Internet key exchange

Internet key exchange (IKE) is the protocol used to set up a security association in the IPSec protocol suite, which is in turn a mandatory part of the IETF IPv6 standard which is being adopted (slowly) throughout the Internet. IPSec is an optional part of the IPv4 standard.

IKE is defined in RFC 2409. IKE uses a Diffie-Hellman key exchange to set up a shared secret, from which cryptographic keys are derived. Public key techniques or, alternatively, preshared secrets, are used to mutually authenticate the communicating parties.

IKE incoporates parts of the proposed Oakley protocol.