Server algorithms to improve space based authentication

Patent metadata

Field	Value
Publication number	US-9698987-B2
Application number	US-201414457092-A
Country	US
Kind code	B2
Filing date	Aug 11, 2014
Priority date	Oct 16, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A system and methods for location authentication are presented. An estimated server signal is estimated based on a generated known code signal, and a client received satellite signal is received from a client device. The client received satellite signal is compared to the estimated server signal to provide a comparison result.

First claim

The invention claimed is:

1. A method for location authentication, the method comprising:
constructing an estimated server unknown high-rate encrypted code signal based on an estimated server unknown low-rate code signal and a generated known high-rate code signal;
receiving a client received unknown high-rate encrypted code satellite signal from a client device; and
comparing the client received unknown high-rate encrypted code satellite signal to the estimated server unknown high-rate encrypted code signal to provide a code comparison result.

2. The method of claim 1 , further comprising authenticating a location of the client device based on the code comparison result.

3. The method of claim 2 , wherein:
the client device is allowed access to a protected resource if the location of the client device is valid; and
the client device is not allowed access to the protected resource if the location of the client device is invalid.

4. The method of claim 1 , further comprising:
receiving a server received unknown high-rate coded satellite signal comprising a public code and an encrypted code from a satellite receiver device, the encrypted code comprising a product of a unknown low-rate code and a known high-rate code synchronized to the public code;
estimating a time synchronization of the public code to provide an estimated code time synchronization;
generating the known high-rate code based on the estimated code time synchronization to provide an estimated server known high-rate code; and
removing the estimated server known high-rate code from the encrypted code of the server received coded satellite signal to provide the estimated server unknown low-rate code signal.

5. The method of claim 4 , further comprising the generated known high-rate code signal comprising the estimated server known high-rate code.

6. The method of claim 4 , wherein the public code comprises a GPS C/A code, the encrypted code comprises a GPS P(Y) code, the unknown low-rate code comprises a GPS W code, and the known high-rate code comprises a GPS P code.

7. The method of claim 4 , wherein the server received unknown high-rate coded satellite signal is transmitted from at least one of the group consisting of: an LEO satellite, an MEO satellite, a GEO satellite, a Global Navigation Satellite System (GNSS) satellite, and a Global Positioning System satellite.

8. The method of claim 1 , further comprising filtering the estimated server unknown high-rate encrypted code signal.

9. The method of claim 1 , further comprising synchronizing the estimated server unknown high-rate encrypted code signal to the client received unknown high-rate encrypted code satellite signal.

10. The method of claim 1 , further comprising:
estimating a coarse unknown low-rate code time synchronization based on the estimated server unknown low-rate code signal and the client received unknown high-rate encrypted code satellite signal;
estimating a fine unknown low-rate code time synchronization based on the coarse unknown low-rate code time synchronization and the client received unknown high-rate encrypted code satellite signal;
constructing the generated known high-rate code signal based on the fine unknown low-rate code time synchronization; and
constructing the estimated server unknown high-rate encrypted code signal further based on the fine unknown low-rate code time synchronization.

11. A location authentication system comprising:
a server comprising a processor and a memory storing instructions, that when executed by the processor, causes the server to:
construct an estimated server unknown high-rate encrypted code signal based on an estimated server unknown low-rate code signal and a generated known high-rate code signal;
receive a client received unknown high-rate encrypted code satellite signal from a client device;
compare the client received unknown high-rate encrypted code satellite signal to the estimated server unknown high-rate encrypted code signal to provide a code comparison result; and

authenticate a location of the client device based on the code comparison result.

12. The system of claim 11 , wherein the server is further configured to:
receive a server received unknown high-rate coded satellite signal comprising a public code and an encrypted code from a satellite receiver device, the encrypted code comprising a product of a unknown low-rate code and a known high-rate code synchronized to the public code;
estimate a time synchronization of the public code to provide an estimated code time synchronization;
generate the known high-rate code based on the estimated code time synchronization to provide an estimated server known high-rate code; and
remove the estimated server known high-rate code from the encrypted code of the server received coded satellite signal to provide the estimated server unknown low-rate code signal.

13. The system of claim 11 , wherein the server is further configured to:
estimate a coarse unknown low-rate code time synchronization based on the estimated server unknown low-rate code signal and the client received unknown high-rate encrypted code satellite signal;
estimate a fine unknown low-rate code time synchronization based on the coarse unknown low-rate code time synchronization and the client received unknown high-rate encrypted code satellite signal;
construct the generated known high-rate code signal based on the fine unknown low-rate code time synchronization; and
construct the estimated server unknown high-rate encrypted code signal further based on the fine unknown low-rate code time synchronization.

14. A location authentication system comprising:
a server comprising a processor and a memory storing instructions, that when executed by the processor, causes the server to:
construct an estimated server unknown high-rate encrypted code signal based on an estimated server unknown low-rate code signal and a generated known high-rate code signal;
receive a client received unknown high-rate encrypted code satellite signal from a client device; and
compare the client received unknown high-rate encrypted code satellite signal to the estimated server unknown high-rate encrypted code signal to provide a code comparison result.

15. The system of claim 14 , wherein the server is further configured to:
receive a server received unknown high-rate coded satellite signal comprising a public code and an encrypted code from a satellite receiver device, the encrypted code comprising a product of a unknown low-rate code and a known high-rate code synchronized to the public code;
estimate a time synchronization of the public code to provide an estimated code time synchronization;
generate the known high-rate code based on the estimated code time synchronization to provide an estimated server known high-rate code; and
remove the estimated server known high-rate code from the encrypted code of the server received coded satellite signal to provide the estimated server unknown low-rate code signal.

16. The system of claim 15 , wherein the generated known high-rate code signal comprises the estimated server known high-rate code.

17. The system of claim 15 , wherein the public code comprises a GPS C/A code, the encrypted code comprises a GPS P(Y) code, the unknown low-rate code comprises a GPS W code, and the known high-rate code comprises a GPS P code.

18. The system of claim 14 , wherein the server is further configured to:
estimate a coarse unknown low-rate code time synchronization based on the estimated server unknown low-rate code s

Assignees

• Boeing Co

Inventors

• Enge Per K
• Lawrence David
• O'Connor Michael L
• Eglington Michael L
• Gutt Gregory M
• Whelan David A

Classifications

• G01S19/215 Primary

  issues related to spoofing · CPC title

• H04W12/06

  Authentication · CPC title

• G01S19/06

  employing an initial estimate of the location of the receiver as aiding data or in generating aiding data · CPC title

• H04L67/42

  Electricity · mapped topic

• H04L9/32 Primary

  including means for verifying the identity or authority of a user of the system {or for message authentication, e.g. authorization, entity authentication, data integrity or data verification, non-repudiation, key authentication or verification of credentials} · CPC title