From: Isidor Zeuner <cryptocurrencies@quidecco.de>
Content-Type: text/plain; charset=UTF-8; format=flowed
To: Bitcoin Development <bitcoin-development@lists.sourceforge.net>
Message-Id: <20150204142323.DEC4BE2DCDE@quidecco.de>
Date: Wed,  4 Feb 2015 15:23:23 +0100 (CET)
Subject: [Bitcoin-development] determining change addresses using the least
	significant digits
Precedence: list

Hi there,

traditionally, the Bitcoin client strives to hide which output
addresses are change addresses going back to the payer. However,
especially with today's dynamically calculated miner fees, this
may often be ineffective:

A user sending a payment using the Bitcoin client will usually enter
the payment amount only up to the number of digits which are
considered to be significant enough. So, the least significant digits
will often be zero for the payment. With dynamically calculated miner
fees, this will often not be the case for the change amount, making it
easy for an observer to classify the output addresses.

A possible approach to handle this issue would be to add a randomized
offset amount to the payment amount. This offset amount can be small
in comparison to the payment amount.

Any thoughts?

Best regards,

Isidor