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From: Luke Dashjr <luke@dashjr.org>
To: bitcoin-development@lists.sourceforge.net
Cc: Justus Ranvier <justusranvier@riseup.net>
Subject: [Bitcoin-development] [SPAM] Re: determining change addresses using the least significant digits
Date: Fri, 6 Feb 2015 04:08:42 +0000	[thread overview]
Message-ID: <201502060408.43700.luke@dashjr.org> (raw)
In-Reply-To: <54D431FD.9020904@riseup.net>

On Friday, February 06, 2015 3:16:13 AM Justus Ranvier wrote:
> On 02/04/2015 02:23 PM, Isidor Zeuner wrote:
> > 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.
> 
> Another possible approach is to randomize the number of change outputs
> from transaction to transaction.
> 
> Doing this, it would be possible to make change outputs that mimic
> real spends (low number of s.d.)

This uses more data.

Why not just round change down (effectively rounding fee up)?

Luke



  reply	other threads:[~2015-02-06  4:09 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-04 14:23 [Bitcoin-development] determining change addresses using the least significant digits Isidor Zeuner
2015-02-06  1:17 ` Peter Todd
2015-02-06  3:16 ` Justus Ranvier
2015-02-06  4:08   ` Luke Dashjr [this message]
2015-02-06 10:11 ` Wladimir
2015-02-06 15:08   ` Jeff Garzik
2015-02-06 17:50     ` Justus Ranvier
2015-02-06 18:21 ` Gregory Maxwell

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