In this paper we show how to strengthen public-key cryptosystems against known attacks, together with the reduction of the public-key. We use properties of subcodes to mask the structure of the codes used by the conceiver of the system. We propose new parameters for the cryptosystems and even a modified Niederreiter cryptosystem in the case of Gabidulin codes, with a public-key size of less than 4000 bits.
Keywords Niederreiter cryptosystem - GPT cryptosystem - Reed-solomon codes - Gabidulin codes - Subcodes
Communicated by: P. Wild
AMS Classification: 11T71