INAKA: Improved Authenticated Key Agreement Protocol Based on Newhope

The Newhope scheme is one of the milestones of the study in key agreement protocol but it lacks the anti-active-attack capability. In this article, we propose a mutual authenticated key agreement scheme named INAKA scheme based on the commitment value and lattice hard problem. This scheme improves the key encapsulation mechanism in the Newhope scheme to generating the commitment values for both communication parties and thus achieves mutual authentication, key agreement and identity privacy protection at the same time. Firstly, the INAKA protocol is combinable, i.e. the common traditional and lattice-based cryptographic algorithms (encryption, decryption, hash operation) can both act as the protocol components. What's more, the INAKA protocol has been analyzed that it can resist the man-in-the-middle attack, replay attack, and other attacks. This scheme satisfies provable security under eCK and indistinguishable game models. Its anti-attack capability and security are significantly enhanced compared with the Newhope scheme. Besides, the INAKA protocol involves the identity authentication feature but keeps at the same level of computational complexity. None of the existing schemes (such as Ding's and BCNS) are able to satisfy the above feature. Lastly, the test results in this article show the INAKA protocol only needs 8.131 milliseconds to complete mutual authentication and key agreement. The outcome of our work could provide lower operation overhead, handy code implementation, and better efficiency to meet the industrial practical requirements.