Feeds

Time-drift technique fingers PCs

Is this the end of anonymous net access?

  • alert
  • submit to reddit

The essential guide to IT transformation

fingerprint Security researchers have developed a technique for remotely fingerprinting an electronic device using clock skews - small, microscopic deviations in device hardware. In a paper, Remote physical device fingerprinting, Tadayoshi Kohno, lead author and PhD student from the University of California San Diego, explains how the technique could be developed to track hardware wherever it is on the net, or in applications such as computer forensics.

Bruce Schneier, the noted cryptographer, described the approach as "nice work"; but the technique has already generated a fierce debate about its reliability. Mostly, the cryptographic community is discussing the ability of remote device fingerprinting to yield evidence good enough for a court of law - are clock skews stable on a particular PC? But there are wider concerns about device fingerprinting: taken at face value, the technology could end anonymous net access, a cause for celebration for repressive governments everywhere.

Kohno's approach is OS independent and relies on TCP Timestamps in TCP headers to "estimate a device's clock skew [drift] and thereby fingerprint a physical device". At 2000 packets per hour, this skew value has greater than six bits of entropy or enough to uniquely identify one computer in a million, according to Kohno's paper. TCP Timestamps can be turned off in Linux or BSD, but otherwise much data can be obtained from a great distance and without any need to modify a fingerprinted device.

"Our techniques report consistent measurements when the measurer is thousands of miles, multiple hops, and tens of milliseconds away from the fingerprinted device, and when the fingerprinted device is connected to the Internet from different locations and via different access technologies. Further, one can apply our passive and semi-passive techniques when the fingerprinted device is behind a NAT or firewall, and also when the device's system time is maintained via NTP or SNTP," the paper explains.

Kohno developed the research with Andre Broido and KC Claffy at the San Diego Supercomputer Center and presents their findings at the IEEE Symposium on Security and Privacy in California in May. ®

Related stories

Fingerprints as ID - good, bad, ugly?
Biometric sensors beaten senseless in tests
Forensic computing uncloaks industrial espionage
FBI retires Carnivore

Next gen security for virtualised datacentres

More from The Register

next story
Ice cream headache as black hat hacks sack Dairy Queen
I scream, you scream, we all scream 'DATA BREACH'!
Goog says patch⁵⁰ your Chrome
64-bit browser loads cat vids FIFTEEN PERCENT faster!
NIST to sysadmins: clean up your SSH mess
Too many keys, too badly managed
Scratched PC-dispatch patch patched, hatched in batch rematch
Windows security update fixed after triggering blue screens (and screams) of death
Researchers camouflage haxxor traps with fake application traffic
Honeypots sweetened to resemble actual workloads, complete with 'secure' logins
Attack flogged through shiny-clicky social media buttons
66,000 users popped by malicious Flash fudging add-on
New Snowden leak: How NSA shared 850-billion-plus metadata records
'Federated search' spaffed info all over Five Eyes chums
Three quarters of South Korea popped in online gaming raids
Records used to plunder game items, sold off to low lifes
Oz fed police in PDF redaction SNAFU
Give us your metadata, we'll publish your data
prev story

Whitepapers

5 things you didn’t know about cloud backup
IT departments are embracing cloud backup, but there’s a lot you need to know before choosing a service provider. Learn all the critical things you need to know.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?