JP2004151778A - Content sending device, content receiving device, and content sending/receiving system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure that equipment sending and receiving content data for copyright protection can be identified. <P>SOLUTION: This content sending/receiving system includes a local-area wireless network 2 to which a content sending device (source device) 1 with the function of reproducing the contents of a DVD player or the like and the function of delivering the contents belongs; and a local-area wireless network 5 to which content receiving devices (sink devices) 3, 4 receiving the contents belong. A combined ID obtained by combining the device ID of each sink device with a MAC address is registered in an ID management part of the source device, and the contents requested to be sent are sent from the source device to the sink devices only when the combined ID of the sink device requesting the sending of the contents matches the one registered in the ID management part. Thus, the copyright of the contents is protected to prevent illicit use of the contents. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a content transmitting apparatus, a content receiving apparatus, and a content transmitting / receiving system for transmitting / receiving various contents including contents to be protected by copyright.
[0002]
[Prior art]
In recent years, with the spread of devices having digital input / output functions, such as televisions, videos, and PCs, digital contents such as movies, music, and documents can be easily handled.
[0003]
One thing to consider here is copyright protection. Since digital data can be copied without deteriorating the quality, illegal copying ignoring the copyright of the content has become a problem. For this reason, standards such as IEEE 1394 used when connecting digital devices require a function to authenticate a valid device, perform data encryption on a communication path, and exclude a device capable of illegal copying. (See Patent Document 1).
[0004]
[Patent Document 1]
JP 2001-285284 A
[0005]
[Problems to be solved by the invention]
In the prior art, once the device authentication in the copyright protection layer succeeds, the device on the content transmission side transmits the content to the device on the content reception side. There is a problem that it cannot be identified.
[0006]
This is a particular problem when the content transmission device counts the number of distribution destinations. For example, when it is necessary to set transmission restrictions so that the content transmitting device permits transmission only to registered receiving devices, the individual devices must be identified. This device identification is particularly problematic in wireless communications.
[0007]
In order to transmit and receive contents by wire, devices need to be connected by a physical cable, and a user can naturally limit the connection by connecting the devices to be connected by a cable.
[0008]
However, when devices are connected wirelessly, if the devices are successfully authenticated by the copyright protection layer as valid devices, not only the will of the owner of the content transmission device but also the content transmission device in principle It is connected to the device and can receive content.
[0009]
For this reason, it is desirable to eliminate unauthorized devices and to enable the content transmission device to identify the device to which the content is to be distributed, even if the device is legitimate.
[0010]
The present invention has been made in view of such a point, and an object of the present invention is to provide a content transmitting apparatus, a content receiving apparatus, and a content transmitting / receiving system capable of reliably identifying a device that transmits / receives content data whose copyright should be protected. Is to provide.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problem, the present invention provides a content transmitting apparatus for transmitting content requiring copyright protection to one or more receiving apparatuses via a network, comprising: Authentication / key exchange processing means for performing exchange processing; identification information registration means for registering the identification information while managing the number of unique identification information for identifying the receiving device not to exceed a predetermined number; Only when the identification information of the receiving device that has made the request is registered in the identification information registering device, transmission control means for permitting content transmission to the receiving device, Encryption processing means for encrypting using the key exchanged by the key exchange processing means, packet generation means for generating a packet corresponding to the encrypted content, It has a network interface unit for transmitting the serial generated packet to the receiving device.
[0012]
Also, the present invention provides a content receiving apparatus for receiving content requiring copyright protection from a transmitting apparatus via a network, wherein the authentication / key exchange processing means for performing authentication / key exchange processing with the transmitting apparatus. And identification information registering means for registering the identification information while managing the number of unique identification information for identifying the transmission device so as not to exceed a predetermined number; and wherein the identification information of the transmission device is the identification information registration means. And transmission control means for permitting the transmission of the content to the own device only when registered in the device.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a content transmission device, a content reception device, and a content transmission / reception system according to the present invention will be specifically described with reference to the drawings.
[0014]
(1st Embodiment)
FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of a content transmitting / receiving system according to the present invention. The content transmission / reception system shown in FIG. 1 includes a local area wireless network 2 to which a content transmission device (hereinafter, referred to as a source device) 1 having a content reproduction function and a content distribution function, such as a DVD player, belongs, and a content reception device ( The local area wireless network 5 to which the sink devices 3 and 4 belong.
[0015]
The local area wireless network 2 includes wireless devices 6 and 7 in addition to the source device 1, and the source device 1 and the wireless device 6 or the source device 1 and the wireless device 7 can communicate with each other on a one-to-one basis. It is.
[0016]
A wireless base station 8 belongs to the local area wireless network 5 in addition to the sink devices 3 and 4, and the sink devices 3 and 4 communicate with each other via the wireless base station 8.
[0017]
As shown in FIG. 1, the source device 1 and the sink devices 3 and 4 may belong to one local area wireless network without providing a plurality of local area wireless networks 2 and 5.
[0018]
In FIG. 1, it is assumed that the source device 1 and the sink devices 3 and 4 perform direct wireless communication with the wireless base station 8 respectively, but the source device 1 and the sink devices 3 and 4 do not have a wireless communication function, Although a bridge device (not shown) connected by wire to the source device 1 and the sink devices 3 and 4 performs wireless communication with the wireless base station 8 or the source device 1 and the sink devices 3 and 4 have a wireless communication function, The present invention is also applicable when performing wireless communication with the wireless base station 8 via a bridge device.
[0019]
Here, the contents refer to, for example, moving image data and audio data such as MPEG4 data, and the contents to be transferred after copyright protection are considered.
[0020]
In this specification, the description will be made assuming that the local area wireless networks 2 and 5 are IEEE802.11. IEEE 802.11 is a kind of wireless LAN, and is currently mounted on many PCs, and is expected to be mounted on various AV devices in the future (for example, http://www.ieee802.org/). The details are described in the document disclosed to be obtainable at No. 11.) In addition, the notation of 802.11 used below is short for IEEE 802.11.
[0021]
Hereinafter, a case where the source device 1 transmits contents to the sink devices 3 and 4 will be considered.
[0022]
FIG. 2 is a block diagram showing an example of the internal configuration of the sink devices 3 and 4. The sink devices 3 and 4 in FIG. 2 include a network interface unit 11 that performs 802.11 physical layer processing, a communication processing unit 12 that performs 802.11 data link layer processing, and a DTCP device ID of the sink devices 3 and 4. A device ID recording unit 13 for recording a device-specific value, a device ID transmission unit 15 for transmitting the acquired device ID, and a DTCP authentication / key for copyright protection. An authentication / key exchange processing unit 16 for performing exchange processing; an encryption processing unit 17 for encrypting / decrypting data to be transmitted; and an 802.11 packet received from the wireless base station 8 or the source device 1 for transmitting content data or DTCP management data. A packet processing unit 18 for converting the packet into a packet, and a content for outputting and storing the packet on a display device or the like. And a processing unit 19.
[0023]
The device-specific value obtained by the device-specific ID obtaining unit 14 is, for example, a MAC address of a network interface managed by a network device manufacturing vendor, assigned a unique value for each device, and physically recorded in the device. And so on. For example, there are an Ethernet MAC address, a node_vendor_id, a chip_id defined by IEEE 1394, or a value obtained by combining them. In this specification, an example in which the Ethernet MAC address is acquired will be described.
[0024]
Here, the DTCP is an abbreviation of Digital Transmission Content Protection, and is a copyright protection system which is a de facto standard in IEEE 1394, USB and the like. A mechanism is provided for performing authentication and key exchange between a transmitting device and a receiving device for content such as AV data that requires copyright protection, and encrypting and transferring the AV data (for example, http: // www. The details are described in a document disclosed to be obtainable at .dtla.com).
[0025]
FIG. 3 is a block diagram illustrating an example of an internal configuration of the source device 1. The source device 1 in FIG. 3 includes a network interface unit 21 that executes an 802.11 physical layer process, a communication processing unit 22 that executes an 802.11 data link layer process, and a DTCP that records a DTCP device ID of the source device 1. A device ID recording unit 23, an ID processing unit 24 for processing the DTCP device ID and the MAC address transmitted from the sink devices 3 and 4, and recording two values as an ID list or receiving from the sink devices 3 and 4 An ID management unit 25 that performs a comparison process between the obtained ID and a value recorded in the ID list, an authentication / key exchange processing unit 26 that performs a DTCP authentication / key exchange process for achieving copyright protection, An encryption processing unit 27 for encrypting / decrypting, and content data and DTCP management data to be transmitted to the wireless base station 8 and the sink devices 3 and 4. Having a packet processing unit 28 for converting the data into 802.11 packets, and a content supply unit 29 supplies the source device 1 stores the content.
[0026]
FIG. 4 is a diagram showing an example of a specific configuration of the ID list. The ID list is a table in which information on a finite number of sink devices 3 and 4 is recorded, and includes an indispensable item and an optional item. Essential items are a device ID and a MAC address. Although FIG. 4 shows the device ID as "AA" and the unique ID as "XX", the device ID and the unique ID may be described successively as "AAXX".
[0027]
In the option item of FIG. 4, additional information regarding the connected sink devices 3 and 4 is described. FIG. 4 shows an example in which a connection start date, an ID recording date, a current connection status, and the like are described. Note that the option item is not always indispensable in the ID list.
[0028]
FIG. 5 is a diagram illustrating an example of a processing procedure of the sink devices 3 and 4. First, the sink devices 3 and 4 that receive the content perform DTCP authentication and key exchange processing with the source device 1 (step S1). When the authentication is successful, the device unique value (here, the MAC address) acquired from the device unique ID acquisition unit 14 and the device ID acquired from the DTCP device ID recording unit 13 are transmitted to the source device 1 via the packet processing unit 18. (Step S2), and then acquires the content from the source device 1 (step S3).
[0029]
On the other hand, if the authentication fails, a predetermined error process is performed (step S4). Since the device ID is also transmitted to the source device 1 in the DTCP authentication / key exchange process, if the device ID received at this time is stored in the source device 1, only the MAC address needs to be transmitted here.
[0030]
FIG. 6 is a diagram illustrating an example of a processing procedure of the source device 1. As shown in the figure, the source device 1 transmitting the content performs DTCP authentication / key exchange processing with the sink devices 3 and 4 (step S11). If the authentication fails, a predetermined error process is performed (step S12). In this case, the content transmission processing is stopped.
[0031]
If the authentication is successful, the device ID and the device-specific value (here, the MAC address) are obtained from the sink devices 3 and 4 (step S13).
[0032]
Next, it is checked whether the acquired device ID and MAC address are already registered in the ID list of the device ID recording unit 23 (Step S14). If not registered, the acquired device ID and MAC address are registered in the ID list (step S15).
[0033]
In the case where the content has already been registered, such as when there are two or more connection requests from the same device, or when the registration process has been performed, the content is transmitted (step S16). If the device ID is stored during the DTCP authentication / key exchange processing, the stored device ID and a newly received device-specific value (here, the MAC address) may be used.
[0034]
When the content transmission process is completed (step S17), a connection connection process is performed (step S18).
[0035]
FIG. 7 is a diagram showing an example of an ID processing procedure in which the processing procedures of the source device 1 and the sink devices 3 and 4 are summarized.
[0036]
After the sink device issues a content transmission request to the source device 1 (step S21), the DTCP authentication / key exchange process is performed (step S22). If the authentication / key exchange processing is successful, the source device 1 transmits the content to the sink device that has issued the content transmission request (step S23). Note that the processing order of steps S22 and S23 may be reversed.
[0037]
Next, the sink device that has made the content transmission request transmits its own device ID and MAC address to the source device 1 (step S24), and the source device 1 registers the device ID and MAC address of the sink device in the ID list. (Step S25).
[0038]
Next, when the sink device issues a content reception stop request to the source device 1 (step S26), the source device 1 stops transmitting the content (step S27).
[0039]
According to the above processing, the source device 1 can identify the destination sink devices 3 and 4 and can transmit the content only to the registered sink devices 3 and 4, and the number of the registerable sink devices 3 and 4 is within a certain number. Can be restricted to
[0040]
What is important here is that the device can be identified by using the device ID and the MAC address. The device ID is not always a unique value. For this reason, as shown in FIG. 4, when there is a device having the same device ID “AA”, the device cannot be identified only by the device ID. Therefore, by using both the device ID and the device-specific ID (here, the MAC address), the device is a legitimate device, and a unique device can be specified.
[0041]
When the value can be added to the ID list but cannot be rewritten, for example, when the ID list is recorded in a non-rewritable memory, the registered sink devices 3 and 4 are not deleted, so the number of registered devices is limited. If there is, there is no possibility that a new sink device will be temporarily registered.
[0042]
The ID list counts the number of sink devices 3 and 4 to which the “connection state” of the option item is connected, and if necessary, limits the number of sink devices 3 and 4 to which the source device 1 can be connected at the same time. It becomes possible.
[0043]
In the above description, the MAC address that guarantees a unique value in the network layer is used as the device-specific ID to identify the device. However, in order to indicate that the device is unique, in addition to the MAC address, for example, (1) ID uniquely assigned to CPU, (2) value obtained by combining MAC address and (1), (3) value output from random number generator with (1) and (2) as initial values, etc. May be used.
[0044]
However, using the MAC address of the network interface is particularly effective when confirming the distribution destination of the copyright-protected content and limiting the distribution range. An example is shown below.
[0045]
FIG. 8 is a detailed flowchart of the content transmission processing procedure by the source device 1 shown in step S16 of FIG. As shown in the figure, in the process of transmitting the content, a MAC address is obtained from the combined ID (a combination of the device ID and the MAC address) transmitted from the sink devices 3 and 4 (step S31), and the MAC address is obtained. Is compared with the MAC address of the ID management unit 25 corresponding to the destination address (for example, IP address) (step S32). As a means for obtaining the IP address of the sink device from the MAC address or obtaining the MAC address from the IP address, for example, ARP or RARP may be used. For ARP and RARP, see http: // www. ief. It is described in detail in documents available at org. The content is transmitted only when these values match (step S33), and the content is not transmitted when these values do not match (step S34).
[0046]
The content may be directly transmitted to the MAC address acquired from the combined ID without performing the comparison process in step S32. As a result, even if the sink devices 3 and 4 transmit the combined ID with the false MAC address, the content is not transmitted to the sink devices 3 and 4 with the false MAC address. Therefore, it is possible to prevent distribution of contents to the illegal sink devices 3 and 4 that falsify the MAC address.
[0047]
As described above, in the first embodiment, the combination ID obtained by combining the device ID and the MAC address of the sink device is registered in the ID management unit 25 of the source device, and the combination ID of the sink device that has issued the content transmission request is registered. Only when the ID matches the one registered in the ID management unit 25, the requested content is transmitted from the source device to the sink device, so that the copyright of the content can be protected and the illegal use of the content can be ensured. Can be prevented.
[0048]
(Second embodiment)
In the first embodiment, an example in which the source device 1 individually registers device-specific values such as a device ID and a MAC address in an ID list has been described. However, in a second embodiment described below, a device ID and A value converted by a predetermined function using the MAC address as a parameter is registered in the ID list.
[0049]
The following mainly describes differences from the first embodiment. FIG. 9 is a block diagram showing the internal configuration of the second embodiment of the sink devices 3 and 4 according to the present invention. The sink devices 3 and 4 in FIG. 9 include an ID coupling unit 20 that converts a device ID and a device-specific value into another value using a predetermined function, as compared with the sink devices 3 and 4 in FIG. (The converted value is hereinafter referred to as a combination ID).
[0050]
The internal configuration of the source device 1 is the same as in FIG. However, the difference is that the ID processing unit 24 passes the combined ID value obtained by combining the device ID and the MAC address to the ID management unit 25 without discriminating between the device ID and the device-specific value (for example, the MAC address). .
[0051]
FIG. 10 is a diagram showing a configuration of the second embodiment of the ID list. Unlike the ID list of FIG. 4, the essential item in the ID list of FIG. 10 is only the value of the combination ID.
[0052]
FIG. 11 is a diagram illustrating a processing procedure of the sink devices 3 and 4 according to the second embodiment. The processing when the DTCP authentication with the source device 1 succeeds is different from the processing in FIG. When the DTCP authentication / key exchange is successful (step S1), the device unique value (here, the MAC address) from the device unique ID acquisition unit 14 and the device ID from the DTCP device ID recording unit 23 are acquired. Then, a combined ID is generated (step S5), and the combined ID is transmitted to the source device 1 through the packet processing unit 18 (step S6).
[0053]
At this time, a signature may be added and transmitted to indicate that the binding ID has not been tampered with. A well-known method such as ISO / IEC14888 may be used for the signature. In the DTCP authentication / key exchange process, a process is performed to add a signature to the device ID to indicate that the sink devices 3 and 4 are not unauthorized devices and to transmit the signature to the source device 1. May be used instead of the combination ID. In such a case, it is possible to omit the process of generating the combined ID performed after the DTCP authentication / key exchange process.
[0054]
FIG. 12 is a diagram illustrating a processing procedure of the source device 1 according to the second embodiment. As shown in FIG. 12, the source device 1 transmitting the content performs DTCP authentication / key exchange processing with the sink devices 3 and 4 (step S11). If the authentication is successful, a combined ID is obtained from the sink devices 3 and 4 (step S41).
[0055]
Next, it is checked whether the acquired combined ID is already registered in the ID list of the ID recording unit 23 (Step S42). If not registered, the combined ID is registered in the ID list (step S43).
[0056]
If the connection ID has already been registered, such as when two or more connection requests have been made from the same device, or if registration processing of the connection ID has been performed, the content is transmitted (step S16). At this time, if a signature is given to the combined ID received from the source device 1, the signature may be verified. If the combined ID is used instead of the device ID during the DTCP authentication / key exchange processing, the registration processing of the combined ID may be performed during the authentication / key exchange processing.
[0057]
FIG. 13 is a diagram showing an example of an ID processing procedure in which the processing procedures of the source device 1 and the sink devices 3 and 4 are summarized. After the source device 1 transmits the content (step S23), the sink device generates a connection ID (step S51), and transmits the generated connection ID to the source device 1 (step S52). The source device 1 registers the transmitted combination ID in the ID list (Step S53).
[0058]
As described above, in the second embodiment, the ID management unit 25 does not write the device ID and the device-specific value together in the ID list, but registers only the combined ID obtained from those two values in the ID list. As a result, the table length of the ID list can be shortened, and the number of sink devices 3 and 4 registered when using the same capacity of memory can be increased as compared with the first embodiment. The memory capacity can be reduced.
[0059]
Further, for example, if a combined ID is obtained from the device ID and the device-specific ID using a one-way function, devices other than the sink devices 3 and 4 cannot easily guess the device ID and the device-specific ID. Confidentiality of the combined ID can be improved.
[0060]
(Third embodiment)
In the first and second embodiments, a unique ID recorded on a physical device such as a MAC address is used as a device-specific value. In the third embodiment, this unique ID is a logical address uniquely determined for each connection.
[0061]
Here, the logical ID indicates, for example, an IP address of TCP / IP or a node ID defined by IEEE1212. Here, the IEEE 1212 is an addressing scheme adopted in IEEE 1394.
[0062]
For example, when a fixed IP address is assigned to a device by an ISP or the like that manages a network, the logical address is guaranteed to be a unique value for the managed segment, and in general, communication is performed. Since the IP address does not change during the process, the purpose of the source device 1 identifying the sink devices 3 and 4 is achieved.
[0063]
The logical address may change for each connection or segment. For example, when the IP addresses of the sink devices 3 and 4 are assigned by DHCP (Dynamic Host Configuration Protocol), an IP address that is not currently used is selected from the IP addresses distributed from the DHCP server on the segment. . Of course, different segments have different lists of IP addresses to be distributed. However, for the same reason, during communication, the purpose of the source device 1 uniquely identifying the sink devices 3 and 4 is achieved.
[0064]
As described above, in the third embodiment, since a logical value is used as a device-specific value, a device can be specified without depending on a network layer to which the device is connected. For example, if TCP / IP is used as the communication protocol, the IP address can be used as the unique ID regardless of whether the communication physical layer is IEEE1394 or Ethernet. Further, since the process of acquiring the MAC address from the network interface unit 11 becomes unnecessary, the configuration of the device can be simplified.
[0065]
(Fourth embodiment)
In each of the embodiments described above, an example in which the identification information is compared inside the source device 1 has been described, but the identification information may be compared inside the sink device. The internal configurations of the sink device and the source device in this case are represented by block diagrams as shown in FIGS. 14 and 15, respectively.
[0066]
The sink device in FIG. 14 processes the DTCP device ID and the MAC address transmitted from the source device 1, and records the DTCP device ID and the MAC address as an ID list, or transmits the DTCP device ID and the MAC address from the source device 1. An ID management unit 32 for comparing the DTCP device ID and the MAC address with values registered in the ID list.
[0067]
The source device in FIG. 15 includes a device unique ID acquisition unit 33 that acquires a unique value of the own device, and a device ID transmission unit 34 that transmits the acquired device ID.
[0068]
As shown in FIGS. 14 and 15, even when the sink device compares the device ID and the MAC address, the content requested to be transmitted can be transmitted from the source device to the sink device only when the comparison result matches. Copyright protection.
[0069]
【The invention's effect】
As described above in detail, according to the present invention, only when the identification information of the receiving device that has made the content transmission request is registered in the identification information registration unit, the content transmission to the receiving device is permitted. The content can be provided only to the receiving device that has received the content, and copyright of the content can be protected.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of a first embodiment of a content transmission / reception system according to the present invention.
FIG. 2 is a block diagram showing an example of an internal configuration of the sink device.
FIG. 3 is a block diagram showing an example of an internal configuration of a source device.
FIG. 4 is a diagram showing an example of a specific configuration of an ID list.
FIG. 5 is a diagram showing an example of a processing procedure of the sink device.
FIG. 6 is a diagram showing an example of a processing procedure of the source device.
FIG. 7 is a diagram showing an example of an ID processing procedure that summarizes the processing procedures of the source device and the sink device.
FIG. 8 is a detailed flowchart of a content transmission processing procedure by the source device shown in step S16 of FIG. 6;
FIG. 9 is a block diagram showing the internal configuration of a sink device according to a second embodiment of the present invention.
FIG. 10 is a diagram illustrating a configuration of an ID list according to a second embodiment.
FIG. 11 is a view showing a processing procedure of a sink device according to a second embodiment.
FIG. 12 is a view showing a processing procedure of a second embodiment of the source device.
FIG. 13 is a diagram showing an example of an ID processing procedure that summarizes the processing procedures of the source device and the sink device.
FIG. 14 is a block diagram showing a schematic configuration of a fourth embodiment of a sink device.
FIG. 15 is a block diagram showing a schematic configuration of a fourth embodiment of the source device.
[Explanation of symbols]
1 Source equipment
2 Local area wireless network M
3 sink device A
4 sink device B
5 Local area wireless network L
6 Wireless device C
7 Wireless device D
8 wireless base stations
11 Network interface
12 Communication processing unit
13 DTCP device ID recording unit
14 Device unique ID acquisition unit
15 Device ID transmission unit
16 Authentication / key exchange processing unit
17 Cryptographic processing unit
18 Packet processing unit
19 Content processing unit
21 Network interface
22 Communication processing unit
23 DTCP device ID recording unit
24 ID processing unit
25 ID Management Department
26 Authentication / key exchange processing unit
27 Cryptographic processing unit
28 Packet processing unit
29 Content Supply Department

Claims (8)

In a content transmitting apparatus for transmitting content requiring copyright protection to one or more receiving apparatuses via a network,
Authentication / key exchange processing means for performing authentication / key exchange processing with the receiving device;
Identification information registration means for registering the identification information while managing the number of unique identification information for identifying the receiving device not to exceed a predetermined number;
Only when the identification information of the receiving device that has made the content transmission request is registered in the identification information registering device, transmission control means for permitting content transmission to the receiving device,
Encryption processing means for encrypting the content requested to be transmitted using the key exchanged by the authentication / key exchange processing means;
Packet generating means for generating a packet corresponding to the encrypted content;
And a network interface unit for transmitting the generated packet to the receiving device. 2. The content transmitting apparatus according to claim 1, wherein the network interface transmits the content wirelessly. 3. The device according to claim 1, wherein the identification information registration unit individually registers a device ID and an Ethernet (registered trademark) MAC address for each of the receiving devices as the unique identification information. Content transmission device. The identification information registration unit registers, as the unique identification information, a combined ID obtained by converting a device ID and an Ethernet MAC address by using a predetermined function as a parameter for each of the receiving devices,
The transmission control unit determines whether or not the connection ID of the receiving device that has issued the content transmission request is registered in the connection ID registered in the identification information registration unit. 3. The content transmission device according to 1 or 2. 3. The content transmitting apparatus according to claim 1, wherein the identification information registration unit registers, as the unique identification information, logical identification information determined by a network method for each of the receiving apparatuses. 4. . In a content receiving device that receives content requiring copyright protection from a transmitting device via a network,
Authentication / key exchange processing means for performing authentication / key exchange processing with the transmitting device;
Identification information registration means for registering the identification information while managing the number of unique identification information for identifying the transmission device not to exceed a predetermined number;
A transmission control unit for permitting content transmission to the own device only when identification information of the transmission device is registered in the identification information registration unit. In a content transmitting / receiving system for transmitting content requiring copyright protection from a transmitting device to one or more receiving devices via a network,
The transmitting device,
First authentication / key exchange processing means for performing authentication / key exchange processing with the receiving device;
Identification information registration means for registering the identification information while managing the number of unique identification information for identifying the receiving device not to exceed a predetermined number;
Only when the identification information of the receiving device that has made the content transmission request is registered in the identification information registering device, transmission control means for permitting content transmission to the receiving device,
Encryption processing means for encrypting the content requested to be transmitted using the key exchanged by the authentication / key exchange processing means;
Packet generating means for generating a packet corresponding to the encrypted content;
Network interface means for transmitting the generated packet to the receiving device,
The receiving device,
Content transmission requesting means for making the content transmission request to the transmission device,
Second authentication / key exchange processing means for performing authentication / key exchange processing with the transmitting device;
A content transmitting / receiving system, comprising: identification information transmitting means for transmitting unique identification information for identifying the own device to the transmitting device. In a content transmitting / receiving system for transmitting content requiring copyright protection from a transmitting device to one or more receiving devices via a network,
The receiving device,
Content transmission requesting means for making the content transmission request to the transmission device,
First authentication / key exchange processing means for performing authentication / key exchange processing with the transmitting device;
Identification information registration means for registering the identification information while managing the number of unique identification information for identifying the transmission device not to exceed a predetermined number;
Only when the identification information of the transmission device that is the content transmission destination is registered in the identification information registration device, has transmission permission means for permitting content transmission to the own device,
The transmitting device,
Second authentication / key exchange processing means for performing authentication / key exchange processing with the receiving device;
Transmission control means for performing content transmission to the receiving device only when content transmission is permitted by the transmission permission means,
Encryption processing means for encrypting the content requested to be transmitted using the key exchanged by the second authentication / key exchange processing means;
Packet generating means for generating a packet corresponding to the encrypted content;
And a network interface unit for transmitting the generated packet to the receiving device.

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