Median time-past as endpoint for lock-time calculations

The five-minute read

One action, walked through

1. Open BIP 113 and read the status line before the examples.
2. Write down the rule in one sentence. A fair version of that sentence is: This BIP is a proposal to redefine the semantics used in determining a time-locked transaction's eligibility for inclusion in a block.
3. Name the object that changes: BIP65, CHECKLOCKTIMEVERIFY, BIP68.
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 113 at the status the text itself states: Deployed.
• The object that has to change is BIP65, CHECKLOCKTIMEVERIFY, BIP68. A neighbouring document with a similar name is not this one.
• Activation is a separate mechanism from the opcode or the sighash. This page does not pick a height.

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

• Which bytes become invalid under Median time-past as endpoint for lock-time calculations, and which old transactions stay valid?
• Is enforcement in consensus, or only in the mempool policy of one client?
• Which of these objects does the text actually define: BIP65, CHECKLOCKTIMEVERIFY, BIP68?

Terms

BIP 113

The public text titled Median time-past as endpoint for lock-time calculations.

Deployed

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

The problem the paper names

Bitcoin script and block validity only change when a soft fork says an old pattern is now invalid. Without that rule, every node is free to accept what this document wants to reject.

What the design proposes

• This BIP is a proposal to redefine the semantics used in determining a time-locked transaction's eligibility for inclusion in a block.
• The median of the last 11 blocks is used instead of the block's timestamp, ensuring that it increases monotonically with each block.
• At present, transactions are excluded from inclusion in a block if the present time or block height is less than or equal to that specified in the locktime.

How the mechanism is specified

• Taken from the specification, the next constraint is: The median of the last 11 blocks is used instead of the block's timestamp, ensuring that it increases monotonically with each block.
• Locate BIP65, CHECKLOCKTIMEVERIFY, BIP68 in BIP 113 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 soft fork does not bind a node that never upgrades. It binds the nodes that enforce the new rejection.
• Activation is a separate mechanism from the opcode or the sighash. This page does not pick a height.
• 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 113 when a pitch says 'Median time-past as endpoint for lock-time calculations' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.