Cryptography is a foundation in cybersecurity. It is the underlying building block of many defense mechanisms, systems, and protocols. Without crypto, we will not be able to safely conduct many things on the Internet, such as web browsing, online banking, working remotely, etc. Without crypto, blockchain and cryptocurrency will not exist.

In this course, we systematically study the basic principles of cryptography. In particular, we focus on the three essential pillars of cryptography, including secret-key encryption, one-way hash function, and public-key cryptography. We study how they work and how they are used in the real-world applications. We also look at the risks they face, and how these risks are mitigated in the real world. Furthermore, we study the common mistakes people make when using crypto algorithms and protocols. We show how these mistakes can be exploited in attacks.

The course emphasizes hands-on learning. For each topic covered, students not only learn the theory, they also get to work on the hands-on exercises developed by the instructor. These exercises are called SEEDlabs, and they are being used by over 1000 institutes worldwide. The course is based on the widely-adopted textbook written by the instructor. The title of the book is "Computer &Internet Security:A Hands-on Approach".