1994-07-06 - Re: stream ciphers and realtime communications?

Header Data

From: schneier@chinet.chinet.com (Bruce Schneier)
To: jrochkin@cs.oberlin.edu (Jonathan Rochkind)
Message Hash: ee614ce3aedfa0cf1079689bfb89ef6076cd768bca2882172603d94b740a7828
Message ID: <m0qLce4-0002IqC@chinet.chinet.com>
Reply To: <199407061721.NAA19360@cs.oberlin.edu>
UTC Datetime: 1994-07-06 19:49:05 UTC
Raw Date: Wed, 6 Jul 94 12:49:05 PDT

Raw message

From: schneier@chinet.chinet.com (Bruce Schneier)
Date: Wed, 6 Jul 94 12:49:05 PDT
To: jrochkin@cs.oberlin.edu (Jonathan Rochkind)
Subject: Re: stream ciphers and realtime communications?
In-Reply-To: <199407061721.NAA19360@cs.oberlin.edu>
Message-ID: <m0qLce4-0002IqC@chinet.chinet.com>
MIME-Version: 1.0
Content-Type: text/plain


Stream ciphers are very efficient in hardware encryption applications, but
suck eggs in software.  They have been the workhorse of military cryptography
for at least 40 years, but those are all hardware applications.  If you
are working in software, it is much easier to deal with data in 64-bit
blocks than in individual bits.  The Shrinking Generator, which has only
two LFSRs, is slower than DES in software.  You need to iterate the
Shrinking Generator 64 times to encrypt the data that DES handles in just
one iteration.

Bruce




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