Abstract:
A method for storing important information for a user in a database and securely managing the stored important information is provided. The method includes an encrypting step, a storing step, and a determining step. In the encrypting step, synchronizing information, which changes whenever at least one piece of the important information is updated, is stored in the database together with the important information and the synchronizing information is encrypted. In the storing step, the encrypted synchronizing information is distributively stored in predetermined places. In the determining step, the synchronizing information stored in the predetermined places is combined and decrypted, and it is determined whether the combined and decrypted synchronizing information is substantially identical to the synchronizing information stored in the database.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a method for securely managing information in a database, and more particularly, to a method for storing and securely managing important information for a user in a database.  
           [0003]    2. Description of the Related Art  
           [0004]    [0004]FIG. 1 is a diagram of a related art communication system, for example, an Internet system, for Digital Right Management (DRM). User computers  10   a  . . .  10   d,  a content providing server  141 , a key-data management server  142 , and a payment system  143  are connected to one another through a communication network  12 . The content providing server  141  provides content to the user computers  10   a  . . .  10   d  and receives charges related to DRM through the payment system  143 . The key-data management server  142  manages key-data for encrypting and decrypting content files, which the content providing server  141  provides to the user computers  10   a  . . .  10   d.    
           [0005]    Referring to FIG. 2, a related art content file includes a header  31  and data  32 . The header  31  includes encryption information EI, user key-data KU, and DRM information DRM. The encryption information EI contains parameters used for encrypting the data  32 , and the user key-data KU is used for encrypting and decrypting the data  32  of the content file. The DRM information indicates the number of use times permitted to a user.  
           [0006]    However, the related art system and method has various problems and disadvantages. For example, but not by way of limitation, according to a simple method of managing information with such a related art file structure, the header  31  can be decrypted by a hacker even if it has been abstrusely encrypted. Accordingly, the hacker can change important information for a user such as DRM information. Therefore, in addition to encryption of information, it is necessary to efficiently determine whether the encrypted information has been accessed and/or altered without authorization (i.e., hacked) to securely manage information in a database.  
         SUMMARY OF THE INVENTION  
         [0007]    To solve at least the above-described problems, it is an object of the present invention to provide a method for securely managing information in a database by encrypting the information and efficiently determining whether the encrypted information has been hacked.  
           [0008]    To achieve the above object of the invention, there is provided a method for storing important information for a user in a database and securely managing the stored important information for a user is provided. The method includes an encrypting step, a storing step, and a checking step. In the encrypting step, synchronizing information, which changes whenever at least one piece of the important information for a user is updated, is stored in the database together with the important information for a user and the synchronizing information is encrypted. In the storing step, the encrypted synchronizing information is distributively stored in predetermined places. In the checking step, the synchronizing information stored in the predetermined places is combined and decrypted, and it is checked whether the combined and decrypted synchronizing information is the same as the synchronizing information stored in the database.  
           [0009]    According to the present invention, the synchronizing information stored in the predetermined places is combined and decrypted and whether it is the same as the synchronizing information stored in the database is checked, to efficiently determine whether the important information for a user has been hacked. Therefore, the present invention can manage the information in the database more securely than in the related art case of depending solely on encryption. In addition, since the present invention distributively stores the encrypted synchronizing information in predetermined places, the risk of exposing the encrypted synchronizing information is minimized.  
           [0010]    Additionally, to achieve at least the aforementioned objects and overcome at least the aforementioned problems and disadvantages of the related art, a method for storing and securely managing important information for a user in a database is provided, comprising (a) storing synchronizing information, which changes when at least one piece of the important information for a user is updated, in the database together with the important information for a user, and encrypting the synchronizing information, and (b) distributively storing the encrypted synchronizing information in a plurality of predetermined places. The method also comprises (c) combining and decrypting the synchronizing information stored in the predetermined places and determining whether the combined synchronizing information and the decrypted synchronizing information is substantially identical to the synchronizing information stored in the database.  
           [0011]    Further, a content file is provided that comprises a header portion having key-data for synchronizing information and synchronizing information distributively stored in a plurality of predetermined places of a hard disc, and a data portion.  
           [0012]    Also, a content file is provided that comprises a header portion having key-data for digital right management (DRM) information and DRM information distributively stored in a plurality of predetermined places of a hard disc, and a data portion. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The above object and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:  
         [0014]    [0014]FIG. 1 is a diagram of a related art communication network system for Digital Right Management (DRM);  
         [0015]    [0015]FIG. 2 is a block diagram of the structure of a related art content file;  
         [0016]    [0016]FIG. 3 is a block diagram of the structure of a content file according to a preferred embodiment of the present invention;  
         [0017]    [0017]FIG. 4 is a diagram showing a state in which encrypted synchronizing information of the content file of FIG. 3 is distributively stored in predetermined places;  
         [0018]    [0018]FIG. 5 is a flowchart of a first preferred embodiment of a program performed by a user computer to securely manage DRM information of the content file of FIG. 3; and  
         [0019]    [0019]FIG. 6 is a flowchart of a second preferred embodiment of a program performed by a user computer to securely manage DRM information of the content file of FIG. 3.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    [0020]FIG. 3 illustrates a content file according to a preferred embodiment of the present invention that includes a header  41  and data  42 . The header  41  includes encryption information EI, user key-data KU, key-data KS for synchronizing information, key-data KD for Digital Right Management (DRM) information, synchronizing information SI, and DRM information, which is important information for a user. In the present invention, “important information” is defined to include, but is not limited to, DRM information that indicates a number of use times permitted to a user, so as to enable effective performance of DRM.  
         [0021]    In the header  41 , the encryption information EI contains parameters used for encrypting the data  42  of the content file, and the user key-data KU is used for encrypting and decrypting the data  42  of the content file. Also, the key-data KS for synchronizing information is used for encrypting and decrypting the synchronizing information SI, and the key data KD for DRM information is used for encrypting and decrypting the DRM information. The synchronizing information SI is continuously updated to determine whether the important DRM information has been hacked. In a preferred embodiment of the present invention, the synchronizing information SI can be embedded in the DRM information. The important DRM information indicates the number of use times permitted to a user, but is not limited thereto.  
         [0022]    [0022]FIG. 4 illustrates the encrypted synchronizing information SI, which is distributively stored in predetermined places. For example, but not by way of limitation, if an information managing method according to the present invention is applied only to the user computer  10   a  of FIG. 1 (here, the important information will not be the DRM information DRM of FIG. 3), the encrypted synchronizing information SI is distributed and stored in predetermined places of a hard disc drive. In this case, when the information managing method is applied to a communication network system as shown in FIG. 1, the encrypted synchronizing information SI may be distributed and stored in the key-data management server  142 . Since the encrypted synchronizing information SI is distributed and stored in predetermined places, the risk of exposing the encrypted synchronizing information SI is minimized. According to this principle, the synchronizing information SI and the key-data KS for synchronizing information of FIG. 2 are distributed and stored in predetermined places according to a method shown in FIG. 5. The important DRM information DRM and the key-data KD for DRM information can be distributed and stored in predetermined places according to a method shown in FIG. 6.  
         [0023]    [0023]FIG. 5 shows a first preferred embodiment of a program performed by the user computer  10   a  of FIG. 1 to securely manage the important DRM information DRM of the content file of FIG. 3. In the program of FIG. 5, the important DRM information DRM is not encrypted, so the DRM information key-data KD of FIG. 3 is not necessary.  
         [0024]    Key-data for synchronizing information distributively stored in predetermined places is combined and decrypted in step S 501 . Then, synchronizing information distributively stored in predetermined places is combined and decrypted in step S 502 . Here, the synchronizing information is decrypted based on the key-data decrypted in step S 501 .  
         [0025]    Next, encrypted synchronizing information SI of FIG. 3 stored in a database, for example, a hard disk within the user computer  10   a  of FIG. 1, is decrypted in step S 503 . Next, in step S 504 , it is determined whether the synchronizing information decrypted in step S 502  is the same as the synchronizing information decrypted in step S 503 . If the synchronizing information decrypted in step S 502  is not the same as the synchronizing information decrypted in step S 503 , it can be concluded that a content file including the DRM information DRM of FIG. 3 has been hacked. Accordingly, hacking information is displayed in step S 506  and is transmitted to a server, for example, the content providing server  141  or the key-data management server  142  of FIG. 1, in step S 507 .  
         [0026]    If the synchronizing information decrypted in step S 502  is the same as the synchronizing information decrypted in step S 503 , then in step S 504 , update of the important DRM information DRM is monitored in step S 508 . The update of the DRM information DRM is related to, for example, the number of uses of the data  42  of the content file of FIG. 3.  
         [0027]    If the DRM information DRM has been updated, new synchronizing information and important DRM information DRM is stored in the database in step S 509 . Next, the synchronizing information SI stored in the database is encrypted in step S 510 . Next, key-data KS for the encrypted synchronizing information SI is encrypted in step S 511 . Sequentially, the encrypted synchronizing information and key-data is distributed and stored in predetermined places in step S 512 . Steps S 508  through  512  are repeated until a termination signal is input in step S 513 .  
         [0028]    [0028]FIG. 6 shows a second preferred embodiment of a program performed by the user computer  10   a  of FIG. 1 to securely manage the important DRM information DRM of the content file of FIG. 3. In the program of FIG. 6, the important DRM information DRM is encrypted, so the DRM information key-data KD of FIG. 3 is used.  
         [0029]    Key-data for synchronizing information and key-data for DRM information defined as important information for a user, which are distributively stored in predetermined places, are combined and decrypted in step S 601 . Next, synchronizing information and the important DRM information, which are distributively stored in predetermined places, are combined and decrypted in step S 602 . In step S 602 , the synchronizing information and the DRM information are decrypted based on the key-data decrypted in step S 601 . Next, synchronizing information SI and important DRM information DRM of FIG. 3, which is encrypted and stored in a database, for example, a hard disk of the user computer  10   a  of FIG. 1, is decrypted in step S 603 .  
         [0030]    Sequentially, in step S 604  it is determined whether the synchronizing information decrypted in step S 602  is the same as the synchronizing information decrypted in step S 603  and whether the important DRM information DRM decrypted in step S 602  is the same as the important DRM information DRM decrypted in step S 603 . If the information is not the same in step S 604 , it can be concluded that a content file including the DRM information DRM has been hacked. Accordingly, hacking information is displayed in step S 606  and is transmitted to a server, for example, the content providing server  141  or the key-data management server  142  of FIG. 1 in step S 607 .  
         [0031]    If the information is the same in step S 604 , update of the important DRM information DRM is monitored in step S 608 . The update of the DRM information DRM is related to, for example, the number of uses of the data  42  of the content file of FIG. 3. If the DRM information DRM has been updated, new synchronizing information and important DRM information DRM is stored in the database in step S 609 . Next, the synchronizing information SI and the important DRM information DRM of FIG. 3 stored in the database are encrypted in step S 610 . Next, key-data KS for the encrypted synchronizing information SI and key-data KD for the important DRM information DRM are encrypted in step S 611 . Sequentially, the encrypted synchronizing information, important DRM information and key-data are distributed and stored in predetermined places in step S 612 . Steps S 608  through  612  are repeated until a termination signal is input in step S 613 .  
         [0032]    The present invention has various advantages. For example, as described above, according to an information managing method of the present invention, synchronizing information distributively stored in predetermined places is periodically combined and decrypted, and it is determined whether the synchronizing information is the same as synchronizing information stored in a database. Accordingly, it can efficiently be determined whether important information for a user has been hacked, so information in the database can be managed more securely than in the related art case depending solely on encryption. Therefore, the risk of exposing encrypted synchronizing information is minimized.  
         [0033]    While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.