Assessment of Two Privacy Preserving Authentication Methods Using Secure Multiparty Computation Based on Secret Sharing

Secure authentication is an essential mechanism required by the vast majority of computer systems and various applications in order to establish user identity. Credentials such as passwords and biometric data should be protected against theft, as user impersonation can have serious consequences. Some practices widely used in order to make authentication more secure include storing password hashes in databases and processing biometric data under encryption. In this paper, we propose a system for both password-based and iris-based authentication that uses secure multiparty computation (SMPC) protocols and Shamir secret sharing. The system allows secure information storage in distributed databases and sensitive data is never revealed in plaintext during the authentication process. The communication between different components of the system is secured using both symmetric and asymmetric cryptographic primitives. The efficiency of the used protocols is evaluated along with two SMPC specific metrics: The number of communication rounds and the communication cost. According to our results, SMPC based on secret sharing can be successfully integrated in real-word authentication systems and the communication cost has an important impact on the performance of the SMPC protocols.