Explore a bandwidth-efficient threshold EC-DSA protocol presented at PKC 2020. Delve into the motivation behind distributed ECDSA and the challenges in the signing algorithm. Examine previous works, including the full threshold ECDSA-GG from CCS'18, and learn about removing range proofs. Understand the CL framework and its instantiation in class groups of imaginary quadratic fields. Study the interactive setup, key generation, and multi-phase signing process. Compare this protocol with the Gennaro Goldfeder protocol, focusing on improvements in Phase 1 and the ZKAOK. Analyze computational assumptions for soundness and evaluate the efficiency of the full threshold protocol.
Overview
Syllabus
Intro
Motivation for distributed ECDSA
(t, n)-threshold signature scheme
ECDSA protocol
Difficulty in the signing Algorithm
Table of contents
Previous works comparable to ours
Full threshold ECDSA-GG @ CCS'18
Removing range proofs
CL framework
Instantiation in class groups of an imaginary quadratic field
Interactive set up and key generation
Interactive signing - Phase 1
Interactive signing - Phase 2 (peer to peer)
At the end of Phase 2
Phases 3, 4 and 5
Main differences with the Gennaro Goldfeder protocol
Improving Phase 1
Proof that a ciphertext is well formed
Improving ZKAOK
Computational assumptions for soundness
Efficiency of full threshold protocol
Taught by
TheIACR
