Bitcoin Book of BIPs

Schnorr, Taproot, Tapscript

Taproot is one upgrade in three documents. BIP 340 defines Schnorr signatures on secp256k1. BIP 341 defines the SegWit version 1 spending rules: a public key in the output, an optional script tree, and a way to spend with either a key path or a script path. BIP 342 is Tapscript, the validation rules inside those leaves.

Together they are the 2021 consensus change that wallets mean when they say “Taproot address.” Key-path spends look like a single signature. Script-path spends reveal only the leaf they use. Multisig and more complicated policies can hide behind the same output type.

I kept this chapter short on purpose. The three BIPs are meant to be read as a set. If you skipped the SegWit documents in the previous chapter, go back — Taproot is version 1 witness, and BIP 341 assumes you already know version 0.

In this chapter:

  BIP: 340
  Title: Schnorr Signatures for secp256k1
  Authors: Pieter Wuille <pieter.wuille@gmail.com>
           Jonas Nick <jonasd.nick@gmail.com>
           Tim Ruffing <crypto@timruffing.de>
  Comments-Summary: No comments yet.
  Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0340
  Status: Deployed
  Type: Specification
  Assigned: 2020-01-19
  License: BSD-2-Clause
  License-Code: BSD-2-Clause OR MIT OR CC0-1.0
  Discussion: 2018-07-06: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-July/016203.html [bitcoin-dev] Schnorr signatures BIP