A security administrator must implement a system to allow clients to securely negotiate encryption keys
with the company's server over a public unencrypted communication channel.
Which of the following implements the required secure key negotiation? (Choose two.)
Correct Answer: D,E
Section: Cryptography
Explanation/Reference:
Explanation:
Elliptic curve Diffie-Hellman (ECDH) is an anonymous key agreement protocol that allows two parties,
each having an elliptic curve public-private key pair, to establish a shared secret over an insecure channel.
This shared secret may be directly used as a key, or better yet, to derive another key which can then be
used to encrypt subsequent communications using a symmetric key cipher. It is a variant of the Diffie-
Hellman protocol using elliptic curve cryptography.
Note: Adding an ephemeral key to Diffie-Hellman turns it into DHE (which, despite the order of the
acronym, stands for Ephemeral Diffie-Hellman).
Adding an ephemeral key to Elliptic Curve Diffie-Hellman turns it into ECDHE (again, overlook the order of
the acronym letters; it is called Ephemeral Elliptic Curve Diffie-Hellman). It is the ephemeral component of
each of these that provides the perfect forward secrecy.