DNSSEC

The Security Gap DNSSEC Fills

Standard DNSDomain Name System. The hierarchical, distributed naming system that translates human-readable domain names (e.g., example.com) into IP addresses (e.g., 93.184.216.34). Often called the "phonebook of the internet." was designed without authentication: a resolver that receives a response has no way to verify it came from the legitimate authoritative server rather than from a cache poisoning or Man-in-the-Middle AttackAn attack where an adversary secretly intercepts and potentially alters communication between two parties who believe they are communicating directly. HTTPS and certificate pinning are primary defenses against this attack. attack. DNSSEC adds a chain of cryptographic signatures — using public-key infrastructure — so resolvers can verify that DNS records are authentic and have not been tampered with in transit.

How the Chain of Trust Works

DNSSEC uses four new record types: RRSIG (signatures over record sets), DNSKEY (the public key), DS (delegation signer, linking parent to child zone), and NSEC/NSEC3 (authenticated denial of existence). The chain of trust begins at the DNS root zone, whose KSK (Key Signing Key) is publicly known and hardcoded into resolvers. Each child zone's DS record is signed by its parent, creating a verifiable chain from root → TLD → authoritative zone. DNS Lookup

Deployment Limitations

DNSSEC protects the DNS resolution path but does not encrypt queries — a passive observer can still see which domainsA human-readable address (e.g., example.com) that identifies a website or service on the internet. Domain names are registered through registrars and resolved to IP addresses by the DNS system. you resolve. For query privacy, combine DNSSEC with DNS over HTTPS (DoH)A protocol that encrypts DNS queries by sending them over HTTPS (port 443), preventing ISPs and network operators from inspecting or tampering with DNS traffic. Supported by browsers like Firefox and Chrome. or DNS over TLS (DoT)A protocol that encrypts DNS queries by wrapping them in TLS on a dedicated port (853). Unlike DNS over HTTPS, DoT uses a separate port, making it easier for network administrators to identify and manage DNS traffic.. Misconfigured DNSSEC (expired signatures, missing DS records) causes SERVFAIL responses and can take down a domain entirely, so key rollover procedures and monitoring are critical for zone operators.