An encrypted part of the encrypted program loaded in an memory device is received by a one-chip microcomputer and decrypted according to a decrypting program which is stored in advance in an ROM and which cannot be read out to an external bus. The decrypted program is stored in an cache memory, and a...http://www.google.fr/patents/US5982887?utm_source=gb-gplus-shareBrevet US5982887 - Encrypted program executing apparatus
