In a remarkable case of 'scientific parallelism', a secret British group and a public American group, working entirely independently, made very similar discoveries during the early 1970s. The discovery was a revolutionary new form of cryptography. What was 'Non-secret Encryption' to the British and 'Public Key Cryptography' to the Americans, is at the heart of internet commerce and is achieving wide use throughout telecommunication.
Whit Diffie, whose interests are both historical and scientific, was a participant in the American endeavour and has studied the work of the British team since the early 1980s. At a UCL public lecture on 29 April 1999, he ranged from reflections on the personal experience of discovery to an examination of the techniques developed and analysis of the differences in thinking of the two groups.
The talk was organised by the British Society for the History of Mathematics and the Department of Computer Science, UCL.