Enum class cipher

cipher enumerates the various ciphers used within Keychain for the symmetric message encryption keys.

In Keychain, messages are first encrypted using a symmetric key with one of the ciphers in this enumeration. The key is then encrypted for each recipient using asymmetric encryption (i.e. according to their public key) and included in the ciphertext.

Values are self-explanatory.

Since: v2.0