A proactive password checker

Password selection has long been a difficult issue; traditionally, passwords are either assigned by the computer or chosen by the user. When the computer does the assignment, the passwords are often hard to remember; when the user makes the selection, the passwords are often easy to guess. This paper describes a technique, and a mechanism, to allow users to select passwords which to them are easy to remember but to others would be very difficult to guess. The technique is site, user, and group compatible, and allows rapid changing of constraints imposed upon the password. Although experience with this technique is limited, it appears to have much promise.