[lotuseclat79]

Are timestamps enabled for each packet on your computer?

Take the TCP/IP Analyzer SpeedGuide.net test to find out:
http://www.speedguide.net:8080/
If the Timestamps (RFC1191) = ON, then your computer can be tracked to the ends of the earth on the basis of your Clock Skew.

You can disable the timestamps for Windows with the TCPOptimizer program from speedguide at: http://www.speedguide.net/downloads.php

Or, you can edit the registry.

Clock Skew and your computer's fingerprint:
Read this (dated March 13, 2005) at: http://www.spywareinfo.com/newslette...2005/mar13.php

In other words, in the "Kiss your Anonymity Goodbye" article unless you either falsify the timestamps on each packet or instruct the computer not to attach them to each packet - your computer clock skew can identify your computer.

Story Link: http://www.zdnet.com.au/news/securit...9183346,00.htm
Remote Physical Device Fingerprinting (PDF paper download available at): http://www.caida.org/publications/pa...ingerprinting/ (9.94MB)

-- Tom

[WhitPhil]

Note that it is the identity of the computer that can be seen, NOT the identity of the user of that computer.

[brendandonhu]

Remember it would also require your computer to send TCP/IP packets to someone that's trying to track you for them to measure the clock the skew, and those packets would have to be identified as coming from the same computer.

[lotuseclat79]

Originally Posted by brendandonhu

Remember it would also require your computer to send TCP/IP packets to someone that's trying to track you for them to measure the clock the skew, and those packets would have to be identified as coming from the same computer.

Not if "they" are tapped into the Internet backbones and have a way to trap your traffic from listening to everything. "They" probably are using Carnivore surreptitiously anyway - you do know whom I mean by "they" I presume. Assumption is that packets are timestamped.

-- Tom

[BanditFlyer]

Good Info, Tom,

Thanks

[brendandonhu]

Not if "they" are tapped into the Internet backbones and have a way to trap your traffic from listening to everything.

Also remember that the methods in the study that work on default Windows 2000/XP require communicating with the machine being fingerprinted or modifying packets-- packet monitoring isn't enough to do it. Of course, if all traffic is being monitored, you have bigger problems than clock skew anyway