A Snake-Oil FAQ

[Timothy C. May]

At 3:48 PM 7/21/96, David Sternlight wrote:

>So is your comment. What was broken was not public key, but a particular
>key length (and by implication shorter ones). You can do that with just
>about any system, even a one-time pad, by brute force, but it won't buy you
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>much more than sharpening your skills, for longer keys.

This is not correct. The one-time pad is "information-theoretically
secure," as proved early on by Shannon. This is much more than being
"cryptographically secure," for which the term "brute force" is applicable
(albeit essentially still impossible, for a large enough work factor).

(I just looked at later posts and saw your response to Simon Spero's
rebuttal: "Theoretically Simon is right. Nevertheless one-time pads have
been broken
through trial and error when they have been reused either out of laziness
or force majeure." It is _very_ important that people understand that
"reusing a pad" is not a valid use of a _one-time_ pad. Such misuse, while
important in actual cryptanalytic history, is no more a "brute forcing" of
the pad than is buying a key from an opponent, obtaining it through
burglary, etc. All important methods of cracking codes, but not at all what
is meant by "brute force.")

--Tim May

Boycott "Big Brother Inside" software!
We got computers, we're tapping phone lines, we know that that ain't allowed.
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Timothy C. May              | Crypto Anarchy: encryption, digital money,
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