DNSSEC adds an extra layer of security to the Domain Name System (DNS) by digitally signing DNS data. It works by using a chain of trust to verify that the DNS data has not been manipulated in transit.
When a DNS query is made, DNSSEC-enabled servers respond with additional information in the form of digital signatures. These signatures are used to verify that the DNS data is authentic and has not been tampered with.
DNSSEC uses public-key cryptography to perform this verification. Each domain name has a public key associated with it, which is used to encrypt the digital signature. The client uses the domain’s public key to decrypt the signature and verify its authenticity.
Additionally, DNSSEC uses a hierarchical chain of trust to verify the authenticity of the public keys themselves. This chain of trust starts with the root zone key, operated by the Internet Assigned Numbers Authority (IANA), and extends down to individual domain keys.
Overall, DNSSEC helps protect against attacks such as DNS cache poisoning, in which an attacker redirects traffic to a malicious server by corrupting the DNS cache of a legitimate server. By verifying the authenticity of DNS data, DNSSEC helps ensure that clients are accessing the legitimate servers they intend to reach.
