Patent ID: 7270193
Filing Date: 2007-09-18
Classification: G06F

Abstract:
1. A program distribution device for distributing executable programs through a network to a client device having a tamper resistant processor which is provided with a unique secret key and a unique public key corresponding to the unique secret key in advance, the program distribution device comprising: a first communication path set up unit configured to set up a first communication path between the program distribution device and the client device for communications other than transfer of the executable programs; a second communication path set up unit configured to set up a second communication path directly connecting the program distribution device and the tamper resistant processor within the client device and dedicated for transfer of the executable programs such that the executable programs are not accessible by any other parts of the client device, the first and second communication paths being set up as different channels on an identical transmission line or as different transmission lines; an encryption processing unit configured to produce an encrypted program by encrypting an executable program to be distributed to the client device and executed within the tamper resistant processor, by using the unique public key of the tamper resistant processor which is not shared with any other parts of the client device; and a transmission unit configured to transmit the encrypted program to the tamper resistant processor through the second communication path so that the encrypted program is directly delivered to the tamper resistant processor and the encrypted program can be decrypted and executed only within the tamper resistant processor which is an only entity that has the unique secret key corresponding to the unique public key.