993 Encryption Key Name
TYPE=AN MIN=1 MAX=64

Name of the key used for encryption; this name is mutually known to the security originator and the security recipient, is unique for this relationship, and is intended to allow the changing of the key from time to time

Note: If any of the optional fields are present, the Key Name should contain either "PUBLIC" if a public key is being used to encrypt the one-time key or the actual name of the asymmetric key-encrypting-key used to encrypt the one-time key.