DNSSEC: Securing Your DNS
DNSSEC (Domain Name System Security Extensions) adds a layer of trust on top of DNS by providing cryptographic authentication of data.
📖 12 min read
The Vulnerability of Standard DNS
Regular DNS accepts answers from any server claiming to be authoritative. Attackers can exploit this via cache poisoning (injecting fake DNS data), redirecting your users to malicious sites without them knowing.
How DNSSEC Works
DNSSEC does NOT encrypt data (you still see plain text). Instead, it signs data.
- Digital Signatures: Every DNS zone has a public/private key pair.
- RRSIG Records: DNS records (like A or MX) are signed, creating RRSIG records.
- Chain of Trust: The TLD (like .com) signs your domain's key, and the Root signs the TLD. This creates an unbroken chain of trust from the Root Zone down to your domain.
Implementation Steps
Enabling DNSSEC usually involves:
- DNS Provider: Enable DNSSEC at your DNS host (e.g., Cloudflare, AWS Route53). They generate the keys and sign your zone.
- Registrar: Copy the DS (Delegation Signer) record from your DNS provider and add it to your domain's settings at your registrar.
- Verification: Use tools like DNSViz to confirm the chain is complete.
Pros and Cons
Pros: Prevents spoofing,
required for some compliance standards.
Cons: Adds complexity. If
misconfigured (e.g., keys expire without rotation), your domain disappears from the
internet.