Lexmark International, Inc.

Timothy John Rademacher

Jennifer Topmiller Williams

Christopher Alan Adkins

Zachary Nathan Fister

David Allen Crutchfield

Stephen Porter Bush

Galen Arthur Rasche

Nathan Wayne Foley

William Henry Reed

James Howard Ellis

Gregory Scott Woods

Stephen Kelly Cunnagin

Joseph Wade Luciano

Randall David Mayo

Scott Michael Heydinger

John Philip Bolash

Thomas Jon Eade

Shaun Timothy Love

Steven Frank Weed

John Booth Bates

David Kyle Murray

Walter Kevin Cousins

Michael Shayne Wilson

Barry Richard Cavill

Charles Thomas Wolfe

Kevin R Cruise

Christine Ann Trinkle

Patrick Alan Casey

Brian Andrew Brown

Samuel Davidson

A method of determining trust in a supply item in an imaging device for verifying other supply items installed in the imaging device via an algorithm, wherein the imaging device has a plurality of installed supply items. The method comprises: sending challenge data and an indication of the algorithm to a candidate supply item, receiving a challenge response from the candidate supply item, and determining, by the controller, a status of the challenge response, the status being verified or unverified. When the controller determines that the received challenge response is a correct output of the algorithm when the challenge data is input to the algorithm, the status is determined as verified. Further, an imaging device configured to determine trust in a supply item installed in the imaging device for verifying other supply items installed in the imaging device via an algorithm.

Methods and systems for determining the authenticity of a component

Determining authenticity of a component in an imaging device includes generating an analog signal as an authentication challenge to the component. The component then generates 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.

Authentication using analog signal challenge

A method for determining the authenticity of a component in an electronic device, the method comprising: receiving a seed by a component in the electronic device; storing the seed in a block of non-volatile memory in the component; calculating, by the component, the output of a cryptographic function with the input based on the seed and storing the output in the block of non-volatile memory; iteratively calculating, by the component, the outputs of the cryptographic function wherein for each iteration the input for the cryptographic function is based on the seed and all previous outputs, and for each iteration storing the output in the block of non-volatile memory; and determining the authenticity of the component based on a selected output of the cryptographic function F, the selected output being one of the outputs stored in the block of non-volatile memory.

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.

Authentication using magnetic field based on current drawn by security device

A method for determining authenticity of a supply item for an imaging system, the method comprising: performing a cryptographic algorithm on the imaging system, starting with a first algorithm input, performing the cryptographic algorithm on the supply item, starting with the first algorithm input, determining authenticity of the supply item based on an imaging system run time and a supply item run time, wherein the imaging system run time is a run time of the cryptographic algorithm on the imaging system from input of the first algorithm input until a result output is generated, and the supply item run time is a run time of the cryptographic algorithm on the supply item from input of the first algorithm input until the result output is generated.

Security device computation matching

Method of determining authenticity of an item using an elliptic curve E defined over a finite field F, where q is an integer, the method comprising: generating a random integer j, where the random integer j is in the interval of one to the integer q; calculating a point T=j·S, where point S is a point on elliptic curve E(F); calculating a binary value k which is equal to the binary random integer j with a bitmask m applied thereto; sending point T and binary value k to the item; and the item iteratively calculating point U=n·S for different values of integer n, where for each iterative calculation integer n takes different values, wherein for each iteration: the bits of binary integer n corresponding to the unmasked bits of bitmask m are the same as the corresponding bits of binary random integer j; and the bits of binary integer n corresponding to the masked bits of bitmask m are varied in each iteration.

Methods and systems for determining the authenticity of a component using elliptic-curve cryptography

A method for updating an imaging device is described comprising, receiving update information comprising a compatibility update filter indicating which generations of supply item are compatible with the imaging device, and updating a compatibility filter of the imaging device based on the update information, the compatibility filter configured to control which generations of supply item are classified as compatible with the imaging device. An imaging device is also described that comprises firmware and a memory, the memory storing a compatibility filter configured to control which generations of supply item are classified as compatible, wherein the firmware is configured to read the compatibility filter, and the imaging device is configured to update the compatibility filter. Finally, an imaging device supply item is also described.

Methods for updating an electronic device

A supply item has toner for use in an imaging device. A chip has memory storing quanta indicating allowed usage of the supply item over its lifetime and a multiplier correlating the quanta to toner mass. The imaging device requires quanta to conduct imaging operations and loads the quanta and multiplier by way of a certificate stored in the memory. The imaging device retrieves quanta from the chip over time and both devices keep tally. Initialization between the supply item and imaging device includes providing encrypted and unencrypted instances of firmware versions and certificates from the supply item that the imaging device can compare for security. Alternatively, the supply item defines a fuser assembly, imaging unit, intermediate transfer member, or other component installed for use in the imaging device.

Method of setting up electrical communications between an imaging device and a supply item

A method for determining the authenticity of an item, the method comprising: receiving, by an item, a seed; storing the seed in a block of non-volatile memory in the supply item follower component; calculating, by the item follower component, an output of a cryptographic function with the input based on the seed and storing the output in the block of non-volatile memory; iteratively calculating, by the item, the outputs of the cryptographic function wherein for each iteration the input for the cryptographic function is based on the seed and all previous outputs, and for each iteration storing the output in the block of non-volatile memory; and determining the authenticity of the item based on a selected output of the cryptographic function of the item, the selected output being one of the outputs stored in the block of non-volatile memory.

A method for detecting a non-authentic slave component in an electronic printer device which includes receiving a command from a master component in the device, identifying a response to the command based upon a frequency of a plurality of clock pulses used by the master component while sending the command, and sending the response to the master component for use as a basis in determining whether the slave component is one of an authentic slave component and a non-authentic slave component. The disclosed method may be performed by a replaceable slave component in an imaging device including a slave circuit communicating with a master circuit of the master component along a serial communications interface. The master circuit includes an instruction to change a clock frequency when sending a command to the slave circuit to trigger a unique response from slave circuits of authentic slave components.

System and methods for detecting non-authentic slave components using clock frequency changes

Chip and supply item for imaging device, including communication

A method for detecting a non-authentic slave component in an electronic device which includes receiving a command from a master component in the device, identifying a response to the command based upon a frequency of a plurality of clock pulses used by the master component while sending the command, and sending the response to the master component for use as a basis in determining whether the slave component is one of an authentic slave component and a non-authentic slave component. The disclosed method may be performed by a replaceable slave component in an imaging device including a slave circuit communicating with a master circuit of the master component along a serial communications interface. The master circuit includes an instruction to change a clock frequency when sending a command to the slave circuit to trigger a unique response from slave circuits of authentic slave components.

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Lexington, KY, United States of America

Timothy John Rademacher