Interesting new stego application

Udhay Shankar N udhay at
Fri Mar 23 11:41:58 EDT 2007

Hiding messages in plain sight
Mobile phone reads an invisible code
The phone can read invisible images on printed paper

A technology that can "hide" information in plain sight on printed 
images has begun to see the first commercial applications.

Japanese firm Fujitsu is pushing a technology that can encode data 
into a picture that is invisible to the human eye but can be decoded 
by a mobile phone with a camera.

The company believes the technology will have spin off implications 
for the publishing industry.

"The concept is to be able to link the printed page into the digital 
domain," said Mike Nelson, general manager for sales operations at 
Fujitsu Europe.

The technique stems from a 2,500-year-old practice called 
steganography, which saw the Greeks sending warnings of attacks on 
wooden tablets and then covering them in wax and tattooing messages 
on shaved heads that were then covered by the regrowth of hair.

Fujitsu's technique works by taking advantage of the sensitivities of 
the human eye, which struggles to see the colour yellow.

"The key is to take the yellow hue in the picture and we skew that 
ever so slightly to create a pattern," said Mr Nelson.

"A camera is perfectly sensitive to that yellow hue but the human eye 
doesn't see it very well.

"Any camera, even those in mobile phones, can decode it very easily."

Pictures printed with the technique look perfectly normal but a 
camera can see the code printed into the image.

The technique can currently store just 12 bytes of information - soon 
to rise to 24 - the equivalent amount of data in a barcode.

That data could be a phone number, a message or a website link.


((Udhay Shankar N)) ((udhay @ ((

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