Block cipher

About

A block cipher is a symmetric cryptographic algorithm that encrypts fixed-size chunks of data (called blocks, typically 64 or 128 bits) using a secret key, transforming plaintext into ciphertext through repeated rounds of mathematical operations such as substitution, permutation, and XOR mixing. Well-known examples include AES, DES, and the Chinese standard SM4. In robotics and AI systems, block ciphers secure wireless command channels, sensor data streams, and inter-device communications, preventing adversaries from intercepting or tampering with sensitive control signals. They are commonly implemented in dedicated hardware accelerators on FPGAs or custom chips to meet the strict real-time and energy constraints of embedded platforms like IoT sensors and autonomous robots. The importance of block ciphers continues to grow as robots operate in hostile or safety-critical environments where compromised communications could cause physical harm or data breaches. Hardware implementations must also defend against side-channel attacks, such as power analysis, which can extract secret keys from physical measurements of the device during operation.