Davi, who is a super smart guy by the way, has a great post revealing that the RSA trio were not the original inventors of public-key cryptography. You should read his post and his references to:
- A paper from 1987 called The Story of Non-Secret Encryption [PDF] written by James Ellis
- A paper written by Clifford Cocks called "A Note on Non-Secret Encryption"
- A nice review of history, as told by the Living Internet