TSIG

TSIG (Transaction SIGnature) is a computer networking protocol defined in RFC 2845. It is used primarily by the Domain Name System (DNS) to provide a means of authenticating updates to a DNS database. It is most commonly used to update Dynamic DNS or a secondary/slave DNS server. TSIG uses shared secret keys and one-way hashing to provide a cryptographically secure means of authenticating each endpoint of a connection as being allowed to make or respond to a DNS update.