Which type of encryption is characterized by using a single key for both operations?

Symmetric encryption is characterized by the use of a single key for both encryption and decryption operations. This means that the same key that is used to encrypt the data is also used to decrypt it. This type of encryption is efficient and fast, making it suitable for encrypting large amounts of data. It requires both parties in a communication to securely share and manage the key to maintain confidentiality.

This approach contrasts with asymmetric encryption, which utilizes a pair of keys (a public key and a private key). Public key infrastructure refers to the management of public key encryption techniques and does not pertain to a single key. Hashing, on the other hand, is a one-way function that transforms data into a fixed-size string of characters, rather than providing a means of encryption or decryption. Understanding these differences highlights the distinct role of symmetric encryption in ensuring secure data communication.