Abstract:

Recently, the majority of key exchange protocols are based on ring-learning with errors. While the additional ring structure facilitates efficiency and storage, its actual security also needs to be further research. These protocols require a complex structure such as additional signatures to achieve authentication. In this paper, a post-quantum authenticated key exchange protocol based on LWE was proposed. The pre-computation is adopted to improve the efficiency of the protocol. It is verified that both parties of the protocol can correctly calculate the consistent session key. A series of security games are designed to prove the protocol proposed in this paper. The authentication is achieved by introducing the static public and secret keys in the extraction of shared bits and introducing a hash function in the calculation of the session key. The protocol can resist man-in-the-middle attacks and need no additional operations such as encryption or signature. There is currently no quantum algorithm that can distinguish between LWE distribution and uniform random distribution, so the proposed protocol can resist quantum computing attacks.

Key words: lattice-based cryptography, authenticated key exchange, learning with errors, post quantum cryptography