Section: New Results
Cryptanalysis of McEliece cryptosystems based on Generalised Reed–Solomon codes
The McEliece encryption scheme based on binary Goppa codes was one of the first public-key encryption schemes  . Niederreiter  dramatically reduced the (huge) key size—a major problem with McEliece's original proposal—using Generalised Reed–Solomon (GRS) codes, but his modified scheme was broken by Sidelnikov and Shestakov  in 1992. There have been several attempts at repairing these smaller-key McEliece schemes. In collaboration with P. Gaborit, V. Gautier, A. Otmani and J.-P. Tillich, Alain Couvreur found polynomial time attacks on these schemes using the distinguishability of GRS codes from random codes.