Post by Shadow on Dec 16, 2005 6:56:12 GMT -5
New Scientist
# 18:06 13 December 2005
# NewScientist.com news service
# Barry Fox
For over 30 years, Barry Fox has trawled the world's weird and wonderful patent applications each week, digging out the most exciting, intriguing and even terrifying new ideas. His column, Invention, is available exclusively online. Scroll down for a round-up of previous Invention articles.
Sonic watermark
Counterfeiters and forgers will soon face a new challenge - creating fake credit or ID cards that generate the right noise.
An audio watermarking scheme, developed at Philips’s labs in the Netherlands, uses cards made from a polymer with a carefully distributed pattern of impurities buried inside. When the card is placed into a reader, a miniature loudspeaker injects sound into the material and a miniature microphone picks up the signal that comes out the other side.
The signal will be distorted in a characteristic way as a result of the impurities in the card, and the resulting sound is checked against a stored reference to ensure the card is genuine. To make the system even more secure, the patent suggests using several speakers and microphones at different positions on the card.
# 18:06 13 December 2005
# NewScientist.com news service
# Barry Fox
For over 30 years, Barry Fox has trawled the world's weird and wonderful patent applications each week, digging out the most exciting, intriguing and even terrifying new ideas. His column, Invention, is available exclusively online. Scroll down for a round-up of previous Invention articles.
Sonic watermark
Counterfeiters and forgers will soon face a new challenge - creating fake credit or ID cards that generate the right noise.
An audio watermarking scheme, developed at Philips’s labs in the Netherlands, uses cards made from a polymer with a carefully distributed pattern of impurities buried inside. When the card is placed into a reader, a miniature loudspeaker injects sound into the material and a miniature microphone picks up the signal that comes out the other side.
The signal will be distorted in a characteristic way as a result of the impurities in the card, and the resulting sound is checked against a stored reference to ensure the card is genuine. To make the system even more secure, the patent suggests using several speakers and microphones at different positions on the card.