Abstract: A computer-implemented method, medium, and system are disclosed. In one computer-implemented method, an invocation request sent by an initiator is received by a blockchain node in a blockchain network. The invocation request is associated with invocation of a smart contract in the blockchain network. The smart contract includes contract code, data, and pre-update metadata. A pre-update data structure described by the pre-update metadata is parsed by the blockchain node and by execution of the contract code. The pre-update data structure is associated with the data comprised in the smart contract. Following parsing of the pre-update data structure, the pre-update data structure is represented by the blockchain node using a computer programming language. The pre-update data structure specified by the computer programming language is sent by the blockchain node to the initiator.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for blockchain-based hierarchical data storage. One of the methods includes: determining, based on a blockchain stored in a database that includes multiple levels of storage, a block number interval that includes one or more block numbers associated with data nodes to be migrated to a lower level of storage in response to the data nodes meeting a data migration condition, wherein each of the data nodes is included in a state Merkle tree and is associated with a block number of a block of the blockchain where the corresponding data node was last updated, and the lower level of storage corresponds to a storage media with lower storage cost.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for blockchain-based hierarchical data storage. One of the methods includes determining, based on a blockchain stored in a database that includes multiple levels of storage, a level of storage of the multiple levels of storage that meets a data migration condition as a target level of storage, wherein state data of the blockchain are stored as state Merkle trees in data worksheets of the multiple levels of storage, generating, for the target level of storage, an empty data worksheet in response to determining that the target level of storage meets the data migration condition, and storing at least a portion of a state Merkle tree corresponding to a newly created block of the blockchain to the empty data worksheet.

Abstract: Implementations of this specification provide signature verification methods and apparatuses for a blockchain ledger. An example method includes receiving by a server, a signature verification instruction that comprises a verification object parameter and a hash value. The verification object parameter includes a third-party parameter, a platform parameter, or a time service certificate parameter, the verification object parameter indicates a type of a to-be-verified object, and the server is configured to store data by using the blockchain ledger. The server obtains the to-be-verified object based on the verification object parameter and the hash value. The type of the to-be-verified object includes a third-party digital signature, a server digital signature, or a time service certificate. The server sends the to-be-verified object to a client for verification by the client.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing blockchain-based centralized ledger systems. One of the methods includes: transmitting a timestamp request for a to-be-timestamped block in a blockchain to a trust time server by a ledger server in a centralized ledger system that stores data in the blockchain, the trust time server being associated with a trust time authority and independent from the centralized ledger system, the blockchain including a plurality of blocks storing transaction data, receiving a timestamp and associated signature for the to-be-timestamped block from the trust time server by the ledger server, and storing information of the timestamp and the associated signature for the to-be-timestamped block in the blockchain by the ledger server.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for performing a map iteration by a network node of a blockchain network. One of the methods includes receiving a request to obtain a number of keys included in a map by the network node, the map storing a number of key-value pairs that include the number of keys and a number of values corresponding to the number of keys. The network node maintains data representing a forest that stores the number of keys that are stored in the map. The forest includes a number of trees, each tree includes up to a respective number of storage nodes, and each storage node stores a subset of the number of keys. The network node traverses the forest to retrieve the number of keys stored in the forest, and return the number of keys.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: A computer-implemented method includes: obtaining, by a blockchain node, an invoking request for a first smart contract based on receiving a data structure update transaction, where the transaction comprises an input parameter indicating an updated data structure. The updated data structure that is based on a computer programming language is obtained. The first smart contract is run, comprising: parsing the updated data structure and converting the updated data structure characterized by the computer programming language into updated metadata characterized by a definition description language. A second smart contract comprising pre-update metadata and data is invoked using the updated metadata as input parameters. The second smart contract is run, comprising: replacing the pre-update metadata with the updated metadata, parsing the updated metadata in the second smart contract, and updating a pre-update data structure of the data in the second smart contract based on a parsing result.

Abstract: One or more embodiments of the present specification provide data retrieving and recording methods and apparatuses, and electronic devices. One method comprises: identifying, by a blockchain node in a blockchain network, a data retrieving and recording request for a smart contract, wherein the data retrieving and recording request is configured to trigger a data retrieving and recording operation on a target object in a data set comprised in the smart contract; and parsing, by the blockchain node and to generate a parsing result, metadata comprised in the smart contract, wherein the parsing performs instructions comprised in the smart contract, and wherein the parsing result indicates a storage field corresponding to the target object in the data set for implementing the data retrieving and recording operation on the storage field.

Abstract: Implementations of this specification provide signature verification methods and apparatuses for a blockchain ledger. An example method includes receiving by a server, a signature verification instruction that comprises a verification object parameter and a hash value. The verification object parameter includes a third-party parameter, a platform parameter, or a time service certificate parameter, the verification object parameter indicates a type of a to-be-verified object, and the server is configured to store data by using the blockchain ledger. The server obtains the to-be-verified object based on the verification object parameter and the hash value. The type of the to-be-verified object includes a third-party digital signature, a server digital signature, or a time service certificate. The server sends the to-be-verified object to a client for verification by the client.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for managing transaction requests in ledger systems.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for blockchain-based hierarchical data storage. One of the methods includes: determining, based on a blockchain stored in a database that includes multiple levels of storage, a block number interval that includes one or more block numbers associated with data nodes to be migrated to a lower level of storage in response to the data nodes meeting a data migration condition, wherein each of the data nodes is included in a state Merkle tree and is associated with a block number of a block of the blockchain where the corresponding data node was last updated, and the lower level of storage corresponds to a storage media with lower storage cost.

Abstract: A method of storing blockchain state data, including: after execution of a transaction in a target block is completed, based on a latest account state of a target account related to the transaction in the target block after update, generating updated data nodes corresponding to the current Merkle state tree of the target block and, based on generated historical data nodes and data nodes other than the reused data nodes corresponding to the target account on the historical Merkle state tree of the previous block of the target block, creating the historical Merkle state tree for the target block.

Abstract: Computer-implemented methods, systems, and apparatus are described for storing keys of multiple key-value pairs by a network node of a blockchain network. One method includes maintaining data representing a forest that stores multiple keys of the multiple key-value pairs that are stored in a map. The forest includes multiple trees, each tree includes respective storage nodes, and each storage node stores a subset of the multiple keys. The network node receives a request to add a key of a key-value pair into the forest. A first hash value of the key is computed using a first hash function. One of the multiple trees to store the key is determined based on the first hash value. The network node determines a target storage node of the one of the multiple trees to store the key, and stores the key in the target storage node.

Abstract: A computer-implemented method for performing authentication includes: determining, by a database server storing data in a blockchain ledger, a target ledger segment on which time service authentication is to be performed; generating a Merkle tree corresponding to the target ledger segment; determining a root hash of the Merkle tree, the root hash of the Merkle tree being based on a block hash of each data block in a set of one or more data blocks; executing a predetermined time capture process in a trusted execution environment to obtain a trusted time from an interface provided by a trusted time service organization; generating a digital signature for the trusted time and the root hash in the trusted execution environment; and generating a time service certificate including the trusted time, the root hash, and the digital signature.

Abstract: Disclosed herein are methods, systems, and apparatus, including computer programs encoded on computer storage media, for blockchain-based hierarchical data storage. One of the methods includes determining, based on a blockchain stored in a database that includes multiple levels of storage, a level of storage of the multiple levels of storage that meets a data migration condition as a target level of storage, wherein state data of the blockchain are stored as state Merkle trees in data worksheets of the multiple levels of storage, generating, for the target level of storage, an empty data worksheet in response to determining that the target level of storage meets the data migration condition, and storing at least a portion of a state Merkle tree corresponding to a newly created block of the blockchain to the empty data worksheet.