Program control apparatus, method and program

A non-transitory computer-readable storage medium storing a basic program for causing a computer to execute a program control method of restricting activation of an expansion program that is capable of expanding the functions of the basic program, said method comprising:

• a specifying step of specifying a target program, which is to be activated, based upon identification information of a designated expansion program and constituent information of the basic program;
• a decryption step of decrypting signature information, which is included in the target program and which has been obtained by encrypting the identification information of the expansion program and the constituent information using a secret key, the signature information being decrypted using a public key that corresponds to the secret key;
• a checking step of checking the decrypted information, which has been decrypted at said decryption step, against the identification information of the designated specified expansion program and the constituent information of the basic program;
• and
• a step of enabling, for expanding the basic program, execution of the target program, which has been specified at said specifying step, if result of the check performed at said checking step indicates a match, and to disable execution of the target program, which has been specified at said specifying step, if result of the check performed at said checking step indicates a non-match.

A program control method of restricting activation of an expansion program, which expands the functions of a basic program, by a computer, said method comprising:

• a specifying step of specifying a target program, which is to be activated, based upon identification information of a designated expansion program and constituent information of the basic program;
• a decryption step of decrypting signature information, which is included in the target program and which has been obtained by encrypting the identification information of the expansion program and constituent information using a secret key, the signature information being decrypted using a public key that corresponds to the secret key;
• a checking step of checking the decrypted information, which has been decrypted at said decryption step, against the identification information of the designated specified expansion program and the constituent information of the basic program;
• and
• a step of enabling, for expanding the basic program, execution of the target program, which has been specified at said specifying step, if result of the check performed at said checking step indicates a match, and to disable execution of the target program, which has been specified at said specifying step, if result of the check performed at said checking step indicates a non-match.