The best known non-structural attacks against code-based cryptosystems are based
on information-set decoding. Stern's algorithm and its improvements are well optimized and the complexity is reasonably well understood. However, these algorithms only handle codes over F_2.
This paper presents a generalization of Stern's information-set-decoding algorithm for decoding linear codes over arbitrary finite fields F_q and analyzes the complexity. This result makes it possible to compute the security of recently proposed code-based systems over non-binary fields.
As an illustration, ranges of parameters for generalized McEliece cryptosystems using classical Goppa codes over F_31 are suggested for which the new information-set-decoding algorithm needs 2^128 bit operations.
|Title of host publication||Post-Quantum Cryptography (3rd International Workshop, PQCrypto 2010, Darmstadt, Germany, May 25-28, 2010)|
|Place of Publication||Berlin|
|Publication status||Published - 2010|
|Name||Lecture Notes in Computer Science|