×

Methods and apparatus for locking communications devices

  • US 5,864,757 A
  • Filed: 12/12/1995
  • Issued: 01/26/1999
  • Est. Priority Date: 12/12/1995
  • Status: Expired due to Term
First Claim
Patent Images

1. A method of unlocking a pre-locked device, the device adapted to receive signals from a remotely located facility, and further adapted to receive, and having received, an identification module containing a first value and a second value, the method comprising the steps of:

  • computing a key as a function of a signal received from the remotely located facility;

    computing a checkword as a function of the key and the first identification module value;

    comparing the checkword with the second identification module value; and

    if the checkword matches the second identification module value, unlocking the device for operation.

View all claims
  • 3 Assignments
Timeline View
Assignment View
    ×
    ×