Block 709,632 · 14 November 2021
Taproot activates
Taproot was the first change to the rules of Bitcoin since SegWit, four years earlier. It gathers three proposals: Schnorr signatures (BIP 340), Taproot itself (BIP 341) and a revised scripting language, Tapscript (BIP 342).
Schnorr signatures can be combined, so that several parties sign together and the chain sees a single signature. Taproot lets a coin be locked by a set of conditions of which only the one used is ever revealed; when the parties simply agree, spending it looks like any ordinary payment. Complex arrangements become cheaper and more private, without anyone having to publish them.
Activation went quietly this time. Miners signalled support during a short trial period, and the rule was locked in in June 2021, with more than 90 % of the blocks of a period in favour. It was set to take effect at a height chosen months in advance: 709,632, reached on 14 November 2021.
Most of the ideas behind it had been discussed for years, some since the early days of the project. With this block they became part of the rules every node checks.