Explore the essential principles of secure communicating systems with this comprehensive guide. Designed for advanced undergraduate and graduate students, as well as computer professionals, this book delves into the design, analysis, and implementation of robust security mechanisms. Discover detailed insights into the Advanced Encryption Standard (AES) Rijndael, practical RSA public-key encryption, and formal security models for information flow. The text addresses crucial moral, legal, and political aspects of security, alongside a novel approach to specifying and debugging security protocols using model-checking tools. With numerous implementation exercises and a supporting website offering Java source code and resources, ‘Secure Communicating Systems’ is an indispensable resource for mastering cryptographic systems and ensuring secure information flow in modern computing environments.