Co-authored-by: David A. Harding <dave@dtrt.org>
Co-authored-by: Jon Atack <jon@atack.com>
Co-authored-by: Pieter Wuille <pieter@wuille.net>
Tree-SHA512: dd9ac416ff22276833111198445d76cf8417012a6faad0c3560276f1dcf24586ff41c65ac3430fbf1e840aaa563d3dd101671cff306b0fd92aa2ee03bb7f926b
@ -44,9 +44,98 @@ when macOS "dark mode" is activated.
Notable changes
===============
RPC
---
## Taproot Soft Fork
Included in this release are the mainnet and testnet activation
parameters for the taproot soft fork (BIP341) which also adds support
for schnorr signatures (BIP340) and tapscript (BIP342).
If activated, these improvements will allow users of single-signature
scripts, multisignature scripts, and complex contracts to all use
identical-appearing commitments that enhance their privacy and the
fungibility of all bitcoins. Spenders will enjoy lower fees and the
ability to resolve many multisig scripts and complex contracts with the
same efficiency, low fees, and large anonymity set as single-sig users.
Taproot and schnorr also include efficiency improvements for full nodes
such as the ability to batch signature verification. Together, the
improvements lay the groundwork for future potential
upgrades that may improve efficiency, privacy, and fungibility further.
Activation for taproot is being managed using a variation of BIP9
versionbits called Speedy Trial (described in BIP341). Taproot's
versionbit is bit 2, and nodes will begin tracking which blocks signal
support for taproot at the beginning of the first retarget period after
taproot’s start date of 24 April 2021. If 90% of blocks within a
2,016-block retarget period (about two weeks) signal support for taproot
prior to the first retarget period beginning after the time of 11 August
2021, the soft fork will be locked in, and taproot will then be active
as of block 709632 (expected in early or mid November).
Should taproot not be locked in via Speedy Trial activation, it is
expected that a follow-up activation mechanism will be deployed, with
changes to address the reasons the Speedy Trial method failed.
This release includes the ability to pay taproot addresses, although
payments to such addresses are not secure until taproot activates.
It also includes the ability to relay and mine taproot transactions
after activation. Beyond those two basic capabilities, this release
does not include any code that allows anyone to directly use taproot.
The addition of taproot-related features to Bitcoin Core's wallet is
expected in later releases once taproot activation is assured.
All users, businesses, and miners are encouraged to upgrade to this
release (or a subsequent compatible release) unless they object to
activation of taproot. If taproot is locked in, then upgrading before
block 709632 is highly recommended to help enforce taproot's new rules
and to avoid the unlikely case of seeing falsely confirmed transactions.
Miners who want to activate Taproot should preferably use this release
to control their signaling. The `getblocktemplate` RPC results will
automatically be updated to signal once the appropriate start has been
reached and continue signaling until the timeout occurs or taproot
activates. Alternatively, miners may manually start signaling on bit 2
at any time; if taproot activates, they will need to ensure they update
their nodes before block 709632 or non-upgraded nodes could cause them to mine on
an invalid chain. See the [versionbits
FAQ](https://bitcoincore.org/en/2016/06/08/version-bits-miners-faq/) for
details.
For more information about taproot, please see the following resources:
- Technical specifications
- [BIP340 Schnorr signatures for secp256k1](https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki)
- [BIP341 Taproot: SegWit version 1 spending rules](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki)
- [BIP342 Validation of Taproot scripts](https://github.com/bitcoin/bips/blob/master/bip-0342.mediawiki)
- Popular articles;
- [Taproot Is Coming: What It Is, and How It Will Benefit Bitcoin](https://bitcoinmagazine.com/technical/taproot-coming-what-it-and-how-it-will-benefit-bitcoin)
- [What do Schnorr Signatures Mean for Bitcoin?](https://academy.binance.com/en/articles/what-do-schnorr-signatures-mean-for-bitcoin)
W. J. van der Laan
4 years ago