Paper by M. Bishop, 1991. The author 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. [Postscript] http://seclab.cs.ucdavis.edu/papers/mb91c.ps
Java-powered iButton based personal identity management security services and digital certificate authentication for secure logon, secure messaging, and digital signatures. http://www.idexsys.com