Block Ciphers Fundamentals and Operation Modes | Learn in 5-Mins

The video provides an extensive overview of block cipher, an encryption and decryption method that processes plaintext in fixed-size blocks rather than individual bits. It details the fundamental principles of block cipher design, which include determining the number of rounds, designing the function F for non-linearity, and implementing a sound key schedule algorithm. Furthermore, the video thoroughly explains the five important modes of operation defined by NIST—Electronic Code Book (ECB), Cipher Block Chaining (CBC), Cipher Feedback (CFB), Output Feedback (OFB), and Counter Mode (CTR)—noting the advantages and limitations of each in securing data and handling issues like repeating text or bit errors. The video aims to clarify how block ciphers work, their underlying structure, and various practical implementations in cryptography. Watch this video till the end for a complete understanding.