Greetings and welcome to the specialization on the introduction to applied cryptography. My name is WIlliam Bond and I'm an Instructor of computer science at the University of Colorado, Colorado Springs. Like many folks my age, I came to the field of information assurance along a highly nonlinear path. Most of my professional career has been designing full custom integrated circuits, but I became involved in the palm of jam resisted communication without shared secrets while I was teaching at the US Air Force Academy and that became the focus of my PhD work, albeit in electrical engineering. As part of that research, I became rather immersed in the field of cryptography and haven't looked back yet. >> And my name is Sanyong Cheng and I'm an Assistant Professor also at the computer science department at UCCS, University of Colorado, Colorado Springs. I research in computer security and computer network with focuses on wireless, and embedded systems. My research also has high synergy with the recent developments in IoT, Internet of Things in cyber-physical systems. At UCCS, I teach intro to computer security, applied cryptography and wireless and embedded system security. In this specialization, Bill and I will focus on applied cryptography. >> The first course in this specialization covers classical cryptosystems and many of the core concepts in cryptography. We'll learn about a number of ancient and not so ancient cryptosystems. Some noteworthy for their successes, but many more for their failures. We'll not only explore how the field of cryptography was born and matured, but use this as a vehicle to learn many of the key concepts and terminology we'll be using throughout this specialization. We'll learn about the difference between codes and cyphers and we'll spend time learning about cryptanalysis, the breaking of codes and cyphers. Finally, we'll explore one of the most fundamental building blocks of modern cryptography, the hash function. In the second course, we will delve into the mathematics that underlies the bulk of modern cryptography. In particular, we'll look at modular arithmetic in some depth, paying particular attention to modular exponentiation and primality testing both of which are central to most of today's asymmetric cryptographic protocols. We'll also become familiar with the Chinese remainder theorem which provides a very useful and powerful way to look at, and work with the structure of numbers in a modular a modular arithmetic world. >> In the next course, we will discuss about symmetric cryptography which relies on shared secret key to ensure message confidentiality, so that the unauthorized attackers cannot retrieve the message. Then in the course Asymmetric Cryptography and Key Management, we will introduce public keys which enables cryptographic applications not only for message confidentiality, but also for authentication and integrity. The use of public keys require asymmetric operations between the sender and receiver, and the key distribution, and management. >> We are excited to present to you the introduction to applied cryptography specialization. >> Welcome aboard.