What Is DNSSEC?
Understanding DNSSEC (DNS Security Extensions) and DNS security
Table of Contents
What Is DNSSEC?
DNSSEC (DNS Security Extensions) is a security protocol that adds cryptographic signatures to DNS records to prevent DNS spoofing and cache poisoning attacks. DNSSEC uses public-key cryptography to sign DNS records, allowing DNS resolvers to verify DNS response authenticity.
DNSSEC provides: DNS data authentication (verifying DNS records are authentic), DNS data integrity (ensuring DNS records haven't been tampered with), and protection against DNS attacks (preventing spoofing and cache poisoning).
DNSSEC uses DNSKEY, DS, RRSIG, and NSEC3PARAM records to implement cryptographic security. Check DNSSEC configuration to verify DNS security.
DNSSEC Purpose
1. DNS Data Authentication
DNSSEC verifies DNS records are authentic and come from authoritative name servers, preventing DNS spoofing.
2. DNS Data Integrity
DNSSEC ensures DNS records haven't been tampered with during transmission, protecting against DNS cache poisoning.
3. Protection Against Attacks
DNSSEC protects against DNS attacks including spoofing, cache poisoning, and man-in-the-middle attacks.
4. Trust Chain
DNSSEC creates a chain of trust from root DNS servers to authoritative name servers, ensuring DNS security.
5. Email Security
DNSSEC enhances email security by protecting DNS records used for email authentication (SPF, DKIM, DMARC).
How DNSSEC Works
1. Cryptographic Signing
Authoritative name servers cryptographically sign DNS records using private keys, creating RRSIG (Resource Record Signature) records.
2. Public Key Publication
Public keys are published as DNSKEY records, allowing DNS resolvers to verify signatures.
3. Chain of Trust
DS (Delegation Signer) records create a chain of trust from parent zones to child zones, linking DNSKEY records.
4. Signature Verification
DNS resolvers verify DNS record signatures using public keys, ensuring records are authentic and untampered.
5. Validation
DNSSEC validation checks signatures and chain of trust, rejecting invalid or tampered DNS records.
DNSSEC Records
DNSSEC uses several record types:
DNSKEY Records
DNSKEY records store public keys used to verify DNS record signatures.
DS Records
DS records (Delegation Signer) create chain of trust by linking parent zone DNSKEY records to child zones.
RRSIG Records
RRSIG records (Resource Record Signature) contain cryptographic signatures for DNS records.
NSEC3PARAM Records
NSEC3PARAM records specify parameters for NSEC3 (Next Secure) records used for authenticated denial of existence.
DNSSEC Validation
What Is DNSSEC Validation?
DNSSEC validation is the process of verifying DNS record signatures and chain of trust to ensure DNS records are authentic and untampered.
Validation Process
DNS resolvers validate DNSSEC by: verifying RRSIG signatures using DNSKEY public keys, checking DS record chain of trust, and ensuring signatures are valid and not expired.
Validation Failure
If validation fails, DNS resolvers reject DNS records. Learn more about why DNSSEC validation fails.
Validation Benefits
DNSSEC validation protects against DNS attacks, ensures DNS security, and provides trust in DNS responses.
Checking Validation
Use DNS tools to check DNSSEC validation status and verify DNS security configuration.
