.bit domains

To access a website, a browser first finds the IP address associated with the domain. These domain name and IP address mappings are stored in DNS servers, which are controlled by large companies and governments. Therefore, domain names are prone to censorship. Governments and companies usually block domain names if the website is doing something illegal or making loss for them or due to some other reason.

Due to this, there was a need for a decentralized domain name database. As Namecoin stores key-value data just like DNS servers, Namecoin can be used to implement a decentralized DNS, and this is what it has already been used for. The d and ds namespaces contain keys ending with .bit, representing .bit domain names. Technically, a namespace doesn't have any naming convention for the keys but all the nodes and clients of Namecoin agree to this naming convention. If we try to store invalid keys in d and ds namespaces, then clients will filter invalid keys.

A browser that supports .bit domains needs to look up in the Namecoin's d and ds namespace to find the IP address associated with the .bit domain.

The difference between the d and ds namespaces is that ds stores domains that support TLS and d stores the ones that don't support TLS. We have made DNS decentralized; similarly, we can also make the issuing of TLS certificates decentralized.

This is how TLS works in Namecoin. Users create self-signed certificates and store the certificate hash in Namecoin. When a client that supports TLS for .bit domains tries to access a secured .bit domain, it will match the hash of the certificate returned by the server with the hash stored in Namecoin, and if they match, then they proceed with further communication with the server.

A decentralized DNS formed using Namecoin is the first solution to the Zooko triangle. The Zooko triangle defines applications that have three properties, that is, decentralized, identity, and secure. Digital identity is used not only to represent a person, but it can also represent a domain, company, or something else.