"Secret Key Transaction Authentication for DNS (TSIG)" - Francis Dupont, Stephen Morris, Paul Vixie, Donald Eastlake, Olafur Gudmundsson, Brian Wellington

2020-07-10, rev -09: This document describes a protocol for transaction level authentication using shared secrets and one way hashing. It can be used to authenticate dynamic updates to a DNS zone as coming from an approved client, or to authenticate responses as coming from an approved name server.