COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	.require "let.pub[let,jmc]" source
C00007 ENDMK
C⊗;
.require "let.pub[let,jmc]" source;
∂AIL %2Nature%1↓4 Little Essex Street↓London WC2R 3LF↓UNITED KINGDOM∞

Sirs:

	Your editorial "Public-key Cryptography Muddle" of 4 September 1980
unfortunately muddles further the issue concerning academic research
in cryptography.  Public-key cryptography was apparently unknown to
professional cryptographers before it was proposed by Diffie and
Hellman in 1976.  However, even before that academic research in
cryptography had begun and was beginning to worry the American (and
maybe the British) cryptographic establishment.  Before computers
the use of non-trivial codes and ciphers required special equipment or
very tedious clerical work and was used only by people and institutions
with very strong motivations.  Even such people often used easily
breakable ciphers.  There was almost no academic work in cryptography,
because ciphers were tedious to use and test, and because scientists
(mainly mathematicians) who were interested in cryptography were willing
with the government institutions and observe secrecy rules.

	The situation changed when computers made the implementation
of secrecy systems easy and increased the amount of data storage
and communication whose privacy seemed worthwhile ensuring by
encryption.  Moreover, by the late 1960s a generation of scientists
had arisen that was not sufficiently motivated by patriotic and security
considerations to accept security restrictions.  This situation
resulted in the National Bureau of Standards Data Encrypion Standard
based on work by IBM and its criticism by Diffie, Hellman and others
on the grounds that it wasn't secure enough to protect against
massive computational attack by currently conceivable special purpose
computers.

	The invention of the concept of a public-key system by
Diffie and Hellman and an interesting realization by Adelman, Rivest
and Shamir excited additional academic and public attention.

	The issue emphasized recently by Admiral Inman of NSA is
whether some restrictions on academic publication in cryptography
would aid the security of the Free World.  This presumably depends
on secret matters like what foreign ciphers are currently being read
and what unciphered material might become securely ciphered as a
consequence of academic and commercial cryptographic developments.
One could certainly imagine that Admiral Inman's presumed goal of keeping
good cryptography away from people whose messages NSA would like
to read is already lost because of publication that has already
occurred and that NSA is merely acting through bureaucratic momentum.
Moreover, many scientists regard their freedom to publish as more
important than military advantage for the Free World.

	However, if there is a useful part of the academic community
that would accept some restrictions if confident that they were justified,
then people could be found both trusted by the academic community
and clearable by NSA who could report whether restriction of publication
would be worth the academic pain, even though they could not report
the evidence for such a conclusion.

.sgn