The Bitcoin Optech newsletter provides readers with a high-level summary of the most important technical news happening in Bitcoin, along with resources to help them learn more. To help our readers stay up to date with Bitcoin, we’re republishing the latest edition of this newsletter below. Remember to subscribe to receive this content straight to your inbox.
This week’s newsletter celebrates basic soft fork locking, describes a draft BIP to improve transaction privacy by diversifying the fields used to implement anti-fee sniping, and includes an article on the challenges of combining transaction substitution and payment processing. Our regular sections are also included with announcements of new software releases and release candidates, as well as notable changes to popular Bitcoin infrastructure software.
- Taproot locked in: root Soft fork and related changes specified in BIPs 340And the 341, And the 342 They were locked up by referring to miners last weekend. Taproot will be safe to use after block 709632, which is expected in early or mid-November. The delay gives users time to upgrade their nodes to a version (such as Bitcoin Core 0.21.1 or later) that will enforce master root rules, ensuring that funds received for core scripts after block 709632 are safe even if there is a problem with miners.
Developers are welcome to get started Execution of the main root So that they are ready to take advantage of greater efficiency, privacy and redemption once activation is complete.
Readers celebrating the installation of the root master may also want to read the short topic About the origins and history of taproot by developer Pieter Wuille.
- The governor’s BIP suggested setting nSequence by default to the parameters of the master root: Chris Belcher Spread A draft BIP to the Bitcoin-Dev mailing list suggests an alternative method that wallets can implement Anti sniping fee. The alternative method would enhance the privacy and substitution of transactions made by individual signature users, multi-signature users, and users of certain contract protocols such as LN that support master or advanced root currency exchange.
Anti-fee sniping is a technique applied by some wallets to discourage miners from trying to steal fees from each other in a way that reduces the amount of proof of work spent on securing bitcoin and limits users’ ability to rely on confirmation scores. All wallets that implement anti-fee sniping today use nLockTime height locks, but it is also possible to implement the same protection using BIP68 Serial height locks. This wouldn’t be much more effective in preventing fee cuts, but would provide a good reason for normal wallets to set their nSequence values to the same values required for transactions in some multi-signature-based contract protocols, such as coin change ideas and LN root-enabled. This helps make normal wallet transactions look like contract protocol transactions and vice versa.
Belcher’s proposal suggests that wallets choose at random between using either nLockTime or nSequence with a 50% probability when both options are available. In general, if the proposal is implemented, it will allow users of ordinary single-signature transactions or uncomplicated multi-signatures to join users of contract protocols to improve each other’s privacy and mutually switchability.
Field Report: Use of RBF and Additional Fusion
“Additional assembly” is a scheme in which additional outputs are added to the unconfirmed operands in the memory pool. This field report summarizes the efforts Cardcoins It has taken in the introduction to implement a reorganization and secure DoS for such a scheme in the customer payments workflow.
Replace with fees (RBF, BIP125) and assembly They are two important tools for any organization that directly interacts with the Bitcoin mempool. Fees go up and fees go down, but the company must always fight for fee efficiency.
Each tool, despite its power, has its own intricacies and nuances. For example, accumulating customer withdrawals may save the organization’s fees, but it probably will The child pays his parents (CPFP) is not economical for a customer who wants to speed up the transaction. Likewise, RBF is beneficial to the organization that adopts a fee reduction strategy (initial transaction broadcast starts with a low fee, bidding slowly goes up), but exposes its customers to potential confusion As updates their withdrawal transactions in their wallet. It would also be messy for the customer to spend from this transaction while remaining uncertain, since the organization would have to pay for that child’s spending when trying to replace the parent. Even worse, the project may have a withdrawal installed Through another service I got to withdraw the client.
When these two tools are combined, the service provider unlocks new functions but is similarly exposed to new forms of complexity. In the base case, combining an RBF with a single static batch carries a simple mixture of the complexities carried by RBF and aggregation separately. However, when RBF is combined with ‘additional aggregation’, emerging edge cases and dangerous failure scenarios appear.
In an additional RBF pool, the service provider introduces new outputs (and confirmed inputs) to a transaction in the memory pool to combine new customer withdrawals into an unconfirmed transaction. This allows the service provider to give users an instant withdrawal experience while retaining a lot of fee savings from making large batches of customer withdrawals at once. As each client requests a pull, an output is added to the transaction in the memory pool. This transaction continues to be updated until it confirms or reaches some local optimum level.
There are many strategies for this type of additive RBF aggregation. at Cardcoins We have taken a safety first approach in our implementation (with the help of Matthew Zipkin), the details we described in a blog post, RBF Batching CardCoins: Dive into Mempool’s Dark Reorg Forest.
Releases and releases candidates
New Releases and Candidate Releases for Popular Bitcoin Infrastructure Projects. Please consider upgrading to new releases or help test release candidates.
- Rust Bitcoin 0.26.2 It is the latest minor version of the project. Compared to the previous major version, it contains many API improvements and bug fixes. Look Change for details.
- Rust and Lightning 0.0.98.0 Update It is a minor release that contains many improvements and bug fixes.
- LND 0.13.0 beta. rc5 It is a release filter that adds support for using a full-trimmed Bitcoin node, and allows receiving and sending payments using Atomic MultiPath (AMP), and more than PSBT capabilities, among other improvements and bug fixes.
Notable changes to code and documentation
Notable changes this week in Bitcoin CoreAnd the C- lightningAnd the EclairAnd the LNDAnd the rust and lightningAnd the libsecp256k1And the Hardware Wallet Interface (HWI)And the rust bitcoinAnd the BTCPay serverAnd the Bitcoin Improvement Proposals (BIPs), And the lightning bolt.
- Bitcoin Core GUI #4 Adds initial support for the use of Hardware Wallet Interface (HWI) External websites via GUI. Once this feature is completed, users will be able to use HWI compatible hardware wallets directly from the Bitcoin Core GUI.
- Bitcoin Core #21573 It updates the version of libsecp256k1 included with Bitcoin Core. The most notable change is the use of an improved modular inverse code described in newsletters # 136 And the # 146. Performance evaluations posted on PR found that it sped the legacy block validation process by about 10%.
- Sea-lightning #4591 Adds support for analysis bech32m addresses. C-Lightning will now allow the peer who negotiated the option_shutdown_anysegwit feature to specify any native v1+ segwit address as a shutdown or pull-down destination.
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