The invention generally relates to a system for disk copy protection, and more particularly, to a method for increasing the extendibility of disk copy protection and a system for the same.
For any new optical disk (compact disc) standard, copy protection is a key factor for it to be accepted by the content industry. For a recordable disk, the copy protection system can exchange the information with the recorder so that it is easier to update the copy protection. strategies. But for the pre-recorded compact disc, it is not easy to do it in this way. Although the disk copy protection includes the method for revocation, the method for revocation can just revoke a limited number of illegal users and the premise is that the system hasn't been broken yet. Once the copy protection system is broken, no further method can be taken for remedying. For example, the DVD copy protection system CSS (Content Scrambling System) has once been treated as a powerful tool to prevent piracy. Once it is cracked by decryption software, the system doesn't work again. So, a remedying measure is very important to prevent the whole copy protection system from collapsing.
The object of the present invention therefore seeks to provide a method for increasing the extendibility of compact disc copy protection and a system for the same. Using this method, it is very easy to upgrade the system for disk protection and player protection, thereby to prevent piracy effectively.
To achieve the object of the present invention, there is a method used in a player for increasing the extendibility of disk copy protection, including the following steps: a) Compare the version number in the system for disk copy protection with that of corresponding system for the copy protection in the player and confirm whether it is needed to revoke data; b) If the data is needed to be revoked, read the information on the revocation data in said compact disc, then confirm whether to revoke the partial relevant playing license or revoke all the relevant playing license; c) If the partial relevant playing license is to be revoked, undertake revoking confirmation.
According to another aspect of the present invention, we provide a player of increasing the extendibility of disk copy protection, which includes a drive part and a decoding part. Said drive part includes an authentication module, a bus encryption module and an ID confirmation module. Said decoding part includes an authentication module, a bus decryption module, a revocation confirmation module and an ID confirmation module. Wherein, when said player judges it needs to revoke all the relevant playing license according to the information of revocation data in said played compact disc, the ID confirmation module in said drive part, updating the software of the bus encryption module in the drive part, firstly confirms if the player holds legal authorization, if it holds, updates the software of the bus decryption module and updates the software of the bus decryption module and revocation confirmation module in the decoding part; when said player needs to implement the revoking partial relevant playing license, the revocation confirmation module in the decoding part receives revocation data read from the compact disc and confirms revoking partial revocation data.
Accordingly, using the method of the present invention for increasing the extendibility of disk copy protection and the system for the same, it is very easy to upgrade the system for disk protection and player protection, and thereby to prevent piracy effectively.
The following will describe in detail the present invention with reference to the accompanying drawing figures wherein:
The idea of the present invention is as follows:
If the player can access the web site, it can download the software from the web site and flash the player to upgrade the copy protection system thereof. If the player can't access the web site, the special upgrading compact disc or floppy disk can be used to flash the player to upgrade the copy protection system thereof;
If the hardware chip for the copy protection part is affected, it needs to be replaced by a new hardware chip.
The specific embodiment of the present invention will be described in detail as follows.
When the old copy protection system is threatened, the newly issued compact disc must have new copy protection module. The newly issued compact disc is characterized in the change of version number to distinguish from the old one. The revocation data 13 and key data 12, which are set in the guiding area and data area of the compact disc respectively, are also refreshed. In the guiding area of the compact disc, there is a controlling data block including 192 ECCs (Error Correction), each of which includes 16 sectors. Table 1 shows the contents of the 16 sectors.
In the 16 sectors, each includes 2048 bytes. The second sector stores encrypted disk keys that are 16 bytes or over or less, depending on the actual copy protection system. Here, take 16 bytes of the encrypted disk keys as an example. Table 2 is the structure of the second sector. Before storing the disk keys, 16 bytes are used to store the information on the version number and padding byte “0×FF”. The rest bytes are empty for the present and set 0×00.
When the compact disc player reads the compact disc 14, it will firstly read the data in the guiding area, when it can check the information on version number and compare it with its own version number so as to judge whether updating is needed. If it is needed, read the information on revocation data 13 further, which is set in a system file of the header of data area and read it before playing the compact disc content. The revocation data 13 is divided into two categories, one is partial revocation, i.e. the revocation of part keys that have been disclosed. Said partial revocation is the revocation of illegal users data whose partial keys have been disclosed. The other is all the keys have been disclosed and all the players need to be updated, calling it as complete revocation.
Regarding the partial revocation, the firmware of the disk player doesn't need to be upgraded. The partial revocation can be implemented just by updating the compact disc because the player can gain the information from the compact disc. The servo drive part 20 of the player can transfer information from the compact disc to the decoding part 30, then the revocation confirmation module 34 will confirm and change the flag value of copy protection system. Therefore, the partial revocation can be accomplished without adopting special upgrading method.
As for the complete revocation, it must firstly revoke all the key data, that is to say, the users must update the disk player before reading newly issued compact disc, when the message “need to update the player before reading” is shown on the disk player.
The updating method of disk player for complete revocation will be described in detail as follows.
If the player has the function of accessing the network, it can access web site 40 to upgrade the copy protection system. The servo drive part 20 of the disk player can implement the bus encryption transmission. When in complete revocation, the firmware of the bus encryption module 22 needs updating, which can be implemented by downloading the corresponding new software from the special web site 40 when the player is on the status of stand-by. An authentication process is necessary before downloading the software to prevent the illegal player from downloading the new software. Every player has its own specific series number and ID before leaving factory. The users just know the series number, and the server will find its corresponding ID flag after encrypting it according to the series number. If this player shows the message of the player needing updating, the user can send the series number to the server of the appointed web site. The server will encrypt it and find the corresponding ID of the player according to the sent series number, then give the new software of the corresponding module of this player according to the ID. The users can thus download it. Before the new software is installed, it is also necessary to confirm whether it matches with the old software, that is to confirm whether the player has legal ID or not, which is implemented. by ID confirmation module 23 in the servo drive part 20. Only after matching can the firmware of servo drive part be updated.
As far as the complete revocation is concerned, the bus decryption module 32 and the revocation module 34 in the decoding part 30 also need updating. The users send their series number to the server of the appointed web site 40. The server will encrypt it and find the corresponding ID of the player according to the sent series number, then give the new software of the bus decryption module 32 and the revocation confirmation module 34 of the corresponding player. The users can thus download it. Before the new software is installed, it is also necessary to confirm whether it matches with the old software, which is implemented by ID confirmation module 36 in the decoding part. Only after matching can the bus decryption module 32 and the revocation module 34 in the decoding part be updated. And only when the copy protection system is updated can the player play the new compact disc with the other modules', such as the encrypted disk key module 33, the device key module 35, decryption data module 37 and decompression module 38.
As for the player that has no function of connecting with the web site, its servo drive part and decoding part are updated and extended by different method. Refer to
If the module involving copy protection in decoder part 30 is done with hardware, it needs to be replaced by a new hardware module or chip directly.
The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.
Number | Date | Country | Kind |
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02158391.9 | Dec 2002 | CN | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/IB03/06244 | 12/29/2003 | WO | 1/26/2006 |