Common-input-ownership heuristic - Revision history

Belcher: Add see also section

2019-02-20T22:52:38Z

Add see also section

← Older revision		Revision as of 22:52, 20 February 2019
Line 12:		Line 12:

	This [[transaction]] would be an indiciation that [[address]]es B and C are owned by the same person who owns [[address]] A, assuming that the common-input-ownership heuristic is true.		This [[transaction]] would be an indiciation that [[address]]es B and C are owned by the same person who owns [[address]] A, assuming that the common-input-ownership heuristic is true.

			== See also ==
			* [[CoinJoin]]
			* [[PayJoin]]

	==References==		==References==

Belcher: Add other name for this heuristic

2019-02-19T01:14:01Z

Add other name for this heuristic

← Older revision		Revision as of 01:14, 19 February 2019
Line 1:		Line 1:
	The common-input-ownership heuristic (also called the ''multi-input heuristic'' or ''Nakamoto/Meiklejohn heuristic'') is a heuristic or assumption that all inputs to a [[transaction]] are owned by the same entity.		The common-input-ownership heuristic (also called the ''multi-input heuristic'', ''Nakamoto/Meiklejohn heuristic'' or ''co-spending heuristic'') is a heuristic or assumption that all inputs to a [[transaction]] are owned by the same entity.

	Transactions with multiple inputs usually arise if the user's wallet does not have a single UTXO large enough to fulfil the user's payment amount. Wallets will then usually choose to spend more than one input in their [[transaction]]. In this situation the common-input-ownership heuristic is true; all inputs belonged to the same wallet. [[Address]]es which are spent in transactions with multiple inputs are sometimes called ''co-spent addresses''.		Transactions with multiple inputs usually arise if the user's wallet does not have a single UTXO large enough to fulfil the user's payment amount. Wallets will then usually choose to spend more than one input in their [[transaction]]. In this situation the common-input-ownership heuristic is true; all inputs belonged to the same wallet. [[Address]]es which are spent in transactions with multiple inputs are sometimes called ''co-spent addresses''.

Belcher: Create page

2019-02-16T01:32:08Z

Create page

New page

The common-input-ownership heuristic (also called the ''multi-input heuristic'' or ''Nakamoto/Meiklejohn heuristic'') is a heuristic or assumption that all inputs to a [[transaction]] are owned by the same entity.

Transactions with multiple inputs usually arise if the user's wallet does not have a single UTXO large enough to fulfil the user's payment amount. Wallets will then usually choose to spend more than one input in their [[transaction]]. In this situation the common-input-ownership heuristic is true; all inputs belonged to the same wallet. [[Address]]es which are spent in transactions with multiple inputs are sometimes called ''co-spent addresses''.

The assumption is first mentioned in the original bitcoin whitepaper which says that the heuristic is always true. This is one of the few errors in the paper. It is possible for multiple entities to cooperate to create and sign a single [[transaction]] which spends inputs owned by multiple people. This is known as [[CoinJoin]] and one of its main purposes is to break this heuristic.

For example, consider this transaction with inputs A, B and C; and outputs X and Y.

A (1 btc) --> X (4 btc)
B (2 btc) Y (2 btc)
C (3 btc)

This [[transaction]] would be an indiciation that [[address]]es B and C are owned by the same person who owns [[address]] A, assuming that the common-input-ownership heuristic is true.

==References==
<references />

[[Category:Privacy]]