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.