Thursday, September 21, 2006

Tamper detection

How do you tell if audio or video evidence has been tampered with? If protections were built in before hand, such as with watermarking, a CRC (cyclical redundancy check), or hash (e.g. MD5), it is easy. If not, then what? This popular technical media article from CNET on tamper detection for photos (photographs) gives a decent overview.


Keith said...

Maybe it was all the recent photoshopping by MSM local stringers, but here is another photo tamper detection press release (this time from John Hopkins Applied Physics Laboratory, also known as APL):

a.a said...

Very interesting.

Prof Farid's group seems to have a number of publications, almost all dealing with photographs. This includes a recent phd thesis.

I wonder how this would scale to audio (starting with just the definition of authenticity).

Audio and image data are as 'similar' as they are different.

I'm 'guardedly optimistic' :).