Leonard Adleman (born 1945), American theoretical computer scientist and professor of computer science and molecular biology
He invented the widely used encryption algorithm now commonly known as RSA, about three years before it was independently developed by Rivest, Shamir, and Adleman at MIT.
When, a few years later, Diffie and Hellman published their 1976 paper, and shortly after that Rivest, Shamir, and Adleman announced their algorithm, Cocks, Ellis, and Williamson suggested that GCHQ announce that they had previously developed both.
It was the need to synchronize the scramblers that suggested to James H. Ellis the idea for non-secret encryption which ultimately led to the invention of both the RSA encryption algorithm and Diffie-Hellman key exchange well before either was reinvented publicly by Rivest, Shamir, and Adleman, or by Diffie and Hellman.