Location-sensitive decryption of an encrypted message

• US 5,640,452 A
• Filed: 04/28/1995
• Issued: 06/17/1997
• Est. Priority Date: 04/28/1995
• Status: Expired due to Term

• Current Assignee: Trimble Navigation Limited (Trimble Inc.)
• Original Assignee: Trimble Navigation Limited (Trimble Inc.)
• Inventors: Murphy, Michael D.
• Primary Examiner(s): Cain, David C.
• Application Number:
  US08/430,415
• Time in Patent Office: 781 Days
• Field of Search: 380/3, 380/4, 380/5, 380/10, 380/20, 380/23, 380/49, 380/21
• US Class Current: 380/258
• CPC Class Codes: H04N 21/4524 involving the geographical location of the client retrieval from the Internet by querying based on geographical locations G06F16/9537; systems specially adapted for using geographical information in broadcast systems H04H60/70; protocols in which the network application is adapted for the location of the user terminal in communication control or processing H04L67/52; services making use of the location of users or terminals in wireless networks H04W4/02; locating users or terminals in wireless networks H04W64/00
• CPC Class Codes: H04N 7/165 Centralised control of user terminal subsequent to an upstream request signal H04N7/17345; Registering at central by two-way working H04N7/17309

Abstract

A system for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals ES received from an encrypted signal source. The decryption chip operates in association with a licensed signal receiver and is licensed for use at a selected site or location L_i and is positioned adjacent to a Satellite Positioning System (SATPS) antenna and receiver/processor that determine the present location L of this antenna. If the SATPS-determined location L is within a region R(L_i ;d_i), centered at the location L_i and having a selected diameter d_i, and if the signal ES is associated with a channel that is authorized for reception by this signal receiver, the deception chip is enabled, and the signal ES is decrypted for audible or visual display on the signal receiver. Otherwise, the decryption chip does not decrypt the incoming signal ES. The licensed site location L_i can be changed and the group of channels for which signal receipt and decryption is authorized can be changed. This system can operate on encrypted television signals and other similar signals. The SATPS may be a Global Positioning System (GPS) or a Global Orbiting Navigational Satellite System (GLONASS), or another suitable satellite-based location determination system.

Claims

1. A method for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals received from an encrypted signal source, the method comprising the steps of:

providing a signal receiver that can receive an encrypted signal from an encrypted signal source;

providing an SATPS antenna and SATPS receiver/processor connected to the antenna, to receive and process SATPS signals from at least three SATPS signal sources and to determine and issue a receiver/processor output signal indicating the location coordinates of the present location L of the SATPS antenna;

providing a decryption chip that, in an enabled state, receives an encrypted signal, decrypts this signal and issues the decrypted version of this encrypted signal as a decryption chip output signal; and

providing an enablement module that contains the location coordinates (x_i, y_i, z_i) of a selected location L_i, that contains a diameter d_i of a selected region R(L_i ;

d_i) surrounding the location L_i, that receives the SATPS receiver/processor output signal, and that determines whether the SATPS antenna present location L is within the selected region R(L_i ;

d_i),

where the enablement module issues an output signal enabling the decryption chip only if the SATPS antenna present location L is within the selected region R(L_i ;

d_i).

2. The method of claim 1, further comprising the step of causing said enablement module to transmit a distress signal that includes the location coordinates of said SATPS antenna present location L when the SATPS antenna present location L is not within the selected region R(L_i ;

d_i).

3. The method of claim 1, further comprising the step of automatically causing at least partial destruction of at least one of said decryption chip and said SATPS receiver/processor if a user of said chip attempts to disassemble or modify said decryption chip or said SATPS receiver/processor.

4. The method of claim 1, further comprising the step of providing location adjustment means, connected to at least one of said decryption chip and said SATPS receiver/processor, that allows said location coordinates of said selected location L_i to be changed to the location coordinates corresponding to another selected location L_i.

5. A method for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals received from an encrypted signal source, the method comprising the steps of:

providing a signal receiver that can receive an encrypted signal from an encrypted signal source;

providing an SATPS antenna and SATPS receiver/processor connected to the antenna, to receive and process SATPS signals from at least three SATPS signal sources and to determine and issue a receiver/processor output signal indicating the location coordinates of the present location L of the SATPS antenna;

providing a decryption chip, connected to the signal receiver, that, in an enabled state, receives an encrypted signal ES, determines a channel corresponding to this encrypted signal, determines if the receiver is authorized to receive the encrypted signal channel, and, if the encrypted signal channel appears on a list of authorized channels the signal receiver is authorized to receive, the decryption chip decrypts this signal ES and issues the decrypted version of this encrypted signal as a decryption chip output signal; and

providing an enablement module that contains the location coordinates (x_i, y_i, z_i) of a selected location L_i, that contains a diameter d_i of a selected region R(L_i ;

d_i) surrounding the location L_i, that receives the SATPS receiver/processor output signal, and that determines whether the SATPS antenna present location L is within the selected region R(L_i ;

d_i),

where the enablement module issues an output signal enabling the decryption chip only if the SATPS antenna present location L is within the selected region R(L_i ;

d_i).

6. The method of claim 5, further comprising the step of providing encryption signal channel adjustment means that allows said authorized channel list to be changed by at least one of the actions of (i) adding an encryption signal channel to said list of authorized channels and (ii) removing an encryption signal channel from said list of authorized channels.

7. The method of claim 5, further comprising the step of causing said enablement module to transmit a distress signal that includes the location coordinates of said SATPS antenna present location L when the SATPS antenna present location L is not within the selected region R(L_i ;

d_i).

8. The method of claim 5, further comprising the step of automatically causing at least partial destruction of at least one of said decryption chip and said SATPS receiver/processor if a user of said chip attempts to disassemble or modify said decryption chip or said SATPS receiver/processor.

9. The method of claim 5, further comprising the step of providing location adjustment means, connected to at least one of said decryption chip and said SATPS receiver/processor, that allows said location coordinates of said selected location L_i to be changed to the location coordinates corresponding to another selected location L_i.

10. Apparatus for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals received from an encrypted signal source, the apparatus comprising:

a signal receiver that can receive an encrypted signal from an encrypted signal source;

an SATPS antenna and SATPS receiver/processor connected to the antenna, to receive and process SATPS signals from at least three SATPS signal sources and to determine and issue a receiver/processor output signal indicating the location coordinates of the present location L of the SATPS antenna;

a decryption chip that, in an enabled state, receives an encrypted signal, decrypts this signal and issues the decrypted version of this encrypted signal as a decryption chip output signal; and

an enablement module that contains the location coordinates (x_i, y_i, z_i) of a selected location L_i, that contains a diameter d_i of a selected region R(L_i ;

d_i) surrounding the location L_i, that receives the SATPS receiver/processor output signal, and that determines whether the SATPS antenna present location L is within the selected region R(L_i ;

d_i),

where the enablement module issues an output signal enabling the decryption chip only if the SATPS antenna present location L is within the selected region R(L_i ;

d_i).

11. The apparatus of claim 10, wherein said enablement module transmits a distress signal that includes the location coordinates of said SATPS antenna present location L when the SATPS antenna present location L is not within the selected region R(L_i ;

d_i).

12. The apparatus of claim 10, wherein at least one of said decryption chip and said SATPS receiver/processor is automatically at least partially destroyed if a user of said chip attempts to disassemble or modify said decryption chip or said SATPS receiver/processor.

13. The method of claim 10, further comprising location adjustment means, connected to at least one of said decryption chip and said SATPS receiver/processor, that allows said location coordinates of said selected location L_i to be changed to the location coordinates corresponding to another selected location L_i.

14. Apparatus for assuring the location integrity of a decryption chip used to receive and decrypt encrypted signals received from an encrypted signal source, the apparatus comprising:

a signal receiver that can receive an encrypted signal from an encrypted signal source;

an SATPS antenna and SATPS receiver/processor connected to the antenna, to receive and process SATPS signals from at least three SATPS signal sources and to determine and issue a receiver/processor output signal indicating the location coordinates of the present location L of the SATPS antenna;

a decryption chip, connected to the signal receiver, that, in an enabled state, receives an encrypted signal ES, determines a channel corresponding to this encrypted signal, determines if the receiver is authorized to receive the encrypted signal channel, and, if the encrypted signal channel appears on a list of authorized channels the signal receiver is authorized to receive, the decryption chip decrypts this signal ES and issues the decrypted version of this encrypted signal as a decryption chip output signal; and

an enablement module that contains the location coordinates (x_i, y_i, z_i) of a selected location L_i, that contains a diameter d_i of a selected region R(L_i ;

d_i) surrounding the location L_i, that receives the SATPS receiver/processor output signal, and that determines whether the SATPS antenna present location L is within the selected region R(L_i ;

d_i),

where the enablement module issues an output signal enabling the decryption chip only if the SATPS antenna present location L is within the selected region R(L_i ;

d_i).

15. The apparatus of claim 14, further comprising channel adjustment means that allows said authorized channel list to be changed by at least one of the actions of (i) adding an encryption signal channel to said list of authorized channels and (ii) removing an encryption signal channel from said list of authorized channels.

16. The apparatus of claim 14, wherein said enablement module transmits a distress signal that includes the location coordinates of said SATPS antenna present location L when the SATPS antenna present location L is not within the selected region R(L_i ;

d_i).

17. The method of claim 14, wherein at least one of said decryption chip and said SATPS receiver/processor is automatically at least partially destroyed if a user of said chip attempts to disassemble or modify said decryption chip or said SATPS receiver/processor.

18. The method of claim 14, further comprising location adjustment means, connected to at least one of said decryption chip and said SATPS receiver/processor, that allows said location coordinates of said selected location L_i to be changed to the location coordinates corresponding to another selected location L_i.