07321966 is referenced by 3 patents and cites 9 patents.

By providing a secure EEPROM (Electrically Erasable Programmable Read Only Memory) device or other non-volatile memory (NVM) as a system operation key (SOK) to control the configurable machine option attributes, various problems associated with machine option configuration and updates may be accommodated. At initial SOK install the identity of the machine is written to the NVM, i.e. the machine serial number. This is performed during the initial machine power up or reboot sequence. As part of the power on or reboot routine the machine will check to ensure no tampering has taken place and that the machine identity and the NVM serial number location data match. A new swapped in SOK can be installed so long as the NVM serial number location has not been previously written to with a conflicting identification number. The machine will then write the serial number to the new SOK thereby protecting it.

Title
Machine post-launch configuration and option upgrade
Application Number
10/447737
Publication Number
7321966 (B2)
Application Date
May 29, 2003
Publication Date
January 22, 2008
Inventor
Christian G Midgley
Fairport
NY, US
David S Shuman
Honeoye Falls
NY, US
Heiko Rommelmann
Penfield
NY, US
Christian Redder
Rochester
NY, US
Robert A Koontz
Webster
NY, US
Agent
Christopher D Wait
Assignee
Xerox Corporation
CT, US
IPC
G06F 15/177
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