Description: While working on Bulletproofs++ I realized there were gaps in my understanding of zero-knowledge proofs. I did a quick search through the literature …
Nov 29 th , 2020
Abstract : Multi-signatures enable a group of signers to produce a single signature on a given message. Recently, Drijvers et al. (S&P’19) showed that all thus far proposed two-round multi-signature schemes in the DL setting (without pairings) are insecure under concurrent sessions, i.e., if a single signer participates in multiple signing sessions concurrently. While Drijvers et al. improve the situation by constructing a secure two-round scheme, saving a round comes with the price of having less compact s
In this work, we propose MuSig2, a novel and simple two-round multi-signature scheme variant of the MuSig scheme. Our scheme is the first multi-signature scheme that simultaneously i) is secure under concurrent signing sessions, ii) supports key aggregation, iii) outputs ordinary Schnorr signatures, iv) needs only two communication rounds, and v) has similar signer complexity as regular Schnorr signatures. Furthermore, our scheme is the first multi-signature scheme in the DL setting that supports preprocess