Comment by sdoowpilihp
12 years ago
There is an aspect of deniability though it's weak, especially with something that is both updated at regular time intervals, and was otherwise reliably updated.
Maybe a better solution would be a system that generated an indicator with only a certain level of assurance that it is accurate, and have it err on the side of NOT giving false positives. This would have a built in level of deniability.
I wish it were as easy as that, but the thing is that there is always a human in the loop to design such a system, and that person does not have deniability. For instance, say that on days without subpoenas, bob@google flips a coin, and only updates the canary if it comes up heads. With a subpoena, he doesn't update the canary regardless of the coin flip. If I were a government prosecutor, I would simply subpoena bob@google and ask him under oath whether he ever disregarded the coin flip.
Of course, this all assumes that this disclosure even comes to the government's attention. But that's a calculated risk any canary-user will take.
That is where plausible deniability comes in to play. He could lie under oath, and it's still plausible that he is telling the truth.
The only play on the government's part at that point, as far as I can tell, would be to acknowledge that the NSL did exist in order to prove that he was lying. They likely would not do this though, as it defeats the purpose of the gag order.