Authentication and encryption protocols : design, attacks and algorithmic improvements
Diana Maimuţ · HAL (Le Centre pour la Communication Scientifique Directe) · 2015
This thesis addresses various topics in cryptology, namely protocol design, algorithmic improvements and attacks. In addition, we venture out of cryptography and propose two new applications of cryptographic techniques to error correcting codes. Our main results comprise a provably secure co-signature protocol and a provably secure authenticated encryption scheme. Our co-signature protocol achieves legal fairness, a novel fairness variant that does not rely on third parties. Legal fairness is implemented using Schnorr signatures. We also present a distributed Fiat-Shamir authentication protocol. The second part of the thesis is devoted to computational improvements, we discuss a method for doubling the speed of Barrett’s algorithm by using specific composite moduli, devise new BCH speed-up strategies using polynomial extensions of Barrett’s algorithm, describe a new backtracking-based multiplication algorithm suited for lightweight microprocessors and present a new number theoretic error-correcting code. Fault injection attacks are further overviewed and a new fault attack on ECC implementations is proposed.