This last observation is important, and combined with the flexibility of DNS, is crucial to our work. Since the domain name hierarchy is used by many modern electronic applications, there are several advantages to being able to store related information about a domain name (such as a public key in the form of a certificate) in DNS. To see this, consider a separate infrastructure for locating certificates. This system must provide a global infrastructure, similar to how DNS works, so that it is possible to look up information from everywhere without any special knowledge of which server to query etc. Such attempts exist, and they often use.