Security and Complexity of the McEliece Cryptosystem Based on QC-LDPC Codes
In the context of public key cryptography, the McEliece cryptosystem represents a very smart solution based on the hardness of the decoding problem, which is believed to be able to resist the advent of quantum computers. Despite this, the original McEliece cryptosystem, based on Goppa codes, has encountered limited interest in practical applications, partly because of some constraints imposed by this very special class of codes. The authors have recently introduced a variant of the McEliece cryptosystem including low-density parity-check codes, that are state of-art codes, now used in many telecommunication standards and applications. In this paper, they discuss the possible use of a bit-flipping decoder in this context, which gives a significant advantage in terms of complexity.