This assignment delves into the realm of cyber security and encryption, offering a comprehensive analysis of block ciphers, CBC mode, and CTR mode. The solution begins with an introduction to the concept of encryption within networked control systems, referencing relevant academic sources. The assignment then proceeds to explore basic encryption and decryption using a provided substitution cipher, highlighting its inherent security weaknesses. Following this, the solution demonstrates encryption and decryption using the same block cipher in CBC (Cipher Block Chaining) mode, incorporating the use of an initialization vector (IV). Finally, the assignment examines encryption and decryption using the block cipher in CTR (Counter) mode, comparing the ease of use and security implications of both CBC and CTR modes. The solution concludes with a discussion on the relative security strengths of CBC and CTR modes and provides references to supporting literature.