WO2022206454A1

WO2022206454A1 - Method and apparatus for providing cross-chain messages

Info

Publication number: WO2022206454A1
Application number: PCT/CN2022/082018
Authority: WO
Inventors: 余逸荣
Original assignee: 支付宝(杭州)信息技术有限公司; 蚂蚁区块链科技(上海)有限公司
Priority date: 2021-03-30
Filing date: 2022-03-21
Publication date: 2022-10-06
Also published as: CN112737782B; CN112737782A

Abstract

Provided in the embodiments of the present description are a method and an apparatus for providing cross-chain messages, the method being executed by an endorsing node of a Fabric blockchain, and comprising: receiving transaction information of a first transaction from a Fabric blockchain, a first contract being invoked in the transaction proposal of the first transaction, and a first cross-chain message being provided to the first contract; determining the execution state of the first transaction; when determining that the first transaction can be successfully executed, recording the first cross-chain message in a message queue in the account state of the first contract; receiving a transaction proposal of a second transaction from a client terminal node, a query function in the first contract being invoked in the second transaction; pre-executing the second transaction in order to read the first cross-chain message from the message queue; generating a read-write set of the second transaction, the read-write set comprising the first cross-chain message; and sending the read-write set of the second transaction to the client terminal node.

Description

Method and apparatus for providing cross-chain messages

technical field

The embodiments of this specification relate to the field of blockchain technology, and more particularly, to a method and apparatus for providing cross-chain messages in Fabric blockchain, and a method and apparatus for obtaining cross-chain messages in Fabric blockchain.

Background technique

Blockchain technology, also known as distributed ledger technology, is a decentralized distributed database technology characterized by decentralization, openness, transparency, immutability, and trustworthiness. With the popularity of blockchain technology, many different types of chains have emerged, which are applied in the fields of finance, health care, supply chain, asset management and traceability. At present, how to make different types of chains cooperate and realize the circulation of value is an important exploration direction. In the existing cross-chain technology, the cross-chain messages sent by the account in the blockchain to the outside of the chain are usually obtained by reading the block data in the blockchain ledger. For example, in the Hyperledger Fabric blockchain (hereinafter referred to as the Fabric blockchain), each peer node stores a full amount of consistent ledger data. The peer node has its own query chain code (Query System Chaincode, qscc). When the peer node needs to query the ledger data, it can query the local block data by calling the qscc system chain code. However, when an off-chain user wants to query the target block data in the channel, the off-chain user needs to start a peer node to query the block data in the Fabric blockchain.

Therefore, a more efficient scheme for delivering messages across chains is needed.

SUMMARY OF THE INVENTION

The embodiments of the present specification aim to provide a more effective solution for transmitting messages across chains, so as to solve the deficiencies in the prior art.

In order to achieve the above object, one aspect of this specification provides a method for providing cross-chain messages, the method is executed by an endorsement node of the Fabric blockchain, and includes: receiving transaction information of a first transaction from the Fabric blockchain, the The transaction information includes a transaction proposal of the first transaction and at least one read-write set, and the transaction proposal of the first transaction calls the first contract and provides the first cross-chain message to the first contract; determine The execution status of the first transaction; in the case of determining that the first transaction can be successfully executed, record the first cross-chain message in the message queue in the account status of the first contract; from the client node Receive a transaction proposal of a second transaction, in which the query function in the first contract is called; pre-execute the second transaction to read the first cross-chain message from the message queue; generating a read-write set of the second transaction, the read-write set including the first cross-chain message; sending the read-write set of the second transaction to the client node.

In one embodiment, the method further includes, after sending the read-write set of the second transaction to the client node, receiving transaction information of the second transaction from the Fabric blockchain, the first The transaction information of the second transaction includes the transaction proposal of the second transaction and at least one read-write set; determining the execution status of the second transaction; in the case of determining that the second transaction can be successfully executed, in the message The state of the first cross-chain message is changed in the queue.

In one embodiment, the first contract invokes a predetermined chain code for obtaining information about the account that initiates the proposal, and pre-executing the second transaction further includes: obtaining the information of the second transaction by pre-executing the predetermined chain code. A proposal initiating account, verifying whether the proposal initiating account is a predetermined account, and in the case that the proposal initiating account is a predetermined account, reading the first cross-chain message from the message queue.

Another aspect of this specification provides a method for obtaining a cross-chain message, the method being executed by a client node of the Fabric blockchain, comprising: sending a transaction proposal of the second transaction to at least one endorsement node of the Fabric blockchain, where the The query function in the first contract is called in the transaction proposal of the second transaction, the account status of the first contract includes a message queue of cross-chain messages, and the query function is used to read the cross-chain message in the message queue. message; respectively receiving read-write sets of the second transaction from the at least one endorsement node, each of the read-write sets including the first cross-chain message in the message queue.

In one embodiment, the method further includes, after respectively receiving the read-write sets of the second transaction from the at least one peer node, verifying each of the read-write sets based on a predetermined endorsement policy; After the verification is passed, the transaction information of the second transaction is sent to the ordering node in the Fabric block chain, and the transaction information of the second transaction includes the transaction proposal of the second transaction and each of the read-write sets.

In an implementation manner, the query function in the first contract is called with a query parameter as an incoming parameter in the second transaction, and the query parameter is used to indicate the first cross-chain message.

In one embodiment, sending the transaction proposal of the second transaction to at least one endorsing node of the Fabric blockchain includes sending the transaction proposal of the second transaction to the first endorsing node of the Fabric blockchain, the first endorsing node Including TEE.

Another aspect of the present specification provides an apparatus for providing a cross-chain message, the apparatus is deployed on an endorsement node of the Fabric blockchain, and includes: a first receiving unit configured to receive a transaction of the first transaction from the Fabric blockchain information, the transaction information includes a transaction proposal of the first transaction and at least one read-write set, and the transaction proposal of the first transaction calls the first contract and provides the first cross to the first contract. chain message; a first determination unit, configured to determine the execution state of the first transaction; and a recording unit, configured to, in the case of determining that the first transaction can be successfully executed, in the account state of the first contract the first cross-chain message is recorded in the message queue in ; a pre-execution unit, configured to pre-execute the second transaction to read the first cross-chain message from the message queue; a generation unit, configured to generate a read-write set of the second transaction, The read-write set includes the first cross-chain message; the sending unit is configured to send the read-write set of the second transaction to the client node.

In one embodiment, the apparatus further includes a third receiving unit configured to, after sending the read-write set of the second transaction to the client node, receive the second transaction from the Fabric blockchain transaction information of the transaction, the transaction information of the second transaction includes a transaction proposal of the second transaction and at least one read-write set; a second determination unit configured to determine the execution state of the second transaction; a modification unit , and is configured to change the state of the first cross-chain message in the message queue when it is determined that the second transaction can be executed successfully.

In one embodiment, the first contract invokes a predetermined chain code for obtaining information about the account that initiates the proposal, and the pre-execution unit includes an obtaining subunit configured to obtain by pre-executing the predetermined chain code The proposal initiating account of the second transaction, the verification subunit, is configured to verify whether the proposal initiating account is a predetermined account, and the reading subunit is configured to, in the case that the proposal initiating account is a predetermined account, from the The first cross-chain message is read from the message queue.

Another aspect of this specification provides an apparatus for obtaining a cross-chain message, the apparatus is deployed on a client node of the Fabric blockchain, and includes: a first sending unit configured to send to at least one endorsement node of the Fabric blockchain The transaction proposal of the second transaction, the query function in the first contract is called in the transaction proposal of the second transaction, the account status of the first contract includes a message queue of cross-chain messages, and the query function is used to read the cross-chain message in the message queue; the receiving unit is configured to respectively receive read-write sets of the second transaction from the at least one endorsement node, and each read-write set includes the first read-write set in the message queue Cross-chain messages.

In one embodiment, the apparatus further includes a verification unit configured to, after respectively receiving the read-write set of the second transaction from the at least one peer node, verify each of the read-write sets based on a predetermined endorsement policy. The second sending unit is configured to send the transaction information of the second transaction to the ordering node in the Fabric blockchain after the verification is passed, and the transaction information of the second transaction includes the first Two transaction proposals and read-write sets for each of the transactions.

In an embodiment, the first sending unit is further configured to send a transaction proposal of the second transaction to a first endorsement node of the Fabric blockchain, where the first endorsement node includes a TEE.

Another aspect of the present specification provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed in a computer, the computer is made to execute any of the above-mentioned methods executed by an endorsement node of the Fabric blockchain .

Another aspect of the present specification provides a computing device, including a memory and a processor, where executable code is stored in the memory, and when the processor executes the executable code, any one of the above-mentioned processing by the Fabric blockchain is implemented. The method executed by the endorsing node.

Another aspect of the present specification provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed in a computer, the computer is made to execute any of the above-mentioned functions executed by the client node of the Fabric blockchain. method.

Another aspect of the present specification provides a computing device, including a memory and a processor, where executable code is stored in the memory, and when the processor executes the executable code, any one of the above-mentioned processing by the Fabric blockchain is implemented. The method executed by the client node.

Through the solution for transmitting cross-chain messages according to the embodiments of this specification, the cross-chain message is saved in the account state of the message sending contract deployed in the Fabric blockchain, and the cross-chain message in the account state is queried by calling the query function of the message sending contract. Chain message provides a novel method of querying the blockchain ledger in the Fabric blockchain. Through this method, you can also set a verification program in the query function, and you can also verify whether the query account is an allowed preset account. Thereby improving security.

Description of drawings

By describing the embodiments of the present specification in conjunction with the accompanying drawings, the embodiments of the present specification can be made clearer:

FIG. 1 shows a schematic diagram of a cross-chain system based on Fabric blockchain according to an embodiment of the present specification;

FIG. 2 shows a flowchart of a method for executing transaction 1 in the Fabric blockchain according to an embodiment of the present specification;

3 shows a flowchart of a method for executing transaction m in the Fabric blockchain according to an embodiment of the present specification;

FIG. 4 shows an apparatus 400 for providing a cross-chain message according to an embodiment of the present specification;

FIG. 5 shows an apparatus 500 for acquiring a cross-chain message according to an embodiment of the present specification.

Detailed ways

The embodiments of the present specification will be described below with reference to the accompanying drawings.

First, let's introduce the construction and transaction process of the Fabric blockchain. The Fabric blockchain is an enterprise-oriented consortium chain. The Fabric blockchain includes the following types of nodes: client nodes, peer nodes, orderer nodes, and so on. The peer nodes further include an endorsement (Endorsor) node, an management (Anchor) node, a commit (Committer) node, and the like. The Fabric blockchain includes multiple channels, and each channel has its own closed ledger data and chaincode, which is the smart contract in the Fabric blockchain. Peers can choose which channels to join, and they can join the channel after being authenticated by peers already in the channel. The client node (that is, the node device of the client node) can initiate a transaction proposal to a channel in the Fabirc blockchain, so that the client node can endorse at least two predetermined endorsement nodes in the channel according to the endorsement policy of the channel Send a transaction proposal. The endorsement node in the channel has a transaction proposal system interface, so that the endorsement node can pre-execute the transaction proposal received from the client node by calling the system interface to obtain the read-write set of the pre-executed transaction, and digitally sign the read-write set. And after the pre-execution, the pre-execution result (that is, the read-write set) and the digital signature are returned to the client node. After receiving the transaction pre-execution result and digital signature from each endorsement node, the client node sends it to the ordering node. The sorting node is used to sort transactions, and pack the sorted transactions into blocks at fixed time intervals and send them to the management node. After receiving the block, the management node broadcasts the block to each submitting node. After the submitting node receives the block, it verifies the execution status of each transaction in the block, marks its execution status in each transaction of the block, and then adds the block to the node's ledger data (ie, submits the block). Among them, each peer node is a commit node, that is, each peer node locally includes the ledger data of the channel.

FIG. 1 shows a schematic diagram of a cross-chain system based on the Fabric blockchain according to an embodiment of the present specification. As shown in Figure 1, the cross-chain system includes an endorsement node 11, a first client node 12, a second client node 13 and an ordering node 14 in the Fabric blockchain, and these nodes all correspond to specific node devices , hereinafter, the node refers to the corresponding node device. A business contract and a message sending contract are deployed in the endorsement node 11. The business contract is, for example, a cross-chain transfer contract, and the business contract includes a call of a message sending contract, and the message sending contract is used to send cross-chain messages. When a user in the Fabric blockchain wishes to perform a cross-chain transfer, the corresponding first client node 12 can send transaction 1 to at least one predetermined endorsement node (for example, including the endorsement node 11 ) in the Fabric blockchain In the proposal of transaction 1, the business contract is called, and the parameters related to the transfer are passed to the business contract, such as the blockchain identifier for receiving the transfer, the account for receiving the transfer, the transfer amount, the receiving contract account, and so on. After receiving the proposal of transaction 1, the endorsement node 11 pre-executes transaction 1, that is, pre-executes the business contract, records in the read-write set of pre-execution transaction 1: reads the account balance that initiates transaction 1, and reduces the account balance by any amount. The transfer amount is described, and a cross-chain message (message 1 in Figure 1) is generated. Message 1 includes, for example, the identifier of the sending blockchain, the identifier of the receiving blockchain, the sending account, the receiving account, the receiving contract account and the pairing of the message 1. The balance of the receiving account is increased by the amount, etc., and then the message sending contract is pre-executed, and message 1 is provided to the message sending contract. When pre-executing the message sending contract, "message 1" is added to the message queue recorded in the account status of the message sending contract in the above-mentioned read-write set. After completing the above pre-execution, the endorsement node 11 signs the generated read-write set, and sends the read-write set of transaction 1 and its signature back to the first client node 12 . After the first client node 12 collects the read-write set of each endorsement node and its signature, it verifies it based on the predetermined endorsement policy, and after the verification is passed, the information of the transaction 1 is packaged and sent to the ordering node 14. The ordering node 14 The received transactions (including transaction 1) are sorted and packaged into blocks based on predetermined rules, and the blocks are sent to a management node in the Fabric blockchain (not shown in Figure 1). The management node sends the block to each submission node in the Fabric blockchain, including, for example, the endorsement node 11, that is, the endorsement node 11 acts as both an endorsement node and a submission node. After receiving the block, the endorsement node 11 verifies the read-write set of transaction 1 based on the current world state, and after determining that transaction 1 is executable, updates the world state according to the write set in the read-write set, that is, updates the sending of transaction 1 account balance of the account, and add message 1 to the message queue in the account state of the message sending contract. Message 1 - Message 5 arranged in sequence in FIG. 1 schematically illustrate the message queue in the account state of the message sending contract.

The second client node 13 is used to transfer messages between the Fabric blockchain 11 and other blockchains. Similar to the above, the second client node 13 can obtain the cross-chain message by sending a transaction proposal (for example, the proposal of transaction m in FIG. 1 , where m is the transaction number) to a predetermined endorsement node in the Fabric blockchain 11 . . The query function of the message sending contract is called in transaction m to query the above message queue. After receiving the proposal of transaction m, the endorsement node 11 pre-executes transaction m, that is, pre-executes the query function, reads message 1 in the message queue of the message sending contract, and then records the message in the read set of transaction m. The read of 1, and the deletion of message 1 in the message queue are recorded in the write set. After generating the read-write set of transaction m, the endorsement node 11 signs the read-write set, and sends the read-write set and its signature back to the second client node 13 . After the second client node 13 receives the responses to the transaction m sent back by each endorsement node, it verifies each response, so that the message 1 can be obtained from any read-write set. After verifying the responses of each endorser node to transaction m, the second client node 13 can package the transaction information of transaction m, and send the transaction information of transaction m to the ordering node 14 .

The sorting node 14 sorts the received multiple transactions, and packs the multiple transactions into a block, for example, the block includes transaction m. Afterwards, the ordering node 14 sends the block to the management node (not shown in FIG. 1 ), which in turn sends the block to each submitting node (including the endorsing node 11). After receiving the transaction information of transaction m, the endorsement node verifies whether transaction m can be executed based on the world state. In the case of verifying that transaction m is executable, the world state is updated based on the read-write set of transaction m, that is, in the account of the message sending contract. Message 1 is deleted from the message queue in the state.

It can be understood that the above description with reference to FIG. 1 is only illustrative, and is not used to limit the embodiments of the present specification. For example, the business contract is not limited to be a cross-chain transfer contract, and the message 1 is not limited to the above-mentioned form. The method for providing messages across chains according to embodiments of the present specification will be described in detail below.

FIG. 2 shows a flowchart of a method for executing transaction 1 in the Fabric blockchain according to an embodiment of the present specification. It is shown in FIG. 2 that the method is performed jointly by the first client node 12 , the endorsing node 11 and the ordering node 14 .

First, in step S201, the first client node 12 sends a proposal of transaction 1 to a predetermined endorsement node, where the predetermined endorsement node includes the endorsement node 11.

In each channel of the Fabric blockchain, the endorsement nodes and endorsement policies are preset, and only the endorsement nodes are deployed with chaincodes, so that only the endorsement nodes can pre-execute each chaincode. The client node makes the endorsement node pre-execute the transaction by sending a transaction proposal to at least one preset endorsement node. As mentioned above, the first client node 12 sends a proposal for transaction 1 for cross-chain transfer to the endorsement node 11, and the proposal includes a call to a business contract, and the business contract includes a call to the message sending contract. Called to send cross-chain messages.

In step S202, the endorsement node 11 pre-executes transaction 1, and generates a read-write set of transaction 1.

The endorsement nodes in the Fabric blockchain perform the endorsement process according to the preset process relative to the endorsement nodes. Specifically, after receiving the transaction 1, the endorsement node 11 pre-executes the transaction 1, and the pre-execution is the simulated execution of the transaction 1, but does not store the acquired transaction execution result (ie, the change to the world state) into the local ledger , but generate a read-write set corresponding to transaction 1, and store the changes to the world state caused by the execution into the read-write set. After the endorsing node 11 starts to pre-execute transaction 1, it pre-executes the business contract. The pre-execution process includes, for example, reading the account balance of account 1 that sends the transaction 1 proposal, and reducing the balance of this account 1 by the transfer amount. Therefore, The account balance of account 1 is recorded in the read set of transaction 1, and the balance of account 1 after reducing the transfer balance is recorded in the write set of transaction 1. Then, the endorsement node 11 generates the message 1 based on the program in the business contract, executes the message sending contract called in the business contract, and provides the message 1 to the message sending contract. During the execution of the message sending contract, the message 1 added to the message queue in the account state of the message sending contract is recorded in the write set of transaction 1, thereby completing the pre-execution of transaction 1.

In step S203, the endorsement node 11 sends the read-write set of transaction 1 to the first client node 12.

After completing the pre-execution of transaction 1, the endorsement node signs the generated read-write set of transaction 1, and returns the read-write set and its signature to the first client node 12.

In step S204, the first client node 12 verifies the read-write set of transaction 1.

After receiving the read-write set of transaction 1 and its signature from at least one endorsement node, the first client node 12 first verifies whether the signature of each read-write set is the signature of each endorser node through the public key of each endorser node, and then, based on The predetermined endorsement policy verifies the read-write set, for example, the predetermined endorsement policy is an endorsement requiring at least three endorsing nodes, an endorsement requiring a specific number of endorsing nodes, and so on. If the verification is passed, the subsequent step S205 is executed, and if the verification is not passed, the processing of the transaction 1 is ended.

In one embodiment, a secure execution environment (TEE) is included in the endorsement node 11 . The first client node 12 may verify the TEE in the endorsing node 11 . Specifically, the first client node 12 may send an authentication request to the TEE. After receiving the verification request, the TEE generates authentication information based on its internal mechanism, and sends the authentication information and the hardware public key of the TEE to the first client node 12 . The authentication information includes, for example, signature information, hardware information, software information, and the like of the TEE. Wherein, the signature information is generated by, for example, the hardware key of the TEE; the hardware information includes, for example, various hardware indicators, such as CPU frequency, memory capacity, etc.; the software information includes the code hash value of each program , code name, version, run log, etc. As is known to those skilled in the art, a TEE can perform "measurements" of a program running in it through memory hardware, such as obtaining a code hash of the program, a hash of the program's memory occupancy at a particular point of execution, etc., and The authentication information includes "measurement" information for the program, which is authentic and credible because the "measurement" information is executed by the TEE's own entity (memory hardware) without involving any software or operating system. After receiving the authentication information, the first client node 12 may send the authentication information to the remote authentication server of the TEE, so as to receive the verification result of the TEE from the server. The verification result includes the identity verification of the TEE, the verification of the internal execution program of the TEE, and the like. Therefore, based on the verification result, the first client node 12 can determine that the TEE is credible, and the processing result of the TEE is credible. At the same time, the first client node 12 locally saves the hardware public key of the TEE for subsequent verification of the signature of the TEE.

In the case where a secure execution environment (TEE) is included in the endorsing node 11, the endorsing node 11 is trusted, so the first client node 12 can only receive the read-write set of transaction 1 from the endorsing node 11, and use the After the signature of the read-write set is verified by the public key of the TEE, it can be confirmed that the read-write set is a real read-write set.

In step S205 , the first client node 12 sends the transaction information of transaction 1 to the ordering node 14 .

After the first client node 12 passes the verification of the read-write set of transaction 1, it packages the transaction information of transaction 1, and the transaction information includes the proposal of transaction 1, each read-write set of transaction 1 and the corresponding read-write set of each endorsement node. After writing the signature of the set, the first client node 12 sends the transaction information of transaction 1 to the ordering node 14 for block entry.

In step S206, after receiving the transaction information of transaction 1, the sorting node 14 sorts the multiple transactions that have been received, and packages the multiple transactions into block 1.

The ordering node 14 may order the plurality of transactions based on a predetermined ordering rule, for example, the transactions may be ordered based on their proposal sending time. After sorting, the sorting node 14 packages the respective transaction information of the plurality of transactions into, for example, a block 1 in the above-mentioned sorting order, and the block 1 includes the transaction information of the transaction 1 .

In step S207, the ordering node 14 sends the block 1 to a plurality of submitting nodes, including the endorsing node 11.

The submission node is used to determine the execution state of the transaction, put the transaction into a block, and update the world state according to the read-write set of the transaction. That is to say, the submission node stores the ledger data in the Fabric blockchain. Includes block and world state. Since the endorsement node 11 needs to perform operations such as querying the ledger data, the endorsement node 11 needs to act as a submitting node to enter a transaction block to update the local ledger data.

In step S208, the endorsement node 11 determines the execution status of transaction 1.

After receiving block 1, the endorsement node 11 needs to process each transaction in sequence according to the arrangement order of each transaction in block 1. When processing the transaction information of transaction 1, the endorsement node 11 first determines the execution status of transaction 1, that is, determines whether transaction 1 can be successfully executed. Specifically, the endorsement node 11 determines whether there is a read-write conflict based on the read-write set of transaction 1 and the current world state, so as to determine whether transaction 1 can be successfully executed. For example, if the read-write set of transaction 1 includes reading and modification of the balance of account 1, the endorsement node 11 determines whether the balance of account 1 read during pre-execution in the read-write set of transaction 1 has any value after the read. The transaction that is sorted before transaction 1 is changed. If there is this change, there is a read conflict, and the transaction 1 cannot be successfully executed. If there is no such change, it means that there is no read-write conflict, and the transaction 1 can be successfully executed.

In step S209, the endorsement node 11 records the message 1 in the message queue in the account state of the message sending contract.

After the endorsement node 11 determines that the transaction 1 can be successfully executed, it changes the world state based on the read-write set of the transaction 1, and stores the transaction information of the transaction 1 and its execution status (ie, the successful execution status) in the Fabric blockchain. As mentioned above, the read-write set of transaction 1 includes changes to account 1's balance and changes to the message queue, therefore, the endorsing node 11 stores the changes locally, ie changes the world state, that is, makes changes to account 1 The change in the balance of the message 1 is logged in the message queue in the account state of the message sending contract. After the record is made, the processing of transaction 1 in the Fabric blockchain ends, and thus, through the processing of transaction 1, message 1 is stored in the Fabric blockchain as a message to be sent across chains.

FIG. 3 shows a flowchart of a method for executing transaction m in the Fabric blockchain according to an embodiment of the present specification. It is shown in FIG. 3 that the method is performed jointly by the second client node 13 , the endorsing node 11 and the ordering node 14 .

In step S301, the second client node 13 sends a proposal for transaction m.

The second client node 13 does not store the ledger data of the Fabric blockchain. The second client node 13 obtains the cross-chain message from the endorsing node by sending a specific transaction proposal to the endorsing node in the Fabric blockchain. Specifically, for example, as shown in FIG. 1 , the second client node 13 may send a proposal for transaction m to at least one predetermined endorsement node (including the endorsement node 11 ) in the Fabric blockchain, and the proposal for transaction m calls The query function included in the message sending contract is used to read cross-chain messages in the above message queue.

In step S302, the endorsement node 11 pre-executes the transaction m, and generates a read-write set of the transaction m, and the read-write set includes the message 1.

When the endorsement node 11 pre-executes the transaction m, it pre-executes the query function in the message sending contract in the transaction m. The query function can be preset to allow the query account to verify whether the account that sends the proposal of the transaction m is an allowed query account. . Therefore, when the query function is pre-executed, the account that sends the proposal of transaction m is first verified. If the verification fails, the query failure is returned. If the verification succeeds, the cross-link is read from the message queue in the account status of the message sending contract. chain message. It can be understood that in the case where the query account does not need to be verified, when the query function is pre-executed, the cross-chain message can be directly read from the message queue in the account status of the message sending contract.

In one embodiment, the query function includes, for example, the GetProposer interface. When the query function is pre-executed, the certificate of the proposer is first obtained by calling GetProposer. The certificate includes the account, public key and other information of the proposer, so that the Verify that the proposer is allowed to query based on the account or public key preset in the query function. In one embodiment, the query function includes, for example, the GetCreator interface. When the query function is executed, the proposer's account is first obtained by calling GetCreator, and then whether the proposer's account is verified based on the allowable account preset in the query function for allowed accounts.

The reading method of cross-chain messages in the query function can be set according to requirements. For example, it can be preset that each time the query function is pre-executed, the oldest message is read from the message queue. Referring to Figure 1, assuming that the current Message 1 is the earliest recorded message, and message 2 to message 5 are all messages recorded after message 1. Therefore, when the query function is executed this time, message 1 in the message queue is read. It can be understood that the query function is not limited to reading the oldest message, but can be preset to read the oldest predetermined number (for example, 5, etc.) messages in the message queue, or can be preset to read The latest predetermined number of messages in the message queue, or it can be preset to read the message with the specified sequence number, and the specified sequence number can be passed to the query function as an incoming parameter when calling the query function, or it can be preset to read the specified sequence number. The content of the message, the specified content is the content included in the message, such as accepting the contract account number, receiving the blockchain identifier, etc. The specified content can also be passed to the query function as an incoming parameter when calling the query function. . After reading, for example, message 1 from the message queue in the above-described manner, the endorsement node 11 records message 1 in the read set relative to the read-write set generated by transaction m.

The query function can also be preset to pre-modify the state of the message sending contract after reading the cross-chain message, that is, not to modify the world state immediately, but to record the changes to the world state in the write set. Specifically, in one embodiment, after, for example, reading the message 1 in the message queue, record and delete the message 1 in the message queue in the write set of the transaction m, so that the endorsement node 11 will, after submitting the transaction m, record the message 1 according to the write set of the transaction m. The content of the set record deletes message 1 in the message queue so that message 1 will not be read repeatedly the next time the query function is executed. In one embodiment, after reading message 1, message 1 may be marked in the write set record to indicate that off-chain device 12 has read message 1, in this embodiment, the endorsing node 11 is submitting transaction m Message 1 will then be marked according to the records in the write set, so that the second client node 13 can read the message 1 repeatedly, or, in the case of more than one client node reading the cross-chain message from the endorsing node 11, at After the second client node 13 reads the message 1, other client nodes can also read the message 1.

The endorsement node 11 pre-executes the transaction m as described above, thereby generating a read-write set corresponding to the transaction m, and the read-write set includes the read message 1 .

In step S303, the endorsement node 11 sends the read-write set of the transaction m to the second client node 13.

In step S304, the second client node 13 verifies the read-write set of the transaction m.

For the step S303 and the step S304, reference may be made to the description of the step S203 and the step S204 above, which will not be repeated here.

In step S305, the second client node 13 obtains the message 1 from the read-write set of the transaction m.

According to the above description, when the endorsement node 11 pre-executes the transaction m, it records the message 1 read from the message queue into the read set. Therefore, the second client node 13 can read the read set in the read-write set of the transaction m. The content is the content of message 1.

In one embodiment, after acquiring the message 1, the second client node 13 can determine the receiving chain identifier from the message 1 based on the predetermined data structure of the message 1, so that each read-write set of the transaction m and its signature can be obtained Provided to the corresponding receiving chain, so that the corresponding receiving chain can verify each read-write set of transaction m based on the signature of each read-write set, and determine whether the each read-write set is credible according to the predetermined endorsement strategy, and then verify each read-write set. If the read-write set is trusted, message 1 can be obtained from it.

In one embodiment, in the case where the second client node 13 is a trusted node, after acquiring the message 1, the second client node 13 determines the receiving chain identifier from the message 1, so as to directly provide the message 1 to the corresponding receive chain.

In step S306, the second client node 13 sends the transaction information of the transaction m to the ordering node 14.

In step S307, the sorting node 14 sorts the plurality of transactions to generate block 2.

In step S308, the ordering node 14 sends the block 2 to a plurality of submitting nodes, including the endorsing node 11.

In step S309, the endorsement node 11 determines the execution status of the transaction m.

For steps S306-S309, reference may be made to the description of steps S205-S208 above, and details are not repeated here.

In step S310, the endorsement node 11 deletes message 1 from the message queue in the account state of the message sending contract.

When the endorsement node 11 determines that the transaction m can be successfully executed, it stores the transaction information of the transaction m and the execution state of the transaction m in the Fabric blockchain, and changes the world state according to the write set of the transaction m. For example, deletion of message 1 in the message queue is recorded in the write set. Therefore, the endorsement node performs deletion of message 1 in the message queue. If, as described above, the write set records the deletion of message 1 in the message queue. If marking is performed, the endorsing node will perform the marking of message 1 correspondingly. By submitting the transaction m in the Fabric blockchain, the world state can be changed according to the execution of the transaction m, thereby facilitating the subsequent reading of the message queue by the second client node 13 .

FIG. 4 shows an apparatus 400 for providing a cross-chain message according to an embodiment of the present specification. The apparatus 400 is deployed on an endorsement node of the Fabric blockchain, and includes: a first receiving unit 401 configured to receive data from the Fabric blockchain The transaction information of the first transaction is received in the transaction information, and the transaction information includes the transaction proposal of the first transaction and at least one read-write set. The first contract provides the first cross-chain message; the first determining unit 402 is configured to determine the execution state of the first transaction; the recording unit 403 is configured to, in the case of determining that the first transaction can be successfully executed, Record the first cross-chain message in the message queue in the account state of the first contract; the second receiving unit 404 is configured to receive a transaction proposal of the second transaction from the client node, in the second transaction The query function in the first contract is called; the pre-execution unit 405 is configured to pre-execute the second transaction to read the first cross-chain message from the message queue; the generation unit 406 is configured to , generating a read-write set of the second transaction, and the read-write set includes the first cross-chain message; the sending unit 407 is configured to send the read-write set of the second transaction to the client node .

In an embodiment, the apparatus 400 further includes a third receiving unit 408, configured to, after sending the read-write set of the second transaction to the client node, receive from the Fabric blockchain Transaction information of the second transaction, the transaction information of the second transaction includes a transaction proposal of the second transaction and at least one read-write set; the second determining unit 409 is configured to determine the execution state of the second transaction ; The changing unit 410 is configured to, in the case of determining that the second transaction can be executed successfully, change the state of the first cross-chain message in the message queue.

In one embodiment, the first contract invokes a predetermined chain code for obtaining information about the account that initiates the proposal, and the pre-execution unit 405 includes an obtaining sub-unit 4051 configured to pre-execute the predetermined chain by pre-executing the predetermined chain code. The code obtains the proposal initiating account of the second transaction, the verification subunit 4052 is configured to verify whether the proposal initiating account is a predetermined account, and the reading subunit 4053 is configured to, when the proposal initiating account is a predetermined account In this case, the first cross-chain message is read from the message queue.

FIG. 5 shows an apparatus 500 for acquiring cross-chain messages according to an embodiment of the present specification. The apparatus 500 is deployed on a client node of the Fabric block chain, and includes: a first sending unit 51 configured to send a message to the Fabric block chain. At least one endorsement node of the chain sends a transaction proposal of the second transaction, the query function in the first contract is called in the transaction proposal of the second transaction, and the account status of the first contract includes the message queue of cross-chain messages, so The query function is used to read the cross-chain message in the message queue; the receiving unit 52 is configured to respectively receive the read-write set of the second transaction from the at least one endorsement node, and each of the read-write sets includes The first cross-chain message in the message queue.

In one embodiment, the apparatus 500 further includes a verification unit 53, configured to, after receiving the read-write set of the second transaction from the at least one peer node respectively, verify each transaction based on a predetermined endorsement policy. The read-write set is verified; the second sending unit 54 is configured to, after the verification is passed, send the transaction information of the second transaction to the ordering node in the Fabric blockchain, where the transaction information of the second transaction includes The transaction proposal of the second transaction and each of the read and write sets.

In an embodiment, the first sending unit 51 is further configured to send a transaction proposal of the second transaction to a first endorsement node of the Fabric blockchain, where the first endorsement node includes a TEE.

It should be understood that the descriptions of "first", "second" and so on herein are only for the simplicity of description to distinguish similar concepts, and have no other limiting effect.

Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, as for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the partial descriptions of the method embodiments.

The foregoing describes specific embodiments of the present specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that in the embodiments and still achieve desirable results. Additionally, the processes depicted in the figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Those of ordinary skill in the art should further realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two, in order to clearly illustrate the hardware and software interchangeability, the components and steps of each example have been generally described in terms of functions in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Persons of ordinary skill in the art may use different methods of implementing the described functionality for each particular application, but such implementations should not be considered beyond the scope of this application. Wherein, the software module can be placed in random access memory (RAM), internal memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or technical fields in any other form of storage medium known in the art.

The specific embodiments described above further describe the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

A method for providing cross-chain messages, the method being performed by an endorsement node of the Fabric blockchain, comprising:

Receive transaction information of the first transaction from the Fabric blockchain, the transaction information includes a transaction proposal of the first transaction and at least one read-write set, the transaction proposal of the first transaction calls the first contract, and providing the first cross-chain message to the first contract;

determining the execution status of the first transaction;

In the case of determining that the first transaction can be successfully executed, recording the first cross-chain message in the message queue in the account state of the first contract;

Receive a transaction proposal of the second transaction from the client node, and the query function in the first contract is called in the second transaction;

pre-executing the second transaction to read the first cross-chain message from the message queue;

generating a read-write set of the second transaction, where the read-write set includes the first cross-chain message;

Send the read-write set of the second transaction to the client node.
The method of claim 1, further comprising, after sending the read-write set of the second transaction to the client node, receiving transaction information of the second transaction from the Fabric blockchain, the second transaction The transaction information of the transaction includes the transaction proposal of the second transaction and at least one read-write set; determining the execution status of the second transaction; in the case of determining that the second transaction can be successfully executed, in the message queue to change the state of the first cross-chain message.
The method according to claim 1 or 2, wherein the first contract invokes a predetermined chaincode for acquiring the relevant information of the proposal initiating account, and pre-executing the second transaction further comprises: acquiring by pre-executing the predetermined chain code The proposal initiating account of the second transaction verifies whether the proposal initiating account is a predetermined account, and in the case where the proposal initiating account is a predetermined account, reads the first cross-chain message from the message queue.
A method for obtaining cross-chain messages, the method is executed by a client node of the Fabric blockchain, including:

Send a transaction proposal of the second transaction to at least one endorsement node of the Fabric blockchain, the transaction proposal of the second transaction calls the query function in the first contract, and the account status of the first contract includes the cross-chain message. a message queue, where the query function is used to read cross-chain messages in the message queue;

The read-write sets of the second transaction are respectively received from the at least one endorsing node, and each of the read-write sets includes the first cross-chain message in the message queue.
The method of claim 4, further comprising, after respectively receiving the read-write sets of the second transaction from the at least one peer node, verifying each of the read-write sets based on a predetermined endorsement policy; After passing, the transaction information of the second transaction is sent to the ordering node in the Fabric blockchain, where the transaction information of the second transaction includes the transaction proposal of the second transaction and each of the read-write sets.
The method according to claim 4 or 5, wherein in the second transaction, a query function in the first contract is called with a query parameter as an incoming parameter, and the query parameter is used to indicate the first cross-chain message.
The method according to claim 4 or 5, wherein sending the transaction proposal of the second transaction to at least one endorsing node of the Fabric blockchain comprises sending the transaction proposal of the second transaction to the first endorsing node of the Fabric blockchain, The first endorsement node includes a TEE.
A device for providing cross-chain messages, the device is deployed on an endorsement node of the Fabric blockchain, including:

The first receiving unit is configured to receive transaction information of the first transaction from the Fabric blockchain, where the transaction information includes a transaction proposal of the first transaction and at least one read-write set, the transaction of the first transaction Invoke the first contract in the proposal and provide the first cross-chain message to the first contract;

a first determining unit, configured to determine the execution state of the first transaction;

a recording unit, configured to record the first cross-chain message in a message queue in the account state of the first contract in the case of determining that the first transaction can be successfully executed;

a second receiving unit, configured to receive a transaction proposal of a second transaction from the client node, where the query function in the first contract is invoked in the second transaction;

a pre-execution unit, configured to pre-execute the second transaction to read the first cross-chain message from the message queue;

a generating unit, configured to generate a read-write set of the second transaction, the read-write set including the first cross-chain message;

The sending unit is configured to send the read-write set of the second transaction to the client node.
The apparatus according to claim 8, further comprising a third receiving unit configured to receive the second transaction from the Fabric blockchain after sending the read-write set of the second transaction to the client node The transaction information of the second transaction includes a transaction proposal of the second transaction and at least one read-write set; a second determination unit, configured to determine the execution state of the second transaction; a modification unit, is configured to change the state of the first cross-chain message in the message queue in the case that it is determined that the second transaction can be executed successfully.
The apparatus according to claim 8 or 9, wherein the first contract invokes a predetermined chain code for acquiring information about the proposal initiation account, and the pre-execution unit includes an acquisition sub-unit configured to perform pre-execution The predetermined chain code obtains the proposal initiating account of the second transaction, and a verification subunit is configured to verify whether the proposal initiating account is a predetermined account, and the reading subunit is configured to verify that the proposal initiating account is a predetermined account. In the case of an account, the first cross-chain message is read from the message queue.
A device for acquiring cross-chain messages, the device is deployed on a client node of the Fabric blockchain, including:

The first sending unit is configured to send a transaction proposal of the second transaction to at least one endorsement node of the Fabric blockchain, where the transaction proposal of the second transaction calls the query function in the first contract, and the first contract's transaction proposal calls the query function in the first contract. The account state includes a message queue of cross-chain messages, and the query function is used to read the cross-chain messages in the message queue;

A receiving unit, configured to respectively receive read-write sets of the second transaction from the at least one endorsement node, each of the read-write sets including the first cross-chain message in the message queue.
11. The apparatus of claim 11, further comprising a verification unit configured to, after respectively receiving the read-write set of the second transaction from the at least one peer node, perform a verification on each of the read-write based on a predetermined endorsement policy The second sending unit is configured to send the transaction information of the second transaction to the ordering node in the Fabric block chain after the verification is passed, and the transaction information of the second transaction includes the second transaction information. The transaction proposal for the transaction and each said read-write set.
The apparatus according to claim 11 or 12, wherein in the second transaction, a query function in the first contract is called with a query parameter as an incoming parameter, and the query parameter is used to indicate the first cross-chain message.
The apparatus according to claim 11 or 12, wherein the first sending unit is further configured to send a transaction proposal of the second transaction to a first endorsement node of the Fabric blockchain, wherein the first endorsement node includes a TEE .
A computer-readable storage medium on which a computer program is stored, when the computer program is executed in a computer, the computer is made to perform the method of any one of claims 1 to 3.
A computing device includes a memory and a processor, wherein executable codes are stored in the memory, and when the processor executes the executable codes, the method of any one of claims 1 to 3 is implemented.
A computer-readable storage medium on which a computer program is stored, when the computer program is executed in a computer, the computer is made to perform the method of any one of claims 4 to 7.
A computing device includes a memory and a processor, wherein executable codes are stored in the memory, and when the processor executes the executable codes, the method of any one of claims 4 to 7 is implemented.