[6754] in cryptography@c2.net mail archive
Looking for a cryptographic primitive
daemon@ATHENA.MIT.EDU (bram)
Thu Mar 9 09:30:14 2000
Date: Thu, 9 Mar 2000 05:50:50 -0800 (PST)
From: bram <bram@gawth.com>
To: cryptography@c2.net
Message-ID: <Pine.LNX.4.10.10003090547340.20126-100000@ultra.gawth.com>
MIME-Version: 1.0
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Does anybody know of a field in which a + b and a * b can be computed
quickly but (and this is important) it's computationally intractable to
compute the additive inverse of a?
I need it for a technique I'm working on.
-Bram
[Bram: All fields of n elements are isomorphic to all other fields of
n elements, and in any of the fields I'm familiar with, it is trivial
to compute an additive (or multiplicative) inverse. Given this, I
suspect what you want to do is rather hard -- you would have to
conceal the isomorphism to, say, GF(n) somehow. Any readers have any
other insights here? --Perry]
