full-disclosure - Re: Skype chat encryption with OTR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20080620084633.1ae9c014@wssyg117.sygroup-int.ch>
Date: Fri, 20 Jun 2008 08:46:33 +0200
From: Tonnerre Lombard <tonnerre.lombard@...roup.ch>
To: JM <ubahmapk@...il.com>
Cc: full-disclosure@...ts.grok.org.uk
Subject: Re: Skype chat encryption with OTR

Salut, JM,

On Thu, 19 Jun 2008 08:55:01 -0500, JM wrote:
> Actually, the shared keys are *published* once they're discarded to
> improve plausible deniability.  That lets anyone forge an *old*
> message, but ensures you wont' accept a forged message during the
> course of the conversation.

Oh, hm, right. But either way, the plausible deniability is provided
only by that mechanism, not through changing the keys after each
message. That's only the mechanism used to recover the security of the
algorithm after key disclosure. It's the typical cryptographic type of
proof if authenticity which is executed in a way which is only ever
trustworthy to the recipient, so the recipient cannot prove anything to
others with it.

				Tonnerre
-- 
SyGroup GmbH
Tonnerre Lombard

Solutions Systematiques
Tel:+41 61 333 80 33		Güterstrasse 86
Fax:+41 61 383 14 67		4053 Basel
Web:www.sygroup.ch		tonnerre.lombard@...roup.ch

Download attachment "signature.asc" of type "application/pgp-signature" (836 bytes)

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/