I want to verifiably demonstrate that there are no hidden partitions, or hidden messages in a given message.
In this scenario, assume the subject is being monitored (consensually) and agrees to align with whatever audits or restrictions need to be in place. OR the receiver agrees to have messages filtered as to reduce the chance such a message is being received.
Edit: I want to highlight the fact that I'm looking for ways to reduce the statistical probability that a subversive message exists... since the premise of steganography uses statistics to identify these covert messages. Basically, I'm just trying to help them along but implementing anti-stenographic techniques.
How can I normalize media in such a way as to reduce the chance a hidden message is contained therein?
In the case of a TrueCrypt hidden partition, I am thinking that I can show that all unallocated (or unused space) is set to either 1 or 0, however that verification process would be time consuming.
In the case of steganography, I can normalize images, to a simple format of my choosing which would add noise or eliminate any message if present.
Finally in the case of written text, I can perform substitutions (Thesaurus) or grammar replacements as needed (Yoda-fi the text for lack of a direct example)
Delay the time that a message is sent, or only release messages at a fixed time