Proprietary programs for execution in game systems or other computers are downloaded from an Internet server in encrypted form to protect the programs from unauthorized use. The encrypted programs can be decrypted and executed only in a secure cryptoprocessor that initially ordered the software for download. Unlike DRM protected music, video, and text, decrypted program instructions need never be revealed to users. Each cryptoprocessor contains a unique chip identifier that is transmitted to the server in encrypted form to control encryption of a random session key that controls decryption of the downloaded programs. Hence, each copy of the encrypted software is encrypted differently. If the crypto processor is in a cartridge, it can be manually unplugged from one computer or game system and plugged into another system. Although some of the software may be non-encrypted and be executed and processed in conventional processor(s), this non-encrypted software would be useless without the decrypted program instructions executing in the cryptoprocessor.