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Computing and indicating device

  • US 4,856,062 A
  • Filed: 11/24/1987
  • Issued: 08/08/1989
  • Est. Priority Date: 11/30/1984
  • Status: Expired due to Term
First Claim
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1. In a verification system wherein a first mechanism generates a first non-predictable code in accordance with a predetermined algorithm in response to both a unique static variable and a dynamic variable, a second mechanism generates a second non-predictable code in accordance with the predetermined variable and a second dynamic variable corresponding to the first dynamic variable, and means are provided for comparing the two non-predictable codes, a portable, hand-held computing and indicating device forming the first mechanism comprising:

  • a processor having said algorithm preprogrammed therein;

    means for causing the program stored in said processor to be erased if an effort is made to gain access to the program;

    means for storing a unique static variable in said device;

    means for generating a time varying dynamic variable, said means being adapted to generate the same dynamic variable as that generated at said second mechanism at substantially the same instant of time;

    means for applying the stored unique static variable and the currently generated dynamic variable to said processor, said processor being adapted to generate said first non-predictable code in response to the two variable applied thereto; and

    means for affording person sensing of the non-predictable code currently being generated by said processor.

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