# US 7,612,382 B2 · Method for defeating reverse engineering of integrated circuits by optical means > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,612,382 B2 - Document ID: US7612382B2 - Status: Granted - Kind: B2 - Application number: 12/140,714 - Filed: 2008-06-17 - Published: 2008-10-16 - Granted: 2009-11-03 - Earliest claimed: 2000-06-23 - Assignees: International Business Machines Corporation - Inventors: Jeffrey A. Kash; James C. Tsang; Daniel R. Knebel - Web page: https://patentgrep.com/patent/US7612382B2 ## CPC - H10W 42/405: {using active circuits} - G01R 31/311: of integrated circuits {(G01R31/31728 takes precedence)} - G01R 31/31719: {Security aspects, e.g. preventing unauthorised access during test} - H10D 89/00: Aspects of integrated devices not covered by groups H10D84/00 - H10D88/00 - H10D 89/10: Integrated device layouts - H10W 42/40: protecting against tampering, e.g. unauthorised inspection or reverse engineering - Y10S 257/922: with means to prevent inspection of or tampering with an integrated circuit, e.g. "smart card", anti-tamper - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A method for an electronic device is provided for preventing reverse engineering by monitoring light emissions emitted from transistors and such electrically active devices in the electronic device. The method emits extraneous randomized light emissions in substantial close proximity to the transistors to hide a pattern of light emissions emitted from the transistors. As one feature, the device can include a source of randomized light emissions in substantial close proximity to the transistors to hide a pattern of the emitted light from the transistors in randomized light emissions emitted by the source. As a second feature, the device can emit the randomized light emissions by randomly delaying an electrical signal that is electrically coupled to the transistors and, in response to the randomly delayed electrical signal, the transistors randomly emitting light emissions thereby hiding a separate pattern of light emission emitted from the transistors. ## Claims ### Claim 1 A method of hiding a pattern of light emission emitted from at least one active device in an integrated circuit, the method comprising: emitting extraneous light emission from an integrated circuit, the extraneous light emission being emitted in substantial close proximity to at least one active device in the integrated circuit thereby hiding a pattern of light emission emitted from the at least one active device, and wherein the emitting extraneous light emission comprises emitting randomized light emissions thereby hiding a pattern of light emission emitted from the at least one active device. ### Claim 2 (depends on 1) The method of claim 1, wherein the randomized light emissions being emitted in substantial close proximity to the at least one active device in the integrated circuit by a separate at least one active device in the integrated circuit. ### Claim 3 (depends on 1) The method of claim 1, wherein the randomized light emissions being emitted in substantial close proximity to the at least one active device in the integrated circuit by at least one of: randomized light emissions from a separate at least one active device in the integrated circuit, and randomized light emissions from randomly delaying an electrical signal that is electrically coupled to the at least one active device and, in response to the randomly delayed electrical signal, the at least one active device randomly emitting light emissions, thereby hiding a pattern of light emission emitted from the at least one active device. ### Claim 4 (depends on 3) The method of claim 3, wherein the pattern of light emission emitted from the at least one active device comprises a time-based pattern of light emission that is separate from the randomized light emissions in substantial close proximity to the at least one active device. ### Claim 5 A method of hiding a pattern of light emission emitted from at least one active device in an integrated circuit, the method comprising: hiding a pattern of emitted light from at least one active device disposed on a circuit supporting substrate by emitting randomized light emissions in substantial close proximity to the at least one active device. ### Claim 6 (depends on 5) The method of claim 5, wherein the hiding of a pattern of emitted light is performed by at least one source of randomized light emissions disposed on the circuit supporting substrate and in substantial close proximity to the at least one active device. ### Claim 7 (depends on 5) The method of claim 5, wherein the hiding of a pattern of emitted light is performed by at least one dummy circuit disposed on the circuit supporting substrate in substantial close proximity to an actual circuit also disposed on the circuit supporting substrate and comprising the at least one active device, the dummy circuit emitting randomized light emissions that hide a pattern of the emitted light from the at least one active device. ### Claim 8 (depends on 5) The method of claim 5, wherein the pattern of the emitted light from the at least one active device comprises a time-based pattern of emitted light that is separate from the randomized light emissions in substantial close proximity to the at least one active device. ### Claim 9 A method of hiding a pattern of light emission emitted from at least one active device in an electronic device, the method comprising: hiding a pattern of emitted light from at least one active device in an electrical circuit by emitting randomized light emissions in substantial close proximity to the at least one active device. ### Claim 10 (depends on 9) The method of claim 9, wherein the hiding of a pattern of emitted light is performed by at least one source of randomized light emissions in the electronic device and in substantial close proximity to the at least one active device. ### Claim 11 (depends on 9) The method of claim 9, wherein the hiding of a pattern of emitted light is performed by at least one dummy circuit in substantial close proximity to an actual circuit comprising the at least one active device, the dummy circuit emitting randomized light emissions that hide a pattern of the emitted light from the at least one active device. ### Claim 12 (depends on 9) The method of claim 9, wherein the pattern of the emitted light from the at least one active device comprises a time-based pattern of emitted light that is separate from the randomized light emissions in substantial close proximity to the at least one active device.