Recent advances in post-quantum signatures based on the MPC-in-the-Head paradigm

Zero-knowledge proofs of knowledge are useful tools for designing signature schemes. Among the existing techniques, the MPC-in-Head (MPCitH) paradigm provides a generic framework to build quantum-resilient proofs using techniques from secure multiparty computation. This paradigm has recently been improved in a series of works which makes it an effective and versatile tool. In this talk, I will present the recent advances in post-quantum signatures relying on the MPC-in-the-Head. After a general introduction to MPCitH, I will provide an overview of the state of the art that led to the MPCitH-based candidates that have been submitted to the additional NIST call for post-quantum signatures. Then, I will present the Threshold-Computation-in-the-Head (TCitH) framework, based on joint works with Matthieu Rivain. This framework extends common MPC-in-the-Head techniques by using Shamir’s secret sharing (instead of additive sharing) to achieve significant improvements in terms of sizes and timings.