Purpose of DNSSEC
• Ensure authenticity of data origin
• And integrity of data received by a resolver
from an authoritative DNS server
• Done by signing Resource Record (RR) sets
– With a private key
– And including the signature (RRSIG) with the
record
Chain of Trust
• Resolver can verify the RRSIG with the server's
Public Key
– Published by the server in its zone file
– Vouched for by the parent zone
– Vouched for by its parent...
– Unbroken chain of trust up to the root zone
• Only works if all higher‐level zones are signed