Boot Validation in Imaging Devices

Abstract

A boot validation system and method may be used in a computer system to validate boot code before allowing the computer system to execute the boot code. In particular, a secure hash algorithm may be used to compute a hash value of the boot code and the computed hash value may be compared to a preprogrammed hash value stored in a secure non-volatile device. If the hash values match the boot code may be validated and the system may then be allowed to execute the boot code. Once the boot code is validated, the boot code may be executed to validate other code (e.g., firmware) in the computer system. In an exemplary embodiment, the boot validation system and method may be used in an imaging device, such as a printer.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]The present application is a divisional of U.S. patent application Ser. No. 11 / 425,893, filed Jun. 22, 2006, which is incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]None.REFERENCE TO SEQUENTIAL LISTING, ETC.[0003]None.BACKGROUND[0004]1. Field of Invention[0005]The present invention relates to securely booting computer systems, and more particularly, to a boot validation system and method for use in an image forming device such as, for example, an electrophotographic printer, an inkjet printer, a fax device, a copier, an all-in-one device or a multipurpose device.[0006]2. Description of Related Art[0007]Imaging devices, such as printers, may include various security systems, for example, to protect billing information and / or to protect confidential customer data. In general, mechanisms for achieving printer security may include both hardware and software. In any security...

AI Technical Summary

Benefits of technology

[0008]One embodiment of the present invention provides a system for boot validation in an image forming device including at least one central processing unit (CPU). The system includes a firmware storage device including firmware, the firmware including at least boot code. The system further includes a secure non-volatile storage device storing a preprogrammed hash value corresponding to the boot code. The system further includes logic configured to hold at least the CPU in reset in response to a power on signal to prevent the CPU from executing the boot code upon powering on the image forming device, to retrieve the boot code, to compute a hash value of the boot code, to retrieve the preprogrammed hash value, to compare the computed hash value to the preprogrammed hash value, and to allow the image forming device to execute the boot code if the computed hash value matches the preprogrammed hash value. In one such embodiment, the boot code includes tamper detection code configured to validate other firmware. The system may include, for example, an application specific integrated circuit (ASIC) including the logic, or a boot validation device including the logic, or an ASIC and a boot validation device operatively coupled to one another, wherein the boot validation device includes the logic. In another particular case, the firmware storage device is for storing the boot code together with other executable code including firmware other than boot code. In another particular case, the logic is configured to inhibit operation of at least one component of the image forming device if the computed hash value does not match the preprogrammed hash value. The image forming device may be, for example, one of a printer, a fax device, a copier, or a combination thereof. The system may be contained in a cartridge configured for use in the image forming device. The firmware storage device may include, for example, programmable non-volatile memory.

Problems solved by technology

In any security system, the weakest link may limit the overall security of the system.

In the printer architecture, for example, one of the weakest links may be the vulnerability of the embedded firmware to tampering.

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