Clock slew vulnerability in FreeBSD?

Anthony Atkielski atkielski.anthony at
Fri Mar 11 09:36:22 PST 2005

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

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.


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