Authentication using magnetic field based on current drawn by security device

Abstract

Systems and methods for determining authenticity of a security device of a component in an imaging device includes receiving, by the security device, an authentication challenge including one or more commands and executing, by the security device, the one or more commands in response to receiving the authentication challenge. A magnetic field profile is generated based on current drawn by the security device from a power source while the security device is executing the one or more commands, the generated magnetic field profile indicating an authentication response of the security device to the authentication challenge for use in determining authenticity of the security device.

1 . A supply item for installation in an imaging device, comprising:
 a housing; and   a security device chip connected to the housing, the security device chip being configured to draw current through a conductor from a power source during execution of an authentication challenge thereby generating a magnetic field about the conductor and sending to itself the generated magnetic field.   
     
     
         2 . The supply item of  claim 1 , wherein the security device chip determines authenticity of the supply item by comparing the generated magnetic field with an expected magnetic field. 
     
     
         3 . The supply item of  claim 2 , wherein the expected magnetic field profile is predetermined and stored in memory available to the security device chip. 
     
     
         4 . The supply item of  claim 2 , wherein the security device chip is configured to dynamically generate the expected magnetic field. 
     
     
         5 . The supply item of  claim 1 , further including a magnetometer connected to the housing, the magnetometer for measuring the magnetic field. 
     
     
         6 . The supply item of  claim 5 , wherein the magnetometer is configured to measure the magnetic field during a measurement duration started by a trigger condition of a controller in the imaging device. 
     
     
         7 . The supply item of  claim 5 , wherein the magnetometer includes either a magnetoresistance or hall effect sensor. 
     
     
         8 . The supply item of  claim 5 , further including a substrate, the magnetometer and the security device chip securing to the substrate. 
     
     
         9 . The supply item of  claim 8 , wherein the substrate further includes the conductor. 
     
     
         10 . The supply item of  claim 1 , wherein the power source is a voltage regulator. 
     
     
         11 . The supply item of  claim 1 , wherein the housing contains toner for imaging media in the imaging device. 
     
     
         12 . The supply item of  claim 1 , wherein the security device chip is configured to receive the authentication challenge from the imaging device when the housing is installed in the imaging device. 
     
     
         13 . The supply item of  claim 1 , wherein the security device chip is configured to receive the authentication challenge from another security device chip on another supply item having another housing when said housing and said another housing are installed in the imaging device. 
     
     
         14 . The supply item of  claim 1 , wherein the security device chip is configured to execute a statistical correlation algorithm to determine authenticity of the supply item when comparing the generated magnetic field with an expected magnetic field. 
     
     
         15 . The supply item of  claim 1 , wherein the security device chip connects to and communicates with a controller of the imaging device over a shared bus. 
     
     
         16 . The supply item of  claim 15 , wherein the shared bus carries data in a bidirectional manner over a two-wire serial bus. 
     
     
         17 . The supply item of  claim 16 , wherein one wire of the two-wire serial bus carries clocking signals. 
     
     
         18 . A toner cartridge for installation in an imaging device, comprising:
 a housing having toner for imaging media in the imaging device; and   a security device chip connected to the housing, the security device chip being configured for self-authentication when the housing is installed in the imaging device including being configured to generate an authentication challenge and an authentication response thereto whereby during execution of the authentication challenge the security device chip is configured to draw current through a conductor from a power source thereby generating a magnetic field about the conductor and the security device chip determines authenticity of the supply item by comparing the generated magnetic field with an expected magnetic field.   
     
     
         19 . The supply item of  claim 18 , whereby the security device chip dynamically-generates the expected magnetic field or reads from an available memory the expected magnetic field. 
     
     
         20 . The supply item of  claim 18 , further including a substrate securing the security device chip and a magnetometer in proximity to the conductor to measure the magnetic field about the conductor.