Understanding Data Encryption Standard (DES): A Symmetric-Key Encryption Algorithm

To understand the Data Encryption Standard (DES) algorithm in more detail, it's important to first understand what symmetric-key encryption is. Symmetric-key encryption is a type of encryption where the same key is used to both encrypt and decrypt the data. This means that both the sender and receiver need to have access to the same key in order to communicate securely. The key is kept secret, and if it falls into the wrong hands, the encrypted data can be decrypted by anyone who has the key. DES is a symmetric-key encryption algorithm that uses a block cipher. This means that the data is divided into blocks of a fixed size (in the case of DES, 64 bits) before it is encrypted. The key used to encrypt and decrypt the data is also 64 bits long, although 8 of these bits are used for parity checking and are not actually used in the encryption process. This means that the effective key length for DES is 56 bits. The encryption process in DES involves a series of mathematical operations ...