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Data key

(also data encryption key, encryption key)

Data key definition

A data key is a string of data representing a variable value that is used for encryption and decryption. Data keys enable secure communications between parties because anyone not privy to the correct data key cannot see the contents of the data. Data keys can only encrypt or decrypt data — they cannot be used to encrypt other keys.

Types of data keys

  • Secret key: In symmetric encryption, both the sender and receiver of information use the same data key, known as the secret key. As a result, symmetric encryption is often called secret key encryption. Using only one data key at both ends makes both encryption and decryption quicker but more vulnerable to exploitation.
  • Public/private keys: Asymmetric encryption involves using two different data keys — a public key (available to anyone) and a private key (held by the receiver). The sender encrypts information using the receiver’s public key and the receiver decrypts it using their unique private key. Asymmetric encryption is slower but more secure than symmetric encryption.