Which of the following is an example of a symmetric key algorithm?

The Data Encryption Standard (DES) is a prime example of a symmetric key algorithm. Symmetric key algorithms use the same key for both encryption and decryption of data, which means that both the sender and receiver must have access to the shared secret key. DES operates on fixed-size blocks of data and employs a series of transformations using the same key to secure the information.

In contrast, RSA is an asymmetric encryption algorithm, which utilizes a pair of public and private keys for secure communications. Diffie-Hellman is primarily a key exchange protocol rather than a direct encryption method, allowing two parties to establish a shared secret key over an insecure channel. Elliptic Curve Cryptography (ECC) is also an asymmetric algorithm that offers similar functionalities as RSA but relies on elliptic curves for security.

Understanding the differences in key management between symmetric and asymmetric algorithms is crucial for implementing secure communication methods. DES, being a symmetric key algorithm, highlights the importance of secure key distribution and management among communicating parties.