The origin of, of public key really goes back to the late 1960s. Someone called James Ellis at TCHQ, who was looking at ways of, IM improving the way we manage our keys. And he came up with the idea that actually maybe you don't need to distribute keys to start a secure communication. And then it took a little while to come up with the actual mechanisms that make those things work. So certainly James' concept was the first breakthrough. The next breakthrough came probably about four years later when I had the fortune to be shown the problem that people are tried to find an implementation and had failed. And I came up with the idea of using prime numbers multiplied together as the key building block of this. Then shortly after, a colleague of mine, Malcolm Williamson, came up with what we now call Diffy Hillman. So over the course of a fairly short space of time, we, we came up with the two algorithms, which these days are still the main ones, Diffie, Hellman, and RSA as they're now known. The reason that we worked on this problem, particularly James, when he came up with the concept, was the fact that key management was getting more and more expensive. Military communications, especially were being deployed at low, lower level. There were far more of these devices, and nevertheless, the keys have to be managed in exactly the same way, physically distributed, stored carefully, and then destroyed securely. And so it was a, a cost reason, really, uh, how can we do this more efficiently, but still securely? Uh, that led James to come up with the idea. And then the motivation after that was to actually just find a mechanism that actually achieved his concept. The way technology has moved and the massive increase in communications has meant, these techniques have become really quite fundamental to really most communications. And indeed, cryptography is essentially everywhere. I mean, cryptography is now in a completely different place from how it was 50 years ago. Looking back, it's almost a surprise, a shock when you think back to how things were 50 years ago and how different it is now with these things being sort of well understood, well researched by lots of people. So it, it obviously took a bit of an adjustment as this was, was happening and going from something that was in a very private, small world to public world. I, I mean, I remember perhaps 20 years after being kind of shocked to have people behind me in the, on the train discussing public key and thinking, oh, it really is part of everyday life now.
