Patent ID: 7237121

Claim:
A method for ensuring security during the power-on process of a digital device and its contents comprising the steps of: disposing a read only memory storing a bootloader program for control of the programmable data processor, a first read only memory location storing a manufacturer identifier and a second read only memory location storing a device identifier unique to that digital device on a same semiconductor chip as a programmable data processor, the first read only memory location and the second read only memory location not accessible external to the semiconductor chip and not modifiable; upon each power-up of the digital device controlling the programmable data processor via the bootloader program to: A. read the manufacturer identifier from the first read only memory location; B. read the device identifier from the second read only memory location; C. compute a first encryption/decryption key using the manufacturer identifier and the device identifier; D. read an encrypted second encryption/decryption key from a memory; E. decrypt the second encryption/decryption key using the first encryption/decryption key; F. read an encrypted program file from a memory; G. compute a hashing value for said encrypted program file; H. decrypt said encrypted program file using the decrypted second encryption/decryption key; I. store said decrypted program file in a memory; J. read a hashing value associated with the program file from a memory; K. compare said computed hashing value with said read hashing value; L. execute said decrypted program file via the programmable data processor if said comparison was equal; and M. assert an error message if said comparison was not equal.