JPH11112494A - Client/server system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high resistance against illegal copying by providing an illegal copying detect means for a client so as to detect illegal copying when illegal copying is tried in data cipher-released at the time of reproducing ciphered contents while dynamically releasing. SOLUTION: At the client 13, a video reproducing application 16 executes an illegal copying detect module 17 and cipher releasing module 14. At the time of detecting illegal copying, the module 17 daises an illegal copying detect flag. Next, the application 16 checks the illegal copying detect flag. When the flag is raised, the execution of the module 14 is immediately finished and information on the detection of illegal copying is given to a video server 9. When the flag is not raised, ciphered video data 11 sent from the server 9 is cipher-released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to the use of encrypted content in a client / server system connected by a network.

[0002]

2. Description of the Related Art In a client / server system connected by a network, a configuration of a conventional system for performing a reproduction process while dynamically decrypting encrypted content stored in a server by a client is shown in FIG. Shown in In FIG. 11, 1 is a network, 2 is an encrypted content (encrypted content)
And 3 are encrypted content data stored in the server 2. Reference numeral 4 denotes a client that receives the encrypted content via the network 1, 5 denotes a decryption module that dynamically decrypts the encrypted content data sent from the server 2, and 6 denotes a decryption module that decrypts the content data. A decoding module 7 decodes the encrypted content data, and a content reproduction application 7 reproduces the encrypted content.

[0003] The server 2 distributes the encrypted content data 3 through the network 1 in response to a distribution request from the content reproduction application 7 on the client 4.
The content reproduction application 7 is a client 4
The decryption module 5 and the decoding module 6 perform a reproduction process on the encrypted content data 3 sent to the server.

[0004]

SUMMARY OF THE INVENTION A conventional client
Since the server system is configured as described above, the encrypted content data decrypted by the decryption module 5 may be illegally copied by using a hook function or the like.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a client / server system having a function of detecting illegal copy in a client and having high resistance to illegal copy. I do.

[0006]

According to a first aspect of the present invention, in a client-server system connected by a network, a client decrypts encrypted content transferred from a server, and detects unauthorized copy. Means for detecting unauthorized copy, when the encrypted content is reproduced while being dynamically decrypted by the decryption means, if unauthorized decryption is attempted on the decrypted data, Is detected.

According to a second aspect of the present invention, in the client-server system according to the first aspect, the unauthorized copy detecting means stops decryption when detecting that an unauthorized copy has been attempted on the data. It is.

According to a third aspect, in the client-server system according to the first aspect, when the unauthorized copy detecting means detects that an unauthorized copy has been attempted on the data, the server notifies the server that the unauthorized copy has been attempted. Is to be notified.

According to a fourth aspect of the present invention, in the client-server system according to the first aspect, if the unauthorized copy detecting means detects that an unauthorized copy has been attempted on the data, the unauthorized copy detecting means transmits the contents of the unauthorized copy and the user information to the server. Is to be notified.

According to a fifth aspect, in the client-server system according to the third or fourth aspect, an unauthorized copy is attempted to the server, or the content of the unauthorized copy and user information are notified to the server. The server stops distribution of the encrypted content to the client.

According to a sixth aspect of the present invention, in a client-server system connected by a network, the server includes encryption means for encrypting video data taken from a video camera while encoding the data in real time, and the client is transferred from the server. Decryption means for decrypting the encrypted video data that has been received, and unauthorized copy detection means, wherein the unauthorized copy detection means reproduces the encrypted video data sent from the server while dynamically decrypting the encrypted video data. In such a case, if an unauthorized copy is attempted on the decrypted video data, the unauthorized copy is detected.

According to a seventh aspect, in the client-server system according to the sixth aspect, when the unauthorized copy detecting means detects that an unauthorized copy has been attempted, the decryption is stopped.

According to an eighth invention, in the client-server system according to the sixth invention, when the unauthorized copy detecting means detects that the unauthorized copy has been attempted, the unauthorized copy detecting means notifies the server that the unauthorized copy has been attempted. It is like that.

According to a ninth aspect, in the client-server system according to the sixth aspect, when the unauthorized copy detecting means detects that the unauthorized copy has been attempted, the unauthorized copy content and the user information are notified to the server. It is like that.

According to a tenth aspect, in the client-server system according to the eighth or ninth aspect, when an illegal copy is attempted to the server, or when the contents of the illegal copy and user information are notified to the server. The server stops distribution of the encrypted content to the client.

According to an eleventh aspect, in a client-server system connected by a network, the server holds encrypted content usage right information as user information, and when the client accesses content that does not have the content usage right, The non-encrypted partial content corresponding to a part of the encrypted content is distributed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 is a system configuration diagram according to the present embodiment. In the figure, reference numeral 8 denotes a network, and 9 denotes a video which distributes a normal video (unencrypted video) or an encrypted video (encrypted video) through the network 8. Server 10, user information,
11 is normal video data, and 12 is encrypted video data. Reference numeral 13 denotes a client that receives a normal video or an encrypted video through the network 8, 14 denotes a decryption module that decrypts encrypted video data transmitted from the video server 9, and 15 denotes a decryption module that is transmitted from the video server 9. A decoding module for decoding normal video data or video data decrypted by the decryption module 14;
Video playback application for video playback etc., 17
Is an illegal copy detection module for detecting an illegal copy of an encrypted video. Although the present embodiment deals with video as content, the present invention is also applicable to audio, moving images, still images, and other contents.

Next, the operation will be described with reference to FIGS. 2, 3 and 4. Here, FIG. 2 shows a flowchart of the video playback process, and FIGS. 3 and 4 respectively show a key exchange process (step 13) in the flowchart of the video playback process.
And a detailed flowchart of an encrypted video reproduction process (step 14).

In the flowchart of the video reproduction process shown in FIG. 2, first, the video reproduction application 16 displays a login dialog box to authenticate whether the user can use the system, and inputs a user name and a password. To the video server 9 (step 1). The video server 9 uses the registered user information, performs user authentication based on the received user name and password, and returns a result. Only when the client 13 can log in (step 2), the following processing can be executed. Next, the video playback application 16
Waits for a request from the user (step 3), and if there is a video playback request (step 5), the video server 9
Request video title information. The video server 9 returns video title information according to the request from the client 13. The video playback application 16 displays a list of videos stored in the video server 9 based on the sent video title information, displays a video selection dialog box, and prompts the user to select a video (step 6). In this embodiment, in order to simplify the description, the request from the user will be described only as a video playback request, a video playback end request, and an application end request. Next, the information of the selected video is inquired to the video server 9 to check whether the selected video is encrypted (step 7). If not encrypted, video playback is performed as usual (steps 8 and 9). On the other hand, if it is encrypted, it inquires the user information 10 to the video server 9 and checks whether the user has the right to use the encrypted video (step 10).

Here, the structure of the user information 10 is shown in FIG. The user information 10 includes a user name, a password, and encrypted video use right information. In the encrypted video usage right information, information indicating only whether or not the encrypted video can be used may be stored, or the level of a user who can use the video may be set for each video, and the encrypted video usage right information may be stored in the encrypted video usage right information. The level may be stored, and it may be determined whether or not the level can be used based on the stored level. Further, information indicating which video can be used may be stored in the encrypted video usage right information.

If the user does not have the right to use the encrypted video (step 11), the video reproduction application 16 may display a message indicating that reproduction is not possible, return to the state of waiting for a request from the user without reproducing the video, or If possible, partial playback corresponding to the encrypted video, such as the first few seconds of the video, may be performed (step 12).

FIG. 6 shows a method of storing a video when performing partial reproduction. Since the partial data corresponding to the encrypted video data is not encrypted, it can be normally reproduced and there is no need to exchange keys. Here, the partial data is obtained by converting a part of the actual file name of the encrypted video data as an example, but another method such as using the same file name in another directory may be used.

On the other hand, if the user has the right to use the encrypted video, a key exchange process is performed (step 13). FIG. 3 shows a flowchart of the key exchange process. In the present embodiment, a common key,
A key exchange process is performed using a public key and a secret key. This is an example, and other key exchange methods can be used. The encryption of the encrypted video uses a common key. In FIG. 3, first, the video reproduction application 16 generates a public key and a secret key (step 31). Next, the user information and the generated public key are sent to the video server 9 (step 3).
2). On the other hand, the video server 9 performs user authentication again from the received user information (the encrypted video use right is also checked) (step 22). If the user authentication is successful (step 23), the common key of the encrypted video is encrypted with the received public key (step 24) and sent to the video reproduction application 16 (step 25). Next, the video reproduction application 16 decrypts the common key encrypted with the public key sent from the video server 9 with the private key, and ends the key exchange processing (step 34).

Next, the video playback application 16 performs an encrypted video playback process. FIG. 4 shows a flowchart of the encrypted video reproduction process. First, the video reproduction application 16 causes the unauthorized copy detection module 17 and the decryption module 14 to execute before decrypting (steps 41 and 42). The illegal copy detection module 17 operates as a separate thread of the video reproduction application 16 and always detects an illegal copy until the execution ends (step 43). If an illegal copy is detected (step 44), the illegal copy detection is performed. Set the flag. The method of detecting an illegal copy includes checking the address of a function and monitoring I / O, but other methods may be used. Next, the video reproduction application 16 checks the illegal copy detection flag.
If the flag is set, decryption module 1 immediately
4 is terminated (step 45), and the video server 9
Is notified of unauthorized copy detection (step 46).
finish. On the other hand, if the flag is not set, the encrypted video data 11 sent from the video server 9
Is decrypted (step 47). Next, the decrypted encrypted video data 11 is decoded (step 48), and video and audio are output (step 49). This is repeated until the video ends or a video playback end request is received from the user (step 5).
0), play the encrypted video. When the video is completed, the execution of the decryption module 14 is immediately terminated (step 51), and the opportunity for unnecessary unauthorized copying is eliminated.
Next, the system waits for a request from the user. When a video playback request is issued, the video playback is performed as described above. When an application termination request is issued, the video playback application 16 is terminated. Video playback processing is performed as described above.

Embodiment 2 Next, a second embodiment of the present invention will be described with reference to FIGS. FIG.
FIG. 7 is a system configuration diagram in the present embodiment. In FIG. 7, 18 is a network, 19 is a video server that distributes an encrypted live video (encrypted live video) through the network 18, 20 is user information, and 21 is a video. A camera 22 is an encoding module that encodes live video input from the video camera 21 in real time, and 23 is an encryption module that dynamically encrypts live video data encoded by the encoding module 22. Reference numeral 24 denotes a client that receives the encrypted live video through the network 18;
Is a decryption module for decrypting the encrypted live video data sent from the video server 19, 26 is a decode module for decoding the live video data decrypted by the decryption module 25, 27 is user authentication and key exchange , An encrypted live video playback application that performs encrypted live video playback and the like; and 28, an unauthorized copy detection module that detects an unauthorized copy of the encrypted live video. Although the present embodiment deals with live video as content, the present invention can also be applied to live audio, video stored in a server, audio, moving images, still images, and other contents.

Next, the operation will be described with reference to FIGS. FIG. 8 is a flowchart of the encrypted live video distribution processing in the video server 19, and FIG. 8B is a flowchart of the encrypted live video distribution processing (step 7) of FIG.
5 is a detailed flowchart of FIG. FIG. 9 is a flowchart of an encrypted live video playback process in the client 24. First, in FIG. 8, the video server 19
Then, according to an encoding start request from a user (not a client user but a server user and an administrator or the like) (step 72), live video data from the video camera 21 is encoded in real time by the encoding module 22 (step 72). 73). Next, the live video data is dynamically encrypted by the encryption module 23 (step 74). In this state, a request from the client is waited (step 80).

On the other hand, in the client 24 shown in FIG. 9, in order for the encrypted live video playback application 27 to authenticate whether the user can use the present system, a login dialog box is displayed, and a user name and a password are input. Send to video server 19 (step 5
9).

Then, the video server 19 shown in FIG. 8 uses the registered user information 20 to perform user authentication based on the transmitted user name and password (step 8).
1) Return the result and return to waiting for a request from the client (step 80).

Only when the client 24 can log in (step 60), the following processing can be executed. Encrypted live video playback application 27
Waits for a request from the user (step 61), and when there is an encrypted live video playback request (step 62).
The video server 19 is inquired of user information 20 to the server, and based on the user information from the server (step 8)
2) Check whether the user has the right to use the encrypted live video (step 63).

As the user information 20, the same information as in the first embodiment may be used, or the encrypted live video usage right information may be separately held as shown in FIG.

If the user does not have the right to use the encrypted live video (step 64), the encrypted live video playback application 27 displays that the live video cannot be played back (step 65) and does not play the live video. Return to the request waiting state. On the other hand, if the user has the right to use the encrypted live video, a key exchange process is performed (step 6).
6). The key exchange process is the same as in the first embodiment (FIG. 3). Next, the live video playback application 27 performs an encrypted live video playback process (step 67). The encrypted live video playback processing is the same as in the first embodiment (FIG. 4). In the encrypted live video playback processing, the unauthorized copy detection module 28 detects that an unauthorized copy has been attempted, and if the video server 19 receives an unauthorized copy detection notification (step 83), the video server 19 executes the live video The encoding, encryption, and distribution of the encrypted live video to other clients continue, and only distribution of the encrypted live video to the client in which the illegal copy is detected is stopped. In the case of distribution by multicast, the distribution is stopped by removing the client in which the illegal copy is detected from the members (step 8).
4). Further, the video server 19 adds the user information and the illegal copy information sent from the client to the history information and analyzes the illegal copy (step 8).
5). As described above, the encrypted live video reproduction / distribution processing is performed.

[0032]

The client / server system according to the first aspect of the present invention can detect that an unauthorized copy has been attempted, and therefore decrypts the encrypted content stored in the server with the client. In this case, there is an effect that high resistance to illegal copying can be maintained.

The client / server system according to the second invention is capable of canceling the decryption upon detecting that an illegal copy has been attempted.
When the client decrypts the encrypted content stored in the server, an illegal copy can be prevented from the client side.

The client-server system according to the third aspect of the present invention notifies the server when it detects that unauthorized copying has been attempted, so that the server can stop the distribution of the stored encrypted content. There is an effect that can be.

When the client-server system according to the fourth invention detects that an illegal copy has been attempted, it notifies the server of the user information and the contents of the illegal copy. It is possible to take countermeasures for the user.

In the client-server system according to the fifth invention, when an illegal copy is attempted or when the contents of the illegal copy and the user information are notified to the server, the server stops the distribution of the encrypted content to the client. Thus, there is an effect that unauthorized copying can be prevented from the server side.

The client-server system according to the sixth aspect of the present invention can detect that an illegal copy has been attempted, so that when the server decrypts the dynamically encrypted content at the client, the client-server system can detect the unauthorized copy. There is an effect that high resistance to copying can be maintained.

In the client-server system according to the seventh invention, the decryption is stopped when an illegal copy is attempted, so that the server dynamically decrypts the content dynamically encrypted by the client. In this case, there is an effect that illegal copying can be prevented from the client side.

In the client-server system according to the eighth aspect, the server is immediately notified that an illegal copy has been attempted, so that the server can stop the distribution of dynamically encrypted content. There is an effect that can be.

When the client-server system according to the ninth invention detects that an illegal copy has been attempted, it notifies the server of the user information and the contents of the illegal copy. There is an effect that it is possible to take a measure for the user.

In the client-server system according to the tenth aspect, when the illegal copy is attempted, the server stops the distribution of the dynamically encrypted contents, so that the illegal copy can be prevented from the server side. effective.

[0042] The client-server system according to the eleventh aspect of the present invention holds encrypted content usage right information in a server, and allows a user who does not have a usage right to the content to obtain one of the encrypted content. Access to the encrypted content.
There is an effect that the part can be auditioned.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a flowchart of a video reproduction process according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a flowchart of a key exchange process in the first and second embodiments of the present invention.

FIG. 4 is a diagram showing a flowchart of encrypted video and live video playback processing in the first and second embodiments of the present invention.

FIG. 5 is a diagram showing a structure of user information according to the first embodiment of the present invention.

FIG. 6 is a diagram illustrating a method of storing partial data corresponding to an encrypted video according to the first embodiment of the present invention.

FIG. 7 is a system configuration diagram showing a second embodiment of the present invention.

FIG. 8 is a flowchart of an encrypted live video distribution process in the video server according to the second embodiment of the present invention.

FIG. 9 is a flowchart illustrating an encrypted live video playback process in a client according to the second embodiment of this invention.

FIG. 10 is a diagram showing a structure of user information according to the second embodiment of the present invention.

FIG. 11 is a configuration diagram of a conventional client / server system that distributes encrypted content.

[Explanation of symbols]

1 network, 2 servers, 3 encrypted data, 4
Client, 5 decryption module, 6 decoding module, 7 encrypted content playback application, 8 network, 9 video server, 10 user information, 11 normal video data, 12 encrypted video data, 13 client, 14 decryption module, 15 decoding Module, 16 video playback application, 17 illegal copy detection module, 18
Network, 19 video server, 20 user information, 21 video camera, 22 encoding module 23 encryption module, 24 client, 25
Decryption module, 26 Decoding module, 27
Encrypted live video playback application, 28 illegal copy detection module.

Claims (11)

[Claims] 1. In a client-server system connected by a network, a client includes decryption means for decrypting encrypted content transferred from a server, and unauthorized copy detection means, wherein the unauthorized copy detection means comprises: In the case where an unauthorized copy has been attempted on the decrypted data when the encrypted content is reproduced while being dynamically decrypted by the decryption means,
Clients characterized by detecting unauthorized copying
Server system. 2. The client-server system according to claim 1, wherein said unauthorized copy detecting means stops decryption when detecting that an unauthorized copy has been attempted on the data. 3. The client / server according to claim 1, wherein said unauthorized copy detecting means, when detecting that an unauthorized copy has been attempted on the data, notifies the server that the unauthorized copy has been attempted. Server system. 4. The client server according to claim 1, wherein the illegal copy detecting means notifies the server of the contents of the illegal copy and user information when detecting that an illegal copy has been attempted on the data. system. 5. An unauthorized copy attempt on the server;
5. The client-server system according to claim 3, wherein when the contents of the illegal copy and the user information are notified to the server, the server stops the distribution of the encrypted contents to the client. 6. In a client-server system connected by a network, the server includes encryption means for encrypting video data captured from a video camera while encoding the data in real time, and the client encrypts the video data transferred from the server. Decryption means for decrypting the encrypted video data; and unauthorized copy detection means, wherein the unauthorized copy detection means reproduces the encrypted video data sent from the server while dynamically decrypting the encrypted video data. A client-server system for detecting an unauthorized copy when an unauthorized copy is attempted on the decrypted video data. 7. The client-server system according to claim 6, wherein said unauthorized copy detecting means stops the decryption when detecting that an unauthorized copy has been attempted. 8. The client-server system according to claim 6, wherein when the illegal copy detecting means detects that the illegal copy has been attempted, the illegal copy detecting means notifies the server that the illegal copy has been attempted. 9. The apparatus according to claim 6, wherein said illegal copy detecting means notifies the server of the contents of the illegal copy and user information when the illegal copy is detected.
The client-server system as described. 10. The server stops distribution of encrypted content to a client when an illegal copy is attempted to the server, or when the contents of the illegal copy and user information are notified to the server. Item 10. The client-server system according to Item 8 or 9. 11. In a client-server system connected by a network, a server holds encrypted content usage right information as user information, and when a client accesses content that does not have the content usage right, the server encrypts the content. A non-encrypted partial content corresponding to a part of the encrypted content.