[3967] in cryptography@c2.net mail archive
Re: Matrix stuff...
daemon@ATHENA.MIT.EDU (Stefan Lucks)
Thu Jan 14 10:46:21 1999
Date: Thu, 14 Jan 1999 09:24:21 +0100 (CET)
From: Stefan Lucks <lucks@informatik.uni-mannheim.de>
To: pcw@flyzone.com
Cc: cryptography@c2.net
In-Reply-To: <3.0.6.32.19990113195555.007eb580@mail.flyzone.com>
On Wed, 13 Jan 1999 pcw@flyzone.com wrote:
> I vaguely remember reading several papers about matrix based public-key
> systems back in the early 1980's. They were in Cryptologia, I think. This
> idea doesn't sound too different, but my memory might be wrong. Can anyone
> else offer any insight?
You'll find one such system (from the *late* 1980's, though) in:
H. Isselhorst:
The use of Fractions in Public-Key Cryptosystems,
Eurocrypt '89, page 47-55.
Roughly spoken, the scheme was based on using an invertible matrix A as
the secret key, but only an approximation of A as the public key. The
decryption algorithm used the inverse of A -- which is easy to find if A
is known, but quite hard if only an approximation of A is known.
I don't think this has much in common with recent developments. The
security of Isselhorst's public-key system is quite questionable:
J. Stern, P. Toffin:
Cryptoanalysis of a Public-Key Cryptosystem Based on
Approximateions of Rational Numbers,
Eurocrypt '90, page 313-317.
Stefan
--
Stefan Lucks Th. Informatik, Univ. Mannheim, 68131 Mannheim, A5, Germany
e-mail: lucks@th.informatik.uni-mannheim.de
home: http://th.informatik.uni-mannheim.de/m/lucks/
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