A variant of the McEliece cryptosystem with increased public key security

Abstract

We propose a new variant of the McEliece cryptosystem which ensures that the code used as the public key is not permutation-equivalent to the secret code. This allows to increase the security of the public key, and to reconsider possible adoption of classical families of codes, like Reed-Solomon codes. A reduction in the key size or, equivalently, an increased level of security against information set decoding are the main advantages of the modified cryptosystem. As a drawback, the domain of intentional error vectors must be restricted, but we show that this has no significant impact on the security level.