The Realm is a unique identifier for each site. Typically, it is the domain name with an optional Domain Extension to separate distinct sub-sites under the same domain.
To be a flexible as possible, SQRL accepts standard URLs that look like:
In this example, SQRL would use the hostname (fully qualified domain name, or IP address) as the Realm. Optionally, sites can specify that we include a part of the path in the Realm using a "d=" query parameter.
If a site chooses, they may include a "d=n" parameter in the query portion of the URL. When a client sees this, it concatenates n characters of the path (starting with the initial '/') onto the end of the hostname to create the Realm. For example,
URL: sqrl://domain.com/alpha/auth.php?nut=ABC Realm: domain.com URL: sqrl://domain.com/bravo/auth.php?d=6&nut=ABC Realm: domain.com/bravo URL: sqrl://domain.com:8080/charlie/auth.php?nut=ABC&d=8 Realm: domain.com/charlie