A Key Recovery System Based on Password-Protected Secret Sharing in a Permissioned Blockchain

摘要

In today’s fourth industrial revolution,various blockchain technologies are being actively researched.A blockchain is a peer-to-peer data-sharing structure lacking central control.If a user wishes to access stored data,she/he must employ a private key to prove ownership of the data and create a transaction.If the private key is lost,blockchain data cannot be accessed.To solve such a problem,public blockchain users can recover the key using a wallet program.However,key recovery in a permissioned blockchain(PBC)has been but little studied.The PBC server is Honest-but-Curious(HBC),and should not be able to learn anything of the user;the server should simply recover and store the key.The server must also be resistant to malicious attacks.Therefore,key recovery in a PBC must satisfy various security requirements.Here,we present a password-protected secret sharing(PPSS)key recovery system,protected by a secure password from a malicious key storage server of a PBC.We describe existing key recovery schemes and our PPSS scheme.