# US 10,873,598 B2 · Method for mitigating a DoS attack on a device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,598 B2 - Document ID: US10873598B2 - Status: Granted - Kind: B2 - Application number: 15/433,288 - Filed: 2017-02-15 - Published: 2017-08-17 - Granted: 2020-12-22 - Earliest claimed: 2016-02-17 - Assignees: ARM IP Limited - Applicants: ARM IP Limited - Inventors: Milosch Meriac - Web page: https://patentgrep.com/patent/US10873598B2 ## CPC - H04L 63/1458: {Denial of Service} - H04L 63/0876: {based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint} - H04L 63/10: {for controlling access to devices or network resources} - 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: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract There is described a method for mitigating a power-denial of service attack on a first device by a second device, the method comprising: transmitting, from the first device to the second device, a first communication comprising a first task to be solved by the second device; receiving, at the first device from the second device, a second communication comprising one of a proposed solution to the first task and at least one trust credential; verifying, at the first device, the second communication; responsive to an unsuccessful verification of the second communication, transmitting, from the first device to the second device a third communication comprising a second task to be solved by the second device. ## Claims ### Claim 1 A method for mitigating a power-denial of service attack on a first device by a second device, the method comprising: transmitting, from the first device to the second device, a first communication comprising a first task to be solved by the second device before establishing a connection between the first device and second device, where the first task requires a solution comprising a first pattern of bits to be returned; receiving, at the first device from the second device, a second communication comprising at least one trust credential comprising one or more incomplete solutions for the first task generated by the second device, where the one or more incomplete solutions each comprise bits in a pattern different from the first pattern of bits; verifying, at the first device, whether a trust threshold for the second device is reached based on or in response to the one or more incomplete solutions for the first task; responsive to a successful verification, establishing a connection between the first device and second device. ### Claim 2 (depends on 1) The method according to claim 1, wherein the at least one trust credential further comprises a device identifier of the second device. ### Claim 3 (depends on 1) The method according to claim 1, wherein establishing a connection comprises one or more of: performing, at the first device, a function requested by the second device and undertaking a negotiation protocol between the first device and the second device. ### Claim 4 (depends on 3) The method according to claim 3, wherein the negotiation protocol comprises exchanging connection data between the first device and the second device. ### Claim 5 (depends on 4) The method according to claim 4, wherein the connection data includes one or more of: synchronisation data and authorisation data. ### Claim 6 (depends on 5) The method according to claim 5, wherein the synchronisation data is derived from the solution to the first task or wherein the synchronisation data comprises timing data and/or channel data. ### Claim 7 (depends on 1) The method according to claim 1, further comprising: generating, at the first device, the first task to be solved. ### Claim 8 (depends on 7) The method according to claim 7, wherein generating the first task to be solved comprises one or more of: transforming a data input to provide a transformed value, defining data to be generated by the second device and defining a challenge-response test to be solved by a user interacting with the second device. ### Claim 9 (depends on 8) The method according to claim 8, wherein the data input comprises an n-bit number or the device identifier of the second device. ### Claim 10 (depends on 1) The method according to claim 1, the method further comprising: setting a complexity of the first task based on one or more of: an attribute of the first device, an attribute of the second device, and an attribute of one or more communications received at the first device. ### Claim 11 (depends on 10) The method according to claim 10, wherein setting the task complexity comprises one or more of: modifying the length of the data to be generated by the second device and modifying the validity period of the first task. ### Claim 12 (depends on 1) The method according to claim 1, wherein the complexity of the second task is lower than that of the first task or wherein the complexity of the second task is higher than that of the first task. ### Claim 13 (depends on 1) The method according to claim 1, wherein the first device distributes information relating to the second device to one or more devices in communication therewith. ### Claim 14 (depends on 1) The method according to claim 1, wherein a solution to the first or second tasks involves the second device solving cuckoo cycles.