Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 03 Mar 2005 19:10:16 -0500
From:      "Perry E. Metzger" <perry@piermont.com>
To:        "Poul-Henning Kamp" <phk@phk.freebsd.dk>, tls@rek.tjls.com
Cc:        cryptography@metzdowd.com
Subject:   Re: FUD about CGD and GBDE
Message-ID:  <87wtsogtjr.fsf@snark.piermont.com>
In-Reply-To: <20050303215114.GA18604@panix.com> (Thor Lancelot Simon's message of "Thu, 3 Mar 2005 16:51:14 -0500")
References:  <Pine.NEB.4.62.0503031625170.12890@server.duh.org> <11487.1109886334@critter.freebsd.dk> <20050303215114.GA18604@panix.com>

next in thread | previous in thread | raw e-mail | index | archive | help

Thor Lancelot Simon <tls@rek.tjls.com> writes:
> I think there's a misunderstanding here.  Why do you think secrecy
> (unpredictability?) is an important property of an IV for a block
> cipher used in CBC mode?  It's not an encryption key, it's an IV.

Indeed. The IV can (subject to some constraints) be anything you
like. Not having it public at very, very best denies one block from
the ciphertext to the attacker -- ultimately not very useful in this
application to prevent cracking given the low unicity distance.

-- 
Perry E. Metzger		perry@piermont.com



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?87wtsogtjr.fsf>