CN111464536A - A blockchain cross-chain method and device - Google Patents

Abstract

The invention discloses a blockchain cross-chain method and device, belonging to the technical field of communication. The blockchain cross-chain method includes: a first user sends an asset locking message to a second user; wherein the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first user is a user of the second blockchain. The blockchain and the second blockchain have one or more common nodes; the first user's assets are locked according to the asset locking time point and asset locking duration in the asset locking message; the verification random number is sent to the second user to enable the first user The second user verifies the accuracy of the asset lock message, and executes the asset transfer operation according to the accuracy verification result of the asset lock message. It is not necessary to introduce institutions such as third-party trading platforms that will generate new centralized nodes, so as to achieve a safe, reliable and efficient system. On-chain asset transfer to improve user experience.

Description

A blockchain cross-chain method and device

technical field

The present invention relates to the field of communication technologies, in particular to a method and device for cross-chain blockchain.

Background technique

The concept of blockchain was first proposed by Satoshi Nakamoto, and in the years that followed, the blockchain became a core component of the electronic currency Bitcoin as a public ledger of all transactions. In essence, the blockchain is a shared database, the data or information stored in it cannot be tampered with, and has the characteristics of decentralization, non-tampering, full traces, traceability, collective maintenance, openness and transparency, etc. Based on these characteristics, blockchain technology has laid a solid "trust" foundation and created a reliable "cooperation" mechanism, so it has broad application prospects. With the rapid development of blockchain technology and applications, various independent blockchain networks have emerged, and the realization of cross-chain transactions has become an urgent need for current blockchain applications. Cross-chain technology is a bridge to achieve connectivity between independent blockchains. In the existing cross-chain technology, the transfer and exchange of assets between different blockchain projects is mainly realized through a third-party trading platform. However, the introduction of third-party trading platforms will bring new centralized nodes, therefore, there are inevitably problems that threaten the security and credibility of assets.

In view of this, the present invention provides a blockchain cross-chain method, which can not introduce institutions such as third-party trading platforms that generate new centralized nodes, thereby realizing safe, reliable and efficient on-chain asset transfer and improving user experience.

SUMMARY OF THE INVENTION

Therefore, the present invention provides a blockchain cross-chain method and device to solve the problem that the introduction of a third-party trading platform during cross-chain transactions will generate new centralized nodes, thereby threatening the security and credibility of assets.

In order to achieve the above purpose, the first aspect of the present invention provides a blockchain cross-chain method, which is applied to the first user, including:

Send an asset locking message to the second user; wherein the asset locking message includes a hash value, the second user's blockchain identifier, an asset locking time point and an asset locking duration, and the hash value is the first A hash value corresponding to a random number generated by a user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first blockchain is associated with all said second blockchain has one or more common nodes;

Lock the asset of the first user according to the asset locking time point and the asset locking duration in the asset locking message;

A verification random number is sent to the second user, so that the second user verifies the accuracy of the asset locking message, and performs an asset transfer operation according to the verification result of the accuracy of the asset locking message.

Further, before the sending the asset locking message to the second user, the method further includes:

The first user signs a smart contract with the second user; wherein, the smart contract stipulates detailed rules for asset transfer and return between the first user and the second user.

Further, the sending an asset locking message to the second user includes:

broadcasting the asset lock message to the first blockchain for the common node to receive the asset lock message;

The common node broadcasts the asset lock message on the second blockchain, so that the second user receives the asset broadcast message.

Further, after sending the verification random number to the second user, the method further includes:

If the second user passes the accuracy verification of the asset lock message, receiving the asset of the second user transferred by the second user;

If the verification random number returned by the second user is received within a preset time interval, the assets of the second user are transferred back to the second user.

In order to achieve the above purpose, a second aspect of the present invention provides a blockchain cross-chain method, which is applied to a second user, including:

Receive an asset locking message sent by the first user; wherein the asset locking message includes a hash value, the blockchain identifier of the second user, an asset locking time point and an asset locking duration, and the hash value is the The hash value corresponding to the random number generated by the first user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first blockchain is the same as the second blockchain has one or more common nodes;

Lock the asset of the second user according to the asset locking time point and the asset locking duration in the asset locking message;

Receive the verification random number sent by the first user, and verify the accuracy of the asset lock message based on the verification random number;

After the accuracy verification of the asset locking message is passed, the assets of the second user are transferred to the first user.

Further, the receiving an asset locking message sent by the first user includes:

The second blockchain receives the asset lock message broadcast by the common node, and broadcasts it in the second blockchain; wherein, the asset lock message is the first user in the first A message broadcast by the blockchain and broadcast in the second blockchain after being received by the common node;

Receive the asset lock message broadcast by the common node on the second blockchain.

Further, after receiving the asset locking message sent by the first user, before locking the assets of the second user according to the asset locking time point and asset locking duration in the asset locking message, the method further includes:

Signature verification is performed on the asset lock message.

Further, the verification of the accuracy of the asset lock message based on the verification random number includes:

Calculate the verification hash value corresponding to the verification random number;

comparing whether the verification hash value is consistent with the hash value in the asset lock message;

If the verification hash value is consistent with the hash value in the asset locking message, the accuracy verification of the asset locking message passes.

Further, if the second user returns the verification random number to the first user at a preset time interval, the assets of the second user transferred back by the first user are received.

In order to achieve the above purpose, a third aspect of the present invention provides a blockchain cross-chain device, which is applied to the first user, including:

The first sending module is configured to send an asset locking message to the second user; wherein, the asset locking message includes a hash value, a blockchain identifier of the second user, an asset locking time point and an asset locking duration, and the The hash value is the hash value corresponding to the random number generated by the first user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the The first blockchain and the second blockchain have one or more common nodes;

a locking module, configured to lock the assets of the first user according to the asset locking time point and the asset locking duration in the asset locking message;

A second sending module, configured to send a verification random number to the second user, so that the second user can verify the accuracy of the asset lock message, and execute asset transfer according to the verification result of the asset lock message accuracy operate.

The present invention has the following advantages:

In the blockchain cross-chain method provided by the present invention, a first user sends an asset locking message to a second user; wherein, the asset locking message includes a hash value, the second user's blockchain identification, the asset locking time point and the asset locking duration, the hash value is the hash value corresponding to the random number generated by the first user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first blockchain is the same as the user of the second blockchain. The second blockchain has one or more common nodes;

The first user locks the assets of the first user according to the asset locking time point and the asset locking duration in the asset locking message, and sends a verification random number to the second user, so that the second user can verify the accuracy of the asset locking message. The asset transfer operation is performed on the result of the accuracy verification of the locked message, thereby avoiding the introduction of third-party trading platforms and other institutions that generate new centralized nodes, realizing safe, reliable and efficient on-chain asset transfer and improving user experience.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and together with the following specific embodiments, are used to explain the present invention, but do not constitute a limitation to the present invention.

FIG. 1 is a flowchart of a blockchain cross-chain method provided by the first embodiment of the present invention;

FIG. 2 is a flowchart of a blockchain cross-chain method provided by the second embodiment of the present invention;

FIG. 3 is a flowchart of a method for cross-chain blockchain provided by the third embodiment of the present invention;

FIG. 4 is a flowchart of a method for cross-chain blockchain provided by the fourth embodiment of the present invention;

FIG. 5 is a schematic block diagram of a blockchain cross-chain device provided by a fifth embodiment of the present invention.

Detailed ways

The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, but not to limit the present invention.

The blockchain cross-chain method provided by the embodiments of the present invention takes into account that in the blockchain cross-chain technology that realizes the transfer and exchange of assets between different blockchain projects through a third-party trading platform, the introduction of a third-party trading platform will bring new Therefore, there will inevitably be problems that threaten the security and credibility of assets. A new blockchain cross-chain method is proposed, which can avoid the introduction of third-party trading platforms and other institutions that will generate new centralized nodes. Realize safe, reliable and efficient on-chain asset transfer and improve user experience.

FIG. 1 is a flowchart of a blockchain cross-chain method provided by the first embodiment of the present invention, which is applied to a first user. As shown in Figure 1, the blockchain cross-chain method may include the following steps:

Step S101, sending an asset lock message to the second user.

The asset lock message includes the hash value, the second user's blockchain identifier, the asset locking time point and the asset locking duration, and the hash value is the hash value corresponding to the random number generated by the first user; the first user is the first user's A user of one blockchain, the second user is a user of the second blockchain, and the first blockchain and the second blockchain have one or more common nodes.

In some existing blockchain cross-chain technologies, the transfer and exchange of assets between different blockchain projects requires the introduction of a third-party trading platform and the creation of corresponding centralized nodes for the third-party trading platform, so as to realize cross-chain assets. transfer and exchange. However, the introduction of centralized nodes on third-party trading platforms will inevitably threaten the security and credibility of assets. Therefore, in the embodiment of the present invention, the first user sends an asset lock message to the second user, and based on the asset lock message, the asset transfer and exchange between cross-chain users is realized without introducing a third-party trading platform, so it can be safe and reliable. And efficiently realize the transfer of assets on the chain to improve the user experience.

It should be noted that before the first user sends the asset lock message to the second user, the first user and the second user have signed a smart contract. Among them, the content of the smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user, and the signing method of the smart contract includes on-chain signing and off-chain signing.

In one embodiment, it is assumed that there are two blockchains with different consensus mechanisms and founders, namely a first blockchain and a second blockchain, and the first blockchain and the second blockchain have One or several common nodes. The common node is a node belonging to both the first blockchain and the second blockchain, and the common node has a corresponding blockchain identifier and a blockchain public-private key pair in the first blockchain and the second blockchain, respectively. For example, node A is a common node of the first blockchain and the second blockchain, and node A has its corresponding first blockchain ID-a1 and first blockchain public key in the first blockchain key-ag1 and the first blockchain private key key-as1, similarly, node A has its corresponding second blockchain ID-a2, second blockchain public key key- ag2 and the second blockchain private key key-as2. The first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first user and the second user have signed a smart contract off-chain. The smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user. The specific content is: the first user sends an asset lock message to the second user, wherein the asset lock message includes the hash value corresponding to the random number. , the second user's blockchain identification, asset locking time point and asset locking duration, etc.; the first user and the second user lock their respective assets according to the content of the asset locking message; if the second user receives within the specified time interval The correct random number sent by the first user, the smart contract automatically executes the operation of transferring the assets of the second user to the first user; if the first user receives the assets of the second user and receives the second user's assets within a specified time interval If the user returns the correct random number, the smart contract returns the second user's assets received by the first user to the second user. According to the content of the smart contract, the first user generates a random number, calculates the hash value corresponding to the random number locally, and sends an asset lock message to the second user. The asset locking message includes the hash value, the blockchain identifier of the second user, the asset locking time point and the asset locking duration.

In one embodiment, the first user sends an asset lock message to the second user, including:

After the first user signs the asset lock message with the first user's blockchain private key, the asset lock message is broadcast on the first blockchain. All nodes of the first blockchain receive the asset lock message, and after any common node receives the asset lock message, it queries the ledger of the first blockchain through the first user's blockchain ID, and obtains the first user Based on the blockchain public key of the first user, the signature verification of the asset lock message is performed. If the signature verification of the asset lock message passes, the common node uses the second blockchain private key of the common node to re-sign the asset lock message, and broadcasts the re-signed asset lock message on the second blockchain. The second user receives the asset lock message broadcast by the common node on the second blockchain.

Step S102, lock the asset of the first user according to the asset locking time point and the asset locking duration in the asset locking message.

Locking the assets of the first user can prevent hackers from illegally transferring the assets of the first user.

In one embodiment, after the first user sends an asset lock message to the second user, according to the asset lock time point and asset lock duration in the asset lock message, the first user's assets are locked after the asset lock time point is reached, and the lock is performed. The duration is the asset lock duration in the asset lock message.

For example, the asset lock time point in the asset lock message is 00:00:00 on January 1, 2020, and the lock time is 20 minutes, then the system time of the first blockchain reaches 00 on January 1, 2020. After 00:00:00, the assets of the first user will be locked for 20 minutes.

Step S103, sending a verification random number to the second user, so that the second user verifies the accuracy of the asset locking message, and executes the asset transfer operation according to the accuracy verification result of the asset locking message.

The verification random number is the same as the random number in the asset lock message.

It should be noted that the methods for the first user to send the verification random number to the second user include on-chain sending and off-chain sending, wherein off-chain sending includes p2p (peer-to-peer, peer-to-peer) or mobile switching network to send. Under normal circumstances, in order to ensure the accuracy of the information received by the second user, a verification random number is sent to the second user in an off-chain way, so as to verify whether the asset lock message received through the on-chain way has been illegally tampered with, so that it can be verified within a certain period of time. To a certain extent, the accuracy of the received information is guaranteed. It can be understood that, no matter what sending method is adopted for the verification random number, it is the sending method agreed in advance between the first user and the second user.

In one embodiment, the first user sends the verification random number to the second user by means of a short message. After receiving the short message sent by the first user, the second user obtains the verification random number, and calculates the hash value corresponding to the verification random number to obtain the verification hash value. The second user compares and verifies whether the hash value is consistent with the hash value in the asset lock message. When the verification hash value is consistent with the hash value in the asset lock message, it means that the accuracy verification of the asset lock message has passed, and the second user transfers his assets to the first user according to the content of the smart contract.

Fig. 2 is a flowchart of a blockchain cross-chain method provided by the second embodiment of the present invention, which is applied to the first user and is basically the same as the first embodiment of the present invention, except that: when sending to the second user After verifying the random number, the second user's revocation of the transfer of assets is also received. As shown in Figure 2, the blockchain cross-chain method may include the following steps:

Step S201, sending an asset locking message to the second user.

The content of step S201 in this embodiment is the same as that of step S101 in the first embodiment of the present invention, and details are not repeated here.

Step S202, lock the asset of the first user according to the asset locking time point and the asset locking duration in the asset locking message.

The content of step S202 in this embodiment is the same as that of step S102 in the first embodiment of the present invention, and details are not repeated here.

Step S203, sending a verification random number to the second user, so that the second user verifies the accuracy of the asset locking message, and executes the asset transfer operation according to the accuracy verification result of the asset locking message.

The content of step S203 in this embodiment is the same as that of step S103 in the first embodiment of the present invention, and details are not repeated here.

Step S204, if the second user passes the accuracy verification of the asset locking message, the second user's assets transferred by the second user are received.

The second user verifies the accuracy of the asset lock message based on the verification random number, and transfers the second user's assets to the first user according to the smart contract after the accuracy of the asset lock message is verified. For the first user, after the accuracy verification of the asset locking message is passed, the second user's assets transferred by the second user are received.

Step S205, if the verification random number returned by the second user is received within the preset time interval, the assets of the second user are transferred back to the second user.

In actual use, it is found that after the second user transfers his assets to the first user, he needs to withdraw his asset transfer. Therefore, in order to improve the user experience, the second user is allowed to withdraw his asset transfer operation.

In one embodiment, after the second user transfers his assets to the first user, the second user wants to perform an asset transfer withdrawal operation. Therefore, the second user returns the verification random number to the first user within a preset time interval. For the first user, after receiving the verification random number returned by the second user within the preset time interval, he knows that the second user wants to withdraw the assets transferred by the second user to the first user, so the first user will The assets of the second user are transferred back to the second user.

FIG. 3 is a flowchart of a method for cross-chain blockchain provided by the third embodiment of the present invention, which is applied to a second user. As shown in Figure 3, the blockchain cross-chain method may include the following steps:

Step S301, receiving an asset locking message sent by a first user.

The asset lock message includes the hash value, the second user's blockchain identifier, the asset locking time point and the asset locking duration, and the hash value is the hash value corresponding to the random number generated by the first user; the first user is the first user's A user of one blockchain, the second user is a user of the second blockchain, and the first blockchain and the second blockchain have one or more common nodes.

It should be noted that, before the second user receives the asset lock message sent by the first user, the first user and the second user have signed a smart contract. Among them, the content of the smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user, and the signing method of the smart contract includes on-chain signing and off-chain signing.

In one embodiment, it is assumed that there are two blockchains with different consensus mechanisms and founders, namely a first blockchain and a second blockchain, and the first blockchain and the second blockchain have One or several common nodes. The common node is a node belonging to both the first blockchain and the second blockchain, and the common node has a corresponding blockchain identifier and a blockchain public-private key pair in the first blockchain and the second blockchain, respectively. For example, node A is a common node of the first blockchain and the second blockchain, and node A has its corresponding first blockchain ID-a1 and first blockchain public key in the first blockchain key-ag1 and the first blockchain private key key-as1, similarly, node A has its corresponding second blockchain ID-a2, second blockchain public key key- ag2 and the second blockchain private key key-as2. The first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first user and the second user have signed a smart contract off-chain. The smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user. The specific content is: the first user sends an asset lock message to the second user, wherein the asset lock message includes the hash value corresponding to the random number. , the second user's blockchain identification, asset locking time point and asset locking duration, etc.; the first user and the second user lock their respective assets according to the content of the asset locking message; if the second user receives within the specified time interval The correct random number sent by the first user, the smart contract automatically executes the operation of transferring the assets of the second user to the first user; if the first user receives the assets of the second user and receives the second user's assets within a specified time interval If the user returns the correct random number, the smart contract returns the second user's assets received by the first user to the second user. According to the content of the smart contract, the first user generates a random number, calculates the hash value corresponding to the random number locally, and sends an asset lock message to the second user. The asset locking message includes the hash value, the blockchain identifier of the second user, the asset locking time point and the asset locking duration. The second user receives the asset lock message sent by the first user.

In one embodiment, the second user receives an asset lock message sent by the first user, including:

The first user generates a random number, calculates the hash value corresponding to the random number locally, and generates an asset lock message based on the hash value, the second user's blockchain ID, asset lock time point and asset lock duration, and then uses the first user to generate a random number. The user's blockchain private key signs the asset lock message, and after the private key is signed, the asset lock message is broadcast on the first blockchain. All nodes of the first blockchain receive the asset lock message, and after any common node receives the asset lock message, it queries the ledger of the first blockchain through the first user's blockchain ID, and obtains the first user Based on the blockchain public key of the first user, the signature verification of the asset lock message is performed. If the signature verification of the asset lock message passes, the common node uses the second blockchain private key of the common node to re-sign the asset lock message, and broadcasts the re-signed asset lock message on the second blockchain. The second user receives the asset lock message broadcast by the common node on the second blockchain.

It can be understood that after the second user receives the asset locking message broadcast by the common node on the second blockchain, in order to ensure the legitimacy of the received asset locking message, the second user needs to perform signature verification on the asset locking message. The process of signature verification includes: the second user searches the ledger of the second blockchain through the identifier of the second blockchain corresponding to the common node that sends the asset lock message, obtains the public key of the second blockchain of the common node, and then uses the common node to obtain the public key of the second blockchain. The second blockchain public key of the node verifies the signature of the asset lock message.

Step S302, lock the asset of the second user according to the asset locking time point and the asset locking duration in the asset locking message.

Locking the assets of the first user can prevent hackers from illegally transferring the assets of the first user.

In one embodiment, after the second user receives the asset locking message sent by the first user, the second user locks the second user's assets according to the asset locking time point and asset locking duration in the asset locking message after reaching the asset locking time point. assets, and the lock duration is the asset lock duration in the asset lock message.

For example, if the asset lock time point in the asset lock message is 00:00:00 on January 1, 2020, and the lock time is 20 minutes, then the system time of the second blockchain reaches 00 on January 1, 2020. After 00:00:00, the assets of the second user will be locked for 20 minutes.

Step S303: Receive the verification random number sent by the first user, and verify the accuracy of the asset locking message based on the verification random number.

The verification random number is the same as the random number in the asset lock message.

It should be noted that the methods for the first user to send the verification random number to the second user include on-chain sending and off-chain sending, wherein off-chain sending includes p2p (peer-to-peer, peer-to-peer) or mobile switching network to send. Under normal circumstances, in order to ensure the accuracy of the information received by the second user, a verification random number is sent to the second user in an off-chain way, so as to verify whether the asset lock message received through the on-chain way has been illegally tampered with, so that it can be verified within a certain period of time. To a certain extent, the accuracy of the received information is guaranteed. It can be understood that, no matter what sending method is adopted for the verification random number, it is the sending method agreed in advance between the first user and the second user.

In one embodiment, the first user sends the verification random number to the second user by means of a short message. After receiving the short message sent by the first user, the second user obtains the verification random number, and verifies the accuracy of the asset locking message. The specific accuracy verification process includes: calculating the hash value corresponding to the verification random number, obtaining the verification hash value, and then comparing whether the verification hash value is consistent with the hash value in the asset lock message. When the verification hash value is consistent with the hash value in the asset locking message, it indicates that the accuracy of the asset locking message is verified; when the verification hash value is inconsistent with the hash value in the asset locking message, it indicates that the asset locking message is accurate Sexual verification failed.

Step S304, after the accuracy verification of the asset locking message is passed, transfer the assets of the second user to the first user.

After the second user verifies the accuracy of the received asset locking message, the second user determines that the transaction with the first user can be executed, and therefore, the second user transfers his assets to the first user.

FIG. 4 is a flowchart of a blockchain cross-chain method provided by the fourth embodiment of the present invention, which is applied to a second user, and is basically the same as the third embodiment of the present invention, except that: when transferring to the first user After the asset, it also includes performing the asset transfer undo operation. As shown in Figure 4, the blockchain cross-chain method may include the following steps:

Step S401, receiving an asset locking message sent by a first user.

The content of step S401 in this embodiment is the same as that of step S301 in the first embodiment of the present invention, and details are not repeated here.

Step S402, lock the asset of the second user according to the asset locking time point and the asset locking duration in the asset locking message.

The content of step S402 in this embodiment is the same as that of step S302 in the first embodiment of the present invention, and details are not repeated here.

Step S403: Receive the verification random number sent by the first user, and verify the accuracy of the asset locking message based on the verification random number.

The content of step S403 in this embodiment is the same as that of step S303 in the first embodiment of the present invention, and details are not repeated here.

Step S404, after the accuracy verification of the asset locking message is passed, transfer the assets of the second user to the first user.

The content of step S404 in this embodiment is the same as that of step S304 in the first embodiment of the present invention, and details are not repeated here.

Step S405, if the verification random number is returned to the first user within the preset time interval, the assets of the second user transferred back by the first user are received.

In actual use, it is found that after the second user transfers his assets to the first user, there is a need to withdraw his asset transfer. Therefore, in order to improve the user experience, the second user is allowed to withdraw his asset transfer operation.

In one embodiment, after the second user transfers his assets to the first user, if he wants to perform the asset transfer revocation operation, the second user returns a verification random number to the first user within a preset time interval. For the first user, after receiving the verification random number returned by the second user within the preset time interval, he knows that the second user wants to withdraw the assets transferred by the second user to the first user, so the first user will The assets of the second user are transferred back to the second user. That is, the second user receives the assets of the second user returned by the first user, thereby realizing the revocation of the asset transfer.

The steps of the above various methods are divided only for the purpose of describing clearly. During implementation, they can be combined into one step or some steps can be split and decomposed into multiple steps. As long as the same logical relationship is included, they are all within the protection scope of this patent. ;Adding insignificant modifications to the algorithm or process or introducing insignificant designs, but not changing the core design of the algorithm and process are all within the scope of protection of this patent.

FIG. 5 is a functional block diagram of a blockchain cross-chain device provided by a fifth embodiment of the present invention, which is applied to a first user. As shown in FIG. 5 , the blockchain cross-chain device includes: a first sending module 501 , a locking module 502 and a second sending module 503 .

The first sending module 501 is configured to send an asset locking message to the second user.

The asset lock message includes the hash value, the second user's blockchain identifier, the asset locking time point and the asset locking duration, and the hash value is the hash value corresponding to the random number generated by the first user; the first user is the first user's A user of one blockchain, the second user is a user of the second blockchain, and the first blockchain and the second blockchain have one or more common nodes.

In some existing blockchain cross-chain technologies, the transfer and exchange of assets between different blockchain projects requires the introduction of a third-party trading platform and the creation of corresponding centralized nodes for the third-party trading platform, so as to realize cross-chain assets. transfer and exchange. However, the introduction of centralized nodes on third-party trading platforms will inevitably threaten the security and credibility of assets. Therefore, in the embodiment of the present invention, the first user sends an asset lock message to the second user, and based on the asset lock message, the asset transfer and exchange between cross-chain users is realized without introducing a third-party trading platform, so it can be safe and reliable. And efficiently realize the transfer of assets on the chain to improve the user experience.

It should be noted that before the first user sends the asset lock message to the second user, the first user and the second user have signed a smart contract. Among them, the content of the smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user, and the signing method of the smart contract includes on-chain signing and off-chain signing.

In one embodiment, it is assumed that there are two blockchains with different consensus mechanisms and founders, namely a first blockchain and a second blockchain, and the first blockchain and the second blockchain have One or several common nodes. The common node is a node belonging to both the first blockchain and the second blockchain, and the common node has a corresponding blockchain identifier and a blockchain public-private key pair in the first blockchain and the second blockchain, respectively. The first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first user and the second user have signed a smart contract off-chain. The smart contract stipulates the detailed rules for asset transfer and return between the first user and the second user. The specific content is: the first user sends an asset lock message to the second user, wherein the asset lock message includes the hash value corresponding to the random number. , the second user's blockchain identification, asset locking time point and asset locking duration, etc.; the first user and the second user lock their respective assets according to the content of the asset locking message; if the second user receives within the specified time interval The correct random number sent by the first user, the smart contract automatically executes the operation of transferring the assets of the second user to the first user; if the first user receives the assets of the second user and receives the second user's assets within a specified time interval If the user returns the correct random number, the smart contract returns the second user's assets received by the first user to the second user. According to the content of the smart contract, the first user generates a random number, locally calculates the hash value corresponding to the random number, and sends an asset lock message to the second user through the first sending module 501 . The asset locking message includes the hash value, the blockchain identifier of the second user, the asset locking time point and the asset locking duration.

In one embodiment, the first user sends an asset lock message to the second user through the first sending module 501, including:

After the first user signs the asset lock message with the first user's blockchain private key, the asset lock message is broadcast on the first blockchain. All nodes of the first blockchain receive the asset lock message, and after any common node receives the asset lock message, it queries the ledger of the first blockchain through the first user's blockchain ID, and obtains the first user Based on the blockchain public key of the first user, the signature verification of the asset lock message is performed. If the signature verification of the asset lock message passes, the common node uses the second blockchain private key of the common node to re-sign the asset lock message, and broadcasts the re-signed asset lock message on the second blockchain. The second user receives the asset lock message broadcast by the common node on the second blockchain.

The locking module 502 is configured to lock the asset of the first user according to the asset locking time point and the asset locking duration in the asset locking message.

Locking the assets of the first user can prevent hackers from illegally transferring the assets of the first user.

In one embodiment, after the first user sends the asset locking message to the second user, the locking module 502 locks the assets of the first user after reaching the asset locking time point according to the asset locking time point and asset locking duration in the asset locking message , and the lock duration is the asset lock duration in the asset lock message.

For example, the asset lock time point in the asset lock message is 00:00:00 on January 1, 2020, and the lock time is 20 minutes, then the system time of the first blockchain reaches 00 on January 1, 2020. After 00:00:00, the locking module 502 locks the assets of the first user for a duration of 20 minutes.

The second sending module 503 is configured to send a verification random number to the second user, so that the second user can verify the accuracy of the asset locking message, and execute the asset transfer operation according to the accuracy verification result of the asset locking message.

The verification random number is the same as the random number in the asset lock message.

It should be noted that the methods for the first user to send the verification random number to the second user include on-chain sending and off-chain sending, wherein off-chain sending includes p2p (peer-to-peer, peer-to-peer) or mobile switching network to send. Under normal circumstances, in order to ensure the accuracy of the information received by the second user, a verification random number is sent to the second user in an off-chain way, so as to verify whether the asset lock message received through the on-chain way has been illegally tampered with, so that it can be verified within a certain period of time. To a certain extent, the accuracy of the received information is guaranteed. It can be understood that, no matter what sending method is adopted for the verification random number, it is the sending method agreed in advance between the first user and the second user.

In one embodiment, the first user sends the verification random number to the second user by means of a short message. After receiving the short message sent by the first user, the second user obtains the verification random number, and calculates the hash value corresponding to the verification random number to obtain the verification hash value. The second user compares and verifies whether the hash value is consistent with the hash value in the asset lock message. When the verification hash value is consistent with the hash value in the asset lock message, it means that the accuracy verification of the asset lock message has passed, and the second user transfers his assets to the first user according to the content of the smart contract.

It is worth mentioning that each module involved in this embodiment is a logical module. In practical applications, a logical unit may be a physical unit, a part of a physical unit, or multiple physical units. A composite implementation of the unit. In addition, in order to highlight the innovative part of the present invention, this embodiment does not introduce units that are not closely related to solving the technical problem proposed by the present invention, but this does not mean that there are no other units in this embodiment.

It can be understood that the above embodiments are only exemplary embodiments adopted to illustrate the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, without departing from the spirit and essence of the present invention, various modifications and improvements can be made, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (10)

1. A blockchain cross-chain method, characterized in that, applied to the first user, comprising: Send an asset locking message to the second user; wherein the asset locking message includes a hash value, the second user's blockchain identifier, an asset locking time point and an asset locking duration, and the hash value is the first A hash value corresponding to a random number generated by a user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first blockchain is associated with all said second blockchain has one or more common nodes; Lock the asset of the first user according to the asset locking time point and the asset locking duration in the asset locking message; A verification random number is sent to the second user, so that the second user verifies the accuracy of the asset locking message, and performs an asset transfer operation according to the verification result of the accuracy of the asset locking message. 2. The blockchain cross-chain method according to claim 1, wherein before the sending the asset locking message to the second user, the method further comprises: The first user signs a smart contract with the second user; wherein, the smart contract stipulates detailed rules for asset transfer and return between the first user and the second user. 3. The blockchain cross-chain method according to claim 1, wherein the sending an asset locking message to the second user comprises: broadcasting the asset lock message to the first blockchain for the common node to receive the asset lock message; The common node broadcasts the asset lock message on the second blockchain, so that the second user receives the asset broadcast message. 4. The blockchain cross-chain method according to claim 1, characterized in that, after the verification random number is sent to the second user, the method further comprises: If the second user passes the accuracy verification of the asset lock message, receiving the asset of the second user transferred by the second user; If the verification random number returned by the second user is received within a preset time interval, the assets of the second user are transferred back to the second user. 5. A blockchain cross-chain method, characterized in that, applied to a second user, comprising: Receive an asset locking message sent by the first user; wherein the asset locking message includes a hash value, the blockchain identifier of the second user, an asset locking time point and an asset locking duration, and the hash value is the The hash value corresponding to the random number generated by the first user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the first blockchain is the same as the second blockchain has one or more common nodes; Lock the asset of the second user according to the asset locking time point and the asset locking duration in the asset locking message; Receive the verification random number sent by the first user, and verify the accuracy of the asset lock message based on the verification random number; After the accuracy verification of the asset locking message is passed, the assets of the second user are transferred to the first user. 6. The blockchain cross-chain method according to claim 5, wherein the receiving an asset locking message sent by the first user comprises: The second blockchain receives the asset lock message broadcast by the common node, and broadcasts it in the second blockchain; wherein, the asset lock message is the first user in the first A message broadcast by the blockchain and broadcast in the second blockchain after being received by the common node; Receive the asset lock message broadcast by the common node on the second blockchain. 7. The blockchain cross-chain method according to claim 5, wherein after receiving the asset locking message sent by the first user, the asset locking time point and Before locking the assets of the second user, the asset lock duration further includes: Signature verification is performed on the asset lock message. 8. The blockchain cross-chain method according to claim 5, wherein the verification of the accuracy of the asset locking message based on the verification random number comprises: Calculate the verification hash value corresponding to the verification random number; comparing whether the verification hash value is consistent with the hash value in the asset lock message; If the verification hash value is consistent with the hash value in the asset locking message, the accuracy verification of the asset locking message passes. 9 . The blockchain cross-chain method according to claim 5 , wherein if the second user returns the verification random number to the first user at a preset time interval, the first user receives the first Assets of the second user transferred back by the user. 10. A blockchain cross-chain device, characterized in that, applied to the first user, comprising: The first sending module is configured to send an asset locking message to the second user; wherein, the asset locking message includes a hash value, a blockchain identifier of the second user, an asset locking time point and an asset locking duration, and the The hash value is the hash value corresponding to the random number generated by the first user; the first user is a user of the first blockchain, the second user is a user of the second blockchain, and the The first blockchain and the second blockchain have one or more common nodes; a locking module, configured to lock the assets of the first user according to the asset locking time point and the asset locking duration in the asset locking message; A second sending module, configured to send a verification random number to the second user, so that the second user can verify the accuracy of the asset lock message, and execute asset transfer according to the verification result of the asset lock message accuracy operate.

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