Lexmark International, Inc.

Marvell International Limited

Zachary Nathan Fister

Timothy John Rademacher

Jennifer Topmiller Williams

Gregory Scott Woods

James Ray Bailey

Christopher Alan Adkins

Duane Edward Norris

Nathan Wayne Foley

Samuel William Gardiner

Joseph Kamal Yackzan

Thomas Elmer Samples

James Lesefme Bush, Iii

Donald William Chapelle

Douglas G Keithley

Keith Bryan Hardin

Thomas Jon Eade

David Allen Crutchfield

Mark Lane Mayberry

James Howard Ellis

Christopher Wilson Case

Curt Paul Breswick

Jimmy Daniel Moore, Jr

Karl Mark Thompson

Bennett Fornal

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

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 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

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

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.

Component circuitry for a replaceable printer component, including a dynamic address generator which selectively generates component addresses, wherein substantially immediately following an event, the component circuitry performs in succession a plurality of sets of operations, each set of operations including receiving an address change request from a master and generating a new component address by the dynamic address generator in response, a last one of the new component addresses generated being available as the component address for the component circuitry in one or more subsequent communications with the master.

Dynamic address change optimizations

A method for reducing electromagnetic emissions by an image scanner comprises cyclically dithering a frequency of a clock signal of the image scanner by repeated dither cycles, determining a phase of the dither cycle when a scan pass of a page of a document commences; and commencing all subsequent scan passes of the page of the document at a particular phase shift from the determined phase of the dither cycle.

Method and apparatus for scanning an image

A method of setting an address of a component that includes determining a characterization value associated with a consumable, calculating a number of address change operations based upon the characterization value, and setting a last address generated from the number of address change operations as the new address of the component, wherein the characterization value is determined based upon a usage of the consumable.

A software program for verifying a system design having at least one integrated circuit chip. The software program, when executed by a processor, result in obtaining a random value for a variable; selecting an unused value for the variable based upon the random value, the variable not having been assigned the unused value during one or more prior verification tests; and creating a new verification test for the system using the unused value for the variable. In this way, the new verification test is created in which variables falling within a random class are more efficiently used.

Verification system and method using constrained random test parameter selection

A master/slave data communication system in which a master device communicates with the slave devices by uniquely addressing each of the slave devices. In order to enhance the security of the data communication system, each slave device includes an address generator for generating unique addresses. Periodically, the master device requests that one or more slave device change its address. In response to the request, the addressed slave device increments its address generating algorithm to provide a new slave address. The master device also includes an algorithm that is synchronized with the slave address generating algorithm, whereby when the slave changes its address, it need not transmit the new slave address to the master device over the bus.

Growing community of inventors

Lexington, KY, United States of America

Zachary Nathan Fister