Subject: [bitcoin-dev] feature: Enhance privacy by change obfuscation

From: Damian Williamson <[email-masked]>
Date: Sun, 18 Mar 2018 01:34:20 +0000

Application: Bitcoin Core

Feature: Enhanced privacy by change obfuscation

Operation: Provide a user selectable 'Enhanced privacy' option for transaction creation, when true the transaction randomly distributes change across up to twenty output addresses (minimum five?), provided each output is not dust.

Suggestions: Perhaps limit the total random number of addresses to distribute to by change amount. Optionally: If necessary, additional inputs can be selected if available to increase change although consider if this may eventually result in a decrease in obfuscation in some cases when the outputs are spent.

Issues: Transaction cost will be higher for the initial spend with the change due to increased outputs and, possibly for later spending the change depending on the future spend amount(s) and the number of inputs required.

Argument: If transaction linkage is possible, it is still possible with the obfuscated change but, it is far more difficult to guess what was retained by the owner of the originating utxo's unless the new change outputs are spent together in the same transaction.

Regards,

Damian Williamson