DNSSEC validation is the process by which a DNS resolver (a client that sends DNS queries and receives DNS responses) verifies the authenticity and integrity of DNS data. This process involves several steps:
The DNS resolver sends a DNS query to the DNS server, requesting a DNS record (such as an A record or an MX record).
The DNS server returns the DNS record along with a digital signature. The digital signature is created using a private key that is known only to the DNS server.
The DNS resolver receives the DNS record and digital signature and uses the public key of the DNS server to verify the signature. The public key is part of a public/private key pair, with the private key being used to create the signature and the public key being used to verify it.
If the signature is valid, it means that the DNS record has not been tampered with or forged and can be trusted by the DNS resolver. If the signature is invalid, it means that the DNS record may have been tampered with and cannot be trusted.
In order for DNSSEC validation to work, the DNS server and the DNS resolver must both be configured to support DNSSEC. This typically involves installing and configuring DNSSEC software, as well as generating and exchanging public and private keys.
It's worth noting that DNSSEC validation is just one step in the overall process of securing DNS. Other measures, such as securing the connection between the DNS resolver and the DNS server (e.g., using TLS), can also help improve the security and trustworthiness of the DNS system.