Horizontal and Vertical Side Channel Analysis of a McEliece Cryptosystem

This paper presents horizontal and vertical side channel analysis techniques for an implementation of the McEliece cryptosystem. The target of this side-channel attack is a state-of-the-art field-programmable gate array (FPGA) implementation of the efficient quasi-cyclic moderate-density parity-check McEliece decryption operation, as presented at Design, Automation and Test in Europe (DATE) 2014. The presented cryptanalysis succeeds to recover the complete secret key after a few observed decryptions. It consists of a combination of a differential leakage analysis during the syndrome computation followed by an algebraic step that exploits the relation between the public key and the private key.