Signal Processing Stack Exchange is a question and answer site for practitioners of the art and science of signal, image and video processing. It only takes a minute to sign up.
Sign up to join this community
I am planning to do a project on data hiding using codeword substitution in encrypted video.
So as an enhancement I am planning to use this data hiding technique for tampering detection, for which I'll be extracting some information from the frames and will be hiding it in a selected frame.
I am actually using the concept of digital signature. The thing is that I am in search of a data to hide. A data which has to be extracted from the frames for verification on the receiver side.
I hope I'm understanding you correctly:
What you want to do is hide data in the encrypted version of a video?
That will break everything. Simple as that. A very important aspect to good encryption is that a small change in the cleartext data (your unencrypted video) will result in a completely changed encrypted video; the same applies in the other direction -- you change a bit in your encrypted video stream, you completely break at least one block of cleartext data. That's not hiding -- in fact, it's the opposite.
Hence, I think your approach is mathematically doomed; but maybe, I'm just misunderstanding.
