Address Format for pay-to-script-hash

The five-minute read

One action, walked through

1. Open BIP 13 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: A new type of Bitcoin address to support arbitrarily complex transactions.
3. Name the object that changes: ECDSA, SHA256.
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 13 at the status the text itself states: Deployed.
• The object that has to change is ECDSA, SHA256. 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 Address Format for pay-to-script-hash?
• Can the same signature be replayed on another chain, account, or message?
• Which primitive does the text require: ECDSA, SHA256?

Terms

BIP 13

The public text titled Address Format for pay-to-script-hash.

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 new type of Bitcoin address to support arbitrarily complex transactions.
• Complexity in this context is defined as what information is needed by the recipient to respend the received coins, in contrast to needing a single ECDSA private key as in current implementations of Bitcoin.
• In essence, an address encoded under this proposal represents the encoded hash of a [https://en.bitcoin.it/wiki/Script script], rather than the encoded hash of an ECDSA public key.

How the mechanism is specified

• Taken from the specification, the next constraint is: Complexity in this context is defined as what information is needed by the recipient to respend the received coins, in contrast to needing a single ECDSA private key as in current implementations of Bitcoin.
• Locate ECDSA, SHA256 in BIP 13 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 13 when a pitch says 'Address Format for pay-to-script-hash' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.