US Patent 7269747 Physical presence determination in a trusted platform

A computer system is presented which provides a trusted platform by which operations can be performed with an increased level trust and confidence. The basis of trust for the computer system is established by an encryption coprocessor and by code which interfaces with the encryption coprocessor and establishes root of trust metrics for the platform. The encryption coprocessor is built such that certain critical operations are allowed only if physical presence of an operator has been detected. Physical presence is determined by inference based upon the status of registers in the core chipset.