Media content decryption method and device, and electronic device

Abstract

The present invention discloses a method for decrypting media content, a device thereof, and an electronic device, and relates to the field of information security technology, wherein the decryption method comprises: obtaining an encrypted media content file from a content distribution end, and obtaining a basic key from a key gateway, obtaining an enhanced key and a combination identifier, combining the basic key and the enhanced key according to a preset combination strategy indicated by the combination identifier, obtaining a combined key, and using the combined key to decrypt the encrypted media content file. The present invention solves the technical problem in the related art that the success rate of decrypting the media content cannot be maintained under the premise of ensuring the encryption security of the media content, which easily leads to playback failure.

Description

Technical Field

[0001] The present invention relates to the field of information security technology, and in particular to a method for decrypting media content, a device thereof, and an electronic device. Background Art

[0002] At present, the audio-visual business is showing an explosive growth trend. In order to prevent the illegal broadcasting of audio-visual content, DRM (Digital Rights Management) technology is generally used in related technologies to encrypt and protect audio-visual content. Before playing the encrypted audio-visual content, the playback end needs to obtain the key from the key gateway and use the key to decrypt the audio-visual content before playing it. During the playback process, the key is usually dynamically changed. For example, the key scheme in the audio-visual DRM standard ChinaDRM is like this. Dynamically changing keys are more difficult to be illegally cracked than fixed keys. The more frequently the key changes, the greater the difficulty of cracking, but the frequency of the key request by the playback end also increases, resulting in an increased possibility of failure. At the same time, too frequent key requests will increase the burden on the key gateway and even cause the service to be unavailable. In addition, if the frequency of key updates is too low, it is not conducive to encryption security. Therefore, there is an urgent need for a technical solution that takes into account both encryption security and reliability.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The embodiments of the present invention provide a method and device for decrypting media content, and an electronic device thereof, so as to at least solve the technical problem in the related art that the success rate of decrypting media content cannot be maintained under the premise of ensuring the encryption security of the media content, which easily leads to playback failure.

[0005] According to one aspect of an embodiment of the present invention, a method for decrypting media content is provided, which is applied to a playback end and includes: obtaining an encrypted media content file from a content distribution end and obtaining a basic key from a key gateway; obtaining an enhanced key and a combination identifier; combining the basic key and the enhanced key according to a preset combination strategy indicated by the combination identifier to obtain a combined key; and using the combined key to decrypt the encrypted media content file.

[0006] Furthermore, the basic key is generated by a key management server, wherein the key management server sends the generated basic key to the key gateway and the media content encryptor; and the same basic key is combined with at least one enhanced key to generate at least one combined key.

[0007] Furthermore, the enhanced key is generated by a media content encryptor, wherein the media content encryptor sends the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end.

[0008] Furthermore, the enhanced key and the combined identifier are pre-stored in a designated place by a media content encryptor, wherein the designated place includes the encrypted media content file or file information, and the file information includes address information of the encrypted media content file.

[0009] Furthermore, the step of obtaining an enhanced key and a combined identifier includes: obtaining the enhanced key and the combined identifier from the designated place, wherein the designated place is derived from local storage information pre-agreed between the playback end and a preset digital copyright management system, or is derived from encryption information carried by the encrypted media content file.

[0010] Furthermore, before the enhanced key and the combined identifier are pre-stored in a designated place through a media content encryptor, it also includes: encrypting the enhanced key and the combined identifier using a preset encryption algorithm, wherein the preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm is pre-stored in the playback end.

[0011] Furthermore, the preset combination strategy includes at least one of the following: splicing combination, insertion combination, and independent encryption combination.

[0012] Furthermore, before obtaining the basic key from the key gateway, it also includes: authenticating the authority of the playback end through a preset digital copyright management system; when the authentication of the playback end is passed, verifying the basic key acquisition request initiated by the playback end through the preset digital copyright management system; when the verification of the basic key acquisition request is passed, controlling the key gateway to send the basic key to the playback end through the preset digital copyright management system.

[0013] According to another aspect of an embodiment of the present invention, a media content decryption device is also provided, which is applied to a playback end and includes: a first acquisition unit, used to acquire an encrypted media content file from a content distribution end and to acquire a basic key from a key gateway; a second acquisition unit, used to acquire an enhanced key and a combination identifier; a combination unit, used to combine the basic key and the enhanced key according to a preset combination strategy indicated by the combination identifier to obtain a combined key; and a decryption unit, used to use the combined key to decrypt the encrypted media content file.

[0014] Furthermore, the basic key is generated by a key management server, wherein the key management server sends the generated basic key to the key gateway and the media content encryptor; and the same basic key is combined with at least one enhanced key to generate at least one combined key.

[0015] Furthermore, the enhanced key is generated by a media content encryptor, wherein the media content encryptor sends the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end.

[0016] Furthermore, the enhanced key and the combined identifier are pre-stored in a designated place by a media content encryptor, wherein the designated place includes the encrypted media content file or file information, and the file information includes address information of the encrypted media content file.

[0017] Furthermore, the second acquisition unit includes: a first acquisition module, used to obtain the enhanced key and the combined identifier from the designated place, wherein the designated place comes from the local storage information pre-agreed between the playback end and the preset digital copyright management system, or comes from the encryption information carried by the encrypted media content file.

[0018] Furthermore, before the enhanced key and the combined identifier are pre-stored in a designated place through a media content encryptor, it also includes: encrypting the enhanced key and the combined identifier using a preset encryption algorithm, wherein the preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm is pre-stored in the playback end.

[0019] Furthermore, the preset combination strategy includes at least one of the following: splicing combination, insertion combination, and independent encryption combination.

[0020] Furthermore, the decryption device also includes: a first authentication module, which is used to perform authority authentication on the playback end through a preset digital copyright management system before obtaining the basic key from the key gateway; a first verification module, which is used to verify the basic key acquisition request initiated by the playback end through the preset digital copyright management system when the playback end is authenticated; and a first sending module, which is used to control the key gateway to send the basic key to the playback end through the preset digital copyright management system when the basic key acquisition request is verified.

[0021] According to another aspect of an embodiment of the present invention, an electronic device is also provided, comprising one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the above-mentioned media content decryption methods.

[0022] In the present invention, an encrypted media content file is obtained from a content distribution end, and a basic key, an enhanced key and a combination identifier are obtained from a key gateway. The basic key and the enhanced key are combined according to a preset combination strategy indicated by the combination identifier to obtain a combined key; the encrypted media content file is decrypted using the combined key.

[0023] In the present invention, the key of the media content file is divided into a basic key and an enhanced key. Only when both keys are obtained by the playback end and combined according to the preset combination strategy, can the encrypted media content file be successfully decrypted. By setting the enhanced key, the frequency of key changes can be faster, which can increase the difficulty of cracking the encrypted media content file, effectively ensuring the security of media content encryption. At the same time, by reducing the update frequency of the basic key, the failure rate of the playback end playing the media content can be reduced, thereby solving the technical problem in the related art that the success rate of decrypting the media content cannot be maintained under the premise of ensuring the security of media content encryption, which easily leads to playback failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0025] Figure 1 is a flow chart of an optional method for decrypting media content according to an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of an optional DRM functional module structure according to an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of a combination structure of different combination keys for different video frames according to an optional embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of a combination structure of different combination keys of different ts files according to an optional embodiment of the present invention;

[0029] Figure 5 is a schematic diagram of an optional structure of a playback end requesting a basic key according to an embodiment of the present invention;

[0030] Figure 6 is a schematic diagram of an optional audio and video digital copyright encryption and decryption process according to an embodiment of the present invention;

[0031] Figure 7 is a schematic diagram of an optional media content decryption device according to an embodiment of the present invention;

[0032] Figure 8 The hardware structure block diagram of an electronic device (or mobile device) for a method for decrypting media content according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0035] The present invention proposes a method for encrypting and decrypting audio and video content, which can take into account both encryption security and reliability. By dividing the key of the audio and video content into a basic key and an enhanced key, the successful decryption of the audio and video can be achieved only when these two keys are obtained by the playback end and combined in the correct way. The acquisition operation of the basic key needs to comply with the DRM system's requirements for the legitimacy of key requests. The setting of the enhanced key can make the key change more frequently, thereby making it more difficult for the audio and video content to be cracked. At the same time, the DRM system can reduce the update frequency of the basic key, and the frequency of users requesting the key gateway will also decrease, thereby reducing the failure rate of the DRM system and the failure rate of the playback end in playing the audio and video content.

[0036] The present invention is described in detail below in conjunction with various embodiments.

[0037] Embodiment 1

[0038] According to an embodiment of the present invention, an embodiment of a method for decrypting media content is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0039] Figure 1 is a flow chart of an optional method for decrypting media content according to an embodiment of the present invention, such as Figure 1 As shown, the method comprises the following steps:

[0040] Step S101: Obtain an encrypted media content file from a content distribution terminal, and obtain a basic key from a key gateway.

[0041] Step S102, obtaining an enhanced key and a combination identifier.

[0042] Step S103: combining the basic key and the enhanced key according to the preset combination strategy indicated by the combination identifier to obtain a combined key.

[0043] Step S104: decrypt the encrypted media content file using the combined key.

[0044] Through the above steps, the encrypted media content file can be obtained from the content distribution end, and the basic key, enhanced key and combination identifier can be obtained from the key gateway. According to the preset combination strategy indicated by the combination identifier, the basic key and the enhanced key are combined to obtain the combined key, and the encrypted media content file is decrypted using the combined key. In the embodiment of the present invention, the key of the media content file is divided into a basic key and an enhanced key. Only when these two keys are obtained by the playback end and combined according to the preset combination strategy can the encrypted media content file be successfully decrypted. By setting the enhanced key, the frequency of key changes can be faster, which can increase the difficulty of cracking the encrypted media content file, effectively ensuring the security of media content encryption. At the same time, by reducing the update frequency of the basic key, the failure rate of the playback end playing the media content can be reduced, thereby solving the technical problem that the related technology cannot maintain the success rate of decrypting the media content under the premise of ensuring the security of media content encryption, which easily leads to playback failure.

[0045] The embodiment of the present invention is described in detail below in combination with the above steps.

[0046] In an embodiment of the present invention, a preset digital copyright management system (i.e., DRM system) is proposed to realize encryption and decryption of video and audio content (i.e., media content). The preset digital copyright management system includes: a playback end, a key gateway, a key management server, a media content encryptor, and a content distribution end.

[0047] Figure 2 is a schematic diagram of an optional DRM functional module structure according to an embodiment of the present invention, such as Figure 2 As shown, the DRM system includes: a playback terminal, a key gateway, a key management server, a media content encryptor, and a content distribution terminal. Among them, the key management server is responsible for generating basic keys and providing the basic keys to the key gateway and the media content encryptor respectively. The key gateway stores the basic keys required for decrypting the media content, which is used by the playback terminal to download and decrypt the media content before playing. The media content encryptor is responsible for encrypting the media content and distributing the encrypted media content to the content distribution terminal. The content distribution terminal stores the encrypted media content, which is used by the playback terminal to download and play.

[0048] In some optional embodiments, the content distribution end includes: a content distribution network (Content Delivery Network, referred to as CDN), which is used to distribute audio-visual media content segments to the playback end.

[0049] In some optional embodiments, the playback end can realize functions such as obtaining audio and video media content, requesting key acquisition, decrypting and playing encrypted media content, and is located on terminal devices such as mobile phones, tablets, smart TVs, and computers.

[0050] Step S101: Obtain an encrypted media content file from a content distribution terminal, and obtain a basic key from a key gateway.

[0051] In step S101, the playback end may obtain the encrypted video and audio content (ie, the encrypted media content file) from the content distribution end, and obtain the basic key from the key gateway.

[0052] Optionally, the basic key is generated by a key management server, wherein the key management server sends the generated basic key to a key gateway and a media content encryptor; the same basic key is combined with at least one enhanced key to generate at least one combined key.

[0053] In an embodiment of the present invention, the basic key can be generated by a key management server, and the specific format and length of the basic key can be predetermined. Then, the key management server can provide the generated basic decryption key to the key gateway and provide the basic encryption key to the media content encryptor.

[0054] In the embodiment of the present invention, the encryption key and its paired decryption key may be the same or different. For ease of description, in the present embodiment, the encryption key and the decryption key are collectively referred to as keys, and accordingly, the basic encryption key and the basic decryption key are collectively referred to as basic keys.

[0055] In the embodiment of the present invention, the same basic key corresponds to one or more enhanced keys, that is, the same basic key can be combined with one or more enhanced keys to form one or more combined keys.

[0056] Exemplarily, a plurality of consecutive video frames may belong to the same basic key, but the enhanced key corresponding to each of the video frames may be different, and thus the combined key of each video frame is also different.

[0057] Figure 3 is a schematic diagram of a combination structure of different combination keys for different video frames according to an optional embodiment of the present invention. Figure 3 As shown, for each video frame in the video stream (for example, video frame 1, video frame 2, video frame 3, video frame 4, etc.), the combined key corresponding to each video frame is different, but the basic keys in the combined key can be the same. For example, the combined key 1 of video frame 1 is obtained by combining the basic key 1 and the enhanced key a; the combined key 2 of video frame 2 is obtained by combining the basic key 1 and the enhanced key b; the combined key 3 of video frame 3 is obtained by combining the basic key 1 and the enhanced key c; the combined key 4 of video frame 4 is obtained by combining the basic key 1 and the enhanced key d.

[0058] As another example, for segmented audio and video files, such as ts files in the HLS (HTTP Live Streaming) protocol (i.e., Transport Stream files, which are encapsulation formats for video and audio data), a basic key can belong to one or more adjacent ts files. Since the enhanced keys of these ts files can be different, the combined keys belonging to these ts files are also different.

[0059] Figure 4 is a schematic diagram of a combination structure of different combination keys of different ts files according to an embodiment of the present invention, such as Figure 4As shown, for each ts file in the video stream (for example, ts file 1, ts file 2, ts file 3, ts file 4, etc.), the combined key corresponding to each ts file is different, but the basic keys in the combined key can be the same, for example, the combined key 1 of ts file 1 is obtained by combining the basic key 1 and the enhanced key a; the combined key 2 of ts file 2 is obtained by combining the basic key 1 and the enhanced key b; the combined key 3 of ts file 3 is obtained by combining the basic key 1 and the enhanced key c; the combined key 4 of ts file 4 is obtained by combining the basic key 1 and the enhanced key d.

[0060] In the embodiment of the present invention, the video frame and the ts file are both exemplary files of the media content file, which are determined by the file format of the media content file and are not limited here.

[0061] Optionally, before obtaining the basic key from the key gateway, it also includes: authenticating the authority of the playback end through a preset digital copyright management system; if the playback end is authenticated, verifying the basic key acquisition request initiated by the playback end through the preset digital copyright management system; if the basic key acquisition request is verified, controlling the key gateway to send the basic key to the playback end through the preset digital copyright management system.

[0062] In an embodiment of the present invention, before the key gateway provides the basic key to the playback terminal, the DRM system can authenticate the playback terminal and its basic key acquisition request. Only when the playback terminal and its basic key acquisition request are authenticated and judged as legal by the DRM system, the key gateway will provide the basic key to the playback terminal, that is, the playback terminal can be authenticated by the preset digital copyright management system first, for example, the playback terminal is authenticated by the authority authentication component in the preset digital copyright management system. If the playback terminal is authenticated, the basic key acquisition request initiated by the playback terminal can be verified by the preset digital copyright management system to verify the legality of the basic key acquisition request (that is, to verify whether the request format, content, etc. of the request meet the preset legal requirements). If the basic key acquisition request is verified, the preset digital copyright management system can control the key gateway to send the basic key to the playback terminal.

[0063] In some optional embodiments, a set of playback terminals with requested permissions may be stored in the permission authentication component in advance, so that the permission authentication component is based on the playback terminal set. It is determined whether the playback terminal that initiates the basic key acquisition request has the requested permission. If so, the authentication is passed, otherwise, the request of the playback terminal is rejected.

[0064] Figure 5 is a schematic diagram of an optional structure of a playback end requesting a basic key according to an embodiment of the present invention, such as Figure 5As shown, if the playback end requests a basic key, the key gateway will first call the permission authentication component in the DRM system before providing the basic key to the playback end, and perform permission authentication and legality verification on the playback end and its basic key request. Only if the playback end and its basic key request pass the authentication and verification, the key gateway will provide the basic key to the playback end.

[0065] Optionally, the enhanced key is generated by a media content encryptor, wherein the media content encryptor sends the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end.

[0066] In an embodiment of the present invention, an enhanced key can be generated by a media content encryption machine. The enhanced key is not used as a key alone, but can be used in combination with a basic key. That is, the enhanced key and the basic key are combined in a specified combination method to form a combined key, and then the media content is encrypted and decrypted by the combined key.

[0067] In the embodiment of the present invention, the enhanced key is generated by the media content encryption machine, and the combination of the enhanced key and the basic key is also completed by the media content encryption machine. Since the encryption of the media content is completed by the media content encryption machine, the generation of the enhanced key and its combination with the basic key are also implemented by the media content encryption machine, and the encryption efficiency is higher.

[0068] In an embodiment of the present invention, the media content encryption machine can send the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end for storage, that is, the media content encryption machine can encrypt the audio and video content with a combined key generated by combining the enhanced key and the basic key.

[0069] In some optional embodiments, the enhanced key is a dynamically changing, unpredictable random number, and the length of the enhanced key is variable. Thus, the key composed of a random number and having a variable length can make the combined key formed by combining the enhanced key with the basic key more difficult to crack.

[0070] Optionally, the enhanced key and the combined identifier are pre-stored in a designated place by a media content encryptor, wherein the designated place includes an encrypted media content file or file information, and the file information includes address information of the encrypted media content file.

[0071] In the embodiment of the present invention, the media content encryptor can store the enhanced key and the identifier of the specified combination method of the enhanced key and the basic key (ie, the combination identifier) ​​in a specified place.

[0072] Preferably, the designated place may be in the encrypted media content file, so that the player can directly obtain the enhanced key and the designated combination identifier of the enhanced key and the basic key from the encrypted media content file, which is simpler and more reliable.

[0073] In this embodiment, if the designated place is in an encrypted media content file, the playback end can directly obtain the enhanced key and the combined identifier after obtaining the encrypted media content file. At the same time, the playback end can only obtain the enhanced key after obtaining the encrypted media content file, which is beneficial to further improve the security of the key, especially in the live broadcast scenario.

[0074] In an embodiment of the present invention, the designated place for storing the enhanced key includes the encrypted audio-visual content or its index file (i.e., in the encrypted media content file, where the index file can indicate the storage location of the audio-visual content), and may also include relevant information of the audio-visual content or its index file (i.e., file information), and the file information includes the address information of the encrypted media content file, i.e., the URL (uniform resource locator) information of the encrypted media content file.

[0075] For example, in the HLS protocol, the ts file is the audio and video content, and the m3u8 file (i.e., a text file format file used to organize multiple media files (such as audio or video) into a playlist) is the index file. The enhanced key can be carried in the ts file or in the m3u8 file, and the relevant information of the audio and video content or its index file includes: the URL of the ts file or the m3u8 file.

[0076] In this way, after the playback end obtains the encrypted audio-visual content or its index file, it is easy to obtain the enhanced key from it without having to obtain it from other places. At the same time, the playback end can only obtain the enhanced key after obtaining the audio-visual content or its index file, which is conducive to further improving the security of the key, especially in the live broadcast scenario.

[0077] In some optional embodiments, the designated place may be a server.

[0078] In this embodiment, the designated combination mode of the enhanced key and the basic key (ie, the preset combination strategy) can be known through the designated combination mode identifier of the enhanced key and the basic key.

[0079] In some optional embodiments, if the designated location is the encrypted audio-visual content or its index file, the playback end can directly obtain the enhanced key and the combination identifier from the encrypted audio-visual content or its index file that has been obtained.

[0080] Optionally, before the enhanced key and the combined identifier are pre-stored in a designated place through a media content encryptor, it also includes: encrypting the enhanced key and the combined identifier using a preset encryption algorithm, wherein the preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm is pre-stored at the playback end.

[0081] In the embodiment of the present invention, before the enhanced key and the identifier of the specified combination of the enhanced key and the basic key are stored in the specified location, the enhanced key and the identifier of the specified combination of the enhanced key and the basic key can be encrypted to further improve the anti-cracking capability. In practical applications, it is necessary to select an encryption algorithm that has a small impact on the encryption and decryption efficiency of the video and audio, so the complexity of the encryption algorithm needs to be small.

[0082] In an embodiment of the present invention, a selected preset encryption algorithm may be used to encrypt the enhanced key and the combination identifier. The preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm may be pre-stored at the playback end.

[0083] Optionally, the preset combination strategy includes at least one of the following: splicing combination, insertion combination, and independent encryption combination.

[0084] In the embodiment of the present invention, the preset combination strategy of the enhanced key and the basic key includes: splicing, insertion, successive independent encryption and other strategies, and the preset combination strategy is variable.

[0085] For example, if the basic key is Rd3gD6uDef8f and the enhanced key is pU3d7, the enhanced key can be spliced ​​to the front of the basic key to form a combined key pU3d7Rd3gD6uDef8f.

[0086] As another example, if the basic key is Rd3gD6uDef8f and the enhanced key is pU3d7, the audio and video content can be encrypted once with the basic key Rd3gD6uDef8f, and then the media content encrypted for the first time can be encrypted again with the enhanced key pU3d7, or encrypted with the enhanced key for the first time and encrypted with the basic key for the second time.

[0087] Step S102, obtaining an enhanced key and a combination identifier.

[0088] Optionally, the step of obtaining an enhanced key and a combined identifier includes: obtaining the enhanced key and the combined identifier from a designated place, wherein the designated place is derived from local storage information pre-agreed between the playback end and a preset digital copyright management system, or is derived from encryption information carried by an encrypted media content file.

[0089] In an embodiment of the present invention, if the playback end and the preset digital copyright management system pre-agree on a designated place for storing the enhanced key and the combination identifier, the playback end may record the agreed designated place for storing the enhanced key and the combination identifier in the local storage information in advance, so that the playback end can obtain the enhanced key and the combination identifier from the designated place. If the playback end and the preset digital copyright management system do not pre-agree on a designated place for storing the enhanced key and the combination identifier, the encrypted media content file may carry encryption information, and the encryption information includes the enhanced key and the designated place for pre-storing the combination identifier, so that the playback end can obtain the enhanced key and the combination identifier from the designated place.

[0090] In some optional embodiments, if the encrypted media content file carries encryption information, the playback end can first parse the encryption information carried by the encrypted media content file to obtain the enhanced key and the designated location of the combined identifier, and then obtain the enhanced key and the combined identifier of the enhanced key and the basic key from the designated location.

[0091] In other optional embodiments, if the playback end and the preset digital rights management system pre-agree on a designated place to store the enhanced key and the combination identifier, the encrypted media content file does not need to carry the enhanced key and the designated place to store the combination identifier.

[0092] In an optional embodiment, the designated location is pre-written into the encrypted information carried by the encrypted media content file by the media content encryptor. That is, the media content encryptor can write the designated location into the encrypted information carried by the encrypted media content file, so that when the playback end obtains the encrypted media content file, it can simultaneously obtain the enhanced key and the designated location combined with the identifier, without having to send a request again, which can improve the subsequent decryption efficiency and success rate.

[0093] Step S103: combining the basic key and the enhanced key according to the preset combination strategy indicated by the combination identifier to obtain a combined key.

[0094] In the embodiment of the present invention, the playback end combines the basic key and the enhanced key into a combined key using a preset combination strategy indicated by a combination identifier, and uses the combined key to decrypt the encrypted audio and video content.

[0095] In the embodiment of the present invention, neither the basic key nor the enhanced key alone can successfully decrypt the video and audio. Only when both keys are obtained by the playback end and combined together in a correct manner can the successful decryption of the video and audio be achieved.

[0096] In the embodiment of the present invention, after the playback end obtains the basic key, the enhanced key and the combined identifier, if the enhanced key and the combined identifier are encrypted, they need to be decrypted first.

[0097] Step S104: decrypt the encrypted media content file using the combined key.

[0098] In step S104, the playback end uses the combined key to decrypt the encrypted media content file, and then can play the decrypted media content.

[0099] Another optional specific implementation is described in detail below.

[0100] Figure 6 is a schematic diagram of an optional audio and video digital copyright encryption and decryption process according to an embodiment of the present invention, such as Figure 6 As shown, the following process is included:

[0101] (1) The key management server provides the basic decryption key to the key gateway and provides the basic encryption key to the media content encryptor;

[0102] (2) Generate an enhanced key, and combine the enhanced key with the basic key in a specified combination method to form a combined key;

[0103] (3) The media content encryption machine encrypts the audio and video content with the combined key, and stores the enhanced key and the designated combination of the enhanced key and the basic key in a designated place;

[0104] (4) distributing the encrypted audio and video media content to the content distribution end;

[0105] (5) The playback end obtains the encrypted video and audio content from the content distribution end, obtains the basic key from the key gateway, and obtains the enhanced key and the identifier of the specified combination of the enhanced key and the basic key from a specified location;

[0106] (6) The playback end combines the basic key and the enhanced key into a combined key by using a specified combination method identifier, and uses the combined key to decrypt the encrypted video and audio content;

[0107] (7) The playback end plays the decrypted audio and video content.

[0108] In the embodiment of the present invention, by dividing the key of the audio-visual content into a basic key and an enhanced key, the audio-visual content can be successfully decrypted only when both keys are obtained by the playback end and combined in the correct way. By setting the enhanced key, the frequency of key changes can be faster, making it more difficult to crack the audio-visual content. At the same time, the DRM system can reduce the frequency of updating the basic key, and the frequency of users requesting the key gateway is also reduced, thereby reducing the failure rate of the DRM system and the failure rate of the playback end in playing the audio-visual content.

[0109] The following is a detailed description in conjunction with another embodiment.

[0110] Embodiment 2

[0111] A media content decryption device provided in this embodiment includes multiple implementation units, each of which corresponds to each implementation step in the above-mentioned embodiment 1.

[0112] Figure 7 is a schematic diagram of an optional media content decryption device according to an embodiment of the present invention, such as Figure 7 As shown, the decryption device may include: a first acquisition unit 70, a second acquisition unit 71, a combination unit 72, and a decryption unit 73.

[0113] The first acquisition unit 70 is used to acquire the encrypted media content file from the content distribution terminal and acquire the basic key from the key gateway;

[0114] A second acquisition unit 71, used to acquire an enhanced key and a combination identifier;

[0115] A combining unit 72, configured to combine the basic key and the enhanced key according to a preset combining strategy indicated by the combining identifier to obtain a combined key;

[0116] The decryption unit 73 is used to decrypt the encrypted media content file using the combined key.

[0117] The above-mentioned decryption device can obtain the encrypted media content file from the content distribution end through the first acquisition unit 70, and obtain the basic key from the key gateway, obtain the enhanced key and the combination identifier through the second acquisition unit 71, and combine the basic key and the enhanced key according to the preset combination strategy indicated by the combination identifier through the combination unit 72 to obtain the combined key, and use the combined key to decrypt the encrypted media content file through the decryption unit 73. In the embodiment of the present invention, the key of the media content file is divided into a basic key and an enhanced key. Only when these two keys are obtained by the playback end and combined according to the preset combination strategy can the encrypted media content file be successfully decrypted. By setting the enhanced key, the frequency of key changes can be faster, and the difficulty of decrypting the encrypted media content file can be increased, which effectively ensures the security of media content encryption. At the same time, by reducing the update frequency of the basic key, the failure rate of the playback end playing the media content can be reduced, thereby solving the technical problem that the success rate of decrypting the media content cannot be maintained under the premise of ensuring the security of media content encryption in the related art, which easily leads to playback failure.

[0118] Optionally, the basic key is generated by a key management server, wherein the key management server sends the generated basic key to a key gateway and a media content encryptor; the same basic key is combined with at least one enhanced key to generate at least one combined key.

[0119] Optionally, the enhanced key is generated by a media content encryptor, wherein the media content encryptor sends the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end.

[0120] Optionally, the enhanced key and the combined identifier are pre-stored in a designated place by a media content encryptor, wherein the designated place includes an encrypted media content file or file information, and the file information includes address information of the encrypted media content file.

[0121] Optionally, the second acquisition unit includes: a first acquisition module, used to obtain an enhanced key and a combination identifier from a designated place, wherein the designated place comes from local storage information pre-agreed between the playback end and a preset digital copyright management system, or comes from encrypted information carried by an encrypted media content file.

[0122] Optionally, before the enhanced key and the combined identifier are pre-stored in a designated place through a media content encryptor, it also includes: encrypting the enhanced key and the combined identifier using a preset encryption algorithm, wherein the preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm is pre-stored at the playback end.

[0123] Optionally, the preset combination strategy includes at least one of the following: splicing combination, insertion combination, and independent encryption combination.

[0124] Optionally, the decryption device also includes: a first authentication module, which is used to perform authority authentication on the playback end through a preset digital copyright management system before obtaining the basic key from the key gateway; a first verification module, which is used to verify the basic key acquisition request initiated by the playback end through the preset digital copyright management system when the playback end is authenticated; and a first sending module, which is used to control the key gateway to send the basic key to the playback end through the preset digital copyright management system when the basic key acquisition request is verified.

[0125] The above-mentioned decryption device may also include a processor and a memory. The above-mentioned first acquisition unit 70, second acquisition unit 71, combination unit 72, decryption unit 73, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions.

[0126] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be provided, and the combined key is used to decrypt the encrypted media content file by adjusting the kernel parameters.

[0127] The above-mentioned memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one storage chip.

[0128] The present invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: obtaining an encrypted media content file from a content distribution end, and obtaining a basic key from a key gateway, obtaining an enhanced key and a combination identifier, combining the basic key and the enhanced key according to a preset combination strategy indicated by the combination identifier to obtain a combined key, and using the combined key to decrypt the encrypted media content file.

[0129] According to another aspect of an embodiment of the present invention, an electronic device is also provided, including one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by one or more processors, the one or more processors implement the above-mentioned method for decrypting media content.

[0130] Figure 8 1 is a hardware structure block diagram of an electronic device (or mobile device) for a method for decrypting media content according to an embodiment of the present invention. Figure 8 As shown, the electronic device may include one or more processors (e.g., Figure 8 The processor 802a, processor 802b, ..., processor 802n, etc., which may include but are not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA, etc.), a memory 804 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, a keyboard, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 8 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 8 More or fewer components as shown, or with Figure 8 Different configurations are shown.

[0131] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0132] The embodiments or examples of the present disclosure are not exhaustive, but are only illustrative of some embodiments or examples, and are not intended to be specific limitations on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment or example can be implemented as an independent example, and the steps can be combined arbitrarily. For example, the scheme after removing some steps in a certain embodiment or example can also be implemented as an independent example, and the order of the steps in a certain embodiment or example can be arbitrarily exchanged. In addition, the optional methods or optional examples in a certain embodiment or example can be combined arbitrarily; in addition, the various embodiments or examples can be combined arbitrarily, for example, some or all steps of different embodiments or examples can be combined arbitrarily, and a certain embodiment or example can be combined arbitrarily with the optional methods or optional examples of other embodiments or examples.

[0133] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0134] In the several embodiments provided by the present invention, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0135] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0136] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0137] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0138] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for decrypting media content, characterized in that: Applied to the playback end, including: Obtain the encrypted media content file from the content distribution end, and obtain the basic key from the key gateway; Obtaining an enhanced key and a combination identifier, wherein the enhanced key is a dynamically changing, unpredictable random number, and the length of the enhanced key is variable; Combining the basic key and the enhanced key according to a preset combination strategy indicated by the combination identifier to obtain a combined key; Decrypting the encrypted media content file using the combined key; Before obtaining the basic key from the key gateway, the method further includes: authenticating the playback terminal through a preset digital copyright management system; if the playback terminal is authenticated, verifying the basic key acquisition request initiated by the playback terminal through the preset digital copyright management system; if the basic key acquisition request is verified, controlling the key gateway to send the basic key to the playback terminal through the preset digital copyright management system; Among them, the basic key is generated by a key management server, the enhanced key is generated by a media content encryption machine, the update frequency of the basic key is less than the change frequency of the enhanced key, and the same basic key is combined with at least one enhanced key to generate at least one combined key.

2. The decryption method according to claim 1, characterized in that: The key management server sends the generated basic key to the key gateway and the media content encryptor.

3. The decryption method according to claim 1, characterized in that: The media content encryptor sends the encrypted media content file encrypted based on the basic key and the enhanced key to the content distribution end.

4. The decryption method according to claim 1, characterized in that: The enhanced key and the combined identifier are pre-stored in a designated place by a media content encryptor, wherein the designated place includes the encrypted media content file or file information, and the file information includes address information of the encrypted media content file.

5. The decryption method according to claim 4, characterized in that: The steps to obtain the enhanced key and the combined identity include: The enhanced key and the combined identifier are obtained from the designated place, wherein the designated place is derived from the local storage information pre-agreed between the playback terminal and a preset digital rights management system, or is derived from the encryption information carried by the encrypted media content file.

6. The decryption method according to claim 4, characterized in that: Before the enhanced key and the combined identifier are pre-stored in a designated place through a media content encryptor, the method further includes: encrypting the enhanced key and the combined identifier using a preset encryption algorithm, wherein the preset encryption algorithm corresponds to a preset decryption algorithm, and the preset decryption algorithm is pre-stored at the playback end.

7. The decryption method according to claim 1, characterized in that: The preset combination strategy includes at least one of the following: splicing combination, insertion combination, and independent encryption combination.

8. A media content decryption device, characterized in that: Applied to the playback end, including: A first acquisition unit, configured to acquire an encrypted media content file from a content distribution terminal and acquire a basic key from a key gateway; A second acquisition unit is used to acquire an enhanced key and a combination identifier, wherein the enhanced key is a dynamically changing, unpredictable random number, and the length of the enhanced key is variable; a combining unit, configured to combine the basic key and the enhanced key according to a preset combining strategy indicated by the combining identifier to obtain a combined key; a decryption unit, configured to decrypt the encrypted media content file using the combined key; The decryption device further comprises: a first authentication module, used to authenticate the playback terminal through a preset digital copyright management system before obtaining the basic key from the key gateway; a first verification module, used to verify the basic key acquisition request initiated by the playback terminal through the preset digital copyright management system when the playback terminal is authenticated; a first sending module, used to control the key gateway to send the basic key to the playback terminal through the preset digital copyright management system when the basic key acquisition request is verified; Among them, the basic key is generated by a key management server, the enhanced key is generated by a media content encryption machine, the update frequency of the basic key is less than the change frequency of the enhanced key, and the same basic key is combined with at least one enhanced key to generate at least one combined key.

9. An electronic device, characterized in that: It includes one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the media content decryption method described in any one of claims 1 to 7.

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