[8376] in cryptography@c2.net mail archive
Re: Cryptographic Algorithm Metrics
daemon@ATHENA.MIT.EDU (Ben Laurie)
Wed Jan 3 18:11:33 2001
Message-ID: <3A53B09D.BCC0C255@algroup.co.uk>
Date: Wed, 03 Jan 2001 23:07:09 +0000
From: Ben Laurie <ben@algroup.co.uk>
MIME-Version: 1.0
To: Peter Fairbrother <peter.fairbrother@ntlworld.com>
Cc: Greg Rose <ggr@qualcomm.com>, John Young <jya@pipeline.com>,
cryptography@c2.net
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Peter Fairbrother wrote:
> > At Crypto a
> > couple of years ago the invited lecture gave some very general results
> > about unconditionally secure ciphers... unfortunately I can't remember
> > exactly who gave the lecture, but I think it might have been Oded
> > Goldreich... forgive me if I'm wrong. The important result, though, was
> > that you need truly random input to the algorithm in an amount equal to the
> > stuff being protected, or you cannot have unconditional security.
>
> Not so. Perfect compression with encryption works too.
You can argue (reasonably, IMO) that the stuff being protected is the
entropy in the stuff you first thought of, which can be no bigger than
the compressed data.
Cheers,
Ben.
--
http://www.apache-ssl.org/ben.html
"There is no limit to what a man can do or how far he can go if he
doesn't mind who gets the credit." - Robert Woodruff
