The human mind treats a new idea the same way the body treats a strange protein; it rejects it.
P. B. Medawar
In the Fall of 1974 I enrolled in CS244, the Computer Security course offered at UC Berkeley and taught by Lance Hoffman. We were required to submit two project proposals, one of which we would complete for the course. I submitted a proposal for what would eventually become known as Public Key Cryptography -- which Hoffman rejected. I dropped the course, but kept working on the idea.
Unfortunately, I lost track of the proposal and didn't find it again until September 8th, 2005, while cleaning out some boxes of old folders. There, neatly labeled "244 Project Proposal" was a folder containing the original 7 page project proposal. Here it is, found after all these years: the first unclassified document describing public key distribution and public key cryptography.
PDF of the first (original) project proposal.
After Hoffman rejected this proposal, I rewrote it to be shorter and simpler. Following is the two-page simplified version, resubmitted to Hoffman and showing his comments.
PDF of the second project proposal.
After I dropped the course, I kept working on the idea. I showed an early draft to Bob Fabry, then on the faculty at Berkeley, who immediately recognized it as both novel and valuable and said "Publish it, win fame and fortune!" I then submitted it to Susan Graham, then an Editor at the Communications of the ACM in August of 1975. As I was to learn, Fabry's response was unusual.
Graham sent it out to be reviewed and received the following response from an "experienced cryptography expert" whose identity is unknown to this day.
"I am sorry to have to inform you that the paper is not in the main stream of present cryptography thinking and I would not recommend that it be published in the Communications of the ACM."
Based on the referees letter, she rejected my article. She "was particularly bothered by the fact that there are no references to the literature. Has anyone else ever investigated this approach. If they consider it and reject it, why?"
I was now quite confident that the idea was novel, as the "experienced cryptography expert" had rather obviously failed to understand what was being proposed and private conversations suggested that no one else had heard of the idea, either. So I persisted for the simple reason that (a) the idea was sound, so they would eventually have to concede this fact and publish the article and (b) they would then have to include the original submission date -- which I would lose if I re-submitted anywhere else, even if that somewhere else miraculously had a clearer understanding of the concept.
A version of the paper dated December 7th 1975 is available in PDF.
And so it proved. CACM eventually published the paper, though only after almost three years of delay, and only after others (who were better able to persuade their editors to publish in a timely fashion).