Page 55 - WashingtonSyCip_Bio_Excerpt_2nd_Edition

Passenger on a Ship

From Bombay, Wash took a long, slow ride on a filthy, rundown cattle train to
Calcutta. “The camp was outside Calcutta, on the banks of the Hoogly River that
flows into the Ganges before emptying into the Bay of Bengal. The tents were pitched
on that land. Occasionally a dead body would surface on the waters. Life was not
valuable in India then,” Wash recalls.

The cryptography center had separate buildings for cryptographers. The teletype
operators who listened to messages and typed out the numbers were in another
building. Wash, the only Filipino, joined about 30 cryptographers who worked under
an American commander. Across the fence were their British counterparts. “They had
scotch, but we had beer. A bottle of scotch was the equivalent of a case of beer, and
we bartered across the fence. It was hot, so iced beer or scotch with water was great.”

The cryptographers worked on transcripts of intercepted Japanese communications.
There were no computers then, and they used IBM sorting machines that couldn’t
break codes by themselves but could reduce the possibilities. The codebreakers began
with a code chart with a thousand blanks, then worked their way to coherence,
beginning with the knowledge, for example, that yesterday, five bombers had been
sent to bomb a certain place; this was the specific information one looked for, the
pattern by which other messages and meanings could be discerned.

“We were given the teletype operators’ reams of papers with series of numbers. That
was the raw material. The code system worked like this: if you had a number like
589, you tried to figure out the additive. But the additive was a non-carry-forward
additive, so first you had to see what it could be. The message did not begin at the
first numbers, and could be at any part of a hundred numbers, so first you had to see
where it started. Once you deciphered a message, the following ones were easier. And
then one day the codes changed, so you had to start all over again. It was like auditing
in many ways. You looked for clues.”

If the cryptographers read a message ahead of an event, the Air Force sent out
interceptors to challenge the bombers. If not, they used the information on the
field as a guide to breaking codes post-mortem. Not all messages had to do with
movements or attacks. Sometimes it was about malaria, but even this information
said something about the status and condition of enemy troops. Secrecy and security
were of paramount importance.

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