The aim of the course is to familiarize the students with the fundamental principles and basic technologies of cryptography and network and communications. Through the study of this course, the students will be provided with a good understanding of network and communication security. The course consists of three parts as follows. Part I: Introduction Part II: Basic theory and tools for communication and network security 1. Methods for evaluation the security performance of the secrecy system (1) Information theory; (2) Computational complexity 2. Foundations of cryptography: basic tools (1) One-way functions; (2) Pseudo random sequence generator; (3) Hash functions; (4) Zero-knowledge verification; (5) Secret sharing 3. Physical security 4. Distributed inference security Part III: Examples 1. Security issues in wireless networks 2. Security issues in adaptive networks 3. Security issues in cloud computing.