Hi everyone, Ed Amoroso here and I want to welcome you to this module. Now our goal here is to kind of dig into encryption with a particular emphasis on public key cryptography and certification authority. So very relevant topics to e-commerce and future IOT and stuff, so I think you'll enjoy the material here. Now there's some papers and optional books and a video I'd like you to look at as companion as you go through the module. So first there's a couple of older papers that lay some of the foundations here. One is the classic paper by Diffie and Hellman, the two great masters of cryptography called New Directions in Crypto. I think you could argue that it might be the most famous and most important paper ever written in cyber security. So you really do want to take some time to go through that. And then second there's a little known paper by a guy named James Ellis who is a British cyber security expert. He didn't call it cyber security then because he lived in the 60s and 70s. And he was still working somewhat in the 80s, but it was more just a basic cryptography then, wrote a paper called Non-Secret Encryption. That's really, astounding, because you could argue that it actually predated the work that Diffie and Hellman had done in cryptography so it's a cool paper to read. And the historical references are just really delightful. Now couple of optional books that we think would make sense as you go through the module, one is an e-book that I've written with my son Matt that's called from CIA to APT An Introduction to Cybersecurity you gotta go through chapters 15 and 16. You get the book on Amazon and again it's optional. You don't have to but a lot of you might like a companion book and it's very inexpensive. Now, one thing that may be a little more expensive is getting yourself a good solid TCP IP book. It's a worth while investment, particularly if you're a young person, I think having a physical TCP IP book is a good idea, at some point maybe you make the investment. But if you decide to do it here, Richard Stevens has written a good one, he's written some versions with companion authors. But if you read the Richard Stevens TCP IP illustrated volume 1, chapter 15 and 16 I think would be a useful place to be as you go through this module. So I'll hope you'll do that, they're optional, but I hope you'll consider doing it. And then there's kind of a cool video from one of my good friends, the chief of security over at Akamai, one of the great content distribution network companies. It's called the Brief History of Cryptography With Akamai Chief Andy Ellis. So you'll enjoy hearing from Andy and learning a little bit more. It'll complement your learning as you go through this module, so I hope you enjoy it.