Remote operating system having secure communication of encoded messages and automatic re-synchronization

• US 5,191,610 A
• Filed: 02/28/1992
• Issued: 03/02/1993
• Est. Priority Date: 02/28/1992
• Status: Expired due to Term

• Current Assignee: Lear Automotive Dearborn, Incorporated (Lear Corporation)
• Original Assignee: United Technologies Automotive, Inc. (Lear Corporation)
• Inventors: Finn, Alan M., Hill, John P.
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US07/843,402
• Time in Patent Office: 368 Days
• Field of Search: 380/21, 380/23-25, 380/46, 380/48, 380/50
• US Class Current: 380/262
• CPC Class Codes: G07C 2009/00238 the transmittted data signal containing a code which is changed
• CPC Class Codes: G07C 2009/00769 with data transmission performed by wireless means
• CPC Class Codes: G07C 2009/00928 for garage doors
• CPC Class Codes: G07C 2209/06 Involving synchronization or resynchronization between transmitter and receiver; reordering of codes
• CPC Class Codes: G07C 9/00182 operated with unidirectional data transmission between data carrier and locks
• CPC Class Codes: H04L 9/0662 with particular pseudorandom sequence generator
• CPC Class Codes: H04L 9/12 Transmitting and receiving encryption devices synchronised or initially set up in a particular manner
• CPC Class Codes: H04L 9/32 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

Abstract

A remote operating system for remote-controlled operation of a device provides secure communication of encoded messages between a transmitter (100) and receiver (150) of the system, and provides automatic re-synchronization of the transmitter and receiver without revealing a loss of synchronization to the operator. A pseudo random binary number (PRBN) generator (105) in the transmitter (100) produces a sequence of identification numbers. Each time the transmitter (100) is activated, the identification number contained in the transmitted encoded message is selected as the next number in the sequence of identification numbers. A PRBN generator (170) in the receiver (150) produces a sequence of reference numbers that is identical to the sequence of identification numbers. The receiver responds to a command code portion of the transmitted encoded message for operation the device when there is identity between the reference number and the identification number. The receiver (150) responds to the transmitted message when there is not identity between the reference number and the identification number provided that a reference number identical to the identification number is generated within a search length in the sequence of reference numbers, thereby providing automatic re-synchronization of the transmitter and receiver. If a reference number matching the identification number is not found within the search length, the transmitter is controlled to produce a re-synchronization signal for re-synchronizing the receiver to the transmitter.

Claims

1. A remote operating system for remote-controlled operation of a device, comprising:

transmitting means having;

means for transmitting encoded messages, each message comprising an identification number portion and a command code portion,

command means for providing at least one command code signal, each command code signal corresponding to an operating condition of the device, said encoded message command code portion containing a command code signal,

pseudo random binary number (PRBN) generating means comprising a generator polynomial derived from a prime polynomial for generating a sequence of identification numbers, the length of said sequence of identification numbers being dependant upon the order of said prime polynomial, said encoded message identification number portion being selected as the next identification number in said sequence of identification numbers each time said transmitting means is actuated; and

receiving means, connected for communication with the device, having;

means for receiving said encoded messages,

PRBN generating means comprising a generator polynomial derived from a prime polynomial for generating a sequence of reference numbers, said receiving means PRBN generating means generator polynomial being identical to said transmitting means PRBN generating means generator polynomial, said sequence of reference numbers being identical to said sequence of identification numbers,

reference number memory means for storing the current reference number in said sequence of reference numbers,

signal processing means responsive to receiving an encoded message for selecting the next reference number from said sequence of reference numbers, and responsive to there being identity between the next reference number and said encoded message identification number portion for replacing the current reference number with the next reference number in said reference number memory means, and for providing said encoded message command code portion to the device.

2. A remote operating system according to claim 1 wherein said signal processing means further comprises automatic re-synchronization means responsive to the next reference number not being identical to said encoded message identification number portion for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches said encoded message identification number portion, and responsive to finding a matching reference number within said search length for replacing the current reference number with said matching reference number in said reference number memory means, and for providing said encoded message command code portion to the device.

3. A remote operating system according to claim 1 wherein said transmitting means further comprises:

manually actuable re-synchronization means for consecutively providing a re-synchronization message and a validation message in response to the activation of said manually actuable re-synchronization means, said re-synchronization message comprising a count signal indicative of the number of times said transmitting means has been activated less a random number having a magnitude smaller than said search length, said validation message comprising an identification number portion and a command code portion, said validation message identification number portion being selected as the next identification number in said sequence of identification numbers;

said signal processing means being responsive to said re-synchronization message for setting said next reference number equal to the reference number in said sequence of reference numbers corresponding to said count signal; and

said signal processing means being responsive to said validation message for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches said validation message identification number portion, and responsive to finding a matching reference number within said search length for replacing the current reference number with said matching reference number in said reference number memory means, and for providing said command code portion of said encoded message to the device.

4. A remote operating system according to claim 1 wherein deriving said PRBN generating means generator polynomials from said prime polynomials results in said generator polynomials being equal to said prime polynomials.

5. A remote operating system according to claim 1 wherein each number in said sequence of identification numbers and in said sequence of reference numbers is provided by selecting a subset of the bits from the total bits of each number produced by said PRBN generating means.

6. A remote operating system according to claim 1 wherein said PRBN generating means in said transmitting means and in said receiving means are linear feedback shift registers which implement said generator polynomials.

7. A remote operating system according to claim 4 wherein said PRBN generating means in said transmitting means and in said receiving means are maximal length linear feedback shift registers which implement said prime polynomials.

8. A remote operating system according to claim 1 wherein said transmitting means and said receiving means further comprise means for providing a non-zero seed number to said PRBN generating means.

9. A remote operating system for remote-controlled operation of at least one lock in an electronic locking system, comprising:

a transmitter having;

means for transmitting encoded messages, each message comprising an identification number portion and a command code portion,

command means for providing a first command code signal corresponding to the locks being in the locked position and for providing a second command code signal corresponding to the locks being in the unlocked position, said encoded message command code portion containing one of said command code signals,

linear feedback shift register (LFSR) means for implementing a generator polynomial derived from a prime polynomial, said LFSR means generating a sequence of identification numbers, the length of said sequence of identification numbers being dependant upon the order of said prime polynomial, the identification number portion of said message being selected as the next identification number in said sequence of identification numbers each time said transmitter is actuated; and

a receiver, connected for communication with the locking system, having;

means for receiving said encoded messages,

LFSR means for implementing a generator polynomial derived from a prime polynomial, said LFSR means generating a sequence of reference numbers, said receiver LFSR means generator polynomial being identical to said transmitter LFSR means generator polynomial, said sequence of reference numbers being identical to said sequence of identification numbers,

reference number memory means for storing the current reference number in said sequence of reference numbers,

signal processing means responsive to receiving an encoded message for selecting the next reference number from said sequence of reference numbers, and responsive to there being identity between the next reference number and said encoded message identification number portion for replacing the current reference number with the next reference number in said reference number memory means, and for providing said command code portion of said encoded message to the locking system.

10. A remote operating system according to claim 9 wherein said signal processing means further comprises automatic re-synchronization means responsive to the next reference number not being identical to said encoded message identification number portion for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches said encoded message identification number portion, and responsive to finding a matching reference number within said search length for replacing the current reference number with said matching reference number in said reference number memory means, and for providing said encoded message command code portion to the locking system.

11. A remote operating system according to claim 9 wherein said transmitting means further comprises:

manually actuable re-synchronization means for consecutively providing a re-synchronization message and a validation message in response to the activation of said manually actuable re-synchronization means, said re-synchronization message comprising a count signal indicative of the number of times said transmitting means has been activated less a random number having a magnitude smaller than said search length, said validation message comprising an identification number portion and a command code portion, said validation message identification number portion being selected as the next identification number in said sequence of identification numbers;

said signal processing means being responsive to said re-synchronization message for setting said next reference number equal to the reference number in said sequence of reference numbers corresponding to said count signal; and

said signal processing means being responsive to said validation message for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches said validation message identification number portion, and responsive to finding a matching reference number within said search length for replacing the current reference number with said matching reference number in said reference number memory means, and for providing said command code portion of said encoded message to the locking system.

12. A remote operating system according to claim 9 wherein deriving said LFSR means generator polynomials from said prime polynomials results in said generator polynomials being equal to said prime polynomials, and wherein said LFSR means are maximal length linear feedback shift registers.

13. A remote operating system according to claim 9 wherein each number in said sequence of identification numbers and in said sequence of reference numbers is provided by selecting a subset of the bits from the total bits of each number produced by said LFSR means.

14. A remote operating system according to claim 9 wherein said transmitting means and said receiving means further comprise means for providing a non-zero, binary number seed to said PRBN generating means.

15. A remote operating system for remote-controlled operation of a device, comprising:

a transmitter having;

means for transmitting a message encoded with an identification number,

identification number generating means comprising a generator polynomial derived from a prime polynomial for generating a sequence of identification numbers, the length of said sequence of identification numbers being dependant upon the order of said prime polynomial, said message being encoded with the next identification number in said sequence of identification numbers each time said transmitter is actuated; and

a receiver, connected for communication with the device, having;

means for receiving said messages, and for decoding said message to provide a received identification number,

reference number generating means comprising a generator polynomial derived from a prime polynomial for generating a sequence of reference numbers, said sequence of reference numbers being identical to said sequence of identification numbers, said reference number generating means being responsive to said receiver receiving a message for selecting the next reference number from said sequence of reference numbers, and

signal processing means responsive to there being identity between the next reference number and said received identification number for operating the device.

16. A remote operating system according to claim 15 wherein said signal processing means further comprises automatic re-synchronization means responsive to the next reference number not being identical to said received identification number for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches the received identification number, and responsive to finding a matching reference number within said search length for operating the device.

17. A remote operating system according to claim 15 wherein said transmitting means further comprises:

manually actuable re-synchronization means for consecutively providing a re-synchronization message and a validation message in response to the activation of said manually actuable re-synchronization means, said re-synchronization message being encoded with a count signal indicative of the number of times said transmitting means has been activated less a random number having a magnitude smaller than said search length, said validation message being encoded with an identification number selected as the next identification number in said sequence of identification numbers;

said signal processing means being responsive to said re-synchronization message for setting said next reference number equal to the reference number in said sequence of reference numbers corresponding to said count signal; and

said signal processing means being responsive to said validation message for searching for a matching reference number in said sequence of reference numbers, within a search length of reference numbers following the next reference number, which matches the received identification number from said validation message, and responsive to finding a matching reference number within said search length for operating the device.

18. A remote operating system according to claim 15 wherein deriving said identification number generating means generator polynomial and said reference number generating means generator polynomial from said prime polynomials results in said generator polynomials being equal to said prime polynomials.

19. A remote operating system according to claim 15 wherein each number in said sequence of identification numbers and in said sequence of reference numbers is provided by selecting a subset of the bits from the total bits of each number produced by said PRBN generating means.

20. A remote operating system according to claim 15 wherein said identification number generating means and said reference number generating means are linear feedback shift registers (LFSR) which implement said generator polynomials.

21. A remote operating system according to claim 18 wherein said identification number generating means and said reference number generating means are maximal length linear feedback shift registers (LFSR) which implement said prime polynomials.

22. A remote operating system according to claim 20 wherein said transmitting means and said receiving means further comprise means for providing a non-zero seed number to said LFSRs.

23. A remote operating system according to claim 21 wherein said transmitting means and said receiving means further comprise means for providing a non-zero seed number to said maximal length LFSRs.