Electrical computers and digital processing systems: support – Data processing protection using cryptography
Reexamination Certificate
2005-01-25
2010-10-19
Zand, Kambiz (Department: 2434)
Electrical computers and digital processing systems: support
Data processing protection using cryptography
Reexamination Certificate
active
07818584
ABSTRACT:
Circuits, methods, and apparatus that store and prevent modification or erasure of stored encoding keys, serial identification numbers, or other information. An encoding key stored with an embodiment of the present invention may be used to decode a configuration bitstream on an integrated circuit, such as an FPGA. A serial number may be used to track or authenticate an integrated circuit. Embodiments of the present invention store this information in a memory such as an SRAM, DRAM, EPROM, EEPROM, flash, fuse array, or other type of memory. In order to prevent its erasure or modification, write enable circuitry for the memory is then permanently disabled, and if the memory is volatile, a continuous power supply is provided. Further refinements verify that the write enable circuitry has been disabled before allowing the device to be configured or to be operable.
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Jefferson David
Joyce Juju
Langhammer Martin
Streicher Keone
Altera Corporation
Gee Jason K
Ropes & Gray LLP
Zand Kambiz
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