Bitcoin Improvement Proposals

Short description: Design document for introducing features or information to Bitcoin

A Bitcoin Improvement Proposal (BIP) is a design document for introducing features or information to Bitcoin.

The BIP, as amended, has since become the standard way of formally communicating ideas about potential Bitcoin improvements.

History

The concept of the BIP was introduced on 2011-08-19 by Amir Taaki, in the form of the first BIP.^[1] The second BIP, 'BIP2 was published 5 years later.^[2]

Format

The BIP process closely mimicks the RFC process by which the internet is improved, while building on it by referring to- and requiring a document formatted with an RFC822 style header,^[3] addressed to the Bitcoin development mailing list.^[4]

Types

There are three types of BIPs:

Standards Track BIPs - Changes to the network protocol, block or transaction validation, or anything affecting interoperability.
Informational BIPs - Design issues, general guidelines. This type of BIP is NOT for proposing new features and do not represent community consensus
Process BIPs - Describes or proposes a change in process. Similar to Standards BIPs but apply outside the Bitcoin protocol.

Notable BIPs

BIP32

BIP32 is the specification which introduced the standard for hierarchical deterministic (HD) wallets and extended keys to Bitcoin. Deterministic wallets can generate multiple "child" key pair chains from a master private "root" key in a deterministic way.^[5]^[6] With the adoption of this standard, keys could be transferred between wallet software with a single extended private key (xprv), greatly improving the interoperability of wallets.^[7]

BIP39

BIP39 is a proposal describing the use of plain language words chosen from a specific word list,^[8] and the process for using such a string to derive a random seed used to generate a wallet as described in BIP32. This approach of utilizing a mnemonic phrase offered a much more user friendly experience for backup and recovery of cryptocurrency wallets.^[9]

BIP44

BIP44 defines a logical hierarchy for deterministic wallets based on an algorithm described in BIP32 and purpose scheme described in BIP43. It allows the handling of multiple coins, multiple accounts, external and internal chains per account and millions of addresses per chain.^[10]

List of BIPs

Number	Layer	Title	Owner	Type	Status
1		BIP Purpose and Guidelines	Amir Taaki	Process	Replaced
2		BIP process, revised	Luke Dashjr	Process	Active
8		Version bits with lock-in by height	Shaolin Fry, Luke Dashjr	Informational	Draft
9		Version bits with timeout and delay	Pieter Wuille, Peter Todd, Greg Maxwell, Rusty Russell	Informational	Final
10	Applications	Multi-Sig Transaction Distribution	Alan Reiner	Informational	Withdrawn
11	Applications	M-of-N Standard Transactions	Gavin Andresen	Standard	Final
12	Consensus (soft fork)	OP_EVAL	Gavin Andresen	Standard	Withdrawn
13	Applications	Address Format for pay-to-script-hash	Gavin Andresen	Standard	Final
14	Peer Services	Protocol Version and User Agent	Amir Taaki, Patrick Strateman	Standard	Final
15	Applications	Aliases	Amir Taaki	Standard	Deferred
16	Consensus (soft fork)	Pay to Script Hash	Gavin Andresen	Standard	Final
17	Consensus (soft fork)	OP_CHECKHASHVERIFY (CHV)	Luke Dashjr	Standard	Withdrawn
18	Consensus (soft fork)	hashScriptCheck	Luke Dashjr	Standard	Proposed
19	Applications	M-of-N Standard Transactions (Low SigOp)	Luke Dashjr	Standard	Rejected
20	Applications	URI Scheme	Luke Dashjr	Standard	Replaced
21	Applications	URI Scheme	Nils Schneider, Matt Corallo	Standard	Final
22	API/RPC	getblocktemplate - Fundamentals	Luke Dashjr	Standard	Final
23	API/RPC	getblocktemplate - Pooled Mining	Luke Dashjr	Standard	Final
30	Consensus (soft fork)	Duplicate transactions	Pieter Wuille	Standard	Final
31	Peer Services	Pong message	Mike Hearn	Standard	Final
32	Applications	Hierarchical Deterministic Wallets	Pieter Wuille	Informational	Final
33	Peer Services	Stratized Nodes	Amir Taaki	Standard	Rejected
34	Consensus (soft fork)	Block v2, Height in Coinbase	Gavin Andresen	Standard	Final
35	Peer Services	mempool message	Jeff Garzik	Standard	Final
36	Peer Services	Custom Services	Stefan Thomas	Standard	Rejected
37	Peer Services	Connection Bloom filtering	Mike Hearn, Matt Corallo	Standard	Final
38	Applications	Passphrase-protected private key	Mike Caldwell, Aaron Voisine	Standard	Draft
39	Applications	Mnemonic code for generating deterministic keys	Marek Palatinus, Pavol Rusnak, Aaron Voisine, Sean Bowe	Standard	Proposed
40	API/RPC	Stratum wire protocol	Marek Palatinus	Standard	BIP number allocated
41	API/RPC	Stratum mining protocol	Marek Palatinus	Standard	BIP number allocated
42	Consensus (soft fork)	A finite monetary supply for Bitcoin	Pieter Wuille	Standard	Final
43	Applications	Purpose Field for Deterministic Wallets	Marek Palatinus, Pavol Rusnak	Informational	Final
44	Applications	Multi-Account Hierarchy for Deterministic Wallets	Marek Palatinus, Pavol Rusnak	Standard	Proposed
45	Applications	Structure for Deterministic P2SH Multisignature Wallets	Manuel Araoz, Ryan X. Charles, Matias Alejo Garcia	Standard	Proposed
47	Applications	Reusable Payment Codes for Hierarchical Deterministic Wallets	Justus Ranvier	Informational	Draft
49	Applications	Derivation scheme for P2WPKH-nested-in-P2SH based accounts	Daniel Weigl	Informational	Final
50		March 2013 Chain Fork Post-Mortem	Gavin Andresen	Informational	Final
60	Peer Services	Fixed Length "version" Message (Relay-Transactions Field)	Amir Taaki	Standard	Draft
61	Peer Services	Reject P2P message	Gavin Andresen	Standard	Final
62	Consensus (soft fork)	Dealing with malleability	Pieter Wuille	Standard	Withdrawn
63	Applications	Stealth Addresses	Peter Todd	Standard	BIP number allocated
64	Peer Services	getutxo message	Mike Hearn	Standard	Obsolete
65	Consensus (soft fork)	OP_CHECKLOCKTIMEVERIFY	Peter Todd	Standard	Final
66	Consensus (soft fork)	Strict DER signatures	Pieter Wuille	Standard	Final
67	Applications	Deterministic Pay-to-script-hash multi-signature addresses through public key sorting	Thomas Kerin, Jean-Pierre Rupp, Ruben de Vries	Standard	Proposed
68	Consensus (soft fork)	Relative lock-time using consensus-enforced sequence numbers	Mark Friedenbach, BtcDrak, Nicolas Dorier, kinoshitajona	Standard	Final
69	Applications	Lexicographical Indexing of Transaction Inputs and Outputs	Kristov Atlas	Informational	Proposed
70	Applications	Payment Protocol	Gavin Andresen, Mike Hearn	Standard	Final
71	Applications	Payment Protocol MIME types	Gavin Andresen	Standard	Final
72	Applications	bitcoin: uri extensions for Payment Protocol	Gavin Andresen	Standard	Final
73	Applications	Use "Accept" header for response type negotiation with Payment Request URLs	Stephen Pair	Standard	Final
74	Applications	Allow zero value OP_RETURN in Payment Protocol	Toby Padilla	Standard	Rejected
75	Applications	Out of Band Address Exchange using Payment Protocol Encryption	Justin Newton, Matt David, Aaron Voisine, James MacWhyte	Standard	Final
78	Applications	A Simple Payjoin Proposal	Nicolas Dorier	Standard	Draft
79	Applications	Bustapay :: a practical coinjoin protocol	Ryan Havar	Informational	Replaced
80		Hierarchy for Non-Colored Voting Pool Deterministic Multisig Wallets	Justus Ranvier, Jimmy Song	Informational	Deferred
81		Hierarchy for Colored Voting Pool Deterministic Multisig Wallets	Justus Ranvier, Jimmy Song	Informational	Deferred
83	Applications	Dynamic Hierarchical Deterministic Key Trees	Eric Lombrozo	Standard	Rejected
84	Applications	Derivation scheme for P2WPKH based accounts	Pavol Rusnak	Informational	Draft
85	Applications	Deterministic Entropy From BIP32 Keychains	Ethan Kosakovsky	Informational	Draft
90		Buried Deployments	Suhas Daftuar	Informational	Final
91	Consensus (soft fork)	Reduced threshold Segwit MASF	James Hilliard	Standard	Final
98	Consensus (soft fork)	Fast Merkle Trees	Mark Friedenbach, Kalle Alm, BtcDrak	Standard	Draft
99		Motivation and deployment of consensus rule changes ([soft/hard]forks)	Jorge Timón	Informational	Rejected
100	Consensus (hard fork)	Dynamic maximum block size by miner vote	Jeff Garzik, Tom Harding, Dagur Valberg Johannsson	Standard	Rejected
101	Consensus (hard fork)	Increase maximum block size	Gavin Andresen	Standard	Withdrawn
102	Consensus (hard fork)	Block size increase to 2MB	Jeff Garzik	Standard	Rejected
103	Consensus (hard fork)	Block size following technological growth	Pieter Wuille	Standard	Withdrawn
104	Consensus (hard fork)	'Block75' - Max block size like difficulty	t.khan	Standard	Rejected
105	Consensus (hard fork)	Consensus based block size retargeting algorithm	BtcDrak	Standard	Rejected
106	Consensus (hard fork)	Dynamically Controlled Bitcoin Block Size Max Cap	Upal Chakraborty	Standard	Rejected
107	Consensus (hard fork)	Dynamic limit on the block size	Washington Y. Sanchez	Standard	Rejected
109	Consensus (hard fork)	Two million byte size limit with sigop and sighash limits	Gavin Andresen	Standard	Rejected
111	Peer Services	NODE_BLOOM service bit	Matt Corallo, Peter Todd	Standard	Proposed
112	Consensus (soft fork)	CHECKSEQUENCEVERIFY	BtcDrak, Mark Friedenbach, Eric Lombrozo	Standard	Final
113	Consensus (soft fork)	Median time-past as endpoint for lock-time calculations	Thomas Kerin, Mark Friedenbach	Standard	Final
114	Consensus (soft fork)	Merkelized Abstract Syntax Tree	Johnson Lau	Standard	Rejected
115	Consensus (soft fork)	Generic anti-replay protection using Script	Luke Dashjr	Standard	Rejected
116	Consensus (soft fork)	MERKLEBRANCHVERIFY	Mark Friedenbach, Kalle Alm, BtcDrak	Standard	Draft
117	Consensus (soft fork)	Tail Call Execution Semantics	Mark Friedenbach, Kalle Alm, BtcDrak	Standard	Draft
118	Consensus (soft fork)	SIGHASH_NOINPUT	Christian Decker	Standard	Draft
119	Consensus (soft fork)	CHECKTEMPLATEVERIFY	Jeremy Rubin	Standard	Draft
120	Applications	Proof of Payment	Kalle Rosenbaum	Standard	Withdrawn
121	Applications	Proof of Payment URI scheme	Kalle Rosenbaum	Standard	Withdrawn
122	Applications	URI scheme for Blockchain references / exploration	Marco Pontello	Standard	Draft
123		BIP Classification	Eric Lombrozo	Process	Active
124	Applications	Hierarchical Deterministic Script Templates	Eric Lombrozo, William Swanson	Informational	Rejected
125	Applications	Opt-in Full Replace-by-Fee Signaling	David A. Harding, Peter Todd	Standard	Proposed
126		Best Practices for Heterogeneous Input Script Transactions	Kristov Atlas	Informational	Draft
127	Applications	Simple Proof-of-Reserves Transactions	Steven Roose	Standard	Draft
130	Peer Services	sendheaders message	Suhas Daftuar	Standard	Proposed
131	Consensus (hard fork)	"Coalescing Transaction" Specification (wildcard inputs)	Chris Priest	Standard	Rejected
132		Committee-based BIP Acceptance Process	Andy Chase	Process	Withdrawn
133	Peer Services	feefilter message	Alex Morcos	Standard	Draft
134	Consensus (hard fork)	Flexible Transactions	Tom Zander	Standard	Rejected
135		Generalized version bits voting	Sancho Panza	Informational	Rejected
136	Applications	Bech32 Encoded Tx Position References	Велеслав, Jonas Schnelli, Daniel Pape	Informational	Draft
137	Applications	Signatures of Messages using Private Keys	Christopher Gilliard	Standard	Final
140	Consensus (soft fork)	Normalized TXID	Christian Decker	Standard	Rejected
141	Consensus (soft fork)	Segregated Witness (Consensus layer)	Eric Lombrozo, Johnson Lau, Pieter Wuille	Standard	Final
142	Applications	Address Format for Segregated Witness	Johnson Lau	Standard	Withdrawn
143	Consensus (soft fork)	Transaction Signature Verification for Version 0 Witness Program	Johnson Lau, Pieter Wuille	Standard	Final
144	Peer Services	Segregated Witness (Peer Services)	Eric Lombrozo, Pieter Wuille	Standard	Final
145	API/RPC	getblocktemplate Updates for Segregated Witness	Luke Dashjr	Standard	Final
146	Consensus (soft fork)	Dealing with signature encoding malleability	Johnson Lau, Pieter Wuille	Standard	Withdrawn
147	Consensus (soft fork)	Dealing with dummy stack element malleability	Johnson Lau	Standard	Final
148	Consensus (soft fork)	Mandatory activation of segwit deployment	Shaolin Fry	Standard	Final
149	Consensus (soft fork)	Segregated Witness (second deployment)	Shaolin Fry	Standard	Withdrawn
150	Peer Services	Peer Authentication	Jonas Schnelli	Standard	Draft
151	Peer Services	Peer-to-Peer Communication Encryption	Jonas Schnelli	Standard	Withdrawn
152	Peer Services	Compact Block Relay	Matt Corallo	Standard	Final
154	Peer Services	Rate Limiting via peer specified challenges	Karl-Johan Alm	Standard	Withdrawn
155	Peer Services	addrv2 message	Wladimir J. van der Laan	Standard	Draft
156	Peer Services	Dandelion - Privacy Enhancing Routing	Brad Denby, Andrew Miller, Giulia Fanti, Surya Bakshi, Shaileshh Bojja Venkatakrishnan, Pramod Viswanath	Standard	Rejected
157	Peer Services	Client Side Block Filtering	Olaoluwa Osuntokun, Alex Akselrod, Jim Posen	Standard	Draft
158	Peer Services	Compact Block Filters for Light Clients	Olaoluwa Osuntokun, Alex Akselrod	Standard	Draft
159	Peer Services	NODE_NETWORK_LIMITED service bit	Jonas Schnelli	Standard	Draft
171	Applications	Currency/exchange rate information API	Luke Dashjr	Standard	Rejected
173	Applications	Base32 address format for native v0-16 witness outputs	Pieter Wuille, Greg Maxwell	Informational	Final
174	Applications	Partially Signed Bitcoin Transaction Format	Andrew Chow	Standard	Final
175	Applications	Pay to Contract Protocol	Omar Shibli, Nicholas Gregory	Informational	Rejected
176		Bits Denomination	Jimmy Song	Informational	Draft
178	Applications	Version Extended WIF	Karl-Johan Alm	Standard	Draft
179		Name for payment recipient identifiers	Emil Engler, MarcoFalke, Luke Dashjr	Informational	Draft
180	Peer Services	Block size/weight fraud proof	Luke Dashjr	Standard	Rejected
197	Applications	Hashed Time-Locked Collateral Contract	Matthew Black, Tony Cai	Standard	Draft
199	Applications	Hashed Time-Locked Contract transactions	Sean Bowe, Daira Hopwood	Standard	Draft
300	Consensus (soft fork)	Hashrate Escrows (Consensus layer)	Paul Sztorc, CryptAxe	Standard	Draft
301	Consensus (soft fork)	Blind Merged Mining (Consensus layer)	Paul Sztorc, CryptAxe	Standard	Draft
310	Applications	Stratum protocol extensions	Pavel Moravec, Jan Čapek	Informational	Draft
320		nVersion bits for general purpose use	BtcDrak	Standard	Draft
322	Applications	Generic Signed Message Format	Karl-Johan Alm	Standard	Draft
325	Applications	Signet	Karl-Johan Alm, Anthony Towns	Standard	Proposed
330	Peer Services	Transaction announcements reconciliation	Gleb Naumenko, Pieter Wuille	Standard	Draft
339	Peer Services	WTXID-based transaction relay	Suhas Daftuar	Standard	Draft
340		Schnorr Signatures for secp256k1	Pieter Wuille, Jonas Nick, Tim Ruffing	Standard	Draft
341	Consensus (soft fork)	Taproot: SegWit version 1 spending rules	Pieter Wuille, Jonas Nick, Anthony Towns	Standard	Draft
342	Consensus (soft fork)	Validation of Taproot Scripts	Pieter Wuille, Jonas Nick, Anthony Towns	Standard	Draft
350	Applications	Bech32m format for v1+ witness addresses	Pieter Wuille	Standard	Draft

Notes

↑ "BIP Purpose and Guidelines". https://github.com/bitcoin/bips/blob/master/bip-0001.mediawiki.
↑ "BIP process, revised". 2016-02-03. https://github.com/bitcoin/bips/blob/master/bip-0002.mediawiki.
↑ "RFC 822 - Standard for the Format of Arpa Internet Text Messages". https://tools.ietf.org/html/rfc822.
↑ "BIP Purpose and Guidelines". https://github.com/bitcoin/bips/blob/master/bip-0001.mediawiki.
↑ "Bip32". University of Texas at Austin. https://www.cs.utexas.edu/users/moore/acl2/manuals/current/manual/index-seo.php/BITCOIN____BIP32.
↑ "How does Add Account Work". https://docs.binance.org/smart-chain/wallet/extension/add-account.html.
↑ "BIP 32 (Hierarchical Deterministic Wallets)". River Financial. https://river.com/learn/terms/b/bip-32/.
↑ Palatinus, Marek; Rusnak, Pavol; Voisine, Aaron; Bowe, Sean (10 September 2013). "BIP-0039: Mnemonic code for generating deterministic keys". https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki.
↑ "Bitcoin.org Developer Guide". https://developer.bitcoin.org/devguide/wallets.html?highlight=bip39.
↑ Palatinus, Marek; Rusnak, Pavol (24 April 2014). "BIP-0044: Multi-Account Hierarchy for Deterministic Wallets". https://github.com/bitcoin/bips/blob/master/bip-0044.mediawiki.