bjorn freeman had developed an application to store data about his students that allowed them to check their own grades at any time. he used the built-in file protection features of UNIX to restrict access to the database.
now he wanted to implement a similar application using the web. but at the
same time, he did not want to make any modifications or extensions to the
existing server and/or client software.
he solved the problem by introducing special URLs (Uniform Resource Locator). these URLs contain an encrypted 40 .. 60 characters long key. this key cannot be memorized and because of its length it is not fully visible on standard browers. when a student starts her or his browser, the system comes up with a searchable page. she or he has to provide a username and a password. if the information is correct, the appropriate URL with the corresponding key is evaluated so that the student gets to his personal page from where she or he can find her or his confident information.