DNSSEC adds cryptographic verification to DNS so that a resolver can check whether DNS information is authentic and has been altered in transit.
Traditional DNS was designed primarily to answer a question: What address belongs to this name?
It wasn’t originally designed to cryptographically prove that the answer was genuine.
DNSSEC (Domain Name System Security Extensions) helps solve that problem.
How does DNSSEC work?
When DNSSEC is enabled, DNS information can be digitally signed.
A validating DNS resolver checks those signatures and follows a chain of trust through the DNS hierarchy. This allows the resolver to determine whether the response came from the expected DNS zone and whether the signed data has been modified.
You can think of ordinary DNS as receiving a letter.
DNSSEC is like receiving the same letter with a seal that can be independently verified.
Does DNSSEC encrypt DNS?
This is an important distinction.
DNSSEC does not encrypt your DNS queries.
Someone capable of observing your DNS traffic may still be able to see which domain you’re requesting. DNSSEC is primarily concerned with authenticity and integrity, not confidentiality.
Protocols such as DNS over HTTPS (DoH) address a different problem by encrypting communication between a client and DNS resolver. DNSSEC and encrypted DNS can therefore complement each other.
Do you need it?
For domain owners, enabling DNSSEC can provide another layer of protection against forged DNS information.
In many modern DNS platforms, much of the signing process is automated. However, configuration needs to be correct at both the DNS provider and domain registrar so the chain of trust remains intact.
It doesn’t solve every DNS security problem, but it answers one very important question: Can I trust that this DNS answer is authentic?
