This application claims the benefit of Taiwan application Serial No. 100144911, filed Dec. 6, 2011, the disclosure of which is incorporated by reference herein in its entirety.
1. Technical Field
The disclosed embodiments relate in general to a method and an apparatus for enciphering/deciphering digital rights management object.
2. Description of the Related Art
Along with the popularization and diversification of the service of the digital content, the digital rights management is being generally applied to each electronic product or Internet service. The purposes of the digital rights management are for protecting the spread of the digital content from infringement such as unauthorized copy or use of the digital content and for defining the commercial operation mode according to the form of the digital content and the function of the related electronic products. Currently, most of the digital rights systems are combined with the online paying system to form a complete digital online service.
The Open Mobile Alliance (OMA) integrates plenty of service standard organizations (such as WAP forum, Wireless Village, SyncML, LiF, and so on) of the field, and aims to develop joint open standards for being conformed to the market demand and for helping to establish the compatible and interactive services working across nations, operators, and mobile terminals. Currently, the OMA has already been developed into a global standard organization having more than 350 members. The OMA has established 15 work teams, such as Requirements, Architecture, Security, Interoperability, Browser & Content, Location, and Push to talk over cellular, for developing different standards for the application layer with respect to different value-added services.
Different DRM systems are working online, and meantime the OMA defines a standard of DRM. The latest version is OMA DRM 2.1. Each of the standards of OMA and the different DRM systems defines the related rights of the digital content purchased by a user, and encrypts the delivered digital content. Only the authorized users and apparatuses are allowed to use the delivered digital content.
However, a user could have many apparatuses, for example, the home computer, the notebook computer, the handheld device, used in different conditions. Therefore, each DRM system defines a domain or a mechanism similar to a domain. A user may define his/her own devices as being in the same domain, such that the user is allowed to download or copy or use the content in many devices after buying the digital content one time. Certainly, an apparatus can only belong to one domain, and the quantity of the apparatuses in the one domain is limitary. The corresponding relationship of the domain makes the spread of the digital content much easier. Unlike the purchase of general software which provides authorization with respect to a machine (apparatus), the purchase of the digital content provides authorization with respect to a user and his/her machine (apparatus) of the domain because the purchase of the digital content is for the use (or browsing) of the user.
The disclosure is directed to a method and an apparatus for enciphering/deciphering digital rights management object.
According to one embodiment, a DRM enciphering method is provided. The DRM enciphering method is applicable to DRM enciphering apparatus and may be implemented by a processor. The DRM enciphering method includes the following steps. A plurality of content objects which are divided from a digital content are received. A plurality of DRM vectors are generated according to tacit information between the DRM enciphering apparatus and the DRM deciphering apparatus. The content objects are respectively enciphered according to the DRM vectors to generate a plurality of DRM objects.
According to another embodiment, a DRM object deciphering method is provided. The DRM object deciphering method is applicable to a DRM deciphering apparatus having a transaction number of a digital content and may be implemented by a processor. The DRM object deciphering method includes the following steps. A plurality of DRM vectors are generated according to tacit information between the DRM enciphering apparatus and the DRM deciphering apparatus. A plurality of DRM objects are respectively deciphered according to the DRM vectors to generate the content objects.
According to an alternative embodiment, a DRM enciphering apparatus is provided. The DRM enciphering apparatus includes a receiving unit, a DRM vector generation unit and a DRM object generation unit. The receiving unit receives a plurality of content objects which are divided from a digital content. The DRM vector generation unit generates a plurality of DRM vectors according to tacit information between the DRM enciphering apparatus and the DRM deciphering apparatus. The DRM object generation unit respectively enciphers the content objects according to the DRM vectors to generate a plurality of DRM objects.
According to an alternative embodiment, a DRM deciphering apparatus is provided. The DRM deciphering apparatus having a transaction number of a digital content includes a DRM vector generation unit and a content object generation unit. The DRM vector generation unit generates a plurality of DRM vectors according to tacit information between the DRM enciphering apparatus and the DRM deciphering apparatus. The content object generation unit respectively deciphers the DRM objects according to the DRM vectors to generate the content objects.
In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
Referring to
As shown in step 21, the receiving unit 111 receives a plurality of content objects S2 which are divided from a digital content S1. The digital content is such as a book, a magazine, a cartoon, a song or a film. The receiving unit 111 receives a plurality of content objects S2 which are divided from the digital content S1 according to the context or paragraphs recognizable to the user. Alternatively, the receiving unit 111 receives a plurality of content objects S2 which are divided from the digital content S1 according to file size (or stationery points of voice).
As shown in step 22, the DRM vector generation unit 112 generates a plurality of DRM vectors S3 according to tacit information S4 between the DRM enciphering apparatus 11 and the DRM deciphering apparatus 12. The DRM vectors S3 have a fixed length, and are different values from each other. As shown in step 23, the DRM object generation unit 113 enciphers the content objects S2 respectively according to the DRM vectors S3 to generate a plurality of DRM objects S5.
The DRM object deciphering method is applicable to DRM deciphering apparatus 12, and comprising the followings. As shown in step 31, the DRM vector generation unit 121 generates a plurality of DRM vectors S3 according to tacit information S4 between the DRM enciphering apparatus 11 and the DRM deciphering apparatus 12. As shown in step 32, the content object generation unit 122 deciphers the DRM objects S5 respectively according to the DRM vectors S3 to generate a plurality of content objects S2.
It is noted that the tacit information S4 is already obtained by the DRM enciphering apparatus 11 and the DRM deciphering apparatus 12 before the delivery of the DRM object S5. Theoretically, the tacit information does not need to be transmitted during the delivery of the DRM object S5. The tacit information may further include a plurality of tacit values from which the DRM vectors S3 are obtained through a logical operation. The logical operation may have plenty of implementations. For example, the logical operation is an exclusive-or (XOR) operation or a hash function operation. The tacit information, not transmitted during the delivery of the DRM object S5, is further protected from being deciphered by illegal users.
The aforementioned tacit values include, for example, the information related to the content object S2, the ID of the DRM deciphering apparatus 12, the transaction number of the digital content S1, the request time of the DRM deciphering apparatus 12, the previous last requested object ID of the DRM deciphering apparatus 12 or the user information of the DRM deciphering apparatus 12 or any combination of above.
The information related to the content object S2 is such as a serial number of the content object. The ID of the DRM deciphering apparatus 12 is such as a machine number of the DRM deciphering apparatus 12. The transaction number of the digital content S1 is such as transaction information when the user purchases the digital content. The request time of the DRM deciphering apparatus 12 is such as the previous time when the DRM deciphering apparatus 12 requests a DRM object of the RM enciphering apparatus 11. The previous last requested object ID of the DRM deciphering apparatus 12 is such as the serial number of the DRM object requested of the DRM enciphering apparatus 11 by the DRM deciphering apparatus 12. If the
DRM deciphering apparatus 12 has never requested any DRM objects of the DRM enciphering apparatus 11, the default value of the previous last requested object ID is set as 0. The user information is such as an account number or a password.
Referring to
Referring to
In one embodiment, the aforementioned content object generation unit comprises, for example, a key deciphering unit 1221 and a vector deciphering unit 1222. In one embodiment, the aforementioned step 32, for example, further includes steps 321˜322. As shown in step 321, the key deciphering unit 1221 deciphers the DRM objects S5 according to the key information S7 to generate a plurality of vector enciphering objects S6. As shown in step 322, the vector deciphering unit 1222 deciphers the vector enciphering objects according to the DRM vectors S7 to generate a plurality of content objects S2.
Referring to
In one alternate embodiment, the aforementioned content object generation unit includes, for example, an enciphering vector generation unit 1223 and a vector deciphering unit 1224. In one alternate embodiment, the aforementioned step 32, for example, further includes steps 323˜324. As shown in step 323, the enciphering vector generation unit 1223 generates a plurality of enciphering vectors S8 according to the key information S7 and the DRM vectors S3. As shown in step 324, the vector deciphering unit 1224 deciphers the DRM objects S5 according to the enciphering vectors S8 to generate a plurality of content objects S2.
The method and apparatus for enciphering/deciphering DRM object are capable of dividing a digital content into different content objects according to actual context, pattern or browsing mode of the digital content, and further enciphering the content object according to the DRM vectors. When the user only purchases the digital rights for one copy of digital content, theoretically, the user only owns one use right instead of many use rights with respect to the digital content. Therefore, when there are many users, the corresponding use rights should be many as well. That is, at any time, different users are not allowed to own the same use right. To resolve such problem, the method and the apparatus for enciphering/deciphering DRM object of the disclosure not only control the correlation of the content objects browsed by the user with an apparatus but also prohibit the transferability of the same digital content between different apparatuses. Within a short period of time, the DRM apparatus system allows the same DRM object to be browsed by only one apparatus.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed embodiments. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
Number | Date | Country | Kind |
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100144911 | Dec 2011 | TW | national |