Rolling code security system
DCFirst Claim
Patent Images
1. A method of sending codes to operate a controller for a barrier movement operator, the method comprising:
- rf transmitting in trinary format a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to a security code stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code of the sequence for causing operation of the controller;
wherein the controller characterizes received security codes to be in one of a valid window, an invalid window or an insecure window based on the relationship between a received security code and the security code stored in the controller and a received code having the first relationship to the expected security code results in an insecure window characterization.
1 Assignment
Litigations
0 Petitions
Accused Products
Abstract
A rolling code transmitter is useful in a security system for providing secure encrypted RF transmission comprising an interleaved trinary bit fixed code and rolling code. A receiver demodulates the encrypted RF transmission and recovers the fixed code and rolling code. Upon comparison of the fixed and rolling codes with stored codes and determining that the signal has emanated from an authorized transmitter, a signal is generated to actuate an electric motor to open or close a movable barrier.
214 Citations
34 Claims
-
1. A method of sending codes to operate a controller for a barrier movement operator, the method comprising:
-
rf transmitting in trinary format a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to a security code stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code of the sequence for causing operation of the controller; wherein the controller characterizes received security codes to be in one of a valid window, an invalid window or an insecure window based on the relationship between a received security code and the security code stored in the controller and a received code having the first relationship to the expected security code results in an insecure window characterization. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method of operating a transmitter to operator a controller for a barrier movement operator which includes an algorithm to generate a sequence of generated security codes in which a predetermined portion of a security code differs from the predetermined portion of previous security codes in the sequence and which controller interprets received codes in trinary format to be one of an invalid window, a valid window or an insecure code window, the method of operating the transmitter comprising:
-
rf transmitting in a trinary format, a first transmitted code representing a first security code to be interpreted as being in the insecure code window; and rf transmitting in a trinary format after the transmission of the first transmitted code a second transmitted code representing a second security code having a predetermined relationship to the first code. - View Dependent Claims (9, 10, 11)
-
-
12. A transmitter for controlling a controller for a barrier movement operator, comprising an rf transmitter which rf transmits, in trinary format, a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to security code previously stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code transmitted by the rf transmitter for causing operation of the controller;
wherein the controller characterizes received security codes to be in one of a valid window, an invalid window or an insecure window based on the relationship between a received security code and the security code stored in the controller and the controller characterizes a received code having the first relationship to the security code stored in the controller as being in the insecure window. - View Dependent Claims (13, 14, 15, 16, 17, 18)
-
19. A remote actuation system comprising:
an rf transmitter to control an operator which includes an rf receiver and an algorithm to generate a sequence of security codes in which a predetermined portion of a generated security code differs from the predetermined portion of previous security codes in the sequence and which operator interprets security codes received from the rf transmitter, in trinary format, to be in one of an invalid window, a valid window or an insecure code window, and the rf transmitter includes apparatus which rf transmits in trinary format, a first transmitted code representing a first security code to be interpreted by the operator as being in the insecure code window and rf transmits in a trinary format after the transmission of the first transmitted code a second transmitted code representing a second security code having a predetermined relationship to the first code. - View Dependent Claims (20, 21)
-
22. A method of sending codes to operate a controller for a barrier movement operator, the method comprising:
- rf transmitting in trinary format a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to a security code stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code of the sequence for causing operation of the controller;
wherein the controller includes a receiver which converts received codes into a fixed code portion and a rolling code portion and the fixed code portion of the first code and the additional code are the same. - View Dependent Claims (23, 24, 25, 26, 27, 28)
- rf transmitting in trinary format a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to a security code stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code of the sequence for causing operation of the controller;
-
29. A transmitter for controlling a controller for a barrier movement operator, comprising:
-
an rf transmitter which rf transmits, in trinary format, a sequence of security codes, the sequence of security codes comprising a first code having a first relationship to security code previously stored in the controller such that the first code will not cause operation of the controller and an additional code, which has a second relationship to the first code transmitted by the rf transmitter for causing operation of the controller; a carrier frequency generator and a modulator to transmit the first and additional codes by modulating the carrier; apparatus for selectively gating carrier frequency in intervals of modulation at a first level and a second level where the second level is less than the first level. - View Dependent Claims (30, 31, 32, 33, 34)
-
Specification