The invention discloses a multi-center block chain transaction
privacy protection system and method. The
system comprises an alliance control module, an amount
verification module, a range
verification module, an
encryption module, a decryption module and a block
chain system transaction module, wherein the alliance control module is used for generating alliance parameters by multiple participants; the amount
verification module is used for verifying that input and output of an encrypted
ciphertext amount in a transaction are equal; the range verification module is used for verifying that theencrypted
ciphertext amount in the transaction is in a specific interval and is constantly positive; the
encryption module and the decryption module are used for carrying out
homomorphic encryption and decryption on the amount in transmission and reception processes; and the block
chain system transaction module is used for complete bitcoin-like
digital currency transaction systems, and has a complete transaction process which comprises transmission, reception,
broadcasting and block confirmation. The
system is capable of enhancing general structures through block chain transaction privacies under a multi-center supervision mode, so as to realize
privacy protection for trapdoor parameters under joint control of multiple parties and transaction
metadata in transaction process, and effectively strengthen the safety of
plaintext amounts in multi-center block
chain system transaction process.