plausible deniability

[Wei Dai]

On Mon, Jan 29, 2001 at 02:52:03AM -0500, dmolnar wrote:
> I just came across this PhD thesis in philosophy:
> 
> "Cryptography and Evidence" 
> Michael Roe
> http://www.research.microsoft.com/users/mroe/THESIS.PDF

Are you sure this is a thesis in philosophy? It seems to talk about the
rather practical concerns of non-repudiation and its converse, plausible
deniability. The paper reminds me of something I was wondering about: are
there any email security programs that offer plausible deniability as an
option? Sometimes you want to MAC a message with an authenticated
symmetric key instead of signing it in order to preserve plausible
deniability, but PGP for example doesn't seem to offer this.