The Bitcoin Improvement Proposals 340 through 342 were merged into the Bitcoin codebase on Thursday, signaling that the anticipated Taproot upgrade is ready.
Taproot and the associated technology of Schnorr signatures are considered to be the most important upgrade for Bitcoin in the past year. It is primarily a privacy improvement for complex spending conditions on Bitcoin like multisig transactions, time locks and other conditions based on Bitcoin Script.
As Cointelegraph reported previously, Taproot hides every additional spending condition beyond the one that was activated. For example, a transaction might be executed immediately if all four multisig signers agree, or it could require a certain amount of time to pass before funds are unlocke if only three out of four signers are present. Normally, an outsider is able to identify every possible condition, but with Taproot they will see only the one that was eventually triggered.
Furthermore, thanks to Schnorr signatures, a pure multisig transaction can be made indistinguishable from normal transfers. It is worth addressing that Taproot makes no changes to mixing protocols like CoinJoin, which will remain easily distinguishable.
While the initial code for Taproot was submitted for review in January, some complications primarily related to Schnorr signatures required an extensive amount of refinement.
The proposals have now been fully reviewed by Bitcoin core developers and are ready to be included in a client release. Pieter Wuille, the lead developer for Taproot, told Cointelegraph that “it’s all done, except activation.”
Cointelegraph previously reported that consensus for activation may require some time to be reached. The process could potentially last for years, though Taproot is generally considered much less controversial than previous upgrades like SegWit.
The process starts as soon as the activation code is included in Bitcoin Core, allowing miners to signal approval for its inclusion. But Taproot seems to have come slightly at the wrong time for immediate activation.
Jonas Nick, researcher at Blockstream and Bitcoin core developer, told Cointelegraph that “Taproot is not ready for activation yet.”
He explained that activation logic is generally not included in a major release, referring to the upcoming 0.21 version. The codebase reached “feature freeze” on Thursday, with the base Taproot code making it just in time. Nevertheless, only bug fixes will be added from now on. Explaining why developers are cautious, Nick said:
“Major releases can contain changes to dependencies and interfaces (e.g. RPC). Users should be able to run softfork activation logic without the additional work required to be compatible with a new major version.”
The logic to activate Taproot on mainnet is likely to be included in a future minor version, but in the meantime, Nick said that “Taproot could be activated on something like signet or testnet if someone produced the code for that,” as the raw implementation is already present.