[104268] in Cypherpunks
Re: more Toto keys... so what's it all mean
daemon@ATHENA.MIT.EDU (Martin Minow)
Wed Oct 14 14:21:00 1998
In-Reply-To: <199810141529.QAA32138@server.eternity.org>
Date: Wed, 14 Oct 1998 10:49:54 -0700
To: Adam Back <aba@dcs.ex.ac.uk>, cypherpunks@cyberpass.net
From: Martin Minow <minow@pobox.com>
Reply-To: Martin Minow <minow@pobox.com>
Adam Back <aba@dcs.ex.ac.uk> summarizes the Toto-files by noting
>
>As to what it means -- it means that one or more others could have
>been the author of the message the IRS claim Carl Johnson wrote. Heck
>anyone could sign posts with that key now.
>
This suggests that a cynical, paranoid, person could create a
"deniable" signature key by doing what "Toto" did:
1. Choosing a key length that a "very competent attacker" (i.e.
a TLA), and only a "very competent attacker", could factor.
2. Signing a message and leaving the public key that signed
that message on a public site.
Now, when you are accused of signing a message, you can raise
a "reasonable doubt" defence by claiming that the TLA may have
reconstructed the private key that signed the message in question.
Martin Minow
minow@pobox.com
