X-Trace

[Steve Crook]

On Tue, Oct 04, 2011 at 02:12:29PM -0500, John F. Morse wrote:
> I have a user concerned about privacy, specifically his IP being displayed.
> 
> After his request several years ago, I changed the
> "NNTP-Posting-Host" option in /etc/news/inn.conf to:
> 
> addnntppostinghost:     false
> 
> That took care of one possible concern, but now X-Trace is the issue.

Hi John,

In Julien's reply he presents a good example of how to strip the X-Trace
header.  You should also consider including either an Injection-Info or
NNTP-Posting-Host header so users and filtering software can link posts
to a common source.  This doesn't have to be a real IP address or
hostname.  A cryptographic hash is a good solution and can be salted[1]
to preserve users' anonymity.

I'll publish an example of how to do it on my Cleanfeed FAQ page.

[1] http://en.wikipedia.org/wiki/Salt_%28cryptography%29

Steve