Related Concepts
Definition
In the CFS scheme [1], the digital signature is obtained by applying the decoding procedure of some public error correcting code on a digest of the message to be signed, obtained by a cryptographic hash function. Only the legal user, who knows the hidden algebraic structure of the code, can produce the signature, while anyone can check that the signature is a valid answer to the decoding problem.
Theory
The construction for the McEliece-based signature scheme was proposed by Courtois, Finiasz, and Sendrier in 2001 [1]. Despite its name, this construction is based on Niederreiter’s encryption scheme rather than the original McEliece cryptosystem. It was the first practical code-based digital signature scheme with a security reduction to the Syndrome Decoding Problem.
General Idea
The public key is a binary r ×n matrix H, which is an arbitrary parity check matrix of some t-erro...