting its own symmetric key by using the second public key of the second asymmetric key of the destination-chain cross-chain gateway. The transaction plaintext includes the cross-chain call information and the validity proof of the cross-chain transaction; the cross-chain call information includes the destination chain contract address, destination chain contract method and parameters. The transaction ciphertext is obtained by the source chain cross-chain gateway encrypting the transaction plaintext with its own symmetric key. Zero-knowledge proof is a verification protocol generated by the source chain cross-chain gateway to verify the cross-chain transaction with the transaction plaintext and the symmetric key as the private input and the transaction ciphertext as the public input.

Step S302, verifying the verification protocol according to a preset verification rule.

In some embodiments, the preset verification rule is the verification rule of the source chain registered by the source chain cross-chain gateway with the relay chain, and is the verification code of the verification protocol. Different blockchains can register the verification rules with the relay chain in advance through the cross-chain gateway when conducting cross-chain transactions.

In some embodiments, verifying the verification protocol according to the preset verification rules includes: obtaining the verification rules registered by the source chain cross-chain gateway, and the verification rules are verification codes for verifying the zero-knowledge proof; running the verification code to verify the zero-knowledge proof authenticating.

Among them, the cross-chain transaction includes transaction ciphertext, encrypted symmetric key and zero-knowledge proof; the transaction ciphertext is obtained by the source chain cross-chain gateway using the symmetric key to encrypt the transaction plaintext in the cross-chain event; the symmetric key is the cross-chain transaction The key pair generated by the chain gateway; the zero-knowledge proof is that the source chain cross-chain gateway takes the transaction ciphertext as the public input, the transaction plaintext and the symmetric key as the private input, and runs the preset zero-knowledge proof generation code, and the generated verification protocol; the encrypted symmetric key is obtained by encrypting the symmetric key by the source chain cross-chain gateway using the second public key of the second asymmetric key of the destination chain cross-chain gateway.

Exemplarily, the cross-chain event submitted by the source chain to the source-chain cross-chain gateway includes transaction plaintext, and the transaction plaintext includes cross-chain call information and cross-chain transaction validity proof. In the process of generating cross-chain transactions by the source-chain cross-chain gateway, the cross-chain gateway Pa uses the symmetric key K to encrypt the information that needs to be called in the cross-chain event, that is, the cross-chain call information; wherein, the cross-chain call information includes the destination contract address, destination Chain contract methods and parameters. The cross-chain call information is encrypted and recorded as E(Payload, K), and the encrypted cross-chain call information E(Payload, K) is used as the public input for generating the verification protocol (zero-knowledge proof). The cross-chain gateway Pa uses the symmetric key K to encrypt the cross-chain transaction validity proof, the encrypted cross-chain transaction validity proof is recorded as E(Proof, K), and the encrypted cross-chain transaction validity proof E(Proof, K), as public input to generate a verification protocol (zero-knowledge proof). During the verification process of the cross-chain transaction, the relay chain R uses the verification engine to call the verification rules pre-registered by the cross-chain gateway Pa, that is, a verification code of a zkSNARK zero-knowledge proof, with E(payload, K) and E(Proof, K) are input to verify the zero-knowledge proof in cross-chain transactions.

In some embodiments, running verification code to verify the zero-knowledge proof includes:

Take the transaction ciphertext as input, decrypt the transaction ciphertext through the symmetric key in the zero-knowledge proof, and obtain the transaction plaintext to be verified; compare the transaction plaintext to be verified with the transaction plaintext in the zero-knowledge proof; if they are consistent, verify Cross-chain transaction validity proof and cross-chain call information in the transaction plaintext; if the cross-chain transaction verification is valid and the cross-chain call information verification is correct, the verification is passed.

Exemplarily, in the process of generating the zero-knowledge proof, the transaction ciphertext is used as the public input, and the transaction plaintext and the symmetric key are used as the private input; in the verification process, the transaction ciphertext is used as the input, that is, E(payload, K ) and E(Proof, K) is the input, decrypt the input transaction ciphertext through the symmetric key to obtain the transaction plaintext, and compare the transaction plaintext with the transaction plaintext as the privacy input. If the comparison results are consistent, the internal logic of zero-knowledge proof The cross-chain transaction validity proof and cross-chain call information in the transaction plaintext are verified. If the result of the verification is that the cross-chain transaction is valid and the cross-chain call information is correct, the verification is passed.

It should be noted that the zero-knowledge proof is used to verify the cross-chain transaction. While verifying the above-mentioned transaction plaintext, the zero-knowledge proof will complete the validity verification of its own logic of the transaction plaintext as a privacy input, and obtain the verification result. If the verification is passed, there is no need to provide any private data related to the cross-chain transaction to the relay chain, so that the relay chain believes that it has the transaction information of the cross-chain transaction and the verification result proves that the cross-chain transaction is valid and the cross-chain call information is accurate. The proof process of the transaction information implementation logic does not leak any information about the authenticated message to the relay chain; thus, it protects the privacy of both parties to the transaction and completes the verification of the validity of the cross-chain transaction.

It should be noted that the cross-chain transaction validity certificate records the legality and existence proof information of the cross-chain transaction. During the zero-knowledge proof verification process of the cross-chain transaction by the relay chain, there is no need for the cross-chain verification of the relay chain. The engine provides specific verification information to ensure that the privacy of cross-chain transactions is not leaked. There are differences in the field content of the cross-chain transaction validity certificate according to the characteristics and structure of the specific application chain. The specific verification rules and methods can be loaded into the verification process of zero-knowledge proof through flexible verification rules.

Exemplarily, different blockchains correspond to different verification rules for validity verification, that is, the verification logic of the self-validation proof of the transaction plaintext; for example, for the fabric application chain (Fabric is a block with a highly modular and configurable architecture. Chain collectively), the cross-chain gateway needs to register the fabric's verification logic validator and endorsement policy information to the relay chain, and the generated validity proof information proof needs to include the endorsement response of the transaction. For the Ethereum application chain, when the cross-chain gateway generates the validity proof information proof, it needs to carry the simple payment verification (Simplified Payment Verification) of the source chain transaction. Payment Verification (SPV) proof and transaction content, as well as the block header information of the exchange in the last n of the block (the n value is the number of blocks required for the confirmation of Ethereum transactions with high probability).

Step S303, if the verification is passed, the cross-chain transaction is sent to the target-chain cross-chain gateway.

In some embodiments, after the cross-chain transaction is verified by the relay chain verification engine, it is routed to the destination chain and received by the destination chain cross-chain gateway Pb.

In some embodiments, if the verification is passed, the transaction ciphertext and the encrypted symmetric key are sent to the destination chain cross-chain gateway.

The encrypted symmetric key is used to instruct the destination chain cross-chain gateway to decrypt the encrypted symmetric key using the second private key of the second asymmetric key to obtain a symmetric key; the transaction ciphertext is used to instruct the destination chain cross-chain The chain gateway uses the symmetric key to decrypt the transaction ciphertext to obtain the transaction plaintext; the transaction plaintext is used to instruct the destination chain cross-chain gateway to initiate a call to the destination chain according to the cross-chain call information in the transaction plaintext.

Exemplarily, after being received by the cross-chain gateway Pb of the destination chain, the cross-chain gateway Pb decrypts the encrypted symmetric key using the second private key of the second asymmetric key to obtain the symmetric key K, and then uses the symmetric key K Decrypt the encrypted cross-chain call information E(payload, K) to obtain the cross-chain call information payload, which includes the destination chain contract address, method and parameters. The cross-chain gateway Pb converts the decrypted payload into the transaction of the destination chain, and initiates a call to the destination chain.

It should be noted that the cross-chain gateway Pb uses the same method to encrypt the receipt of the destination chain, and generates a zero-knowledge proof, generates a new cross-chain transaction, and submits the new cross-chain transaction to the relay chain.

Referring to FIG. 4 , it is a schematic flowchart of a verification method for a cross-chain transaction provided by another embodiment of the present application. The method is applied to the cross-chain gateway of the destination chain, and the execution body is the cross-chain gateway Pb as shown in Figure 1. The process of this method has been described in the above-mentioned embodiments. Based on the same processing principle, it will not be repeated here. Repeat. The method includes the following steps:

Step S401, receiving a cross-chain transaction sent by the relay chain, where the cross-chain transaction includes the transaction ciphertext and the encrypted symmetric key.

Step S402, decrypt the encrypted symmetric key by using the second private key of the second asymmetric key to obtain a symmetric key.

Step S403, decrypt the ciphertext of the transaction by using the symmetric key to obtain the plaintext of the cross-chain transaction.

Step S404, initiate a call to the destination chain according to the cross-chain call information in the transaction plaintext.

Referring to FIG. 5 , it is a schematic diagram of an interaction flow provided by an embodiment of the present application. In the interaction process of this embodiment, the implementation principles of each step are the same as the implementation processes described in FIG. 2 , FIG. 3 , and FIG. Taking the business interaction between the institution a1 of blockchain A and the institution b1 of blockchain B as an example, as shown in Figure 5, the interaction process includes a registration phase and a cross-chain transaction phase.

The registration stage includes: the cross-chain gateway Pa generates the symmetric key K1 and the first asymmetric key, and registers the information of the relay chain R with the information of the institution a1 and the public key information of the first asymmetric key of the cross-chain gateway Pa Kpuba, and the verification rule 1 of the institution a1; the cross-chain gateway Pb generates the symmetric key K2 and the second asymmetric key, and registers the information of the institution b1 and the second asymmetric key of the cross-chain gateway Pb to the relay chain R The public key information Kpubb, and the verification rule 2 of the organization b1. At the same time, the cross-chain gateway Pa obtains the public key information Kpubb of the cross-chain gateway Pb stored in the relay chain R; the cross-chain gateway Pb obtains the public key information Kpuba of the cross-chain gateway Pa stored in the relay chain R.

As shown in Figure 5, the cross-chain transaction phase includes:

1. Institution a1 invokes the business contract of blockchain A and throws a cross-chain event to the cross-chain gateway Pa;

2. The cross-chain gateway Pa uses the symmetric key K1 to encrypt the cross-chain call information and the cross-chain valid proof information in the transaction plaintext respectively to obtain the transaction ciphertext; uses the public key information Kpubb to encrypt the symmetric key K1; uses the transaction plaintext , transaction ciphertext, and symmetric key K1 as input, run the preset zero-knowledge proof generation code, generate zero-knowledge proof, and obtain the first cross-chain transaction;

3. The cross-chain gateway Pa packages the transaction ciphertext, encrypted symmetric key K1 and zero-knowledge proof, and submits it to the relay chain R;

4. The verification engine of the relay chain R invokes the verification rules of the institution a1 registered by the cross-chain gateway Pa to verify the zero-knowledge proof;

5. After the verification is passed, the relay chain R sends the transaction ciphertext and the encrypted symmetric key K1 to the cross-chain gateway Pb;

6. The cross-chain gateway Pb uses the private key information of the second asymmetric key to decrypt the encrypted symmetric key K1 to obtain the symmetric key K1; uses K1 to decrypt the transaction ciphertext to obtain the transaction plaintext;

7. The cross-chain gateway Pb calls the institution b1 according to the calling information in the plaintext of the transaction;

8. The cross-chain gateway Pb obtains the receipt information of the institution b1;

9. The cross-chain gateway Pb generates the second cross-chain transaction based on the receipt information;

10. Send the second cross-chain transaction to the relay chain R.

In the subsequent processing flow, the same processing method as above is used to verify the transaction and route the second cross-chain transaction to blockchain A.

It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Through the embodiment of the present application, the cross-chain gateway remains lightweight, and does not need to verify the validity of cross-chain transactions; the verification of cross-chain transactions performed by the relay chain is more reliable; the scalability is good, if a new application chain is added, It is only necessary to register the application chain information and verification rules with the relay chain.

Corresponding to the verification method of the cross-chain transaction described in the above embodiment, FIG. 6 shows a block diagram of the structure of the verification device for the cross-chain transaction provided by the embodiment of the present application. relevant part.

Referring to Figure 6, the device includes:

an acquisition unit 61, used to acquire cross-chain events submitted by the source chain;

a processing unit 62, configured to generate a cross-chain transaction based on the cross-chain event, where the cross-chain transaction includes a verification protocol;

The sending unit 63 is configured to send the cross-chain transaction to the relay chain, and instruct the relay chain to send the cross-chain transaction to the destination chain cross-chain gateway after passing the verification of the verification protocol.

FIG. 7 shows a structural block diagram of an apparatus for verifying a cross-chain transaction provided by an embodiment of the present application. For convenience of description, only parts related to the embodiment of the present application are shown.

Referring to Figure 7, the device includes:

A receiving unit 71, configured to receive a cross-chain transaction sent by the source-chain cross-chain gateway, where the cross-chain transaction includes a verification protocol;

a verification unit 72, configured to verify the verification protocol according to a preset verification rule;

The routing unit 73 is configured to send the cross-chain transaction to the destination-chain cross-chain gateway if the verification is passed.

FIG. 8 shows a structural block diagram of an apparatus for verifying a cross-chain transaction provided by an embodiment of the present application. For convenience of description, only parts related to the embodiment of the present application are shown.

Referring to Figure 8, the device includes:

A receiving unit 81, configured to receive a cross-chain transaction sent by the relay chain, where the cross-chain transaction includes a transaction ciphertext and an encrypted symmetric key;

a first decryption unit 82, configured to decrypt the encrypted symmetric key by using the second private key of the second asymmetric key to obtain a symmetric key;

The second decryption unit 83 is configured to decrypt the transaction ciphertext by using the symmetric key to obtain the transaction plaintext of the cross-chain transaction;

The calling unit 84 is configured to initiate a call to the destination chain according to the cross-chain calling information in the plaintext of the transaction.

Corresponding to the verification method of the cross-chain transaction described in the above embodiment, FIG. 9 shows a structural block diagram of the verification system of the cross-chain transaction provided by the embodiment of the present application. relevant part.

The source chain cross-chain gateway 91 is used for generating cross-chain transactions according to cross-chain events of the source chain, and sending the cross-chain transactions to the relay chain;

The relay chain 92 is used to receive the cross-chain transaction sent by the cross-chain gateway of the source chain, verify the verification protocol of the cross-chain transaction through verification rules, and send the cross-chain transaction to the cross-chain gateway of the destination chain after the verification is passed. chain transaction;

The destination chain cross-chain gateway 93 is configured to receive the cross-chain transaction sent by the relay chain, parse the cross-chain transaction, obtain the transaction plaintext, and call the destination chain according to the transaction plaintext.

Through the embodiments of the present application, during the cross-chain transaction process, the cross-chain gateway encrypts the transaction plaintext of the cross-chain event and uses the transaction plaintext as the privacy input for generating the zero-knowledge proof, and instructs the relay chain to verify the zero-knowledge of the cross-chain transaction. The verification of knowledge proof does not need to verify the logic and validity of the transaction plaintext, which protects the privacy of cross-chain transactions; at the same time, it is verified by the relay chain, which reduces the load of data processing by the cross-chain gateway and ensures the verification of cross-chain transactions. Reliability; the cross-chain gateway remains lightweight and does not need to verify the validity of the cross-chain transaction; the verification of the cross-chain transaction by the relay chain is more reliable; the scalability is good, if a new application chain is added, it only needs to The relay chain can register the application chain information and verification rules.

It should be noted that the information exchange, execution process and other contents between the above-mentioned devices/units are based on the same concept as the method embodiments of the present application. For specific functions and technical effects, please refer to the method embodiments section. It is not repeated here.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated in one processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit, and the above-mentioned integrated units may adopt hardware. It can also be realized in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application. For the specific working processes of the units and modules in the above-mentioned system, reference may be made to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

Embodiments of the present application further provide a computer-readable storage medium, where a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the steps in the foregoing method embodiments can be implemented.

The embodiments of the present application provide a computer program product, when the computer program product runs on a mobile terminal, the steps in the foregoing method embodiments can be implemented when the mobile terminal executes the computer program product.

FIG. 10 is a schematic structural diagram of a terminal device 10 according to an embodiment of the present application. As shown in FIG. 10 , the terminal device 10 of this embodiment includes: at least one processor 100 (only one is shown in FIG. 10 ), a processor, a memory 101 , and a processor stored in the memory 101 and available for processing in the at least one processor The computer program 102 running on the processor 100, when the processor 100 executes the computer program 102, implements the steps in any of the foregoing embodiments of the verification methods for cross-chain transactions.

The terminal device 10 may be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server. The terminal device 10 may include, but is not limited to, a processor 100 and a memory 101 . Those skilled in the art can understand that FIG. 10 is only an example of the terminal device 10, and does not constitute a limitation on the terminal device 10. It may include more or less components than the one shown, or combine some components, or different components , for example, may also include input and output devices, network access devices, and the like.

The so-called processor 100 may be a central processing unit (Central Processing Unit, CPU), the processor 100 can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application-specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf Programmable Gate Array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

In some embodiments, the memory 101 may be an internal storage unit of the terminal device 10 , such as a hard disk or a memory of the terminal device 10 . In other embodiments, the memory 101 may also be an external storage device of the terminal device 10, for example, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, flash memory card (Flash Card), etc. Further, the memory 101 may also include both an internal storage unit of the terminal device 10 and an external storage device. The memory 101 is used to store an operating system, an application program, a boot loader (Boot Loader), data, and other programs, for example, program codes of the computer program, and the like. The memory 101 may also be used to temporarily store data that has been output or will be output.

The integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, may be stored in a computer-readable storage medium. Based on this understanding, the present application realizes all or part of the processes in the methods of the above embodiments, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When executed by a processor, the steps of each of the above method embodiments can be implemented. Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include at least: any entity or device capable of carrying the computer program code to the photographing device/terminal device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signals, telecommunication signals, and software distribution media. For example, U disk, mobile hard disk, disk or CD, etc. In some jurisdictions, under legislation and patent practice, computer readable media may not be electrical carrier signals and telecommunications signals.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-mentioned embodiments, those of ordinary skill in the art should understand that: it can still be used for the above-mentioned implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions in the embodiments of the application, and should be included in the within the scope of protection of this application.

Claims (16)

1. A verification method for cross-chain transactions, characterized in that it is applied to a source-chain cross-chain gateway, and the method includes:

   Get the cross-chain events submitted by the source chain;

   generating a cross-chain transaction based on the cross-chain event, the cross-chain transaction including a verification protocol;

   Sending the cross-chain transaction to the relay chain, instructing the relay chain to send the cross-chain transaction to the destination chain cross-chain gateway after passing the verification of the verification protocol.
2. The method of claim 1, wherein before the cross-chain transaction is generated based on the cross-chain event, the method further comprises:

   generating a first asymmetric key and a symmetric key;

   Register the first public key of the first asymmetric key, the address information of the source chain, and the verification rule of the source chain with the relay chain, and obtain the destination stored in the relay chain the second public key of the second asymmetric key of the cross-chain gateway;

   The symmetric key is used to encrypt the transaction plaintext of the cross-chain event, and the verification rule is a verification code for verifying the verification protocol.
3. The method of claim 2, wherein the cross-chain transaction comprises a transaction ciphertext, an encrypted symmetric key, and a zero-knowledge proof;

   The generating a cross-chain transaction based on the cross-chain event includes:

   Encrypt the transaction plaintext of the cross-chain event by using the symmetric key to obtain the transaction ciphertext;

   Taking the transaction ciphertext as the public input and the transaction plaintext and the symmetric key as the private input, run the preset zero-knowledge proof generation code to generate the zero-knowledge proof, and use the zero-knowledge proof as the Describe the verification protocol;

   The symmetric key is encrypted by using the second public key of the second asymmetric key of the destination chain cross-chain gateway to obtain the encrypted symmetric key.
4. The method of claim 3, wherein the method comprises:

   Send the transaction ciphertext, the encrypted symmetric key, and the zero-knowledge proof to the relay chain, instructing the relay chain to run the verification code corresponding to the verification rule, and verify the zero-knowledge Proof to verify.
5. The method of claim 3, wherein the method comprises:

   Send a cross-chain transaction to the relay chain, instructing the relay chain to send the transaction ciphertext and the encryption to the destination chain cross-chain gateway through the relay chain after passing the verification protocol symmetric key;

   The encrypted symmetric key is used to instruct the destination chain cross-chain gateway to decrypt the encrypted symmetric key using the second private key of the second asymmetric key to obtain the symmetric key; The transaction ciphertext is used to instruct the destination chain cross-chain gateway to decrypt the transaction ciphertext using the symmetric key to obtain the transaction plaintext; the transaction plaintext is used to instruct the destination chain cross-chain gateway to use the The cross-chain call information in the transaction plaintext initiates a call to the destination chain.
6. A verification method for cross-chain transactions, characterized in that it is applied to a relay chain, and the method includes:

   Receive a cross-chain transaction sent by the source-chain cross-chain gateway, where the cross-chain transaction includes a verification protocol;

   Verify the verification protocol according to a preset verification rule;

   If the verification is passed, the cross-chain transaction is sent to the destination-chain cross-chain gateway.
7. The method of claim 6, wherein the verifying the verification protocol according to a preset verification rule comprises:

   Obtain the verification rules registered by the source chain cross-chain gateway, where the verification rules are verification codes for verifying zero-knowledge proofs;

   Running the verification code to verify the zero-knowledge proof;

   Wherein, the cross-chain transaction includes transaction ciphertext, encrypted symmetric key and zero-knowledge proof; the transaction ciphertext is obtained by the source-chain cross-chain gateway encrypting the transaction plaintext in the cross-chain event with the symmetric key; The symmetric key is a key pair generated by the cross-chain gateway; the zero-knowledge proof is that the source-chain cross-chain gateway takes the transaction ciphertext as public input, and takes the transaction plaintext and the symmetric key as private input, And run the verification protocol generated by the preset zero-knowledge proof generation code; the encrypted symmetric key is the source chain cross-chain gateway using the second public key pair of the second asymmetric key of the destination chain cross-chain gateway. encrypted with the symmetric key described above.
8. The method of claim 7, wherein the running the verification code to verify the zero-knowledge proof comprises:

   Taking the transaction ciphertext as input, decrypt the transaction ciphertext through the symmetric key in the zero-knowledge proof to obtain the transaction plaintext to be verified; The transaction plaintexts are compared; if they are consistent, the cross-chain transaction validity certificate and cross-chain call information in the transaction plaintext are verified; if the cross-chain transaction is verified to be valid and the cross-chain call information is verified to be correct, the verification is passed.
9. The method of claim 8, wherein the method further comprises:

   If the verification is passed, send the transaction ciphertext and the encrypted symmetric key to the destination chain cross-chain gateway; wherein the encrypted symmetric key is used to instruct the destination chain cross-chain gateway to use the The second private key of the second asymmetric key decrypts the encrypted symmetric key to obtain the symmetric key; the transaction ciphertext is used to instruct the destination chain cross-chain gateway to decrypt the encrypted symmetric key using the symmetric key The transaction ciphertext is obtained to obtain the transaction plaintext; the transaction plaintext is used to instruct the destination chain cross-chain gateway to initiate a call to the destination chain according to the cross-chain call information in the transaction plaintext.
10. A verification method for cross-chain transactions, characterized in that it is applied to a destination chain cross-chain gateway, and the method includes:

    Receive a cross-chain transaction sent by the relay chain, where the cross-chain transaction includes the transaction ciphertext and the encrypted symmetric key;

    Decrypt the encrypted symmetric key by using the second private key of the second asymmetric key to obtain a symmetric key;

    Decrypt the transaction ciphertext by using the symmetric key to obtain the transaction plaintext of the cross-chain transaction;

    Initiate a call to the destination chain according to the cross-chain call information in the plaintext of the transaction.
11. A verification system for cross-chain transactions, comprising:

    The source chain cross-chain gateway is used to generate cross-chain transactions according to the cross-chain events of the source chain, and send the cross-chain transactions to the relay chain;

    The relay chain is used to receive the cross-chain transaction sent by the cross-chain gateway of the source chain, and verify the verification protocol of the cross-chain transaction through the verification rules. After the verification is passed, send the cross-chain transaction to the cross-chain gateway of the destination chain. trade;

    The destination chain cross-chain gateway is used to receive the cross-chain transaction sent by the relay chain, parse the cross-chain transaction, obtain the transaction plaintext, and call the destination chain according to the transaction plaintext.
12. A verification device for cross-chain transactions, comprising:

    The acquisition unit is used to acquire cross-chain events submitted by the source chain;

    a processing unit, configured to generate a cross-chain transaction based on the cross-chain event, where the cross-chain transaction includes a verification protocol;

    The sending unit is configured to send the cross-chain transaction to the relay chain, and instruct the relay chain to send the cross-chain transaction to the target chain cross-chain gateway after passing the verification of the verification protocol.
13. A verification device for cross-chain transactions, comprising:

    a receiving unit, configured to receive a cross-chain transaction sent by the source-chain cross-chain gateway, where the cross-chain transaction includes a verification protocol;

    a verification unit, configured to verify the verification protocol according to a preset verification rule;

    The routing unit is configured to send the cross-chain transaction to the destination-chain cross-chain gateway if the verification is passed.
14. A verification device for cross-chain transactions, comprising:

    a receiving unit, configured to receive a cross-chain transaction sent by the relay chain, where the cross-chain transaction includes a transaction ciphertext and an encrypted symmetric key;

    a first decryption unit, configured to decrypt the encrypted symmetric key by using the second private key of the second asymmetric key to obtain a symmetric key;

    a second decryption unit, configured to decrypt the transaction ciphertext by using the symmetric key to obtain the transaction plaintext of the cross-chain transaction;

    The calling unit is configured to initiate a call to the destination chain according to the cross-chain calling information in the plaintext of the transaction.
15. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, when the processor executes the computer program, the process according to claim 1 to 5 or the method of any one of claims 6 to 9 or claim 10.
16. A computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, the implementation of claims 1 to 5 or 6 to 9 or claim 10 The method of any one.