LibraryStorage and networks2018Design paperCorpus record
Version Extended WIF
BIP 178. Karl-Johan Alm.
BIP 178, Version Extended WIF. An extension to the Wallet Import Format (WIF) to specify what kind of bitcoin address the private key corresponds to.
Status in the source: Draft. A reading of the public specification, not a copy of it and not a certification.
Version Extended WIF is worth reading for the rule it actually adds: An extension to the Wallet Import Format (WIF) to specify what kind of bitcoin address the private key corresponds to.
The five-minute read
The rule
An extension to the Wallet Import Format (WIF) to specify what kind of bitcoin address the private key corresponds to.
What was already failing
A node that cannot fetch, filter, or relay the data it is supposed to validate is not a peer of the network the paper describes.
What the number does not mean
The source marks this draft. It is not a live consensus rule just because it has a number.
What a builder should be able to point at
An implementation either constrains WIF, P2PKH, P2SH or it is a different design.
One action, walked through
- Open BIP 178 and read the status line before the examples.
- Write down the rule in one sentence. A fair version of that sentence is: An extension to the Wallet Import Format (WIF) to specify what kind of bitcoin address the private key corresponds to.
- Name the object that changes: WIF, P2PKH, P2SH.
- Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.
The argument, unpacked
What the text is allowed to settle
Bitcoin Improvement Proposal 178 can settle the shape of Version Extended WIF. It cannot settle whether a later client, a later fork, or a later wallet still does this.
What this page will not pretend
There is no benchmark, no adoption number, and no claim that the mechanism is safe outside the assumptions written in the source.
What has to be true
- You are implementing BIP 178 at the status the text itself states: Draft.
- The object that has to change is WIF, P2PKH, P2SH. A neighbouring document with a similar name is not this one.
- Measurements of delay in one year do not travel with the specification.
What happened after the paper
The source marks this draft. It is not a live consensus rule just because it has a number. Later documents can narrow, replace, or ignore this one. Cite the number you mean.
What to check before you use the idea
- Which message does Version Extended WIF add, and which old peer must still be answered?
- What does a node do when the short form fails and the full object is required?
- Which names are normative: WIF, P2PKH, P2SH?
Terms
- BIP 178
- The public text titled Version Extended WIF.
- Draft
- The document's own label for how finished the text is. It is not a market fact.
The problem the paper names
A node that cannot fetch, filter, or relay the data it is supposed to validate is not a peer of the network the paper describes.
What the design proposes
- An extension to the Wallet Import Format (WIF) to specify what kind of bitcoin address the private key corresponds to.
- There are several types of bitcoin addresses which can all be associated with a given private key: P2PKH (legacy 1...
- format), P2SH-P2WPKH (SegWit public key inside P2SH), P2WPKH (bech32), etc.
How the mechanism is specified
- Taken from the specification, the next constraint is: There are several types of bitcoin addresses which can all be associated with a given private key: P2PKH (legacy 1...
- Locate WIF, P2PKH, P2SH in BIP 178 and apply it to one transaction or call.
- Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.
What this page does not treat as proven
- A peer protocol is not a consensus rule. A peer can disconnect. A block is still valid or not on its own.
- Measurements of delay in one year do not travel with the specification.
- The source marks this draft. It is not a live consensus rule just because it has a number.
Why a venture studio still reads it
Use BIP 178 when a pitch says 'Version Extended WIF' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.
This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.
Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.
