Threshold cryptography has recently been a very active field of research, notably following the NIST call for threshold primitives. Notable works in post-quantum cryptography built threshold signatures by relying on noise flooding [dPKM+23,EKT24,BKLM+24], and designed short and efficient schemes. They however left opened the questions of distributing the key generation, and of making the signing process robust - i.e. guaranteeing that a valid signature is output even in the present of malicious parties. In this talk, I will present our novel techniques for building Distributed Key Generation and Robust Threshold Signatures. To do so, we introduced a novel framework for constructing verifiable short secret sharing based on random submersions — that is projection over a random subspace blinded by a small Gaussian noise. Our techniques apply to all the aforementionned work, and we also showcased their applications to Plover [EENP+24] to build the first hash-and-sign threshold signature, additionally having a DKG and robust signing procedure.
I am a PhD student at PQShield and Univ Rennes 1 under the supervision of Thomas Prest and Pierre-Alain Fouque. I am especially interested in applied cryptography and the construction of efficient primitives and protocols. My works so far included lattice-based constructions for masking-friendly signatures, threshold signatures, and also secure messaging.