From: "Perry E. Metzger" <perry@imsi.com>
Date: Tue, 30 Aug 94 06:00:50 PDT
To: Jonathan Cooper <entropy@intnet.net>
Subject: Re: e$ as "travellers check?
In-Reply-To: <Pine.3.89.9408292156.A25133-0100000@zeus>
Message-ID: <9408301300.AA12819@snark.imsi.com>
MIME-Version: 1.0
Content-Type: text/plain



Jonathan Cooper says:
>    No - it just makes the point that there is almost nothing which is 
> "not forgeable" with a suitable expenditure of effort & resources.

That depends on definitions. For instance, if I say "without stealing
a copy of our one-time pad, or using coercion on one or the other of
us, it would be impossible to forge a message between myself and my
correspondant who shares a one-time pad with me, given that we
properly use the one-time pad only once", I'm being reasonably correct --
no amount of expenditure of resources will do better for you than a
random guess.

It isn't true that "anything can be done given enough effort". Some
things cannot be done period, and some things cannot be done given
that we live in a finite universe.

Myself, I worry about the physical security of my keys a lot more than
about someone factoring them in most instances.

Perry