The invention relates to a
blockchain-based identity
authentication method and a
blockchain-based identity
authentication system. The identity
authentication method based on the block chain comprisesthe following steps that an intelligent contract of the block chain receives an identity authentication request sent by a
server side, the identity authentication request comprises a user public key and E(f (x)), and the E(g (x)), the E(f (x)) and the E(g (x)) are obtained through calculation by a
client side according to a preset
homomorphic encryption algorithm E; the intelligent contract inquires an authentication
certificate Ea of the user on the block chain according to the public key of the user, carries out calculation and
verification according to E (f (x)) , E (g (x)) and the homomorphic attribute of a
homomorphic encryption algorithm E, and passes identity authentication if the homomorphic attribute is met; and the
smart contract returns the identity authentication result to theserver. The method has the beneficial effects that based on the characteristics of the block chain, the threats of replay attacks and violent
cracking can be resisted, so that the
attack cost is increased. By utilizing a
homomorphic encryption attribute equation, the nizk can be constructed, and under the condition that an original credential for user identity authentication is not leaked, the user is proved to have the credential, so that the identity of the user is proved.