New code-based paradigm

A new approach to code-based cryptosystems is pro-posed that extends the classical McEliece cryptosystem because its public code is not equivalent to a secret code, as well as a non-trivial linear transformation of the error vector is used. Moreover, in the new system, legal users decipher secret messages via correction <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$t'$</tex> errors and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$S$</tex> erasures, while illegal users must correct <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$t'+s$</tex> errors what is more complicated. A fairly wide range of well-known universal attacks, in partic-ular, information set decoding,are considered. The corresponding analysis shows some security advantage of the proposed scheme.