WO2012065385A1

WO2012065385A1 - Method, device and mobile terminal for playing digital rights management file

Info

Publication number: WO2012065385A1
Application number: PCT/CN2011/071541
Authority: WO
Inventors: 王军锋
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-11-19
Filing date: 2011-03-04
Publication date: 2012-05-24
Also published as: CN102012983A

Abstract

The present invention discloses a method, device and mobile terminal for playing digital rights management (DRM) file, wherein the method comprises the following steps: a reading step for reading a portion of the DRM file; a decryption step for decrypting the read portion; a playing step for decoding and playing the decrypted portion; and performing the steps from the reading step to the playing step circularly until stopping playing the DRM file. The consumer experience is improved by the invention.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of communications, and in particular to a method and apparatus for playing a digital copyright encryption protection technology file and a mobile terminal. BACKGROUND OF THE INVENTION Digital Rights Management (DRM) effectively solves the problem of how to control and charge users for downloading content and downloading and disseminating media after downloading. The basic working principle of DRM technology is: use the key to lock the media file in the digital program authorization center. When the user clicks on the media file, the user obtains the information of the authorization center and connects and obtains the authorization. After the authorization of the digital program authorization center is authorized, The related key is decrypted before being allowed to play.

OMA DRM is a DRM protocol that can be applied to mobile communication terminals established by the Open Mobile Alliance (abbreviated as ΟΜ A). OMA DRM clarifies the three DRM protection methods available at the terminal. First, the FL way. This method requires the terminal to restrict the user's forwarding of media files. When the terminal obtains the media file, it can be used freely and unlimitedly in the terminal. The terminal must protect the file from being forwarded to other devices through the communication device or mechanism, including using infrared, Bluetooth, USB universal serial bus (Universal Serial Bus, Referred to as USB), external memory card, etc. In the FL mode, the authorization center is only responsible for the transmission of media files, and the responsibility for protecting the files is at the specific terminal used by the user. Pay the copyright fee to the authorization center while the FL file is obtained. Second, the combined send (CD) mode. Compared with the FL method, the CD method will merge and package the media files and the rights files in the authorization center. When the user uses the media file, the terminal software will query the permission object. If the permission is met, the user will play normally. Otherwise, the user permission will be invalid. As with the FL method, the user pays the copyright fee while obtaining the CD object. However, the CD mode is higher than the FL mode, that is, the media file that the terminal must protect the CD mode cannot be forwarded by the user. Third, separate transmission (SD) mode. The SD mode is an improvement of the CD mode. With the development of media content, media objects may be large, and relying solely on the download of mobile communication networks may be difficult. The SD method first encrypts and packages the media file into a specific format (for example, DCF format), which is convenient. Users can get it in a variety of ways. The process of obtaining media files by the user does not require payment. During use, the terminal software first obtains the URL of the authorization center from the content of the DCF format, and starts the browser to download the plaintext xml permission file containing the decryption key. During the process of downloading the rights file, the user pays the corresponding fee to obtain different permission limits. . Regardless of which protection method is used, when the mobile terminal plays the DRM file, it must first determine the protection mode and then decrypt it before playing. Currently, in the playback of DRM files on the mobile terminal, the following playback modes are used: One is to decrypt all the DRM files, and the plaintext files exist separately in a directory that is not visible to ordinary users, and then can be seen by ordinary users. The directory only stores the file name information (in fact, it only displays the file name for the user), so that when the user plays, the software processes and directly plays the corresponding clear text file that has been decrypted. This method is relatively insecure. Another way is to save the encrypted DRM file. After the file is decrypted, the file will be decrypted and then played. After the playback, the plaintext file will be deleted. This way, the security is relatively high. However, as the DRM file becomes larger, regardless of which of the above playback modes, the user needs to wait for a long decryption time before playing, thereby affecting the user experience. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a method, device, and mobile terminal for playing a digital copyright encryption protection technology file to solve at least the above problems. According to an aspect of the present invention, a method for playing a digital copyright encryption protection technology file is provided, including: a reading step of reading a part of the digital copyright encryption protection technology DRM file; a decrypting step, reading the Partially performing decryption; a playing step of decoding and playing the decrypted portion; performing the reading step 4 cyclically to the playing step 4 until the DRM file is stopped. Preferably, reading a part of the DRM file comprises: applying to read M bytes of data from a position of N bytes of a file to be played, wherein the N and M are integers greater than equal zero; Whether the file to be played is a DRM file; in the case where the determination result is YES, M bytes of data are read from the position of the N+L byte of the DRM file, wherein the L is the DRM file The length of the byte in which the DRM information is stored in the file header. Preferably, reading a part of the DRM file comprises: determining whether the file to be played is a DRM file, and reading a part of the DRM file if the determination result is yes. Preferably, determining whether the file to be played is a DRM file, and reading a part of the DRM file if the determination result is yes: determining whether the file to be played is a DRM file, and if the determination result is yes, Determining the validity of the DRM file and reading a portion of the DRM file if the DRM file is valid. Preferably, the method further includes: in the case that the DRM file is invalid, prompting that the DRM file is invalid. According to another aspect of the present invention, a playback apparatus for a digital copyright encryption protection technology file is provided, comprising: a reading module configured to read a part of the digital copyright encryption protection technology DRM file; a decryption module, setting In order to decrypt the read part; the playing module is set to decode and play the decrypted part; the calling module is set to cyclically call the reading module to the playing module, until the DRM is stopped. file. Preferably, the reading module comprises: an application module, configured to apply to read M bytes of data from a position of N bytes of a file to be played, wherein the N and M are integers greater than or equal to zero; a judging module, configured to determine whether the file to be played is a DRM file; and the byte reading module is configured to read M from a position of the N+L byte of the DRM file in a case where the judgment result is yes Byte data, wherein the L is the length of the byte in which the DRM information is stored in the header of the DRM file. Preferably, the reading module is configured to determine whether the file to be played is a DRM file, and read a part of the DRM file if the determination result is yes. Preferably, the reading module is configured to determine whether the file to be played is a DRM file, and if the determination result is yes, determine the validity of the DRM file, and read the file if the DRM file is valid. Part of the DRM file. According to still another aspect of the present invention, there is also provided a mobile terminal comprising the above apparatus. The invention solves the problem that the prior art for playing DRM needs to wait for a long time, thereby improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a method for playing a DRM file according to an embodiment of the present invention; FIG. 2 is a block diagram showing a structure of a playback device for a DRM file according to an embodiment of the present invention; FIG. 4 is a block diagram showing the structure of a mobile terminal according to an embodiment of the present invention; and FIG. 5 is a flowchart of playing a DRM file according to a preferred embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. 1 is a flowchart of a method for playing a DRM file according to an embodiment of the present invention. As shown in FIG. 1, the process includes the following steps: Step S102: Read a part of a DRM file; Step S104, read The retrieved portion is decrypted; step S106, the decrypted portion is decoded and played; step S102 to step S106 are performed cyclically until the playback of the DRM file is stopped. Compared with the prior art, after the entire DRM file is decrypted and then played, the embodiment uses a method of decrypting a part of the playback, thereby avoiding the need to wait for a long decryption before playing in the prior art. Time has improved the user experience. The above steps take advantage of the following principles: Any file system exists on the system of the mobile terminal, and all media files are eventually read when playing, and the file is not read by the entire file when the media file is played. When the department reads into the memory, it reads a part, decodes one part, and plays a part. For the above reasons, according to the characteristics of DRM, the function of segmentation decryption (that is, to give any part of the data of the DRM file, decrypt the corresponding part), and then add this to the original file system for the file system. Read it. Preferably, the judgment can be made in the reading of the file system, and if it is a DRM file, it is read and decrypted (the header of the DRM file stores some DRM-related information, ^_ if its length is L, so true When reading M data from the N position, it is necessary to take the DRM header information into account, and finally read M bytes from N+L. If it is not a DRM file, it can be read directly. Then decode and play. Preferably, it is also possible to perform a judgment before reading, that is, to determine whether the file to be played is a DRM file, and to read a part of the DRM file if the judgment result is YES. If the DRM file is valid, it can be judged whether the file to be played is a DRM file, and if the judgment result is yes, the validity of the DRM file is judged, and a part of the DRM file is read if the DRM file is valid. . At this time, preferably, in the case that the DRM file is invalid, the prompt of the DRM file failure may be performed. Through the above preferred embodiment, the upper layer software (or application) does not have to consider the problem of decryption when implemented. After the validity judgment of the DRM file is completed, the DRM is completely played as an ordinary media file during the real playback, and the decryption work is performed. Completed in the file system. 2 is a structural block diagram of a playback device for a DRM file according to an embodiment of the present invention. As shown in FIG. 2, the device includes: a reading module 22, a decryption module 24, a playback module 26, and a calling module 28, and the following structure Be explained. The reading module 22 is configured to read a part of the digital copyright encryption protection technology DRM file; the decrypting module 24 is configured to decrypt the read portion; the playing module 26 is configured to decode and play the decrypted portion The calling module 28 is set to cyclically call the reading module to the playing module in sequence until the DRM file is stopped. FIG. 3 is a structural block diagram of a reading module 22 according to an embodiment of the present invention. As shown in FIG. 3, the module includes: an application module 32, a first determining module 34, and a byte reading module 36. Description. The application module 32 is configured to apply to read M bytes of data from a position of N bytes of the file to be played, where N and M are integers greater than or equal to zero; the first determining module 34 is configured to determine that the device needs to be played. Whether the file is a DRM file; the byte reading module 36 is set to read M bytes of data from the position of the N+L byte of the DRM file in the case where the judgment result is YES, wherein L is a file of the DRM file The length of the byte in which the DRM information is stored in the header. Preferably, the reading module 22 is configured to determine whether the file to be played is a DRM file, and to read a part of the DRM file if the determination result is yes. Preferably, the reading module 22 is configured to determine whether the file to be played is a DRM file, and if the determination result is yes, determine the validity of the DRM file, and read a part of the DRM file if the DRM file is valid. In this embodiment, a mobile terminal is further provided, the terminal includes the foregoing apparatus, and FIG. 4 is a structural block diagram of a mobile terminal according to an embodiment of the present invention. As shown in FIG. 4, the terminal may include a play/display module and a file. The system (the function of the reading module 22 is implemented in the system), the DRM decryption module (implementing the function of the decryption module 24;), the file decoding module (the module and the play/display module together implement the function of the play module 26;), The functions of these modules have been described above and will not be described here. The following description will be made in conjunction with the preferred embodiments. In this embodiment, the media file format may be judged when the media file is played, and if it is a DRM file, the validity is determined, such as whether the number of times of playing is less than the maximum number of times allowed, and whether the playing time does not exceed the allowed playing. Time, etc., if these conditions are met, then play, read a part of the source file first, then decrypt the part of the source file, then decode the part of the file, then play this part, then read, then decrypt, Decode and play again. FIG. 5 is a flowchart of playing a DRM file according to a preferred embodiment of the present invention. As shown in FIG. 5, the flow includes the following steps: Step A. First, determine whether the DRM media file is played, and if yes, go to B, if not Then go directly to C; Step B. Determine the validity of the DRM file (whether the number of plays has reached the maximum number of times allowed or the time allowed for playback has expired, etc.), if it is valid, run C, otherwise run J; Step C. Apply Reading M bytes of data from the source file N position; Step D. Determine whether it is a DRM file. If it is running E, otherwise run I directly; Step E. Read M bytes of data from the N+L of the source file. The file header of the DRM file will store some DRM related files. Information, if its length is L, so when you want to read M data from the N position, you need 4 bar DRM header information in the calculation, and finally start reading from N+L; Step F. M data is decrypted according to the key, and M byte source data is restored; Step G. Media decoding of the M byte source data; Step H. Decoded data is played; Step I. Directly from Read M bytes of data in the file, run G; Step J. Prompt for DRM validity failure. Compared with the prior art, the preferred embodiment uses the step of reading all the files in the playback of the DRM file, and finally needs to read the file, thereby realizing the segmentation and decryption of the DRM file, and realizing the decryption while playing. Completely solved the problem of security and efficiency when playing DRM files. Through the above embodiment and its preferred embodiment method, a DRM file playing method for efficiently and securely decrypting while playing is provided. Compared to the prior art, ignoring security (such as decrypting into a plaintext file before playing), or high security, ignoring efficiency, affecting the user experience. Improve user physical insurance and ensure the security of DRM files. In addition, the above embodiment also achieves reading and decrypting the DRM file by adding some judgment and reading operations on the DRM in the reading of the original non-DRM file, because only a part of the data is decrypted at a time, and the file of the entire system is read. There is almost no impact on performance. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device, such that they may be stored in the storage device by the computing device and, in some cases, may be different from the order herein. Perform the steps shown or described, or separate them into individual integrated circuit modules, or make multiple modules or steps in them Implemented as a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A method for playing a digital copyright encryption protection technology file, comprising:

Reading step 4, reading a part of the digital copyright encryption protection technology DRM file;

Decrypting step, decrypting the read part;

a playing step of decoding and playing the decrypted portion;

The reading step is performed cyclically to the playing step until the playback of the DRM file is stopped.

2. The method of claim 1, wherein reading a portion of the DRM file comprises:

Applying to read M bytes of data from a position of N bytes of a file to be played, wherein the N and M are integers greater than equal zero;

Determining whether the file to be played is a DRM file;

In the case where the determination result is YES, M bytes of data are read from the position of the N+L byte of the DRM file, wherein the L is the byte length of the DRM information stored in the file header of the DRM file. .

3. The method according to claim 1 or 2, wherein reading a part of the DRM file comprises:

It is judged whether the file to be played is a DRM file, and a part of the DRM file is read in a case where the judgment result is YES.

The method according to claim 1 or 2, wherein determining whether the file to be played is a DRM file, and reading a part of the DRM file if the determination result is yes includes:

It is judged whether the file to be played is a DRM file, and if the result of the determination is YES, the validity of the DRM file is judged, and a part of the DRM file is read if the DRM file is valid.

5. The method according to claim 4, further comprising: In case the DRM file fails, the prompt of the DRM file failure is performed.

6. A playback device for a digital copyright encryption protection technical file, comprising:

a reading module configured to read a portion of the digital copyright encryption protection technology DRM file; and a decryption module configured to decrypt the read portion;

The playing module is configured to decode and play the decrypted portion; the calling module is configured to sequentially call the reading module to the playing module in a loop until the DRM file is stopped.

The device according to claim 6, wherein the reading module comprises:

The application module is configured to apply to read M bytes of data from a position of N bytes of the file to be played, wherein the N and M are integers greater than or equal to zero;

a first determining module, configured to determine whether the file to be played is a DRM file;

a byte reading module, configured to read M bytes of data from a position of an N+L byte of the DRM file in a case where the determination result is YES, wherein the L is a file header of the DRM file The length of the byte in which the DRM information is stored.

8. The apparatus according to claim 6, wherein

The reading module is configured to determine whether the file to be played is a DRM file, and read a part of the DRM file if the determination result is yes.

9. The device according to claim 6, wherein

The reading module is configured to determine whether the file to be played is a DRM file, and if the determination result is yes, determine the validity of the DRM file, and read the DRM file if the DRM file is valid. Part of it.

10. A mobile terminal comprising the apparatus of any one of claims 6 to 9.