| 摘要 |
PROBLEM TO BE SOLVED: To prevent illicit usage even in a network correspondence game system. SOLUTION: A system (100) includes an associated tamperproof circuit (120) that contains a cryptography unit (122) and one or more keys. The cryptography unit and one of the keys contained in the tamperproof circuit are used to decrypt a signature file for a portion of the code. The validity of the portion of the code is determined by using the decrypted signature file. If the portion of the code received by the system, such as a communications protocol, is encrypted prior to receipt of the code by the system, the system obtains a key from a remote server (134) via a secure communications channel and uses the key and the cryptography unit contained in the tamperproof circuit to decrypt the communications protocol. COPYRIGHT: (C)2009,JPO&INPIT |
