A unique Transaction Signature (TSIG) key must be generated for each pair of communicating hosts.

To enable zone transfer (requests and responses) through authenticated messages, it is necessary to generate a key for every pair of name servers. The key also can be used for securing other transactions, such as dynamic updates, DNS queries, and responses. The binary key string generated by most key generation utilities used with DNSSEC is Base64 encoded. TSIG is a string used to generate the message authentication hash stored in a TSIG Resource Record (RR) and used to authenticate an entire DNS message.