Code Poetry
and Text Adventures

by catid posted (>30 days ago) 6:43pm Thu. Jul 11th 2013 PDT
Something that I came up with ages ago is actually somewhat useful to identify phones:

What you do is run a simple time synchronization protocol over the Internet to calculate the difference in clock ticks since the iOS device started up with the server ticks.

The API is mach_absolute_time and you can convert it to nanoseconds from ticks.

The clock delta is fairly unique for each device, but if you want to identify it *between reboots* then you can also measure clock drift, which takes about 2 minutes to accurately measure across several time synchs.

Pair that with general info about the device that cannot change (like screen size etc) and you have a pretty good discriminator for a cellphone.