TKEY record

TKEY is a record type of the Domain Name System. TKEY resource records can be used in a number of different modes to establish shared keys between a DNS resolver and name server.

Mode field values

0 – Reserved
1 – Server assignment
2 – Diffie–Hellman key exchange
3 – Generic [Security Service Algorithm for Secret Key Transaction]
4 – Resolver assignment
5 – Key deletion
6–65534 – Available
65535 – Reserved