Who are the “real” founders of Public Key Cryptography?

                                                                                                                                       Figure 1

In a nut shell, Public-key cryptography uses asymmetric algorithms in communications devices such as computers and mobile equipments to encrypt and decrypt messages. The algorithm on the sender's end uses a code, or key, to encrypt a message, and the recipient uses a different key to decrypt it which relates with the meaning of  “asymmetric."

                                                                                                        

As most people know already, the founders of public key technology are the researchers at Stanford and MIT who discovered it in 1976. More specifically, they are Whitfield Diffie, Martin Hellman, and Ralph Merkle. [1] Later on, their invention was named as “Diffie-Helman Key Exchange”. Although in 2002, Hellman suggested the algorithm should be called as Diffie-Hellman-Merkle key exchange, still it uses without Merkle’s name in most cases. Actually that is not the question. [2]

                                                Figure 2 - Left to Right : Merkle, Hellman and Diffie

In early 1970’s, British researchers named James Ellis, Clifford Cocks, and Malcolm Williamson invented public-key cryptography while working at a British intelligence agency, the Government Communications Headquarters (GCHQ), in Cheltenham, England. But surprisingly they kept it as a secret for nearly 25 years and finally broke the news in 1997. Unfortunately, Ellis died before he could enjoy the public recognition of it.[2]

                                                              Figure 3 - Malcolm Williamson

Even though that story had been revealed for more than 10 years, Diffie, Hellman and Merkle were awarded this year’s (2010) IEEE Richard W. Hamming Medal for invention of public-key cryptography. But in order to respect real owners of that technology, a group of IEEE members from Region 8, nominated the invention by Ellis, Cocks, and Williamson for an IEEE Milestone in Electrical Engineering and Computing, IEEE's 100th. [1]

How to prove first inventors of Public Key Cryptography?

In brief, Ellis came up with that idea but could not proceed because he was not a mathematician. So in 1973, Cocks who was a mathematician was asked to join with him and he had come up with the solution. But his solution was not simple enough to run on computers in that time. So Williamson, who was also a mathematician, had implemented the final solution. [1]

Who are Ron Rivest, Adi Shamir and Leonard Adleman (RSA)?

                                               Figure 4 - Left to Right : Shamir, Rivest and Adleman

They also came up with another ‘independent’ algorithm similar to Ellis, Cocks and Williamson’s scheme when they were at MIT in 1977. It was published in 1978 and became popular as “RSA”. [3]

Summary

1973 - Ellis, Cocks and Williamson came up with initial solution and kept as a secret until 1997. Solution was known as “non-secret encryption”
1976 - Diffie, Hellman and Merkle came up with another similar solution who believed ‘they were the first’ and earned credit for it.
1977 - Rivest, Shamir and Adelman came up with another ‘independent’ solution

Verdict

It is questionable still on who is the real inventor of this technology. Nobody has confirmed ‘officially’ regarding that yet. Most people do not know about this secret too.

References

[1] Bogdanowicz, A. 2010, Cryptography Breakthrough Is 100th Milestone , The Institute, viewed 5 Aug 2010, < http://www.ieee.org/portal/site/tionline/menuitem.130a3558587d56e8fb2275875bac26c8/index.jsp?&pName=institute_level1_article&TheCat=1008&article=tionline/legacy/inst2010/jun10/featurehistory.xml&>

[2] Diffie–Hellman key exchange , Wikipedia, viewed 5 Aug 2010, < http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange > 

[3] Public-key cryptography, Wikipedia, viewed 5 Aug 2010, < http://en.wikipedia.org/wiki/Public-key_cryptography >

[4] ‘Figure 1’ [image] in 2004, ‘Public Key Cryptography & PGP’ , Treachery Unlimited, viewed 5 Aug 2010, http://www.treachery.net/images/public_key_cryptography_and_pgp.jpg 

[5] ‘Figure 2’ [image] in Prevost, E. 2009, ‘Public Key Cryptography’, EdwardPrevost.info, viewed 5 Aug 2010, http://edwardprevost.info/Blog/2009/10/15/public-key-cryptography/

[6] ‘Figure 3’ [image], ‘Public Key Cryptography (PKC) History’, viewed 5 Aug 2010, http://www.livinginternet.com/i/is_crypt_pkc_inv.htm

[7] ‘Figure 4’ [image] in 2008, ‘Leonard Adleman’, Adleman Portraits, viewed 5 Aug 2010, http://www-history.mcs.st-and.ac.uk/PictDisplay/Adleman.html