Log in

Previous Entry | Next Entry

The 1 June 2010 Reigster has an article, Met lab claims 'biggest breakthrough since Watergate';Power lines act as police informers.

An excerpt:
ENF relies on frequency variations in the electricity supplied by the National Grid. Digital devices such as CCTV recorders, telephone recorders and camcorders that are plugged in to or located near the mains pick up these deviations in the power supply, which are caused by peaks and troughs in demand. Battery-powered devices are not immune to to ENF analysis, as grid frequency variations can be induced in their recordings from a distance.

At the Metropolitan Police's digital forensics lab in Penge, south London, scientists have created a database that has recorded these deviations once every one and a half seconds for the last five years. Over a short period they form a unique signature of the electrical frequency at that time, which research has shown is the same in London as it is in Glasgow.

On receipt of recordings made by the police or public, the scientists are able to detect the variations in mains electricity occuring at the time the recording was made. This signature is extracted and automatically matched against their ENF database, which indicates when it was made.
The technique can also be used to detect or rule out covert editing of audio. ENF analysis is made possible by the growing use of digital recording and its greater timekeeping accuracy over analogue.

Digging further in my attempts to learn more about ENF, I searched for info about Dr. Catalin Grigoras, a Rumanian audio forensics expert whose research is the basis for London Met's continuing work.

Dr. Grigoras' Web site has useful links to his papers & presentations (some behind paywalls but few are cost-free): http://www.forensicav.ro/



( 1 comment — Leave a comment )
Oct. 20th, 2010 10:52 am (UTC)
I am very impress on your information , Its a really very impressive blog. I really got some another very nice information , so thanks for sharing these tips,usb protection.
( 1 comment — Leave a comment )


crypto. hebern, secret
Jonathan D. Abolins

Latest Month

April 2013


Page Summary

Powered by LiveJournal.com
Designed by Tiffany Chow