Passphrase-protected private key

The five-minute read

One action, walked through

1. Open BIP 38 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: A method is proposed for encrypting and encoding a passphrase-protected Bitcoin private key record in the form of a 58-character Base58Check-encoded printable string.
3. Name the object that changes: Passphrase-protected private key.
4. 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 has to be true

• You are implementing BIP 38 at the status the text itself states: Deployed.
• The object that has to change is Passphrase-protected private key. A neighbouring document with a similar name is not this one.
• Wallet support is not the same as consensus validity.

What happened after the paper

The source marks this deployed. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

• What is covered by the signed bytes in Passphrase-protected private key?
• Can the same signature be replayed on another chain, account, or message?
• Which primitive does the text require: Passphrase-protected private key?

Terms

BIP 38

The public text titled Passphrase-protected private key.

Deployed

The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.

What the design proposes

• A method is proposed for encrypting and encoding a passphrase-protected Bitcoin private key record in the form of a 58-character Base58Check-encoded printable string.
• Encrypted private key records are intended for use on paper wallets and physical Bitcoins.
• Each record string contains all the information needed to reconstitute the private key except for a passphrase, and the methodology uses salting and ''scrypt'' to resist brute-force attacks.

How the mechanism is specified

• Taken from the specification, the next constraint is: Encrypted private key records are intended for use on paper wallets and physical Bitcoins.
• Locate Passphrase-protected private key in BIP 38 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 signature scheme is not a privacy system. It hides the signer only if the protocol says so.
• Wallet support is not the same as consensus validity.
• The source marks this deployed. That is a statement about the text, not a promise that every wallet or node has shipped it.

Why a venture studio still reads it

Use BIP 38 when a pitch says 'Passphrase-protected private key' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.