Implementations of the present specification provide a computer-implemented method, computer-implemented system, and non-transitory, computer-readable medium. The computer-implemented method includes sending a token acquisition request by a blockchain client to a blockchain node. A commit token fed back from the blockchain node is received by the blockchain client, where the commit token indicates that the blockchain client has permission to submit transaction data to a specific data block in a blockchain. Transaction data is sent by the blockchain client to the blockchain node.