Abstract: The present solution discloses example methods and systems for verifying block data. One example method includes identifying newly added data to be stored in a blockchain, and selecting a data node in a block to store the newly added data. A string is generated based on the newly added data, and then a verification value for the newly added data is developed from the string using a predetermined algorithm. A new verification value for the block is calculated based on the verification value of the newly added data and the original verification values of the unchanged data nodes in the block. The new verification value for the block can then be used to verify the data stored in the block is consistent with data stored in the rest of the blockchain.

Abstract: One or more implementations of the present specification provide cross-blockchain authentication. A subscribing client corresponding to a first blockchain and using a cross-chain client of a cross-blockchain interaction system, retrieves data from a second blockchain, where the data is published by a publishing client for use as an authentication data source, where the cross-blockchain interaction system comprises the subscribing client, the publishing client, and the cross-chain client, where the publishing client corresponds to the second blockchain, where the cross-chain client is separately interconnected with the subscribing client, and where the publishing client and the first blockchain are used as a sidechain that is anchored to the second blockchain, which is used as a main chain. Data to be authenticated is received from the second blockchain. The data to be authenticated is authenticated based on the authentication data source and a data authentication rule configured on the first blockchain.

Abstract: A rental request initiated by a target user for a target service in a blockchain network is received. In response to the rental request, a credit risk assessment on the target user is performed. A determination is performed as to whether the target user passes the credit risk assessment. In response to determining that the target user passes the credit risk assessment, an electronic rental contract that corresponds to the target service is generated. The electronic rental contract is delivered to the target user and a service provider of the target service, in which the target user and the service provider perform an electronic signature on the electronic rental contract. The electronic rental contract with electronic signatures is stored in a distributed blockchain database of the blockchain network, in which the electronic rental contract is used to assess credit information of the target user.

Abstract: A node in a blockchain network receives service data generated in a specified time period, where the service data comprises label information used to represent a processing priority of the service data. The node determines, when a new block is generated, a throughput that corresponds to the label information based on a predetermined mapping relationship between label information and a throughput. The node obtains service data that satisfies the throughput and that comprises the label information from a data processing set based on the throughput, where the service data is stored in the data processing set. The service data is stored in the new block.

Abstract: Techniques for processing blockchain data are described. A node in a blockchain network receives service data generated by a first service, wherein the service data comprises a data structure having a field a value of which indicates that the first service is associated with a first processing level. The node stores, based on the value of the field, the service data in a first data processing queue selected from a plurality of data processing queues, wherein the first data processing queue corresponds to the first processing level, and each of the plurality of data processing queues corresponds to a different processing level. The node generates a new block that stores the service data read from the first data processing queue, and additional service data read from one or more of the plurality of data processing queues.

Abstract: A blockchain node receives a service request, where the service request comprises one or more data types and respective service data corresponding to the one or more data types that are stored in a blockchain. At least one of a service type or identification information is determined corresponding to the service request. The service request is parsed to obtain each data type of the service request and service data corresponding to each data type. Based on a mapping relationship between a data type and service data, the service data that is obtained through parsing in a relational database corresponding to the blockchain node is stored.

Abstract: Techniques for invocating a smart contract are described. One example method includes receiving a target transaction that is used to initiate an invocation of a smart contract, wherein the target transaction comprises invocation data, and wherein the invocation data comprises a data digest associated with target data stored in a third-party storage system interconnected with a blockchain; querying the target data from the third-party storage system; receiving a query result returned by the third-party storage system, wherein the query result comprises encrypted target data; obtaining a key to decrypt the encrypted target data to generate decrypted target data; performing a content verification on the decrypted target data; determining that the content verification succeeds; invoking the smart contract to perform a smart contract computation on the invocation data; and storing a computation result in a distributed database associated with the blockchain after the smart contract computation is completed.

Abstract: Techniques for invocating a smart contract are described. One example method includes receiving a target transaction that is used to initiate an invocation of a smart contract, wherein the target transaction comprises invocation data, and wherein the invocation data comprises a data digest associated with target data stored in a third-party storage system interconnected with a blockchain; querying the target data from the third-party storage system; receiving a query result returned by the third-party storage system, wherein the query result comprises the target data; performing a content verification on the target data; determining that the content verification on the target data succeeds; invoking the smart contract to perform a smart contract computation on the invocation data included in the target transaction; and storing a computation result from the smart contract computation in a distributed database associated with the blockchain after the smart contract computation is completed.

Abstract: A blockchain node obtains first service data. An attribute value of the first service data is determined, where the attribute value is used to represent uniqueness of the first service data. The blockchain node determines whether the first service data has been processed based on stored attribute values of second service data that has been processed and the attribute value of the first service data. In response to determining that the first service data has not been processed, the blockchain node processes the first service data.

Abstract: The present solution discloses example methods and systems for verifying block data. One example method includes identifying newly added data to be stored in a blockchain, and selecting a data node in a block to store the newly added data. A string is generated based on the newly added data, and then a verification value for the newly added data is developed from the string using a predetermined algorithm. A new verification value for the block is calculated based on the verification value of the newly added data and the original verification values of the unchanged data nodes in the block. The new verification value for the block can then be used to verify the data stored in the block is consistent with data stored in the rest of the blockchain.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for adding transaction data into a blockchain are provided. One of the methods includes: obtaining transaction data to be added into the blockchain, assigning the transaction data into transaction subsets, and executing the transaction subsets in parallel, and storing results of the execution into the blockchain. Pieces of the transaction data having at least one of: a same transaction type or an overlapping scope of data change are assigned into a same transaction subset, and pieces of the transaction data with different transaction types and with no overlapping scope of data change are assigned into different transaction subsets.

Abstract: A node in a blockchain network receives service data generated in a specified time period, where the service data comprises label information used to represent a processing priority of the service data. The node determines, when a new block is generated, a throughput that corresponds to the label information based on a predetermined mapping relationship between label information and a throughput. The node obtains service data that satisfies the throughput and that comprises the label information from a data processing set based on the throughput, where the service data is stored in the data processing set. The service data is stored in the new block.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for a data processing method are provided. One of the methods includes: distributing, to one or more computing devices, data of one or more leaf nodes in a blockchain node, for the one or more computing devices to compute checksums of the data of the leaf nodes; and determining, according to the checksums of the data of the leaf nodes, a root checksum of data in the blockchain node. Compared to conventional methods, these methods compute a checksum of data faster and more efficiently, and thus ensure proper generations of blocks and operations of a blockchain.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for transaction processing are provided. One of the methods includes: receiving a transaction request for a target transaction; loading a transaction template matching a transaction type of the target transaction; processing the target transaction according to the transaction template to obtain transaction information; and writing the transaction information into a blockchain.

Abstract: A subscription request initiated by a blockchain node associated with a first blockchain is received by a cross-blockchain interaction end, where the subscription request includes a subscription condition. A message that satisfies the subscription condition is obtained by the cross-blockchain interaction end and from a publishing client that corresponds to a second blockchain. The message is sent to a subscribing client that corresponds to the blockchain node a from the cross-blockchain interaction end, where the blockchain node calls a first smart contract associated with the first blockchain to trigger a corresponding contract operation based on the message.

Abstract: Implementations of the present specification provide for cross-blockchain authentication. A public key of a database engine comprising a trusted node of a second blockchain is determined by a subscribing client included in a system for cross-chain interaction. The public key is used as an authentication data source. The system comprises the subscribing client (corresponding to a first blockchain), a publishing client (corresponding to the second blockchain), and a cross-chain interaction end separately connected to the subscribing client and publishing client. Data that is to be authenticated in the second blockchain is determined using the cross-chain interaction end. The data is published by the publishing client. The data to be authenticated is signed by the database engine using a private key of the database engine. The data authentication performed on the data uses the authentication data source and a signature of the data to be authenticated.

Abstract: One or more implementations of the present specification provide cross-blockchain authentication. A subscribing client corresponding to a first blockchain and using a cross-chain client of a cross-blockchain interaction system, retrieves data from a second blockchain, where the data is published by a publishing client for use as an authentication data source, where the cross-blockchain interaction system comprises the subscribing client, the publishing client, and the cross-chain client, where the publishing client corresponds to the second blockchain, where the cross-chain client is separately interconnected with the subscribing client, and where the publishing client and the first blockchain are used as a sidechain that is anchored to the second blockchain, which is used as a main chain. Data to be authenticated is received from the second blockchain. The data to be authenticated is authenticated based on the authentication data source and a data authentication rule configured on the first blockchain.

Abstract: The present solution discloses example methods and systems for verifying block data. One example method includes identifying newly added data to be stored in a blockchain, and selecting a data node in a block to store the newly added data. A string is generated based on the newly added data, and then a verification value for the newly added data is developed from the string using a predetermined algorithm. A new verification value for the block is calculated based on the verification value of the newly added data and the original verification values of the unchanged data nodes in the block. The new verification value for the block can then be used to verify the data stored in the block is consistent with data stored in the rest of the blockchain.

Abstract: Implementations of the specification include receiving, by a smart contract service provider including a trusted computation execution environment (TEE) from a client associated with a target blockchain network, a request for operating cross-chain data of one or more blockchain networks different from the target blockchain, wherein the smart contract service provider is off the target blockchain network; sending, by the smart contract service provider to a data visiting service provider, a request for the cross-chain data; receiving, by the smart contract service provider, the cross-chain data from the data visiting service provider; generating, by the TEE, a result using the cross-chain data; and returning, by the smart contract service provider, the result to the client.

Abstract: This specification describes techniques for performing cross-blockchain interactions. One example method includes generating, by a blockchain node in a first blockchain, a subscription request to a cross-chain interaction end between the first blockchain and a second blockchain. The blockchain node can then obtain a message from the second blockchain based on the subscription request, and subsequently perform an operation related to the obtained message. In some instances, the message obtained by the blockchain node is a message that is published in the second blockchain and satisfies subscription conditions of the blockchain node.