4 February 1998
Thanks to Richard Snow
The Story Of Non-Secret Encryption (HTML version) by J.H.Ellis (1987) (PostScript version).
The four internal technical papers describing the original systems are now also being made more widely available. These informal technical notes have been set in HTML format for the internet but have not otherwise been edited.
The first demonstration of the ideas behind public-key techniques (which
their inventor James Ellis called Non-Secret Encryption) are described in
The Possibility Of Non-Secret Encryption by J.H.Ellis (1970).
A few years later the first practical implementations of these techniques came with the papers
A note on Non-Secret
Encryption by C. Cocks (1973), which describes what we now call RSA,
Non-Secret Encryption Using A
Finite Field by M. Williamson (1974) , which is essentially Diffie-Hellman,
Thoughts on cheaper Non Secret Encryption by M. Williamson (1976), which details some improvements.
It is interesting to note that although many different ideas for public-key systems have been proposed, the two which have stood the test of time were the first two to be discovered. It is also interesting that the order of discovery in academia was the opposite to the order of discovery at CESG.