Towards Scalable Threshold Cryptosystems

Explore a conference talk that delves into innovative techniques for scaling threshold cryptosystems to accommodate hundreds of thousands of participants. Learn about efficient algorithms for evaluating polynomials at multiple points to accelerate the computation of Lagrange coefficients in threshold signature aggregation. Discover how authenticating multipoint evaluations can enhance the speed of proving polynomial evaluations, a crucial step in communication-efficient Verifiable Secret Sharing (VSS) and Distributed Key Generation (DKG) protocols. Understand the significant improvements in computational complexity for VSS and DKG protocols, reducing them from quadratic to quasilinear time. Examine the practical applications of these techniques, including the ability to aggregate a 130,000 out of 260,000 BLS threshold signature in just 6 seconds and generate a key for the BLS scheme in 2.3 hours. Gain insights into the limitations of this approach, such as the requirement for a trusted setup and the focus on synchronous protocols, while considering its potential impact on large-scale distributed systems.