What type of encryption uses the same key for both encrypting and decrypting data?

Symmetric Key Encryption is a method where the same key is used for both the encryption and decryption processes. This means that both the sender and recipient must possess the same secret key in order to communicate securely. This type of encryption is efficient for processing large amounts of data because it uses less computational power compared to other encryption methods.

In contrast, Public Key Encryption employs two different keys: a public key, which can be shared openly, and a private key, which must be kept secret. This allows for secure communication without the need for both parties to share a common key beforehand. Asymmetric Key Encryption is a broader term that includes Public Key Encryption.

While Data Encryption Standard (DES) is a specific symmetric key encryption algorithm, it is just one example of symmetric key encryption rather than a classification of the type of encryption itself. In summary, the defining feature of symmetric key encryption is its use of a single key for both processes, making it distinct from the other types of encryption mentioned.