ECDH CommandThe ECDH command is used to generate a shared secret between two
devices. By passing an ECC public key from another device and
combining with the ECC private key stored in a slot or with an
ephemeral key stored in TempKey and doing the reverse on the
other device, both devices will generate the same shared master
secret. This can then be further combined with other common data
in both sides to generate a shared session key between the
devices. The KDF command is often used with
TLS sessions to further diversify the shared secret.