COMMENTS AND THOUGHTS FROM READING THE BOOK, 'THE MAN WHO BROKE PURPLE', BY RONALD CLARK

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80B01554R003300010024-3
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 2
• Document Creation Date: December 16, 2016
• Document Release Date: November 30, 2004
• Sequence Number: 24
• Publication Date: January 9, 1978
• Content Type: SUMMARY

Approved For R"se 2005/01/13 : CIA-RDP80BO1554RW3300010014AN 1978
COMMENTS AND THOUGHTS FROM READING THE BOOK,
THE MAN WHO BROKE PURPLE, BY RONALD CLARK
1. William Freedman believed there was no cipher system that
could not be broken down nor did he believe that big computers were
of much use in cryptoanalysis. It appears he was out of date on
this latter point, but particularly when you take into account that
computers can be used for cryptoanalysis it may strengthen his first
point.
a. How do we use computers for cryptoanalysis?
b. How can we be confident that our systems are
not compromised?
(1) What protections do we have for super secret
information? Is the encryption different?
(2) What do we do to check whether our systems
are breakable or not? Do we actually attempt to
exploit them with some of the same diligence we do
other systems?
(3) What do we know about the size and extent
of the Soviets' cryptoanalysis endeavor _- its history
and its present configuration?
2. (Page 114). It was 1929 when Henry Stimson said that "gentlemen
do not read each others mail." Immediately thereafter, at State Depart-
ment initiative, the "Black Chamber" cryptoanalytic organization was
disestablished. In May 1929, the Christian Science Monitor commented:
"This fine gesture will commend itself to all who are trying to develop
the same standards of decency between governments as exists between
individuals."
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a. Fortunately the work of the Black Chamber
went on in other guises. What do we know about our
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3. When we entered World War 11 we certainly a any
cryptographic systems which Freedman thought were truly secure. We
simply used the best we could. The book does not make it clear whether
Freedman feels we ever did develop totally secure systems. How can we:
be quite so confident today?
4. When there was a leak through the Chicago Tribune on our having
broken Purple, there were two side effects:
a. Distribution of Purple material was drastically
cut down and this may have affected the analysis for the
Pearl Harbor situation.
b. It opened up the possibility of the Japanese
sending deliberately misleading messages which they knew
we were deciphering.
When Mrs. Freedman became the principal cryptographer in 1941 for OSS,
she instituted the secrecy oath.
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