A block cipher is an encryption algorithm that encrypts fixed-size blocks of data, typically 64 or 128 bits in length.
Unlike stream ciphers that encrypt data one bit or byte at a time, block ciphers process entire blocks of data in one operation.
Block ciphers use a symmetric key, meaning the same key is used for both encryption and decryption.
One of the key features of block ciphers is their ability to provide high security and resistance to cryptographic attacks, especially when used with large key sizes and strong encryption algorithms.
However, block ciphers can introduce some challenges in handling data that is not a multiple of the block size and may require the use of padding techniques to ensure data integrity.
Common examples of block ciphers include Advanced Encryption Standard (AES) and Data Encryption Standard (DES).