3 results sorted by ID
In this paper, we initiate the study of side-channel leakage in hash-and-sign lattice-based signatures, with particular emphasis on the two efficient implementations of the original GPV lattice-trapdoor paradigm for signatures, namely NIST second-round candidate Falcon and its simpler predecessor DLP. Both of these schemes implement the GPV signature scheme over NTRU lattices, achieving great speed-ups over the general lattice case. Our results are mainly threefold. First, we identify a...
In this paper we cryptanalyze two protocols: Grigoriev-Shpilrain authentication protocol and Wang et al. public key encryption protocols that use computational hardness of some variations of the conjugacy search problem in noncommutative monoids. We devise a practical heuristic algorithm solving those problems. As a conclusion we claim that these protocols are insecure for the proposed parameter values.
We propose new cryptosystems based on self-distributive systems that are defined by conjugator searching problems (CSP) in noncommutative groups. Under the newly developed cryptographic assumptions, our basic construction is proven IND-CPA secure in the standard model. Then, we describe two extensions: The first is proven IND-CCA secure in the random oracle model, while the second achieves the IND-CCA security in the standard model. Moreover, our proposal is instantiated with braid groups,...
