Passwords have long been used as the most common method for providing user authentication when accessing remote computer systems. However, there are many security problems associated with passwords including their susceptibility to the attacks of eavesdropping, playback, and exhaustive search. this paper describes a system which offers an innovative solution to the problem of establishing identities over insecure communications channels. The system embodies the security concept of a one-time pad because it requires that a different password be used for each access. Through the possession of a personal authentication device (the PassPort) and knowledge of a unique PIN number, an authorized user is able to generate the correct password to be used for each access.
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We built the product described in this paper and shipped it as the Sytek PFX Passport. We later sold the product line to Racal Guardata, who renamed it Racal Watchword. The product is still being sold. Here is a Racal Watchword data sheet from 1992.