Milestone-Nomination:Invention of Public-key Cryptography
Docket Number: 2008-15
Proposed citation in English
Secure communication was believed impossible without exchange of a secret key, with key distribution a major impediment. James Ellis was first to prove that a symmetric secret-key system is unnecessary, and Cliford Cocks and Martin Williamson were first to show how such 'public-key cryptography' could be achieved. By 1975 GCHQ had developed the essential principles but research kept secret until 1997.
Historic significance of this work: its importance to the evolution of electrical and computer engineering and science and its importance to regional/national/international development.
Historical significance and supporting material documentation is attached.
What features or characteristics set this work apart from similar achievements?
The research was carried out in complete secrecy at GCHQ and could not be revealed until it was decided that no further benefit to national security could be achieved by not revealing it. Like the cryptanalysis done during World War 2 at Bletchley Park (now an IEEE Historical Milestone site, since March 2003), the significance of the work was available for public assessment only long after the research was actually carried out.