A Novel Polar Code-Based Key Encapsulation Mechanism with Non-permutation Equivalent Public Key

A Novel Polar Code-Based Key Encapsulation Mechanism with Non-permutation Equivalent Public Key

연구 분야: Cryptography

학회: International Conference on Security and Privacy in New Computing Environments

Code-based cryptography is one of the post-quantum cryptography techniques which is able to resist attacks from quantum computers. This paper proposes a novel key encapsulation mechanism (KEM) based on polar codes. As the basic technology of 5G communication, polar codes have efficient encoding and decoding procedures, thus can improve the efficiency of a code-based cryptosystem. We apply polar codes to a variant of the McEliece public-key encryption scheme in which the codes of the public key and secret key are non-permutation equivalent. Then we construct the KEM protocol by Fujisaki-Okamoto transformation method. This KEM is indistinguishably secure from a chosen ciphertext attack. The public key size of the proposed KEM is smaller than that of the Classic McEliece KEM in NIST PQC standardization process, under the same security level.