Definition: In an identity-based encryption scheme, data is encrypted using an arbitrary string as the key. For decryption, a decryption key is mapped to the arbitrary encryption key by a key authority.
Email Example
An email message is encrypted using the recipient's email address as the public key. It is not necessary that the recipient has already installed any software or generated a pair of keys.
When the encrypted email arrives, the recipient can request — upon authentication — a private key that allows them to decrypt all emails encrypted using their email address as the public key.
Certificates and certificate authorities are not necessary for communication to be secure. Authentication between recipient and key authority is crucial, however.
Also Known As: Hierarchical Identity-Based Encryption
