9 - Version bits with timeout and delay
BIP: 9 source Title: Version bits with timeout and delay Authors: Pieter Wuille Peter Todd Greg Maxwell Rusty Russell Status: Deployed Type: Informational Assigned: 2015-10-04 License: PD Table of ContentsAbstractMotivationSpecificationSelection guidelinesStatesBit flagsNew consensus rulesState transitionsWarning mechanismgetblocktemplate changesSupport for future changesRationaleDeploymentsCopyright Abstract This document specifies a proposed change to the semantics of the 'version' field in Bitcoin blocks, allowing multiple backward-compatible changes (further called "soft forks") to be deployed in parallel. It relies on interpreting the version field as a bit vector, where each bit can be used to track an independent change. These are tallied each retarget period. Once the consensus change succeeds or times out, there is a "fallow" pause after which the bit can be reused for later changes. Motivation BIP 34 introduced a mechanism fo...
173 - Base32 address format for native v0-16 witness outputs
BIP: 173 source Layer: Applications Title: Base32 address format for native v0-16 witness outputs Authors: Pieter Wuille Greg Maxwell Comments-Summary: No comments yet. Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0173 Status: Deployed Type: Informational Assigned: 2017-03-20 License: BSD-2-Clause Replaces: 142 Proposed-Replacement: 350 Table of ContentsIntroductionAbstractCopyrightMotivationExamplesSpecificationBech32Segwit address formatCompatibilityRationaleReference implementationsRegistered Human-readable PrefixesAppendicesTest vectorsChecksum designAcknowledgementsDisclosures (added 2024) Introduction Abstract This document proposes a checksummed base32 format, "Bech32", and a standard for native segregated witness output addresses using it. Copyright This BIP is licensed under the 2-clause BSD license. Motivation For most of its history, Bitcoin has relied on base58 addresses with a truncated double-SHA256 checksum. They...
123 - BIP Classification
BIP: 123 source Title: BIP Classification Authors: Eric Lombrozo Status: Deployed Type: Process Assigned: 2015-08-26 License: CC0-1.0 OR FSFAP Table of ContentsAbstractCopyrightMotivationSpecification1. Consensus LayerSoft ForksHard Forks2. Peer Services Layer3. API/RPC Layer4. Applications LayerClassification of existing BIPs Abstract This document describes a classification scheme for BIPs. BIPs are classified by system layers with lower numbered layers involving more intricate interoperability requirements. The specification defines the layers and sets forth specific criteria for deciding to which layer a particular standards BIP belongs. Copyright This BIP is dual-licensed under the Creative Commons CC0 1.0 Universal and FSF All Permissive licenses. Motivation Bitcoin is a system involving a number of different standards. Some standards are absolute requirements for interoperability while others can be considered optional, giving implementers a choice of whether to su...
90 - Buried Deployments
BIP: 90 source Title: Buried Deployments Authors: Suhas Daftuar Comments-Summary: Mostly Recommended for implementation, with some Discouragement Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0090 Status: Deployed Type: Informational Assigned: 2016-11-08 License: PD Table of ContentsAbstractMotivationConsiderationsSpecificationImplementationReferencesAcknowledgementsCopyright Abstract Prior soft forks (BIP 34, BIP 65, and BIP 66) were activated via miner signaling in block version numbers. Now that the chain has long since passed the blocks at which those consensus rules have triggered, we can (as a simplification) replace the trigger mechanism by caching the block heights at which those consensus rules became enforced. Motivation BIPs 34, 65 and 66 were deployed on mainnet using miner signaling using block version numbers. In short, new consensus rules were proposed for use in blocks with a higher version number (N+1) than the prevailing block v...
66 - Strict DER signatures
BIP: 66 source Layer: Consensus (soft fork) Title: Strict DER signatures Authors: Pieter Wuille Status: Deployed Type: Specification Assigned: 2015-01-10 License: BSD-2-Clause Table of ContentsAbstractCopyrightMotivationSpecificationDER encoding referenceExamplesDeploymentCompatibilityImplementationAcknowledgementsDisclosures Abstract This document specifies proposed changes to the Bitcoin transaction validity rules to restrict signatures to strict DER encoding. Copyright This BIP is licensed under the 2-clause BSD license. Motivation Bitcoin's reference implementation currently relies on OpenSSL for signature validation, which means it is implicitly defining Bitcoin's block validity rules. Unfortunately, OpenSSL is not designed for consensus-critical behaviour (it does not guarantee bug-for-bug compatibility between versions), and thus changes to it can - and have - affected Bitcoin software. One specifically critical area is the encoding of signatures. Until recently...