DNSSEC and DNS Filtering

Plain DNS offers no authenticity. Two complementary defenses address this: DNSSEC proves that answers are genuine and untampered, while DNS filtering blocks resolution of known-bad names. Together they protect integrity and reduce attack surface.

This lesson covers how each works and where they fit in a layered DNS security strategy.

DNSSEC (DNS Security Extensions) adds cryptographic signatures to DNS data. It guarantees:

• Origin authenticity — the answer came from the real zone owner.
• Data integrity — the answer was not modified in transit.

Importantly, DNSSEC does not provide confidentiality. Queries and answers remain in cleartext; for privacy you still need DoT/DoH.