1996-01-25 - Re: Why is blowfish so slow? Other fast algorithms?

Header Data

From: “James A. Donald” <jamesd@echeque.com>
To: cypherpunks@toad.com
Message Hash: 050e8102e0720c8601d27774d9ed177f5815b0ed6c9506a88c321a293e570621
Message ID: <199601250629.WAA16623@mailx.best.com>
Reply To: N/A
UTC Datetime: 1996-01-25 07:58:26 UTC
Raw Date: Thu, 25 Jan 1996 15:58:26 +0800

Raw message

From: "James A. Donald" <jamesd@echeque.com>
Date: Thu, 25 Jan 1996 15:58:26 +0800
To: cypherpunks@toad.com
Subject: Re: Why is blowfish so slow?  Other fast algorithms?
Message-ID: <199601250629.WAA16623@mailx.best.com>
MIME-Version: 1.0
Content-Type: text/plain


At 07:32 PM 1/23/96 -0500, David A Wagner wrote:

>If you want authentication, you must use a crypto-strength MAC.
>Encryption (be it RC4, DES, etc.) is not enough.

Not so:  If the message is encrypted and checksummed with a simple
not non cryptographic checksum, this gives you everything a MAC 
gives you, plus the message is secret.

MACs are only useful in the strange and unsual case where you want
authentification using a symmetric key, but you want to transmit in
the clear.  I cannot see any reason why anyone would ever wish to use
a MAC except perhaps to obey government bans on encrypted messages.

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