Patent attributes
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: receiving timestamps and associated signatures from an independent trust time server associated with a trust time authority by a centralized ledger server in a centralized ledger system, storing the timestamps and the associated signatures in a centralized trust timestamp blockchain that stores trust timestamp information of the trust time server for the centralized ledger system that stores data in blockchains each including a plurality of blocks, receiving a timestamp request for a block of a blockchain from a ledger server associated with the blockchain by the centralized ledger server, and transmitting a timestamp and associated signature that is stored in the timestamp blockchain and corresponds to the timestamp request to the ledger server by the centralized ledger server.