Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 11 Mar 2005 18:36:20 +0100
From:      Anthony Atkielski <atkielski.anthony@wanadoo.fr>
To:        freebsd-questions@freebsd.org
Subject:   Re: Clock slew vulnerability in FreeBSD?
Message-ID:  <524507450.20050311183620@wanadoo.fr>
In-Reply-To: <56f756c499c68c62c6706fef0e896cb2@chrononomicon.com>
References:  <751280160.20050311034539@wanadoo.fr> <1735368246.20050311044408@wanadoo.fr> <56f756c499c68c62c6706fef0e896cb2@chrononomicon.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Bart Silverstrim writes:

> Wouldn't the skew resolution necessary for this tracking technique
> become useless with temperature variations, humidity, etc. that can 
> affect most systems over the course of the day/week/year?

That's one of my questions, too.  A technique that could identify 100
million different computers (as some people have speculated) would need
reliable precision to at least nine decimal places.  That's a pretty
tall order for something like measurement of clock slewing in TCP
packets.

There are other related problems.  So you identify computer A using its
unique clock slew.  How do you prove that in court?  If you move the
machine, or if you change anything about it, the RTC is likely to vary a
bit, changing the slew to a different value.  Just temperature
variations in the room can do that.

-- 
Anthony




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?524507450.20050311183620>