Pocket-sized computer access security device

Abstract

A credit-card-sized code-generating device is employed by a user in a computer-access security arrangement. The device has a multi-digit display producing a time-related set of digits, in an X-Y array. The user selects from this X-Y array of digits a multi-digit code based upon a secret code (PIN) memorized by the user. The device may display an array of rows and columns of digits, and the user selects a digit from each row based upon the digits of his secret code, where the column selected corresponds to the value of each digit of the secret code. The array of digits produced on the display is generated within the device by first generating a multi-digit token by some algorithm unique to this user, and using this token to index into a table of sets of display digits, then modifying the digits from the selected set, also based upon digits of the token. In this manner, the code read from the display, i.e., selected from rows and columns of digits based upon the personal password, is encrypted, and will be worthless to an unauthorized user even if the device is stolen.

Dependencies are inferred from the claim text.