JP2011015444A - Content transmitting device, content receiving device, and content transmission method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain protection for copyrights, by suppressing illegal copy production, when transmitting contents while using a LAN, and to prevent transmission of the contents from deviating from a range of personal use.SOLUTION: A content transmitting device and a content receiving device perform mutual authentication prior to the transmission of the contents. After mutually confirming that they are apparatuses correctly treating the contents by respecting their copyrights, the contents are transmitted by encrypting the contents with shared key data. When authentication is performed, it is configured to measure the duration of time, until arrival of reception acknowledgement data with respect to transmission of an authentication request or an authentication response. Only when the value of the measured duration of time does not exceed a fixed upper-limit value, is the transmission of the contents performed. According to this, illegal copy production by a device, other than the authenticated content receiver due to reception of the contents by the device is prevented, and the contents are also prevented from being transmitted beyond a wide-area network, or the like.

Description

  The present invention relates to a transmission device, a reception device, and a content transmission method suitable for protecting the copyright of content to be transmitted when information such as content such as video and audio is transmitted and received via a network.

With the development of processing capability such as the calculation speed and storage capacity of personal computers (hereinafter referred to as PCs), the capacity of hard disk drives (hereinafter referred to as HDDs) incorporated in PCs is also increasing. Under these circumstances, it is now possible to record TV broadcast programs using a HDD and view them on a PC display even on a PC with a rank that is used in general homes. I came.
On the other hand, due to the low price of large-capacity HDDs, HDD recording devices that incorporate HDDs and record video and audio information digitally as home recording devices have also appeared, and discs are used as recording media. Ease of use due to the use is attracting attention.
In video recorders and PCs that use HDDs such as those described above, video and audio information is recorded on the HDD fixed in the device, so it is likely that the user wants to watch a program recorded in another room in the house. In some cases, it is difficult to carry the video / audio information at the medium level so that the apparatus itself can only be carried and a plurality of recording / playback apparatuses using a replaceable medium such as a VTR can be provided.

  Therefore, by installing a wired or wireless LAN (Local Area Network) interface in such a recording device, and transmitting it to other PCs or receiving devices via the network, video / audio information recorded anywhere in the house can be obtained. It is considered to be able to watch.

On the other hand, in order to protect the copyright of information such as contents, there is a Digital Transmission Content Protection (DTCP) system that defines a copy protection method on, for example, an IEEE 1394 bus as an example of a copy protection method taken into a digital AV device. (Described in [Non-Patent Document 1])
Several techniques for realizing copy protection for copyright protection between devices or between networks are disclosed. For example, it is disclosed in [Patent Document 1] and [Patent Document 2].

JP 2000-287192 A JP 2001-358706 A

Hitachi, Ltd. Others, 5C Digital Transmission Content Protection White Paper

  With the above-described conventional technology, a home recording device is equipped with a wired or wireless LAN (Local Area Network) interface, and the content is transmitted to another PC or receiving device via the network, and recorded anywhere in the house. In the past, video / audio information that should be protected for copyright (hereinafter described as content) is not considered, and is recorded on the HDD. The audio / video information can be further stored in the HDD in another PC received via the LAN, and the audio / video information that can be handled had to be “no copy restrictions” content that can be copied freely. .

In general, when digitally recorded content is recorded by being transmitted from one device to another device via a network or the like as described above, there is little deterioration in data quality at the time of transmission, and there is a transmission side device. Because the receiver can create a copy (duplicate) of the same quality as the content, the video and audio data (hereinafter referred to as “content”) that should be protected by copyright is illegal for content that deviates from the scope of personal use. Care must be taken to prevent copying. For example, when content is transmitted between digital AV devices, encryption is performed on the content transmission device side, and information for decryption is shared with the content reception device side, so that the transmission destination Copy protection is implemented to prevent the creation of unlimited copies by preventing content from being correctly received and decrypted by devices other than a content receiving device.

  As an example of such a copy protection method, a DTCP method described in, for example, [Non-Patent Document 1] is adopted in a digital AV device. In the DTCP method, content is classified and managed as “no copy restriction”, “one-time copy allowed”, and “copy prohibited”, and the recording device records only the content of “no copy restriction” and “one-time copy allowed”, Once the content of “one-time copy is possible” is recorded once, it is treated as “copy not possible”, and on the bus, except for the content of “no copy restriction”, the content is encrypted and transmitted on the transmission side. Unlimited copying of content is prohibited.

  In content transmission by wired or wireless LAN, several techniques for realizing copy protection for copyright protection have been disclosed based on the same concept as the DTCP method. For example, [Patent Document 1] discloses a technique for applying a technique similar to DTCP to a copy protection method for distributing digital contents on a network. A technique for configuring devices that communicate with each other in an encrypted manner for copyright protection is disclosed.

  These do not consider whether the transmitting side and the receiving side are in the same house when transmitting content via a wired or wireless LAN. Rather, when downloading from a distribution server, the sending side is usually at the provider's site and the receiving side is usually in a general home.

  Therefore, even if the above technology is applied to the case where the content is recorded by the HDD of the PC or the recording device with the built-in HDD and transmitted from here to another device in the home via the LAN, When connected to the Internet, the content can be received and displayed by a receiving device placed in another home connected via the Internet, and if the range is connected to the Internet, It will spread everywhere.

  In such a situation, even if copy protection is to be performed using the above-described technology, the recording device user can make the recording device accessible from the Internet, so that the reception with the copy protection described above can be performed. The device can freely receive and display the content, and will deviate greatly from the scope of personal use, which is the original purpose of copyright protection.

  An object of the present invention is to enable copy protection to prevent unauthorized duplication of content during content transmission using a wired or wireless LAN in a home, and to make legitimate viewing and duplication of content. Is to provide a content or information transmitting device, receiving device, and content transmission method that can be limited to the range of personal use.

In order to solve the above problems, in the present invention, in a content transmission apparatus that transmits content via a LAN, network communication processing means that transmits and receives data via the LAN,
Transmission content generating means for supplying content to be transmitted to a content receiving apparatus connected via the LAN to the network communication means;
An authentication unit that receives an authentication request from the content receiving device and determines authentication for the authentication request, and issues an authentication request to the content receiving device;
Encryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and performing encryption processing of content to be transmitted to the content receiving device using the key information;
Timer means for measuring a time until arrival of a reception confirmation from the content receiving apparatus with respect to transmission of an authentication request to the content receiving apparatus or transmission of a response to the authentication request from the content receiving apparatus;
When the measurement result by the timer means exceeds a predetermined value, the content is not sent to the content receiving device.

In addition to this, in the content transmission device described above,
If the measurement result of the time until the reception confirmation from the content receiving device reaches the transmission of the authentication request to the content receiving device measured by the timer means exceeds a predetermined value, the content is The authentication of the receiving device is determined as unsuccessful.

On the other hand, in order to solve the above problem, in the present invention, in a content receiving apparatus that receives content via a LAN,
Network communication processing means for transmitting and receiving data via a network;
Content reception processing means for receiving content received from the content transmission apparatus connected via the network from the network communication means;
When issuing and sending an authentication request to the content transmission device and making an authentication determination for the authentication request received from the content transmission device, an authentication unit;
Decryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and for performing encryption / decryption processing of content received from the content transmitting apparatus using the key information; ,
Timer means for measuring the time until arrival of reception confirmation from the content transmission device with respect to transmission of the authentication request to the content transmission device or transmission of a response to the authentication request from the content transmission device;
When the measurement result by the timer means exceeds a predetermined value, content reception from the content transmission device is not performed.

In addition to this, in the content receiving apparatus described above,
When the measurement result of the time until the reception confirmation from the content transmission device reaches the transmission of the authentication request to the content transmission device measured by the timer means exceeds a predetermined value, The authentication of the transmitting device is determined as unsuccessful.

Furthermore, in order to solve the above-mentioned problem, in the present invention,
In a content transmission method between a content transmission device and a content reception device via a network,
In the content transmission device,
Network communication processing means for transmitting and receiving data via a network;
Transmission content generation means for supplying content to be transmitted to the content receiving device to the network communication means;
An authentication unit that receives an authentication request from the content receiving device and determines authentication for the authentication request, and issues an authentication request to the content receiving device;
Encryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and performing encryption processing of content to be transmitted to the content receiving device using the key information;
Providing a timer means for measuring the time until the reception of the reception confirmation from the content receiving apparatus with respect to the transmission of the authentication request to the content receiving apparatus or the response to the authentication request from the content receiving apparatus;
The content receiving device includes:
Network communication processing means for transmitting and receiving data via a network;
Content reception processing means for receiving content received from the content transmission device from the network communication means;
When issuing and sending an authentication request to the content transmission device and making an authentication determination for the authentication request received from the content transmission device, an authentication unit;
Decryption means for generating key information based on key information generated based on information obtained by executing authentication processing by the authentication means, and performing encryption / decryption processing of content received from the content transmission device using the key information;
Timer means for measuring the time until arrival of reception confirmation from the content transmission device with respect to transmission of the authentication request to the content transmission device or transmission of a response to the authentication request from the content transmission device;
Content from the content transmission device to the content reception device when the measurement result of the timer device of the content transmission device or the measurement result of the timer device of the content reception device exceeds a predetermined value Do not send.

  According to the present invention, it is possible to improve the reliability of a content transmission device, a reception device, and content transmission using a home wired or wireless LAN.

It is a block diagram which shows the structure of the content transmitter which is the 1st Embodiment of this invention, and a content receiver. It is a block diagram of LAN comprised by the content transmitter which is the 1st Embodiment of this invention, and a content receiver. It is a sequence diagram which shows the sign procedure which transmits a content between the content transmitter which is the 1st Embodiment of this invention, and a content receiver. It is a block diagram which shows the structure of the content transmitter which is the 2nd Embodiment of this invention, and a content receiver. It is a block diagram of LAN comprised by the content transmitter which is the 2nd Embodiment of this invention, and a content receiver. It is a block diagram of LAN comprised by the content transmitter which is the 1st and 2nd embodiment of this invention, and a content receiver.

Embodiments of the present invention will be described below.
FIG. 1 shows a configuration of a content transmission device 100 and a content reception device 200 according to an embodiment of the present invention. The content transmission device 100 and the content reception device 200 are connected to each other via a LAN.

  The content transmission apparatus 100 includes a content transmission circuit 101 that transmits content to be transmitted to the content reception apparatus 200 via a LAN, an encryption circuit 102 that encrypts content output from the content transmission circuit 101, an output of the encryption circuit 102, and an authentication circuit A network communication processing circuit 103 for exchanging input / output of 104 with other devices via the LAN, an authentication circuit 104 for exchanging information with other devices connected on the LAN and performing mutual authentication between the devices, A nonvolatile memory 105 that stores information necessary for processing in the authentication circuit 104, a key generation circuit 106 that generates key information necessary for content encryption in the encryption circuit 102 based on information output from the authentication circuit 104, and authentication A counter circuit 107 for measuring and holding the number of times of mutual authentication succeeding in the circuit 104; Information such as authentication request testimony circuit 104 is generated from the transmission to another device consisting of the timer circuit 108 that measures the time until the acknowledgment for the information arrives. The content transmitted by the content transmission circuit 101 is not limited to a specific kind of thing. For example, video and audio data of a program received from a TV broadcast, a recording medium such as a disk or tape such as an HDD or DVD, etc. All kinds of information such as video and audio data being reproduced from can be applied.

In FIG. 1, a tuner for receiving a broadcast, a means for recording / reproducing, a data compression processing circuit required prior to transmission over a network, and the like are omitted in the drawing. These means may be appropriately added to the configuration according to the type of content to be transmitted. The content transmitted from the content transmission circuit 101 is transmitted to the content receiving apparatus with identification codes of “no copy restriction”, “one-time copy permitted”, “copy prohibited” and “copy prohibited” indicating how to handle the content. ,
The content receiving apparatus 200 receives the content received from the network communication processing circuit 203 by receiving the content encrypted by the content receiving circuit 201 for receiving the content sent via the LAN and the encryption circuit 102 of the content transmitting apparatus 100, and receiving the content. Between the decryption circuit 202 that outputs to the circuit 201 and the network communication processing circuit 203 that exchanges the input to the decryption circuit 202 and the input and output of the authentication circuit 204 with other devices via the network Authentication circuit 204 for exchanging information with each other to perform mutual authentication between devices, nonvolatile memory 205 for storing information necessary for processing in authentication circuit 204, content decryption in decryption circuit 202 based on information output from authentication circuit 204 Key generation circuit 206 for generating a key necessary for conversion, authentication circuit 20 Consisting timer circuit 208 that measures the time until the acknowledgment for the information arrives from the from the transmission of the information such as authentication request to another device. The video and audio data that are output from the content receiving circuit 201 are displayed on a display device or recorded on a recording medium such as a disk or a tape, and their use forms are various. The present invention is limited to specific forms. Never happen.

  In FIG. 1, the display, the recording means, and the decompression / restoration means for the received data compression processed content are omitted, but may be added to the configuration as appropriate according to the usage form of the received content. The received content is processed according to the identification codes of “no copy restriction”, “one-time copy allowed”, “copy prohibited”, “no copy” sent with the content, and “no copy restriction” “one-time copy allowed” "Can be recorded on the content recording medium, and when the content of" copy only once "is recorded, the content is treated as" copy not possible "thereafter.

  FIG. 2 shows a configuration example of a LAN including the content transmission device 100 and the content reception device 200. One content transmitting apparatus 100 and two content receiving apparatuses 200a and 200b are connected to the network hub apparatus 400 by a wired LAN cable, and the network hub apparatus 400 is further connected to the router 300. The router 300 is connected to the Internet via a modem or photoelectric converter (not shown) or by a modem or photoelectric converter built in the router.

  The type of connection to the Internet may be any type such as a high-speed access line such as an ADSL (Asymmetric Digital Subscriber line) or an optical fiber, a mobile communication network such as an ISDN (Integrated Services Digital Network), an analog telephone line, or a mobile phone. A dotted line in FIG. 2 indicates a device that transmits and receives content and its direction.

  The LAN configuration in FIG. 2 is merely an example, and three or more content receiving apparatuses 200 may be connected. Two or more content transmission apparatuses may be connected. In this case, different contents can be transmitted simultaneously from the respective content transmission apparatuses to the content reception apparatus as long as the LAN bandwidth permits. Note that the minimum necessary configuration in the present invention is a state in which one content transmitting device and one content receiving device are connected to the LAN.

  In the LAN shown in FIG. 2, standard IP (Internet Protocol) is used as a network protocol, and TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are used as upper transport protocols. A higher-level application protocol such as RTP (Real-time Transport Protocol) or HTTP (Hyper Text Transfer Protocol) is used for content transmission. Note that there are IPv4 and IPv6 as IP versions, but the present invention is not limited to either.

  The content transmitting device 100, the content receiving devices 200a and 200b, and the router 300 each have an IP address that identifies itself on the LAN. In addition, a 48-bit MAC (Media Access Control) address is given in advance to the interface unit of each network communication processing circuit at the time of manufacture. For example, the router 300 is operated as a DHCP server by DHCP (Dynamic Host Configuration Protocol), which has been widely used for automatic address setting in the network, and the IP address of each device is set. Should be allocated. When IPv6 is used, each device can determine its own IP address from the upper 64 bits of the IP address of the router 300 and the MAC address by a method called stateless automatic setting.

FIG. 3 shows an example of a procedure at the time of content transmission / reception by the content transmission device 100 and the content reception device 200. The left side represents the content transmitting apparatus 100, and the right side represents the content receiving apparatus 200. The timing and direction of information transmission / reception between the two are indicated by arrows.
Prior to content transmission, the content transmission device 100 and the content reception device 200 mutually authenticate each other's device, and confirm that the other device is a device that is correctly manufactured in accordance with the copyright protection rules. The content will be transmitted afterwards. TCP is used as a protocol for sending and receiving information for authentication. When various information such as an authentication request to the other device and an authentication response to the other device is sent, a reception confirmation for this is returned from the other device. A communication path capable of detecting a transmission error is secured. In FIG. 3, transmission / reception of data for establishing and discarding a connection by TCP is omitted.

  First, an authentication request is created from the content receiving device 200 side. The authentication request is sent to the content transmitting apparatus 100 with a public key unique to the apparatus generated by a specific authentication authority and held in the nonvolatile memory 205 of the content receiving apparatus 200 and a certificate for the public key. The public key and the certificate are stored in advance in the nonvolatile memory 205 when the content receiving device 200 is manufactured. When the authentication request is received and the reception confirmation is sent to the content receiving apparatus 200, the content transmitting apparatus 100 creates an authentication request from its own side, and the content transmitting apparatus 100 issued by the authentication authority is unique as in the case of the content receiving apparatus. The public key and its certificate are attached and sent to the content receiving apparatus side 200, the timer circuit 108 is started, and the time T1 until the reception confirmation for the authentication request is received from the content receiving apparatus is measured.

  On the other hand, the content transmitting apparatus 100 authenticates the content receiving apparatus 200 based on a predetermined public key signature algorithm. The numerical value of the counter 107 is checked. If the current value exceeds a predetermined value, the authentication is unsuccessful, and if the authentication is successful, the value of the counter 107 is increased by 1. If the measured value T1 measured by the timer 108 exceeds a predetermined value, the authentication is determined to be unsuccessful. If the authentication is successful, an authentication response is issued and transmitted to the content receiving apparatus 200. Similarly, the content receiving apparatus 200 also performs authentication after receiving an authentication request from the content transmitting apparatus 100, and if successful, issues an authentication response and transmits it to the content transmitting apparatus 100. As described above, when authentication is successful, a common authentication key is generated and shared. A well-known key exchange algorithm such as Diffie-Hellman may be used to generate the authentication key.

  When the sharing of the authentication key is completed, the content transmitting apparatus 100 generates an exchange key and a random number, encrypts the exchange key and the random number with the authentication key, and sends the encrypted key and the random number to the content receiving apparatus 200. In FIG. 3, the exchange key and the random number are separately transmitted from the content transmitting apparatus 100 to the content receiving apparatus 200, but they may be transmitted together. The content receiving device 200 decrypts the exchange key transmitted from the content transmitting device 100 using the authentication key, and holds it together with the random number received and decrypted. Subsequently, a common key is generated according to a predetermined calculation algorithm using an exchange key and a random number on each side of the content transmission device 100 and the content reception device 200. The content transmitting apparatus 100 encrypts and transmits the content using the common key thus obtained, and the content receiving apparatus 200 can receive the decrypted content.

  When actually starting the content transmission, for example, as shown in FIG. 3, a content transmission request is sent from the content receiving apparatus 200, and the content is transmitted as a trigger. When the content transmission is completed, the content transmission device 100 may notify the completion of the transmission, or conversely, the content reception device 200 may request the end of the transmission. Further, when the data amount of the content to be transmitted is known in advance, it is not particularly necessary to notify or request transmission completion from either side.

  After all necessary content transmissions are completed, the content transmission apparatus 100 discards the authentication key, exchange key, random number, and common key. When the content reception apparatus 200 completes the reception of the content, the authentication key, the exchange key, the random number, and the common key are discarded, and when trying to receive the content again, a new authentication request may be performed. When the transmitting device 100 is transmitting content to another content receiving device and the previous key can be used again, the content receiving device 200 inquires the content transmitting device 100 about the current key information and then the previous key. May be reused.

  The protocol used for transmitting content from the content transmitting apparatus 100 to the content receiving apparatus 200 is not limited to a specific one, and RTP, HTTP, ftp (File Transfer Protocol), etc. are used as described above. It is possible. When transmitting content, the content encrypted by a predetermined algorithm using a common key in the payload portion of each transfer protocol may be accommodated and transmitted. As an encryption algorithm, for example, M6 encryption adopted in DTCP can be used.

  As described above, since the content encrypted using the common encryption key is transmitted and received between the content transmitting apparatus 100 and the content receiving apparatus 200 shown in FIG. Even if the content is received, it cannot be correctly decrypted, and the content can be prevented from being illegally copied under the user.

  As shown in FIG. 2, it is possible to receive content by two or more content receiving devices at a time. In this case, the contents may be transmitted after mutual authentication is performed between each content receiving apparatus and the content transmitting apparatus according to the procedure shown in FIG. At this time, the number of content receiving devices authenticated by one content transmitting device is counted by the counter 107. Therefore, when the content transmitting device authenticates the content receiving device, the upper limit of the number of content receiving devices is determined. It is possible to limit the number of content copies that can be created using a plurality of content receiving apparatuses at the same time. Regarding the upper limit of the number of content receiving apparatuses, for example, the upper limit of 62 content receiving apparatuses that can be connected at once using IEEE 1394 may be set to a value smaller than that.

  Further, when the content receiving apparatus 200 is placed in another house different from the user's house via the Internet, an authentication request from the content transmitting apparatus and a reception confirmation for the authentication request are sent to the wide area network and the router. Since transmission / reception is performed via 300, the required time for round-trip increases compared with transmission / reception in the home. Therefore, if the upper limit value for determining that the authentication is successful with respect to the measurement result of T1 is set to an appropriate value, such as 10 milliseconds as an example, the range in which content can be transmitted is limited to the user's home. Such restrictions are also possible.

  In addition to adding the above-described measurement result of T1 in FIG. 3 to the determination of authentication in the content transmitting apparatus 100, until the reception confirmation of the content receiving apparatus 200 for the authentication response from the content transmitting apparatus 100 shown in FIG. The time T2 is measured by the timer 108, and if the result exceeds the predetermined value, the content is not transmitted to the content receiving device 200 without transmitting the exchange key and the random number thereafter. You can also Alternatively, when authenticating the content receiving device 200 in the content transmitting device 100, it is determined without taking into account the measurement result of T1, and whether or not to transmit the exchange key and random number based on the measurement results of both T1 and T2 You may make it perform determination of.

Similarly, the content receiving device 200 measures the time T3 until the reception confirmation from the content transmitting device 100 for the authentication request arrives, and if the result exceeds the predetermined value, the content transmitting device. An unsuccessful determination may be made for an authentication request from 100. As a result, it is possible to prevent the content receiving apparatus 200 from receiving the content from outside the house, and it is possible to prevent the transmission of content exceeding the range of personal use of the content.
Alternatively, the T3 measurement result in the content receiving device 200 is included and sent back at the time of transmitting an authentication response to the authentication request from the content transmitting device 100, and used to determine whether or not to transmit the content on the content transmitting device side. You can also.

  Furthermore, when sending a TCP packet when sending an authentication request and an authentication response to the result, the lifetime of the IP packet sent by storing a TCP packet or UDP datagram for transmitting content (TTL, Time To Live) may be transmitted at a low value such as 3 or less, and the authentication request may not pass through the router 300 so that content transmission does not exceed the range of personal use.

  FIG. 4 shows the configuration of a content transmission device 500 and a content reception device 600 according to the second embodiment of the present invention. The content transmission device 500 and the content reception device 600 shown in FIG. 4 are different from the content transmission device 100 and the content reception device 200 in FIG. 1 in that content is transmitted using a wireless LAN. The wireless network communication processing circuits 503 and 603 are used, and WEP (Wired Equivalent Privacy) encryption processing circuits 509 and 609 are provided. WEP is a well-known encryption method that is used as a standard for the purpose of security protection in a wireless LAN, and communication with security protection between a transmission device and a reception device can be realized under the control of a user. .

  FIG. 5 shows an example of the configuration of a home network using the content transmission device 500 and the content reception device 600 shown in FIG. In FIG. 5, a data transmission device 500 and two data reception devices 600 a and 600 b are connected by a wireless access point 700 via a wireless LAN. The wireless LAN access point 700 is further connected to the router 300, and the router 300 is connected to the Internet in the same manner as the router 300 shown in FIG.

  When mutual authentication and subsequent content transmission are to be performed between the content transmitting apparatus 500 and the content receiving apparatus 600 shown in FIG. 4, the WEP processing is performed in the WEP encryption processing circuits 509 and 609 by the authentication circuits 504 and 604. Check whether it has been applied. If the WEP process is not used, mutual authentication and subsequent content transmission are not performed, or a necessary process such as a display prompting the user to start the WEP process is performed. To do. As described above, when content is transmitted using a wireless LAN, the WEP process is always performed. As a result, it is possible to prevent unauthorized copying of content by connecting another data receiving device via a wireless LAN without the user of the content transmitting device 500 and the content receiving device 600 being conscious.

  Regarding points other than those described above, the content transmission method and the content transmission method implemented by the content transmission device and the content reception device according to the first embodiment of the present invention shown in FIGS. It is possible to protect the copyright by preventing the creation of unauthorized copies, and at this time, it is possible to prevent the transmission of content that deviates from the range of personal use.

  In the embodiment of the present invention described above, the case of using a wired LAN and the case of using a wireless LAN have been described separately. However, it is also possible to construct a home LAN using these simultaneously. In particular, the present invention can be applied. FIG. 6 shows a configuration when the content transmitting apparatus and the content receiving apparatus according to the embodiment of the present invention are used in a LAN configured by using both wired and wireless.

  In FIG. 6, the content transmission device 100 and the content reception devices 200 a and 200 b are connected to each other via the network hub device 400, and the wireless access point 700 is also connected to the network hub device 400. The wireless access point 700 is connected to a content transmission device 500 and content reception devices 600a and 600b by a wireless LAN. Further, the network hub device 400 is connected to the router 300, whereby the home LAN is connected to the Internet.

  In FIG. 6, the dotted line of the thin arrow indicates the content transmission direction, and each content transmission device and content reception device indicates whether the other party is connected by a wired LAN or a wireless LAN. Content can be transmitted between each other without being conscious. The transmission procedure at that time may be exactly the same as that described with reference to FIG. Further, in the content transmitting device 500 and the content receiving devices 600a and 600b using the wireless LAN, it is only necessary to check the operation of WEP and perform mutual authentication and content transmission in the same manner as described above. Even in this case, as in the case where a wired or wireless LAN is configured alone, it is possible to prevent the creation of unauthorized duplication during content transmission, and to limit content transmission to the range of personal use.

  In the above description, the target to be transmitted via the network has been described as content such as video information. However, the same applies to other types of information other than video information, and the information transmission apparatus and information reception apparatus that handle such information are also the same. The present invention can be implemented.

  In the embodiment of the present invention described above, the authentication circuit, key generation circuit, encryption circuit, decryption circuit, counter circuit, timer circuit, etc. are not limited to hardware implementation, A part or all of the above may be realized by a microprocessor and a software process executed on the microprocessor, and there is no difference in exerting the effect of the present invention.

  For the convenience of the description so far, the content transmission device and the content reception device are separated, but in a device that records and reproduces content on a recording medium such as a disk or a tape, the content transmission device and the content reception device In this case, an authentication circuit, a non-volatile memory, or the like can be shared.

As described above, according to the present invention, when content is transmitted using a wired or wireless LAN in the house, copy protection that prevents unauthorized duplication of the content can be performed, and the content can be viewed and viewed properly. It is possible to provide a content transmission device, a reception device, and a content transmission method capable of limiting the creation of a copy to the range of personal use.

100, 500 ··· Content transmission devices 101, 501 ... Content transmission circuits 102, 502 ... Encryption circuits 103, 503 ... Network communication processing circuits 104, 504 ... Authentication circuits 106, 506 ... Key generation circuits 107, 507 ... counter circuits 108, 508 ... timer circuits 200, 600 ... content reception devices 201, 601 ... content reception circuits 202, 602 ... decryption circuits 204, 604 ..Authentication circuits 206, 606, key generation circuits 208, 608, timer circuits

Claims (12)

Network communication processing means for transmitting and receiving data via a network;
Transmission content generation means for supplying the network communication means with content to be transmitted to a content reception device connected via the network;
An authentication unit that receives an authentication request from the content receiving device and determines authentication for the authentication request, and issues an authentication request to the content receiving device;
Encryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and performing encryption processing of content to be transmitted to the content receiving device using the key information;
Timer means for measuring the time until the reception of the reception confirmation from the content receiving device with respect to the transmission of the authentication request to the content receiving device or the transmission of the response to the authentication request from the content receiving device;
A content transmitting apparatus, wherein content transmission to the content receiving apparatus is not performed when a measurement result by the timer means exceeds a predetermined value.   If the measurement result of the time until the reception confirmation from the content receiving device reaches the transmission of the authentication request to the content receiving device measured by the timer means exceeds a predetermined value, the content is The content transmitting apparatus according to claim 1, wherein authentication of the receiving apparatus is determined to be unsuccessful. When content is transmitted to a content receiving device connected via a network, the authentication request from the content receiving device is received and authentication of the authentication request is determined, and the content receiving device is authenticated itself An authentication means issuing the request;
Timer means for measuring the time until the reception confirmation from the content receiving device with respect to the transmission of the authentication request to the content receiving device,
A content transmitting apparatus, wherein content transmission to the content receiving apparatus is not performed when a measurement result by the timer means exceeds a predetermined value. When content is transmitted to a content receiving device connected via a network, the authentication request from the content receiving device is received and authentication of the authentication request is determined, and the content receiving device is authenticated itself An authentication means issuing the request;
Timer means for measuring a time until arrival of a reception confirmation from the content receiving device with respect to transmission of a response to the authentication request from the content receiving device;
A content transmitting apparatus, wherein content transmission to the content receiving apparatus is not performed when a measurement result by the timer means exceeds a predetermined value. Network communication processing means for transmitting and receiving data via a network;
Content reception processing means for receiving content received from the content transmission apparatus connected via the network from the network communication means;
An authentication unit that issues and sends an authentication request to the content transmission device and performs authentication determination on the authentication request received from the content transmission device;
Decryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and for performing encryption / decryption processing of content received from the content transmitting apparatus using the key information; ,
Timer means for measuring a time until arrival of a reception confirmation from the content transmission device with respect to transmission of an authentication request to the content transmission device or transmission of a response to the authentication request from the content transmission device;
A content receiving apparatus, wherein content reception from the content transmission apparatus is not performed when a measurement result by the timer means exceeds a predetermined value.   When the measurement result of the time until the reception confirmation from the content transmission device reaches the transmission of the authentication request to the content transmission device measured by the timer means exceeds a predetermined value, 6. The content receiving apparatus according to claim 5, wherein authentication of the transmitting apparatus is determined as unsuccessful. A content transmission method between a content transmission device and a content reception device connected via a network,
The content transmitting apparatus
An authentication step for receiving an authentication request from the content receiving device and determining authentication for the authentication request, and issuing an authentication request for the content receiving device;
An encryption step of generating key information from key information generated based on information obtained by executing authentication processing, and performing encryption processing of content to be transmitted to the content receiving device using the key information;
Measuring the time until arrival of a reception confirmation from the content receiving device with respect to transmission of an authentication request to the content receiving device or transmission of a response to the authentication request from the content receiving device,
The content receiving device issues and sends an authentication request to the content transmitting device, and performs an authentication step for determining authentication for the authentication request received from the content transmitting device;
A decryption step of generating key information from key information generated based on information obtained by executing authentication processing, and performing encryption / decryption processing of content received from the content transmission device using the key information;
Measuring the time until the arrival of the reception confirmation from the content transmission device with respect to the transmission of the authentication request to the content transmission device or the transmission of the response to the authentication request from the content transmission device,
A content transmission method, wherein content transmission from the content transmission device to the content reception device is not performed when the measurement result of the content transmission device or the measurement result of the content reception device exceeds a predetermined value . A content transmission method in a content transmission device for transmitting content to a content reception device connected via a network,
An authentication step of receiving an authentication request from the content receiving device and determining authentication for the authentication request when transmitting content, and issuing an authentication request to the content receiving device;
Measuring a time until arrival of reception confirmation from the content receiving apparatus with respect to transmission of an authentication request to the content receiving apparatus,
A content transmission method in a content transmission device, wherein content transmission to the content reception device is not performed when the measurement result exceeds a predetermined value. A content transmission method in a content transmission device for transmitting content to a content reception device connected via a network,
An authentication step of receiving an authentication request from the content receiving device and determining authentication for the authentication request when transmitting content, and issuing an authentication request to the content receiving device;
Measuring a time until reception of a reception confirmation from the content receiving device with respect to transmission of a response to the authentication request from the content receiving device,
A content transmission method in a content transmission device, wherein content transmission to the content reception device is not performed when the measurement result exceeds a predetermined value. When transmitting information to an information receiving apparatus connected via a network, the authentication request from the information receiving apparatus is received and authentication of the authentication request is determined, and the authentication of the information receiving apparatus is performed. An authentication means issuing the request;
A time measuring means for measuring a time until arrival of reception confirmation from the information receiving apparatus with respect to transmission of an authentication request to the information receiving apparatus;
An information transmitting apparatus characterized by not transmitting information to the information receiving apparatus when a measurement result by the time measuring means exceeds a predetermined value. When transmitting information to an information receiving apparatus connected via a network, the authentication request from the information receiving apparatus is received and authentication of the authentication request is determined, and the authentication of the information receiving apparatus is performed. An authentication means issuing the request;
Time measuring means for measuring a time until arrival of reception confirmation from the information receiving apparatus with respect to transmission of a response to the authentication request from the information receiving apparatus;
An information transmitting apparatus characterized by not transmitting information to the information receiving apparatus when a measurement result by the time measuring means exceeds a predetermined value. Network communication processing means for transmitting and receiving data via a network;
Information receiving processing means for receiving from the network communication means information received from an information transmitting apparatus connected via the network;
An authentication unit that issues and sends an authentication request to the information transmission device, and performs authentication determination for the authentication request received from the information transmission device;
Decryption means for generating key information from key information generated based on information obtained by executing authentication processing by the authentication means, and for performing encryption / decryption processing of information received from the information transmitting apparatus using the key information; ,
A time measuring means for measuring a time until arrival of a reception confirmation from the information transmission apparatus with respect to transmission of an authentication request to the information transmission apparatus or transmission of a response to the authentication request from the information transmission apparatus;
An information receiving apparatus characterized by not receiving information from the information transmitting apparatus when the measurement result of the time measuring means exceeds a predetermined value.

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