Described are methods and circuits of programming a programmable logic device with encrypted configuration data using one or more secure decryption keys. Configurable resources within PLDS in accordance with one embodiment are divided into first and second collections of configurable interconnect resources...http://www.google.com/patents/US6996713?utm_source=gb-gplus-sharePatent US6996713 - Method and apparatus for protecting proprietary decryption keys for programmable logic devices
