System time as cookie/deanonymization?

Georgi Guninski guninski at
Wed Jul 27 00:58:58 PDT 2016

One of these days, I saw a box whose system time was off by about a
minute. No big deal in this case, but significantly smaller difference
is a fingerprint of the machine:  Alice is off by -0.58390128310s, etc.

Getting very good approximation of system time from a browser is not
very trivial, but likely writing something like NTP in javascript is

Read that tor browser bundle downgrades the clock resolution possibly
for other reasons, but IIRC the resolution was enough for this purpose.

Can this be used for cookie/deanonymization?

Anyone already implemented it/wrote a paper?

Quick web search didn't answer exactly this.

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