👉 Bitcoin Optech #264 - Field Report: Implementing MuSig2

The first MuSig paper was published in 2018, and the potential of MuSig on Bitcoin was one of the selling points used to gain support for the taproot soft fork. Work on MuSig continued with the publication of MuSig-DN and MuSig2 in 2020. When taproot neared activation on Bitcoin’s mainnet in 2021, excitement about bringing MuSig signing to Bitcoin users was palpable. At BitGo, we were hoping to launch a MuSig taproot wallet concurrent with taproot activation; but the spec, test vectors, and reference implementation were incomplete. Instead, BitGo launched the first tapscript multisig wallet and made the first tapscript multisig transaction on mainnet. Nearly two years later, MuSig2 is specified in BIP327, and we launched the first MuSig taproot multisig wallet.

  • Why MuSig2?
  • Choice of Scripts
  • Nonces (deterministic and random)
  • The Specification Process
  • MuSig and PSBTs
  • Acknowledgements