Abstract: A computer-implemented method for detecting replay attack comprises: obtaining at least one candidate transaction for adding to a blockchain; verifying if an identification of the candidate transaction exists in an identification database, the identification database comprising a plurality of identifications within a validation range; and in response to determining that the identification does not exist in the identification database, determining that the candidate transaction is not associated with a replay attack.

Abstract: A computer-implemented method for detecting replay attack comprises: obtaining at least one candidate transaction for adding to a blockchain, the obtained candidate transaction comprising a timestamp; verifying if the timestamp is within a validation range and if an identification of the candidate transaction exists in an identification database; and in response to determining that the timestamp is within the validation range and the identification does not exist in the identification database, determining that the candidate transaction is not associated with a replay attack.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for adding a node in a blockchain network are provided. One of the methods includes: obtaining, by a current consensus node of the blockchain network, a first transaction comprising a first request for adding the node as a new consensus node of the blockchain network; in response to that consensus verification of the first transaction succeeds, executing the first transaction and numbering the node in a node list based on numbers of a plurality of current consensus nodes of the blockchain network; and performing view change for the node to participate in future consensus verification as the new consensus node of the blockchain network.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for deleting a node in a blockchain network are provided. One of the methods includes: obtaining, by a first consensus node of the blockchain network, a transaction comprising a request for deleting a second consensus node of the blockchain network; in response to that consensus verification of the transaction succeeds, executing the transaction and sequentially numbering in a node list a plurality of remaining consensus nodes of the blockchain network excluding the second consensus node; and performing view change for the remaining consensus nodes to participate in future consensus verification.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for parallel-processing blockchain transactions are provided. One of the methods includes: obtaining a plurality of candidate transactions for adding to a blockchain; grouping the candidate transactions into one or more transaction groups; creating one or more copies of at least a portion of a data structure of a latest block of the blockchain; associating the one or more transaction groups respectively with the one or more copies of the data structure; executing the candidate transactions in each of the transaction groups and updating the associated copies of the data structure; and merging the updated copies of the data structure to obtain at least a portion of a new data structure of a new block to add to the blockchain.

Abstract: Implementations of this specification include identify a plurality of transactions to be executed in the blockchain, wherein the transactions are arranged in an execution order, and wherein the execution order includes a contract call arranged after the plurality of transactions; identify groups of transactions within the plurality of transactions, wherein each transaction in each group is associated with a same account in the blockchain network as the other transactions in the group; instruct nodes of the blockchain network to execute each of the groups of transactions in parallel, wherein executing each group of transactions includes executing the transactions within the group serially and according to the execution order; determine that the nodes of the blockchain network have completed executing all of the groups of transactions; and in response, instruct the nodes of the blockchain network to execute the contract call.

Abstract: Implementations of this specification include identifying a plurality of transactions to be executed in the blockchain, wherein the transactions are arranged in an execution order, wherein the transactions include one or more smart contract calls to smart contracts each having a whitelist identifying one or more accounts that are authorized to execute the smart contract, and wherein the execution order includes a smart contract call to a smart contract that does not have a whitelist arranged after the plurality of transactions; identifying groups of transactions within the plurality of transactions; instructing nodes of the blockchain network to execute each of the groups of transactions in parallel; determining that the nodes of the blockchain network have completed executing all of the groups of transactions; and in response, instructing the nodes of the blockchain network to execute the smart contract call that does not include a whitelist.

Abstract: Implementations of this specification include identifying, by a node of the blockchain network, a request to execute a smart contract stored in a blockchain maintained by the blockchain network, the request identifying a requesting account that is requesting to execute the smart contract; retrieving, by the node, a whitelist from the blockchain associated with the smart contract, the whitelist identifying one or more accounts that are authorized to execute the smart contract; determining, by the node, that the requesting account is authorized to execute the smart contract based on the requesting account being included in the whitelist; and in response to determining that the requesting account is authorized to execute the smart contract, executing, by the node, the smart contract.