The KEY resource record (RR) is used to document a key that is associated with a Domain Name System (DNS) name. It will be a public key as only public keys are stored in the DNS. This can be the public key of a zone, a host or other end entity, or a user. A KEY RR is, like any other RR, authenticated by a SIG RR. Security aware DNS implementations MUST be designed to handle at least two simultaneously valid keys of the same type associated with a name.
The type number for the KEY RR is 25.