An Improved Code-Based Encryption Scheme with a New Construction of Public Key

There are substantial variants of McEliece cryptosystem from coding theory. In general, these attempts always utilize two basic ways to enhance performance of the original cryptosystem: reducing the public key size and improving the efficiency and ability of decoding algorithms. Meanwhile, security level is the goal that has always been pursued. Sometimes we need to sacrifice some advantage to get other claims. Recently, Baldi et al. proposed a novel scheme (BBCRS scheme for short) in which the public code is no longer permutation equivalent to the secret code and this distinctly increases the security level. In this paper, we propose a new construction of public key following the idea of BBCRS scheme. The improvement enhances the correction capability and results in a better protection of the secret code. We also discuss some known attacks in detail as in BBCRS scheme which shows that our new scheme is secure under the current means of attack.