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Method and apparatus for controlling access to a communication system

  • US 4,964,163 A
  • Filed: 04/04/1988
  • Issued: 10/16/1990
  • Est. Priority Date: 04/04/1988
  • Status: Expired due to Fees
First Claim
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1. In a two-way communication system having:

  • a central unit; and

    a plurality of subscriber units each having at least an identification code stored therein;

    a method of controlling access to the two-way communication system comprising the steps of;

    at at least one of said plurality of subscriber units;

    (a) receiving a puzzle comprising;

    (i) at least one digital code;

    (ii) at least one operand code representing at least instructions for processing said at least one digital code;

    (b) solving said puzzle to provide an answer code representing at least a solution to said puzzle;

    (c) transmitting at least said answer code.

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