  The second world war saw a major influx of mathematical talent into the areas
of cryptanalysis and cryptography. This was particularly true at the UK's
Government Codes and Cypher School (GCCS) at Bletchley Park. The success of
introducing mathematical thinking into activities previously dominated by
linguists is well-studied, but the reciprocal question of how the cryptologic
effort affected the field of mathematics has been less investigated. Although
their cryptologic achievements are not as celebrated as those of Turing, Tutte
and Welchman, Bletchley Park's effort was supplemented by more eminent
mathematicians, and those who would achieve eminence and provide leadership and
direction for mathematical research in the United Kingdom. Amongst their number
were Ian Cassels, Sandy Green, Philip Hall, Max Newman and Henry Whitehead.
This paper considers how the experience of these and other mathematicians at
Bletchley Park may have informed and influenced the mathematics that was
produced in their post-war careers.
