A server apparatus including a first communication device and a first computing device. The first communication device communicates with an image forming apparatus via a network. The first computing device includes a processor, and acts as a data acquirer, a dimension reduction processor, and a residual service life calculator, when the processor executes a first control program. The data acquirer acquires observation data of a first number of dimensions from the image forming apparatus, via the first communication device. The dimension reduction processor converts the observation data of the first number of dimensions into characteristic data of a second number of dimensions fewer than the first number of dimensions. The residual service life calculator calculates a residual service life of a replaceable unit in the image forming apparatus, on a basis of the characteristic data.

A logic circuitry package for a replaceable print apparatus component includes a logic circuit and an interface to communicate with a print apparatus logic circuit. The logic circuit is configured to include a plurality of personalities, each personality of the plurality of personalities including an ID and a cryptographic key. The logic circuit is further configured to start a cryptographic session with the print apparatus logic circuit using a selected personality of the plurality of personalities, and transmit a consumable level value to the print apparatus logic circuit in response to a request from the print apparatus logic circuit independent of which personality of the plurality of personalities is the selected personality.

A replaceable unit includes a communication unit to perform communication with a main body, and a non-volatile memory storing code information indicating whether a configuration of an error detection code is a first configuration or a second configuration. The communication unit stores, in a volatile memory, the code information, executes the communication in accordance with the code information in the volatile memory, and, upon receiving a change command, updates the code information stored in the volatile memory. The first configuration uses an error detection code of a first code length, the second configuration uses an error detection code of a second code length longer than the first code length, and the first configuration is used for the change command in order to change from the first configuration to the second configuration.

An image forming apparatus includes: a casing having an opening; a cover for opening and closing the opening; a cartridge attachable to the casing through the opening; and a controller. The casing includes a first memory. The cartridge includes a second memory storing consumption state information representing a consumption state of the cartridge. The controller performs: determining whether the cartridge attached to the casing is unused; storing, when the attached cartridge is unused, the consumption state information acquired from the second memory in the first memory; determining, when the image forming apparatus is powered on or the cover is closed, whether the consumption state information in the first memory and the consumption state information in the second memory match; permitting use of the cartridge when the two sets of consumption state information match; and prohibiting use of the cartridge when the two set of consumption state information does not match.

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.

A consumable chip applied to a consumable includes a memory and a controller. The memory is used to store information of a consumable product of an image formation device. The controller is configured to control the consumable chip to generate a predetermined signal to cause the image formation device to perform a target operation according to the predetermined signal. The consumable chip is mounted at the consumable. The consumable is detachably mounted at the image formation device.

An image forming apparatus includes: a casing having an opening; a cover for opening and closing the opening; a cartridge attachable to the casing through the opening; and a controller. The casing includes a first memory. The cartridge includes a second memory storing consumption state information representing a consumption state of the cartridge. The controller performs: determining whether the cartridge attached to the casing is unused; storing, when the attached cartridge is unused, the consumption state information acquired from the second memory in the first memory; determining, when the image forming apparatus is powered on or the cover is closed, whether the consumption state information in the first memory and the consumption state information in the second memory match; permitting use of the cartridge when the two sets of consumption state information match; and prohibiting use of the cartridge when the two set of consumption state information does not match.

A server apparatus including a first communication device and a first computing device. The first communication device communicates with an image forming apparatus via a network. The first computing device includes a processor, and acts as a data acquirer, a dimension reduction processor, and a residual service life calculator, when the processor executes a first control program. The data acquirer acquires observation data of a first number of dimensions from the image forming apparatus, via the first communication device. The dimension reduction processor converts the observation data of the first number of dimensions into characteristic data of a second number of dimensions fewer than the first number of dimensions. The residual service life calculator calculates a residual service life of a replaceable unit in the image forming apparatus, on a basis of the characteristic data.

A Customer Replaceable Unit Monitoring (CRUM) chip, an image forming apparatus, and a method of authenticating are provided. The apparatus includes a main body that includes a main controller controlling operations of the apparatus, a consumable unit mounted on the main body to communicate with the main controller, and a CRUM chip that is provided in the consumable unit and stores information regarding the consumable unit. The main controller and the CRUM chip transmit and receive signals that include data and integrity detection data between each other. The integrity detection data is generated by using previous integrity detection data.

An image forming device is provided. The device includes a main body which includes a main controller controlling operations of the image forming device, a consumable unit mounted on the main body to enable communication with the main controller, and a CRUM chip which is provided in the consumable unit and stores usage information of the consumable unit and characteristics information. The main controller and the CRUM chip transmit and receive signals which include data and integrity detection data between each other. The integrity detection data is generated by accumulating and reflecting integrity detection data included in a previous signal.