# US 2016/0366178 A1 · System and Method for Guarding a Controller Area Network > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0366178 A1 - Document ID: US20160366178A1 - Status: Published application - Kind: A1 - Application number: 15/178,231 - Filed: 2016-06-09 - Published: 2016-12-15 - Earliest claimed: 2015-06-10 - Assignees: Runsafe Security, Inc. - Applicants: RunSafe Security, Inc. - Inventors: Andrew Michael WESIE; Joseph Michael SAUNDERS - Web page: https://patentgrep.com/patent/US20160366178A1 ## CPC - H04L 63/1466: {Active attacks involving interception, injection, modification, spoofing of data unit addresses, e.g. hijacking, packet injection or TCP sequence number attacks} - G06F 21/55: Detecting local intrusion or implementing counter-measures - G06F 21/552: {involving long-term monitoring or reporting} - G06F 21/554: {involving event detection and direct action} - H04B 1/3822: specially adapted for use in vehicles (H04B1/3827 takes precedence) - H04L 12/40032: {Details regarding a bus interface enhancer} - H04L 63/1416: {Event detection, e.g. attack signature detection} - B60R 16/023: for transmission of signals between vehicle parts or subsystems - H04L 41/069: using logs of notifications; Post-processing of notifications - H04L 67/12: specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks - H04L 2012/40215: {Controller Area Network CAN} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04B: TRANSMISSION - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR ## Abstract Systems and methods for guarding a controller area network are disclosed. In one embodiment, a system for guarding a controller area network comprises one or more processors. The one or more processors may be configured to receive a message destined for the controller area network. The one or more processors may further be configured to determine whether the message is legitimate. The one or more processors may further be configured to modify the message, if the message is determined as illegitimate, as an error message. ## Claims ### Claim 1 A system for guarding a controller area network, comprising one or more processors configured to: receive a message destined for the controller area network; determine whether the message is legitimate; modify the message, if the message is determined as illegitimate, as an error message. ### Claim 2 (depends on 1) The system of claim 1, wherein the one or more processors are further configured to modify the message by injecting six consecutive dominant bits. ### Claim 3 (depends on 2) The system of claim 2, wherein the one or more processors are further configured to inject the six consecutive dominant bits before an end of the message as soon as a portion of the message indicates the message as illegitimate. ### Claim 4 (depends on 1) The system of claim 1, wherein the one or more processors are further configured to determine whether the message is legitimate at line-speed. ### Claim 5 (depends on 1) The system of claim 1, wherein the controller area network is an in-vehicle network. ### Claim 6 (depends on 5) The system of claim 5, wherein the one or more processors are further configured to, if the message is determined as illegitimate, alert a driver of a vehicle for which the in-vehicle network is installed. ### Claim 7 (depends on 1) The system of claim 1, wherein the one or more processors are further configured to log information regarding messages transmitted across the controller area network. ### Claim 8 (depends on 7) The system of claim 7, wherein the one or more processors are further configured to transmit the logged information to an external module. ### Claim 9 (depends on 8) The system of claim 8, wherein the one or more processors are further configured to transmit the logged information via an infrared reader. ### Claim 10 A method for guarding a controller area network, comprising: receiving a message destined for the controller area network; determining whether the message is legitimate; modifying the message, if the message is determined as illegitimate, as an error message. ### Claim 11 (depends on 10) The method of claim 10, further comprising modifying the message by injecting six consecutive dominant bits. ### Claim 12 (depends on 11) The method of claim 11, further comprising injecting the six consecutive dominant bits before an end of the message as soon as a portion of the message indicates the message as illegitimate. ### Claim 13 (depends on 10) The method of claim 10, further comprising determining whether the message is legitimate at line-speed. ### Claim 14 (depends on 10) The method of claim 10, wherein the controller area network is an in-vehicle network. ### Claim 15 (depends on 14) The method of claim 14, further comprising, if the message is determined as illegitimate, alerting a driver of a vehicle for which the in-vehicle network is installed. ### Claim 16 (depends on 10) The method of claim 10, further comprising logging information regarding messages transmitted across the controller area network. ### Claim 17 (depends on 16) The method of claim 16, wherein the one or more processors are further configured to transmit the logged information to an external module. ### Claim 18 (depends on 17) The method of claim 17, wherein the one or more processors are further configured to transmit the logged information via an infrared reader. ### Claim 19 A non-transitory computer readable medium storing a computer-readable program for guarding a controller area network, comprising: computer-readable instructions to receive a message destined for the controller area network; computer-readable instructions to determine whether the message is legitimate; computer-readable instructions to modify the message, if the message is determined as illegitimate, as an error message. ### Claim 20 (depends on 19) The non-transitory computer readable medium according to claim 19, further comprising computer-readable instructions to modify the message by injecting six consecutive dominant bits.