Authentication using magnetic field based on current drawn by security device

Abstract

A method 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 method of determining authenticity of a security device of a component in an imaging device, comprising:
 receiving, by the security device, an authentication challenge including one or more commands;   executing, by the security device, the one or more commands in response to receiving the authentication challenge; and   generating a magnetic field profile 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.   
     
     
         2 . The method of  claim 1 , further comprising measuring, by a magnetometer placed a distance from a conductor carrying the current drawn by the security device while executing the one or more commands, a magnetic field around the conductor, wherein the magnetic field profile is based upon the magnetic field measured by the magnetometer. 
     
     
         3 . The method of  claim 2 , further comprising packaging the security device and the magnetometer into a single device unit. 
     
     
         4 . The method of  claim 1 , further comprising comparing the generated magnetic field profile with an expected magnetic field profile to determine authenticity of the security device. 
     
     
         5 . The method of  claim 4 , further comprising generating a second magnetic field profile of a second security device different from the security device and using the second magnetic field profile as the expected magnetic field profile. 
     
     
         6 . The method of  claim 4 , further comprising reading a predetermined magnetic field profile from memory and using the predetermined magnetic field profile as the expected magnetic field profile. 
     
     
         7 . The method of  claim 1 , further comprising providing a supply item as the component. 
     
     
         8 . The method of  claim 1 , wherein one of the receiving the authentication challenge, the executing the one or more commands, and the generating the magnetic field profile occurs substantially concurrently with one of an act of receiving a second authentication challenge by a second security device of a second component in the imaging device, an act of executing one or more commands included in the second authentication challenge by the second security device, and an act of generating a magnetic field profile based on current drawn by the second security device from the power source while the second security device is executing the one or more commands included in the second authentication challenge. 
     
     
         9 . A method of generating a response to an authentication challenge for determining authenticity of a component in an imaging device, comprising:
 receiving, by the component, an authentication challenge including on or more commands;   executing, by the component, the one or more commands included in the authentication challenge in response to receiving the authentication challenge, the component drawing current from a power source while executing the one or more commands;   measuring, by a magnetometer placed a distance from a conductor carrying the current drawn by the component while executing the one or more commands, a magnetic field around the conductor; and   generating a magnetic field profile based on the measured magnetic field and using the generated magnetic field profile as a response to the authentication challenge.   
     
     
         10 . The method of  claim 9 , further comprising generating the authentication challenge by generating a random challenge. 
     
     
         11 . The method of  claim 9 , further comprising sending the generated magnetic field profile to a master for comparison with an expected magnetic field profile to determine authenticity of the component. 
     
     
         12 . The method of  claim 9 , wherein the generating the magnetic field profile begins upon execution by the component of a first operation of the one or more commands. 
     
     
         13 . The method of  claim 9 , wherein the generating the magnetic field profile ends upon completion by the component of a last operation of the one or more commands. 
     
     
         14 . The method of  claim 9 , further comprising providing the generated magnetic field profile as an expected magnetic field response for a second component in the imaging device different from the component. 
     
     
         15 . A device in a component for use in determining authenticity of the component in an imaging device, comprising;
 a security device electrically connected to a power source that delivers current to the security device via a conductor when the security device executes one or more commands included in an authentication challenge in response to the security device receiving the authentication challenge; and   a magnetometer device positioned a distance from the conductor that carries the current being delivered from the power source to the security device when the security device executes the one or more commands, the magnetometer device is operative to measure a magnetic field around the conductor when the security device executes the one or more commands to generate a magnetic field profile indicating an authentication response of the security device to the authentication challenge.   
     
     
         16 . The device of  claim 15 , wherein the generated magnetic field profile is used as an expected magnetic profile for a second component in the imaging device different from the component. 
     
     
         17 . The device of  claim 15 , wherein the security device and the magnetometer device are assembled in a multi-chip module package where the magnetometer device and the security device are placed horizontally side by side on a substrate. 
     
     
         18 . The device of  claim 15 , wherein the magnetometer device and the security device are assembled in a multi-chip module package where the magnetometer device and the security device are placed vertically in a chip-on-chip stack on a substrate. 
     
     
         19 . The device of  claim 15 , wherein the magnetometer device and the security device are integrated in a single chip where the magnetometer device and the security device are fabricated on the same semiconductor substrate. 
     
     
         20 . The device of  claim 15 , further comprising at least one of a second security device and a second magnetometer device, the second security device is electrically connected to the power source that delivers current to the second security device when the second security device executes commands and the second magnetometer is operative to measure at least one of a second magnetic field that is generated based on the current being delivered to the second security device when the second security device executes the commands and the magnetic field that is generated based on the current being delivered to the security device when the security device executes the one or more commands.