Authentication using analog signal challenge

Abstract

A method of determining authenticity of a component in an imaging device includes generating an analog signal as an authentication challenge to the component. The method further includes generating, by the component, a response to the authentication challenge by converting the analog signal into one or more digital values and capturing a derivative of the one or more digital values as the response. Authenticity of the component is determined by comparing the response with an expected response.

1 . A method of determining authenticity of a component in an imaging device, comprising:
 generating an analog signal as an authentication challenge to the component;   generating, by the component, a response by converting the analog signal into one or more digital values and capturing a derivative of the one or more digital values as the response; and   comparing the response with an expected response to determine authenticity of the component.   
     
     
         2 . The method of  claim 1 , wherein the generating the analog signal includes generating a random analog signal. 
     
     
         3 . The method of  claim 2 , wherein the generating the random analog signal includes generating a signal that is random in at least one of amplitude, frequency, and duration. 
     
     
         4 . The method of  claim 1 , further comprising providing a toner cartridge as the component, wherein the generating the analog signal includes generating the analog signal by another component different from the toner cartridge. 
     
     
         5 . The method of  claim 1 , wherein the generating the analog signal includes generating the analog signal by the component. 
     
     
         6 . The method of  claim 1 , further comprising generating, by the component, a second analog signal based on the response for sending the second analog signal, as the response to the authentication challenge, to another component different from the component. 
     
     
         7 . The method of  claim 1 , further comprising generating a response of a second component different from the component and using the response of the second component as the expected response. 
     
     
         8 . The method of  claim 1 , wherein the comparing the response includes comparing the response with the expected response by the component. 
     
     
         9 . The method of  claim 1 , wherein the comparing the response with the expected response includes using a statistical correlation between the response and the expected response. 
     
     
         10 . A method of generating an authentication challenge to a component of an imaging device for determining authenticity of the component, comprising:
 generating one or more random numbers;   identifying one or more parameters stored in memory based on the one or more random numbers; and   generating, by an analog circuit, a random analog signal based on the one or more parameters and using the random analog signal as the authentication challenge to the component.   
     
     
         11 . The method of  claim 10 , wherein the generating the random analog signal includes generating a signal that is random in at least one of amplitude, frequency, and duration. 
     
     
         12 . The method of  claim 10 , wherein the generating the random analog signal includes generating the random analog signal by another component different from the component with a toner cartridge being provided as the component. 
     
     
         13 . The method of  claim 10 , wherein the generating the random analog signal includes generating the random analog signal by the component. 
     
     
         14 . 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 analog signal as the authentication challenge;   converting the analog signal into one or more digital values; and   capturing a derivative of the one or more digital values as the response to the authentication challenge.   
     
     
         15 . The method of  claim 14 , wherein the receiving the analog signal includes a receiving a random analog signal as the authentication challenge. 
     
     
         16 . The method of  claim 15 , wherein the receiving the random analog signal includes receiving a signal that is random in at least one of amplitude, frequency, and duration. 
     
     
         17 . The method of  claim 14 , further comprising providing a toner cartridge as the component, wherein the receiving the analog signal includes receiving the analog signal from another component different from the toner cartridge. 
     
     
         18 . The method of  claim 14 , wherein the receiving the analog signal includes receiving the analog signal from the component. 
     
     
         19 . The method of  claim 14 , further comprising generating, by the component, a second analog signal based on the response for sending the second analog signal, as the response to the authentication challenge, to another component different from the component. 
     
     
         20 . A security device for use on a supply item, comprising:
 a first analog circuit for generating an authentication challenge by converting one or more digital values into an analog signal and using the analog signal as the authentication challenge when the security device receives a command to generate the authentication challenge; and   a second analog circuit for generating a response to an analog signal authentication challenge by converting the analog signal authentication challenge into one or more digital values and capturing a derivative of the one or more digital values as the response when the security device is being authenticated using the analog signal authentication challenge.