> Your insurance company, faced with a claim that the well established auto dealership and data brokers are making things up for no obvious reason, would just conclude your denial is a lie and double your insurance costs anyway. Well established? Won't have errors? The wrong notes are made all the time on the side of the company, information is frequently misinterpreted, misattributed, etc. You can always claim they made a mistake. Unless of course you give them undeniable evidence. > Only if it was disclosed. Again the issue seems to be loss of privacy. Disclosures will always happen. Chances are everybody will screw up sometimes. But if you can claim you're simply not involved, and that the name was changed, then what? Then it changes from a guarantee of getting screwed to that there need to be information unique to you, something nobody else knew, in there for anybody to be able to blame you. The evidence against you is no stronger than somebody's word. > So if your boss finds a highly plausible chat log of you talking to a competitor about working there, you will say "no the chat log was forged by the competitor" and your boss will say, "oh ok, no problem, how could I ever doubt you" ? > > I think deniability in this case would be unlikely to have any effect. Even a short mention in an otherwise unrelated discussion is sufficient to get in trouble. Yes, that could easily be forged. I'm not exclusively talking about a leak of negotiations or anything else close to that. For a text file to be more convincing than you are, they need to know the full history of it. What device does it come from, who does it being to, where has it been, etc. > So show the full chat log and turn the tables on the bully. Problem solved. Situation A) it doesn't exist. The rest of the conversation was held elsewhere. Situation B) the rest of the contents of it is even more private, you'll lose more on publishing it than not. Both those are frequently occurring today. > Manning already used a deniable chat medium and was hosed anyway, despite being somewhat technically proficient. He told somebody he couldn't trust, and from there on I assume they found an amount of physical evidence in the investigation that's too hard to deny (all those burned CD:s, etc). > For deniability to have any real world effect, there'd need to be a LOT of people forging chat logs pretty routinely. As it's only relevant when there's some breakdown in privacy, and that should hopefully be rare in a good cryptographic system, getting people to routinely forge or edit logs seems .... hard. It doesn't need to be routine, just frequent enough that nobody assumes authencity.