ECDH
acronymcryptography
Stands for: Elliptic-Curve Diffie-Hellman
Elliptic-curve key exchange - the non-ephemeral form lacks forward secrecy.
Elliptic-Curve Diffie-Hellman derives a shared secret over elliptic curves. Without the ephemeral 'E' (as in ECDHE) the keys are long-lived, so a leaked key exposes past sessions - which is why the ephemeral variant is preferred.
Also known as: ecdh