# US 11,122,430 B2 · Security system for a moveable barrier operator

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- Number: US 11,122,430 B2
- Document ID: US11122430B2
- Status: Granted
- Kind: B2
- Application number: 16/843,119
- Filed: 2020-04-08
- Published: 2020-07-23
- Granted: 2021-09-14
- Earliest claimed: 2017-12-21
- Assignees: The Chamberlain Group, Inc.
- Applicants: The Chamberlain Group, Inc.
- Inventors: James J. Fitzgibbon
- Web page: https://patentgrep.com/patent/US11122430B2

## CPC

- H04W 12/06: Authentication
- G07C 9/00309: {operated with bidirectional data transmission between data carrier and locks}
- G07C 9/00896: {specially adapted for particular uses}
- 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}
- H04L 9/3226: {using a predetermined code, e.g. password, passphrase or PIN (network architectures or network communication protocols for supporting authentication of entities using passwords in a packet data network H04L63/083)}
- H04L 9/3228: {One-time or temporary data, i.e. information which is sent for every authentication or authorization, e.g. one-time-password, one-time-token or one-time-key}
- H04L 9/3273: {for mutual authentication (network architectures or network communication protocols for achieving mutual authentication in a packet data network H04L63/0869)}
- H04L 63/0428: {wherein the data content is protected, e.g. by encrypting or encapsulating the payload}
- H04L 63/0853: {using an additional device, e.g. smartcard, SIM or a different communication terminal (cryptographic mechanisms or cryptographic arrangements for entity authentication involving additional secure or trusted devices H04L9/3234)}
- G07C 2009/00412: {the transmitted data signal being encrypted}
- G07C 2009/00769: {with data transmission performed by wireless means}
- G07C 2009/00849: {programming by learning}
- G07C 2009/00888: {programming by learning}
- G07C 2009/00928: {for garage doors}
- G08C 2201/41: Remote control of gateways
- G08C 2201/62: Rolling code
- H04L 63/08: {for authentication of entities (cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32)}
- H04L 2012/2841: {Wireless}
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)
- G07C: TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)
- G08C: TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILAR SIGNALS (fluid pressure transmitting systems F15B; mechanical means for transferring the output of a sensing member into a different variable G01D5/00; mechanical control systems G05G)

## Abstract

Electronic systems are provided for secure actuation of a remote device such as a moveable barrier operator. The systems address the “man in the middle” problem of persons intercepting and duplicating radio frequency signals from a control device by introducing timing parameters into a bidirectional communication sequence between at least two devices.

## Claims

### Claim 1

A method of operation by a second device communicating with a first device to effect an action by the second device, the method comprising:
receiving from the first device a first encrypted message that includes at least a first fixed code and a first changing code;
transmitting to the first device a response from the second device, the response comprising a second encrypted message that includes a second fixed code and a second changing code that is independent from the first changing code, and wherein the response is configured to cause validation by the first device of the response by comparison of the second fixed code and the second changing code to second stored code values;
receiving by the second device a third encrypted message including at least the first fixed code and a changed version of the second changing code; and
effecting performance of the action by the second device in response to a comparison of at least a portion of the third encrypted message to stored code values.

### Claim 2 (depends on 1)

The method of claim 1, further comprising determining, by the second device before the transmitting, a first time window during which to transmit the response to the first device based on at least a portion of the first encrypted message.

### Claim 3 (depends on 2)

The method of claim 2, wherein a receiver of the first device is enabled to receive a transmission from the second device within the first time window.

### Claim 4 (depends on 3)

The method of claim 3, wherein the receiver of the first device is enabled during the first time window by activation of the receiver.

### Claim 5 (depends on 3)

The method of claim 3, wherein the receiver of the first device is enabled during the first time window by commanding the receiver to process incoming transmissions.

### Claim 6 (depends on 2)

The method of claim 2, wherein the first device is configured to determine if the response from the second device was received within a second time window based on at least a portion of the first encrypted message.

### Claim 7 (depends on 1)

The method of claim 1, wherein the first fixed code uniquely identifies the first device and the second fixed code uniquely identifies the second device.

### Claim 8 (depends on 1)

The method of claim 1, wherein the stored code values include a previous fixed code and a previous changing code from a previous communication between the first and second devices.

### Claim 9 (depends on 8)

The method of claim 8, wherein the comparison of at least the portion of the third encrypted message to the stored code values includes a determination of whether the first fixed code matches the previous fixed code from the previous communication and whether the changed version of the second changing code matches a value determined by the second device based on the previous changing code from the previous communication.

### Claim 10 (depends on 8)

The method of claim 8, wherein the comparison includes retrieval of the previous fixed code and the previous changing code from a memory of the second device.

### Claim 11 (depends on 1)

The method of claim 1, wherein at least one of (i) the receiving from the first device the first encrypted message and (ii) the transmitting to the first device the response from the second device is performed wirelessly via a radio frequency signal.

### Claim 12 (depends on 1)

The method of claim 1, wherein the first device includes an in-vehicle transmitter and the second device includes a movable barrier operator.

### Claim 13 (depends on 1)

The method of claim 1, wherein the second device effects performance of the action in response to validation of at least a portion of the third encrypted message.

### Claim 14

An apparatus configured to communicate with a device to effect an action by the apparatus, the apparatus comprising:
a controller circuit;
a transmitter in operative communication with the controller circuit;
a receiver in operative communication with the controller circuit;
wherein the controller circuit is configured to:
control the receiver to receive a first encrypted message that includes at least a first fixed code and a first changing code;
control the transmitter to transmit a response to the device, the response comprising a second encrypted message including a second fixed code and a second changing code that is independent from the first changing code, and wherein the response is configured to cause validation by the device of the response by comparison of the second fixed code and the second changing code to second stored code values;
control the receiver to receive a third encrypted message including at least the first fixed code and a changed version of the second changing code; and
effect performance of the action by the apparatus based on a comparison of at least a portion of the third encrypted message to stored code values.

### Claim 15 (depends on 14)

The apparatus of claim 14, wherein the controller circuit is further configured to determine a first time window in which to transmit the response to the device based on at least a portion of the first encrypted message.

### Claim 16 (depends on 15)

The apparatus of claim 15, wherein the first time window is within a second time window in which the device is able to receive transmissions from the apparatus.

### Claim 17 (depends on 16)

The apparatus of claim 16, wherein the apparatus is configured to determine the first time window relative to activation of the device.

### Claim 18 (depends on 17)

The apparatus of claim 17, wherein the apparatus is configured to determine the first time window relative to receipt of the first encrypted message by the apparatus.

### Claim 19 (depends on 15)

The apparatus of claim 15, wherein the apparatus is configured to determine the first time window based on reference to a timing circuit of the apparatus.

### Claim 20 (depends on 14)

The apparatus of claim 14, wherein the first fixed code uniquely identifies the device and the second fixed code uniquely identifies the apparatus.

### Claim 21 (depends on 14)

The apparatus of claim 14, wherein the stored code values include a previous fixed code and a previous changing code from a previous communication with the device.

### Claim 22 (depends on 21)

The apparatus of claim 21, wherein the comparison of at least the portion of the third encrypted message to the stored code values includes a determination of whether the first fixed code matches the previous fixed code and whether the changed version of the second changing code matches a value determined by the apparatus based on the previous changing code from the previous communication.

### Claim 23 (depends on 21)

The apparatus of claim 21 wherein the comparison of at least a portion of the third encrypted message to the stored code values includes retrieval of the previous fixed code and the previous changing code from a memory circuit.

### Claim 24 (depends on 14)

The apparatus of claim 14, wherein at least one of the transmitter and the receiver is configured to perform wireless communication via a radio frequency signal.

### Claim 25 (depends on 14)

The apparatus of claim 14, wherein the second stored code values are retrieved from a memory circuit.

### Claim 26 (depends on 14)

The apparatus of claim 14, wherein the controller circuit is configured to effect performance of the action in response to validation of at least a portion of the third encrypted message.

### Claim 27

A non-transitory computer readable medium having stored thereon instructions that when executed by a controller circuit of a second device cause the controller circuit to perform operations of communicating with a first device to effect an action by the second device, the operations comprising:
receiving from the first device a first encrypted message that includes at least a first fixed code and a first changing code;
transmitting to the first device a response from the second device, the response comprising a second encrypted message that includes a second fixed code and a second changing code that is independent from the first changing code, and wherein the response is configured to cause validation by the first device of the response by comparison of the second fixed code and the second changing code to second stored code values;
receiving by the second device a third encrypted message including at least the first fixed code and a changed version of the second changing code; and
effecting performance of the action by the second device upon comparing at least a portion of the third encrypted message to stored code values.

### Claim 28 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein the operations further comprise determining, by the second device before the transmitting, a first time window during which to transmit the response to the first device based on at least a portion of the first encrypted message.

### Claim 29 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein the first fixed code uniquely identifies the first device and the second fixed code uniquely identifies the second device.

### Claim 30 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein the stored code values include a previous fixed code and a previous changing code from a previous communication between the first and second devices.

### Claim 31 (depends on 30)

The non-transitory computer readable medium of claim 30, wherein the comparing of the at least a portion of the third encrypted message to the stored code values includes a determination of whether the first fixed code matches the previous fixed code and whether the changed version of the second changing code matches a value determined by the second device based on the previous changing code from the previous communication.

### Claim 32 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein at least one of (i) the receiving from the first device the first encrypted message; and (ii) the transmitting to the first device the response from the second device is performed wirelessly via a radio frequency signal.

### Claim 33 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein the first device includes an in-vehicle transmitter and the second device includes a movable barrier operator.

### Claim 34 (depends on 27)

The non-transitory computer readable medium of claim 27, wherein the operations further comprise validating at least a portion of the third encrypted message.