Hi, everyone. Ed Amaroso here, and I want to welcome you to this module. Our goal here is to take you through some basic encryption, basic cryptography, and also to look at Kerberos. Which is one of the cool implementations of a cryptographic based scheme that allows you take password off networks. It's a very, very cool protocol, you enjoy it. Now, there some papers, optional books and a video I'd like you to take a look at, to complement your learning in this module. A one is [LAUGH] it's not really a paper it's a patent, and I think everyone should have the experience of trying to read a patent. Sometimes they're just terrible, a lot of legalese and stuff in there, but I think you should take the time. Let me just see if I can get the title of this right, this is the Data Encryption Standard Patent, The Method of Implementing the Data Encryption tandard with Reduced Computation, is a mouthful. But I want you to look at that, do the best you can to go through it, you're going to see some things in there that just don't look like they're applicable, but try and get through it as much as you can. It's good experience to read a patent, maybe you're writing one, at some point you probably will write one, so it will be good practice. Now there's a couple of optional books that we think would make sense as resources for this module. One is an ebook you can get on Amazon that I wrote with my son Matt, it's called From CIA to APT. And if you go through chapters 13 and 14 of the book, you'll see that it in some sense compliments the work in this module. Again, it's optional but it might help you, it's a useful companion. And then second I do think you need a good TCP/IP textbook to help you with the material in this module and in anything you do in cyber security. Stevens I think has written one of the best and there are some versions that have co-authors. But the Richard Stevens book TCP/IP Illustrated Volume One, if you go through chapters 13 and 14 I think it will help you with your learning here. Now there's one video I'd like you to watch, it's an interview with a good friend of mine that guy who'se been at Cisco Systems for many years, his name is John Stewart. There's an interview that was done with him in 2013, at the RSA show, so it's RSA Cyber Security with John Stewart. I think it's a cool interview and I'd like you to be exposed to John's kind of wit, humor, and knowledge, I think you'll enjoy that. Hey, hope you enjoy the whole module, and I hope you take advantage of these fine resources, thanks.