🚀 go-pugleaf

In article <24267@alice.att.com> reeds@alice.att.com (Jim Reeds) writes:
>Indeed, to an outsider, a challenge problem of form "here is cipher text,
>please supply plain text and description of crypto algorithm" is eminently
>reasonable.  Is this not what Friedman & company did when faced with
>their first Purple traffic?


That's almost the story.  They had plaintext and matching ciphertext.
They also knew the technology available.  They assumed rotor machines
but soon ruled that out -- stumbled on stepping switches by happy
accident.

Those incidents make good stories.

Friedman and company were employed, full time, to do this.  They spent
several years at it.  They succeeded.

If they had failed, that would not mean that the system was secure.
It would only mean that they had failed, so far.


If they had had a captured machine with operations manual (and maybe some
old key sheets) and still couldn't break any new traffic, *that* would
have meant that the system was secure.

-- 
-- <<Disclaimer: All opinions expressed are my own, of course.>>
-- Carl Ellison						cme@sw.stratus.com
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