A timing attack against Patterson algorithm in the McEliece PKC

Abstract

The security of McEliece public-key cryptosystem is based on the difficulty of the decoding problem which is NP-hard. In this paper we propose a timing attack on the Patterson Algorithm, which is used for efficient decoding in Goppa codes. The attack is based on the relation between the error vector weight and the iteration number of the extended Euclidean algorithm used in Patterson Algorithm. This attack enables the extraction of the secret error vector with minimal overhead. A countermeasure is proposed and verified for a FPGA implementation. © 2010 Springer-Verlag.