Shift register protected against physical attacks

Abstract

The present invention relates to a shift register protected against physical attacks, comprising a coding module, a decoding module, a plurality of basic shift registers of which the respective inputs receive the bits of a codeword supplied by the coding module using an input bit at each clock cycle, and of which the respective outputs are connected to the decoding module in order to supply an output bit, with the codewords being chosen in such a way as to have the same non-zero Hamming weight and two successive codewords having a constant non-zero Hamming distance. The codewords are generated using an internal state machine and/or an external state machine to the coding module.