Abstract:
The present invention provides a disc player that authenticates a disc via the Internet. According to one embodiment of the invention, upon insertion of a disc into a player, the player reads a disc identification (ID) on the disc. The player then sends a registration request with the disc ID to a server over the Internet for obtaining an authentication key for playing the disc, upon proper registration of the disc by the server. To properly register the disc, the server first determines whether the disc ID is included in its database. Upon proper registration of the disc, the server will set a registration status associated with the disc to prevent any subsequent unauthorized registrations for the same disc. Thus, by using the present invention, unauthorized copying of the disc can be effectively eliminated.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The invention relates to a method and system for authenticating a disc over the Internet.  
         [0002]     Copying protection has become an urgent issue to content providers. Each year billions of dollars have been lost by the industry due to piracy. To counter the piracy, various techniques have been proposed such as watermarking, the Contents Scrambling System (CSS), wobble, etc. Digital watermarking is a technique in which watermarks are embedded into audio/video data to indicate whether or not the contents are copyrighted. Watermarks can be easily detected, but can hardly be removed without degrading the content quality. This technique, however, is primarily used for copyright verification, rather than for copying protection. The CSS is a copying protection system developed for protecting against illegal copying of DVD discs. However, it can be easily cracked by software because the CSS uses only 40 bit keys. Wobble is a technique that uses wobble tracks to store the data on a ROM disc, and the wobble is modulated with the copyright information. The contents on such a ROM disc cannot be copied to a recordable disc. This technique is very inflexible since the protection scheme is defined on the physical layer.  
         [0003]     Most of the conventional copying protection schemes including those described above are self-contained, i.e., discs with the copying protection schemes need not communicate with the outside world for authentication except with players. As a result, these copying protection schemes are not very effective and can be easily cracked.  
         [0004]     Therefore, there is a need for a more effective disc authentication technique that does not rely solely on a copying protection scheme on a disc.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention provides a disc player that authenticates a disc via the Internet. According to one embodiment of the invention, upon insertion of a disc into a player, the player reads a disc identification (ID) on the disc. The player then sends a registration request with the disc ID to a server over the Internet for obtaining an authentication key for playing the disc, upon proper registration of the disc by the server. To properly register the disc, the server first determines whether the disc ID is included in its database. If so, the server will then check whether the disc has already been registered. If it has not, the server will send back an encrypted authentication key to the player to enable it to play the disc. Upon proper registration of the disc, the server will set a registration status associated with the disc to prevent any subsequent unauthorized registrations for the same disc. If either the disc ID is not included in the server database or the disc has already been registered, the server will send back a failed registration code to the player that will then reject the disc.  
         [0006]     In accordance with the invention, a pre-selected disc may be properly registered for a pre-determined number of times. In such a case, the server will keep track of the number of registrations with respect to that disc. Thus, by using the present invention, unauthorized copying of the disc can be effectively eliminated.  
         [0007]     Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The invention is explained in further detail, and by way of example, with reference to the accompanying drawings wherein:  
         [0009]      FIG. 1  shows an overview of disc copying prevention through Internet authentication in accordance the invention;  
         [0010]      FIG. 2  is a simplified diagram illustrating the operation of a disc player in accordance with one embodiment of the invention;  
         [0011]      FIG. 3  is a flowchart diagram illustrating a disc registration process performed by a disc player in accordance with one embodiment of the invention; and  
         [0012]      FIG. 4  is a flowchart diagram illustrating a disc registration process performed by a web server in accordance with one embodiment of the invention. 
     
    
       [0013]     Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]      FIG. 1  shows an overview of disc copying prevention through Internet authentication in accordance with the invention. When a new optical disc  10  is inserted into a disc player  20 , the player will register the disc by sending an associated unique disc ID to a web server  30  via the Internet. Web server  30  stores a large database maintained by a content provider of the disc, which contains disc IDs for numerous released disc titles. Before the content provider releases a new disc title, all the unique disc IDs associated with this new title will be added to the database, and a registration status associated with each of these unique disc IDs is set to “unregistered”. Upon proper registration of the disc, the web server will send back an authentication key to enable the player to play the disc. In this way, the copyright of the disc is verified.  
         [0015]     In accordance with the invention, there are several options to generate and store the disc ID. A first option is to store the disc ID in the Burst Cutting Area (BCA) of a disc. In this way, the disc ID can be scrambled and embedded into a long series of random numbers to confuse hackers, and only the content provider knows how to extract it. A second option is, for each disc in a distribution batch, the content provider can embed the disc ID in a program stream and store the disc ID at a particular location on the disc. The web server knows where to find the disc ID and will fetch the disc ID over the Internet. A third option is to store the disc ID on the clamp area of the disc. In such a case, a read-out device needs to be added to the optical pick-up unit (OPU) of the player in order to read the disc ID on the clamp area.  
         [0016]     Once the authentication key is received by the player, it can be used as a decryption key to decrypt the protected contents on the disc. Additionally, in order to protect the information exchanged between the web server and the player from being illegally intercepted or cracked, encryption/decryption measures may be applied to the disc ID and to the authentication key before they are sent out.  
         [0017]      FIG. 2  is a simplified diagram illustrating the operation of a disc player  20  in accordance with one embodiment of the invention. Player  20  may be an operating system independent, stand-alone device with an Internet connection, e.g., a Web DVD player as defined by the DVD Forum, which is an industrial consortium (http://www.dvdforum.org). Player  20  may also be a device in a laptop computer or a desktop PC. Player  20  includes a flash memory  22 , which stores encrypted private data of the player including disc IDs and their associated authentication keys, and a codec  26 , which decodes the encrypted private data. When disc  10  is played for the first time in player  20 , the disc ID is sent to the web server for registration. Upon proper registration, an authentication key is sent back and stored in flash  22  along with the associated disc ID. The authentication key is decoded by codec  26  to enable the player to play disc  10 . When disc  10  is subsequently played in player  20 , the disc ID will be searched by the player from flash memory  22  to find the associated authentication key. The authentication key will then be retrieved and decoded by codec  26  to enable the player to play disc  10 , without requiring further authenticating the disc via the Internet.  
         [0018]      FIG. 3  is a flowchart diagram illustrating a disc registration process  100  performed by the disc player in accordance with one embodiment of the invention. Upon insertion of the disc into the player, the player will read the disc ID (step  102 ) and search an internal flash memory to find a matching disc ID (steps  106 ). If a matching disc ID is found, the associated authentication key is retrieved and decoded (step  114 ), and the player will play the disc (step  116 ). On the other hand, if a matching disc ID is not included in the flash memory because the disc is played for the first time, the player will send the disc ID and a registration request to a web server (step  122 ).  
         [0019]     When the web server receives the registration request with the disc ID from the player, it will check, in a disc ID database, a registration status associated with the disc ID received. If the disc ID is included in the database and has not yet been registered, the web server will send back a response with the authentication key to the player. In the meantime, the web server will set the associated registration status to “registered”. On the other hand, if the disc ID is not included in the database or the disc has already been registered, the web server will assume that the disc is not an authentic one and will send back a response to the player without the required authentication key. A more detailed disc registration process performed by the web server will be described below in conjunction with  FIG. 4 .  
         [0020]     In  FIG. 3 , after receiving a response from the web server (step  126 ), the player will determine whether the response includes an authentication key (step  132 ). If the authentication key is included, it will be stored in the player and then decoded (step  136 ) to enable the player to play the disc (step  116 ). By storing the authentication key in the player, the disc needs not to be registered again when it is subsequently played. By contrast, if the authentication key is not included in the response received from the web server, the player will refuse to play the disc (step  142 ), and notify the user (step  146 ).  
         [0021]      FIG. 4  is a flowchart diagram illustrating a disc registration process  200  performed by the web server in accordance with one embodiment of the invention. Upon receiving the disc ID from the player (step  202 ), the server searches through a database (step  206 ) to determine whether a matching disc ID is included (step  212 ). If there is no matching disc ID, the server will send back a failed registration code to the player (step  216 ). If, however, a matching disc ID is successfully found in the database, the server will next determine whether the disc has already been registered (step  222 ). If it is already registered, the server will also send back a failed registration code to the player (step  216 ). On the other hand, if the disc has not yet been registered, the server will generate an authentication key (step  226 ), set a registration status associated with the disc ID to “registered” (step  232 ), and send back the authentication key to the player (step  236 ).  
         [0022]     There are two possible ways for a web server to generate authentication keys. In one way, the web server can pre-store authentication keys associated with the pre-defined disc IDs in a database. When it receives a registration request with a legitimate disc ID, it will search for a corresponding authentication key from the database and send it back to the disc player. In another way, when the web server receives a registration request with a disc ID, it will generate a corresponding authentication key by running a software routine and then send it back to the disc player.  
         [0023]     In accordance with the invention, content providers may distribute their discs with different editions at different prices. For instance, a disc of home edition may include only one license and can be registered only once with the web server to allow only a specific player to play the disc. On the other hand, a disc of commercial edition may include multiple licenses and can be registered a predetermined number of times with the web server to allow different players to play the disc. This allows a movie rental company to rent a commercial movie title to a specific number of customers. The use of discs with the different editions is monitored by the web server of the content provider. Table 1 illustrates an exemplary format of a disc ID database in the web server. In this table, disc ID 1  and disc ID 2  each represent a home edition and can be registered only once, while disc ID 3  represents a commercial edition and can be registered N times.  
                                         TABLE 1                           Exemplary format of a disc ID database in the web server            Disc   Registration   Registration   Registration       Registration       ID   Status1   Status2   Status3   . . .    StatusN               Disc   Unregistered   n/a   n/a   . . .    n/a       ID1       Disc   Registered   n/a   n/a   . . .    n/a       ID2       Disc   Registered   registered   unregistered   . . .    Unregistered       ID3       . . .    . . .    . . .    . . .    . . .    . . .        . . .    . . .    . . .    . . .    . . .    . . .                   
 
         [0024]     While the invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and scope of the appended claims.