Key Encryption Key

Related Concepts

Cryptographic Key; Key Agreement; Key Exchange; Key Management; Public Key Cryptography; Symmetric Cryptography

Definition

A key encryption key (KEK) is a cryptographic key that is used for encrypting other cryptographic keys.

Background

The security of any use of cryptography depends on keeping the cryptographic keys secure. This follows Kerchoffs’ principle (see [1]) that when analyzing the strength of a cryptosystem, one should assume that the cryptographic algorithms are known to the attacker. This means that it is of utmost importance that cryptographic keys are managed securely when they are used and stored as well as when they are transmitted between parties sharing the keys. Such protection can be achieved by encrypting the keys under other cryptographic keys called key encryption keys. As a key encryption key can encrypt many other keys, proper handling of one key encryption key can be used to secure many other keys.

Theory

When a system or an application...