2020/09/12 by Couvreur, Alain, Lequesne, Matthieu · 1 citation
#Cryptography and Security (cs.CR) #FOS: Computer and information sciences #Information Theory (cs.IT)
paper · doi:10.48550/arxiv.2009.05826
This article discusses the security of McEliece-like encryption schemes using subspace subcodes of Reed-Solomon codes, i.e. subcodes of Reed-Solomon codes over \mathbbFqm whose entries lie in a fixed collection of \mathbbFq-subspaces of \mathbbFqm. These codes appear to be a natural generalisation of Goppa and alternant codes and provide a broader flexibility in designing code based encryption schemes. For the security analysis, we introduce a new operation on codes called the twisted product which yields a polynomial time distinguisher on such subspace subcodes as soon as the chosen \mathbbFq-subspaces have dimension larger than m/2. From this distinguisher, we build an efficient attack which in particular breaks some parameters of a recent proposal due to Khathuria, Rosenthal and Weger.