| Abstract: | Quantum attack–resistant cryptosystems are required for secure communication since there is a big demand to have quantum computers. Lattice‐based cryptography is one of the quantum‐secure families due to its key/ciphertext sizes and performance. NTRU‐based cryptosystems, a member of lattice‐based cryptosystems, have received much more attention. MaTRU, a noncommutative version of NTRU with some matrix properties, is used to obtain a key exchange protocol in 2018. In this paper, we focus on MaTRU‐based key exchange protocols having CCA2 properties. We propose CCA2‐secure versions of MaTRU‐KE and then provide a security analysis of CCA2‐secure key establishment protocols. We also provide a comparison with the previous ones. |
