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Methods and apparatus for data encryption and transmission

  • US 5,524,072 A
  • Filed: 06/17/1994
  • Issued: 06/04/1996
  • Est. Priority Date: 12/04/1991
  • Status: Expired due to Fees
First Claim
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1. A method of encrypting, transmitting, and decrypting an account number based on the use of a reversible mathematical algorithm, the algorithm being a function of time and date, and the algorithm having said account number as argument, the method comprising the steps of:

  • storing said account number in the memory of a hand-held special tone dialing (STD) device;

    storing a first mathematical algorithm in the memory of said STD device;

    storing a second algorithm, which second algorithm is the mathematical inverse of said first algorithm, in a central computer;

    entering a personal identification number (PIN) onto a keypad of said STD device to thereby retrieve said account number and said first algorithm;

    executing said first algorithm using the date and time of encryption to thereby encrypt said account number and the time and date of encryption as a function of said first algorithm;

    applying, by said central computer, said second algorithm to said encrypted account number to thereby compute said account number as the result of said second algorithm being applied to said encrypted account number;

    looking up at least a portion of said account number in an account data base maintained by said central computer to facilitate the authorization of a financial transaction involving the account to which said account number is associated; and

    transmitting a response message from said central computer to said STD device relating to the authorization of said financial transaction.

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