KUPE Key Mode

This key mode uses KUP and a device ephemeral key. Two ECDH shared secrets are generated from these keys and a user/HSM supplied EC public keys. The shared secrets are then used to derive a shared symmetric key, which is used for secure loading of user keys using SPPS. This is more secure than KUP key mode because of randomly generated ephemeral key. However, this key mode takes longer because there are two ECDH operations and key generations.