JP4476756B2 - Tuner card, host device and receiving device - Google Patents

Description

  The present invention relates to a receiving device that receives encrypted content data, and a tuner card and a host device that constitute the receiving device.

In recent years, services for distributing contents including video signals and / or audio signals such as BS digital broadcasting and terrestrial digital broadcasting with digital data are becoming widespread. Along with this, copyright infringement due to unauthorized viewing of content by terminals other than the specific terminal permitted to view the content has become a problem, and content protection has become more important.
On the other hand, with the widespread use of general-purpose devices such as personal computers (hereinafter abbreviated as “PC”) and PDAs, there is an increasing need to use broadcast services in these devices.

  Japanese Patent Laid-Open No. 2002-305512 discloses a tuner that receives encrypted content and an encrypted scramble key, a local CPU that decrypts the encrypted scramble key using a work key in the IO card, and data Based on an identification ID unique to the receiving device and an arbitrary random number, an encryption key for re-encrypting the decryption scramble key and a decryption key for re-decrypting the re-encryption scramble key are generated, Ks encoder for re-encrypting decryption scramble key using encryption key, key storage area for storing decryption key, bus I / F unit for transferring re-encryption scramble key and encrypted content to external device A conventional digital broadcast data transfer processing device for receiving broadcast data is disclosed.

  A general-purpose device such as a PC, which is an external device, can decrypt the encrypted content by inputting the re-encrypted scramble key and the encrypted content transferred by the conventional digital broadcast data transfer processing device. The user can view the broadcast signal encrypted by a general-purpose device such as a PC. Even if the external device is a PC capable of operating an application that performs file operations, the copyright of content data can be protected.

In recent years, general-purpose devices such as PCs and portable terminals that can be equipped with various IO cards are spreading in the market. In addition, there is an increasing need to use broadcasting services in general-purpose devices. If a general-purpose device itself is equipped with a function to receive broadcast waves, it can be accepted by users who want that function, but the general-purpose device becomes expensive and power consumption increases. Will reduce motivation. If a general-purpose device is equipped with only basic functions and an IO card (hereinafter referred to as a “tuner card”) equipped with a tuner capable of receiving broadcast waves is prepared as an option so that the user can attach it to the general-purpose device. The user can acquire a small-sized, light-weight and low-power general-purpose device and IO card having a desired function at an appropriate price.
JP 2002-305512 A

  However, the above-described conventional digital broadcast data transfer processing device has a configuration capable of viewing encrypted digital broadcast content without a host device such as a PC. A system combined with a host device has many unnecessary parts and is expensive.

  If the function of the conventional digital broadcast data transfer processing device is installed in the tuner card, the tuner card is encrypted with the encrypted content from the stream data including the encrypted content and the encrypted scramble key. A processing function for separating scrambled keys must be installed. In general, the process of separating the encrypted content and the encrypted scramble key from the stream data configured according to a complicated protocol is performed by software executed by hardware including a high-performance CPU and a large-scale RAM. Is called.

In general, however, general-purpose devices such as PCs and portable terminals, which are host devices, have hardware including a high-performance CPU and a large-scale RAM, but an IO card is a small, inexpensive CPU with low processing capability. It has only a small RAM.
It is extremely difficult to mount hardware including a high-performance CPU and a large-scale RAM on the IO card. Even if it can be mounted, the IO card is extremely expensive and consumes a large amount of power.

In view of the above problems, the present invention appropriately assigns each function of the receiving device to the host device side and the tuner card side. As a result, an inexpensive receiving device configured such that a complicated processing is left to the host device side such as a PC capable of performing a large amount of processing by software and only a minimum function is provided on the tuner card side, and a tuner configuring the receiving device An object is to provide a card and a host device.
An object of the present invention is to provide a receiving device in which a tuner card capable of receiving broadcast waves using a general-purpose IO card or the like is mounted on a host device such as a general-purpose device such as a PC or a portable terminal. The user can view the broadcast signal encrypted by a general-purpose device such as a PC. Even if file operation is possible in a general-purpose device, the copyright of content data can be protected.

  In order to solve the above problems, the present invention has the following configuration. The invention according to claim 1 receives a tuner that demodulates stream data including encrypted content and an encrypted scramble key from a broadcast wave, and receives the encrypted scramble key and decrypts the scramble key. A key decryptor that sends the stream data to the host device, receives the encrypted scramble key sent by the host device, sends it to the key decryptor, and the key decryptor outputs And a host interface unit that sends the decrypted scramble key to the host device.

  According to a fourth aspect of the present invention, the stream data including the content encrypted from the broadcast wave and the encrypted scramble key are demodulated and sent to the host device, and the encrypted scramble sent from the host device is sent. A card interface unit that reads the stream data and the decrypted scramble key from a tuner card that receives a key, decrypts it, and sends it back, and sends the encrypted scramble key to the tuner card; and A separator for separating and extracting the encrypted content and the encrypted scramble key, and the decrypted encrypted content read from the tuner card via the card interface unit Content decryptor using scramble key A host device comprising a.

  The invention described in claim 7 is a receiving apparatus including the tuner card described in claim 1 and the host apparatus described in claim 4.

  The present invention performs complicated processing with a host device such as a PC that can perform a large amount of processing by software, executes a tuner function for receiving broadcast waves with a tuner card, etc., and overlaps between the host device and the tuner card. An inexpensive receiving device that does not have hardware to perform, a tuner card and a host device constituting the receiving device are realized. Even if file operation is possible in the host device, there is no possibility that the secret of the encryption key will be leaked to a third party because there is no information for decrypting the encrypted scramble key in the host device. The present invention realizes a receiving device capable of protecting the copyright of content data, a tuner card and a host device constituting the receiving device.

  In general, the process of decrypting an encrypted scramble key can be performed by software using a small CPU and a small CPU. For example, if a small and inexpensive general-purpose CPU mounted on a tuner card is configured to perform processing for decrypting an encrypted scramble key, the circuit size, power consumption, and price of the tuner card will be achieved even if this processing is performed. Hardly changes.

  The tuner card may be in the form of a card that can be inserted into and removed from the host apparatus or in the form of a module that is built into the host apparatus, but is preferably a general-purpose IO card that can be inserted and removed (eg, an SDIO card, a PC card, etc.). The tuner may receive a wireless broadcast wave or a wired broadcast wave. Preferably, the host device is a general-purpose device having a data processing function such as a portable PC, a stationary PC, a PDA, and a mobile phone.

  The invention according to claim 2 further includes a host authentication unit that inputs authentication information from a host device via the host interface unit and determines whether the authentication information is predetermined information, 2. The tuner card according to claim 1, wherein only when the authentication information is predetermined information, the scramble key decrypted from the key decryptor is transmitted to the host device via the host interface unit.

  The invention according to claim 5 is the host device according to claim 4, further comprising an authentication information generating unit for storing or calculating authentication information, wherein the card interface unit sends the authentication information to a tuner card.

  The invention described in claim 8 is a receiving device including the tuner card described in claim 2 and the host device described in claim 5.

An unauthorized host device cannot transmit correct authentication information, and therefore cannot obtain a decrypted scramble key from the tuner card. The present invention realizes a receiving device capable of further protecting the copyright of content data, a tuner card and a host device constituting the receiving device.
If the authentication information is a constant protocol, the authentication information generation unit stores the constant authentication information. If the authentication information is a different protocol each time (for example, a challenge / response protocol), the authentication information generation unit is different each time. Generate authentication information.

  The invention according to claim 3 includes an encryptor that encrypts the decrypted scramble key output from the key decryptor, and the host interface unit is re-encrypted output from the encryptor. The tuner card according to claim 1 or 2, wherein the scramble key is transmitted to the host device.

  According to a sixth aspect of the present invention, the tuner card receives and decrypts the encrypted scramble key sent from the host device, then encrypts it again, sends it back, and decrypts the encrypted scramble key again. The host device according to claim 4, further comprising a decoder that transmits the content to the content decoder.

  The invention described in claim 9 is a receiving device including the tuner card described in claim 3 and the host device described in claim 6.

  Receiving device in which it is difficult for a malicious third party to illegally obtain a scramble key because a re-encrypted scramble key is exchanged between the tuner card and the host device, and a tuner card and a host device constituting the receiving device Can be realized.

  According to the present invention, it is possible to obtain an advantageous effect of realizing an inexpensive receiving device for protecting the copyright of content data, a tuner card and a host device constituting the receiving device.

  According to the present invention, the scramble key is output only to an authenticable host device permitted by the tuner card, thereby preventing viewing of the content data by an unauthorized host device, and inexpensive reception that protects the copyright of the content data. The advantageous effect of realizing the device, the tuner card constituting the device and the host device can be obtained.

  According to the present invention, it is difficult for a malicious third party to illegally acquire a scramble key for decrypting content data, and an inexpensive receiving device for protecting the copyright of content data, and a tuner constituting the same The advantageous effect of realizing the card and the host device can be obtained.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that specifically show the best mode for carrying out the present invention will be described below with reference to the drawings.

Embodiment 1
A receiving apparatus for receiving content data based on a digital broadcast signal according to the first embodiment of the present invention will be described with reference to FIG. 1 and FIG. FIG. 1 is a block diagram showing an outline of the configuration of the receiving apparatus according to the first embodiment. The receiving apparatus according to the first embodiment is a receiving apparatus that receives terrestrial digital broadcasting. However, the receiving apparatus may be an apparatus that receives other broadcast waves, for example, satellite digital broadcast or wired digital broadcast. In FIG. 1, the receiving device according to the first embodiment includes a tuner card 1 and a host device 2. In the first embodiment, the tuner card 1 is an SDIO card, and the host device 2 is a mobile phone.

  The tuner card 1 includes an antenna 3, a tuner 4, a scramble key decoder 5, and a host interface unit 6. The host device 2 includes a card interface unit 7, a separator 8, a content decoder 9, and an AV playback unit 10.

The antenna 3 receives a digital broadcast signal.
The tuner 4 demodulates the digital broadcast signal received by the antenna 3 into stream data including the encrypted content data Cs and the encrypted scramble key Ks, and outputs the demodulated data to the host interface unit 6. The encrypted scramble key Ks included in the stream data is updated every second.
The host interface unit 6 has a function for connecting to the host device 2 and performing communication. The host interface unit 6 outputs the stream data input from the tuner 4 to the card interface unit 7, and the scramble key encrypted from the card interface unit 7. Ks is input and output to the scramble key decoder 5, and the scramble key Kd decrypted from the scramble key decoder 5 is input and output to the card interface unit 7.
The scramble key decryptor 5 holds contract information or a predetermined secret key in advance, decrypts the encrypted scramble key Ks inputted thereby, and uses the decrypted scramble key Kd as the host interface unit 6. Output to.

The card interface unit 7 has a function for connecting to the tuner card 1 and performing communication. The card interface unit 7 outputs the stream data input from the host interface unit 6 to the separator 8 and the scramble key encrypted from the separator 8. Ks is input and output to the host interface unit 6, and the scramble key Kd decrypted from the host interface unit 6 is input and output to the content decoder 9.
The separator 8 separates and extracts the encrypted content data Cs and the encrypted scramble key Ks from the stream data, and outputs the encrypted content data Cs to the content decoder 9 for encryption. The scramble key Ks is output to the card interface unit 7.
The content decryptor 9 decrypts the input encrypted content data using the input decrypted scramble key Kd, and outputs the decrypted content data Cd to the AV playback unit 10.
The AV playback unit 10 displays and plays back video data, audio data, and the like on the output device from the decrypted content data Cd.

  Even if the decryption processing mechanism of the content decoder 9 or the scramble key is stolen, the content data cannot be restored because it changes to another scramble key after 1 second. On the other hand, the decoding process of the scramble key decoder 5 can design a circuit for decoding a scramble key that changes every second when the mechanism becomes clear, and decrypts the content data. Therefore, it can be said that the scramble key decoder 5 is required to have higher secrecy. Therefore, it is preferable to execute the scramble key decoder 5 on the tuner card 1 side rather than on the host device 2 side where control specifications such as a PC are disclosed.

Next, details of the operation of the receiving apparatus of the present embodiment configured as described above will be described with reference to FIG. FIG. 2 is a sequence diagram showing communication between the tuner card 1 and the host device 2 and main processing.
First, on the tuner card 1 side, a broadcast signal is received by the antenna 3 (S200), and the received signal is demodulated into stream data by the tuner 4 (S201). The tuner card 1 outputs the obtained stream data to the host device 2.
The host device 2 separates and extracts the input stream data into the content data Cs encrypted by the separator 8 and the encrypted scramble key Ks (S202). The host device 2 outputs only the obtained encrypted scramble key Ks to the tuner card 1.
The tuner card 1 decrypts the input encrypted scramble key Ks to obtain a decrypted scramble key Kd (S203). The tuner card 1 outputs the obtained decrypted scramble key Kd to the host device 2.
The host device 2 decrypts the encrypted content data Cs obtained in S202 using the decrypted scramble key Kd that has been input (S204).

  As described above, the receiving apparatus according to the present embodiment includes a broadcast signal demodulation process (tuner) suitable for hardware processing and a scramble key decryption process (scramble key decoder 5) that requires high confidentiality. ) To the tuner card 1 side, and other processing to the host device 2 such as a PC, it is possible to realize an inexpensive receiving device.

<< Embodiment 2 >>
A receiving apparatus for receiving content data using a digital broadcast signal according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram showing an outline of the configuration of the receiving apparatus according to the second embodiment. The receiving apparatus according to the second embodiment is a receiving apparatus that receives terrestrial digital broadcasting. However, the receiving apparatus may be an apparatus that receives other broadcast waves, for example, satellite digital broadcast or wired digital broadcast. In FIG. 3, the receiving device according to the second embodiment includes a tuner card 31 and a host device 32. In the first embodiment, the tuner card 31 is an SDIO card, and the host device 32 is a portable information terminal.

  The tuner card 31 has a host authentication unit 33 in addition to the configuration of the tuner card 1 of the first embodiment, the host device 32 is a portable information terminal, and the configuration of the host device 2 of the first embodiment. The second embodiment is different from the first embodiment in that the authentication information storage unit 34 is provided. The other points are the same as those in the first embodiment, and detailed description of elements having the same reference numerals is omitted.

The authentication information storage unit 34 stores authentication information for the tuner card 31 to identify the host device 32. The authentication information is a code indicating that the host device 32 is permitted to view content data.
Instead of the authentication information storage unit 34, an authentication information generation unit that generates different authentication information each time the host device 32 sends authentication information to the tuner card 31 may be provided. The authentication information generation unit and the host authentication unit 33 include, for example, the same random number generator, and exchange different authentication information every time they are updated.

  The host authentication unit 33 reads the authentication information stored in the authentication information storage unit 34 of the host device 32 via the host interface 6 and the card interface unit 7 and determines whether the authentication information satisfies a predetermined condition. If the authentication information satisfies the predetermined condition, the determination result A is output to the host interface unit 6. If the authentication information does not satisfy the predetermined condition, the determination result B is output to the host interface unit 6.

When the determination result A is input from the host authentication unit 33, the host interface unit 6 outputs the decrypted scramble key Kd output from the scramble key decoder 5 to the host device 32. When the determination result B is input from the host authentication unit 33, the decrypted scramble key Kd input from the scramble key decoder 5 is not output to the host device 32.
Instead of the above configuration, the host authentication unit 33 sends the determination result A or B to the scramble key decoder 5, and the scramble key decoder 5 receives the determination result A and decrypts it. When the key Kd is output and the determination result B is input, the decrypted scramble key Kd may not be output.

Next, the details of the operation of the receiving apparatus of the present embodiment configured as described above will be described with reference to FIG. FIG. 4 is a sequence diagram showing communication between the tuner card 31 and the host device 32 and main processing.
First, on the tuner card 31 side, a broadcast signal is received by the antenna 3 (S200), and the received signal is demodulated into stream data by the tuner 4 (S201). The tuner card 31 outputs the obtained stream data to the host device 32.
The host device 32 separates and extracts the input stream data into the content data Cs encrypted by the separator 8 and the encrypted scramble key Ks (S202). The host device 31 reads the authentication information (S400). The host device 32 outputs the obtained encrypted scramble key Ks and authentication information to the tuner card 31.

The tuner card 31 decrypts the input encrypted scramble key Ks and obtains a decrypted scramble key Kd (S203). Further, it is determined whether or not the input authentication information satisfies the predetermined condition (S401). If the input authentication information satisfies the predetermined condition, the tuner card 31 uses the decrypted scramble key Kd obtained in S203 as a host. Output to the device 32. The host device 32 can decrypt the encrypted content data Cs obtained in S202 by using the decrypted scramble key Kd that has been input (S204).
In S401, if the input authentication information does not satisfy the predetermined condition, the tuner card 31 does not output the decrypted scramble key Kd to the host device 32. Therefore, the unauthorized host device 32 receives the encrypted content data Cs. It cannot be decrypted.

  As described above, the receiving device according to the present embodiment can prevent an unauthorized host device from viewing content data by outputting the decrypted scramble key only to a host device that satisfies a predetermined condition. A receiving device that protects the copyright of content data can be realized.

<< Embodiment 3 >>
A receiving apparatus for receiving content data based on a digital broadcast signal according to the third embodiment of the present invention will be described with reference to FIGS. FIG. 5 is a block diagram showing an outline of the configuration of the receiving apparatus according to the third embodiment. The receiving apparatus according to Embodiment 3 is a receiving apparatus that receives terrestrial digital broadcasting. However, the receiving apparatus may be an apparatus that receives other broadcast waves, for example, satellite digital broadcast or wired digital broadcast. In FIG. 5, the receiving device according to the third embodiment includes a tuner card 51 and a host device 52. In the third embodiment, the tuner card 51 is an SDIO card, and the host device 52 is a PC.

The tuner card 51 further includes a scramble key re-encryptor 53 in addition to the configuration of the tuner card 31 of the second embodiment, the host device 52 is a PC, and the configuration of the host device 32 of the second embodiment. In addition to the second embodiment, the second embodiment is different from the second embodiment in that a scramble key re-decryptor 54 is provided. The other points are the same as those of the second embodiment, and detailed description of elements having the same reference numerals is omitted.

The scramble key re-encryptor 53 receives the scramble key Kd decrypted from the scramble key decryptor 5 and re-encrypts the decrypted scramble key Kd using a predetermined encryption key. The scramble key Kds encrypted again is output to the scramble key re-decryptor 54 via the host interface unit 6 and the card interface unit 7.
The scramble key re-decryptor 54 has a decryption key corresponding to the encryption key used by the scramble key re-encryptor 53, decrypts the re-encrypted scramble key Kds that is input, The scramble key Kd is output to the content decoder 9.

Next, details of the operation of the receiving apparatus of the present embodiment configured as described above will be described with reference to FIG. FIG. 6 is a sequence diagram showing communication between the tuner card 51 and the host device 52 and main processing.
First, the tuner card 51 receives a broadcast signal by the antenna 3 (S200), and the received signal is demodulated into stream data by the tuner 4 (S201). The tuner card 51 outputs the obtained stream data to the host device 52.
The host device 52 separates and extracts the input stream data into the content data Cs encrypted by the separator 8 and the encrypted scramble key Ks (S202). The host device 52 reads the authentication information (S400). The host device 52 outputs the obtained encrypted scramble key Ks and authentication information to the tuner card 51.

  The tuner card 51 decrypts the input encrypted scramble key Ks to obtain a decrypted scramble key Kd (S203). Further, the decrypted scramble key Kd is re-encrypted to obtain the re-encrypted scramble key Kds (S600). Further, it is determined whether or not the input authentication information satisfies a predetermined condition (S401). If the input authentication information satisfies the predetermined condition, the tuner card 51 outputs the encrypted scramble key Kds obtained in S600 to the host device 52 again. The host device 52 decrypts the input re-encrypted scramble key Kds to obtain the decrypted scramble key Kd (S601). Further, the host device 52 can decrypt the encrypted content data Cs obtained in S202 by using the decrypted scramble key Kd (S204).

If the authentication information input in S401 does not satisfy the predetermined condition, the tuner card 51 does not output the re-encrypted scramble key Kds to the host device 52. Therefore, the unauthorized host device 52 receives the encrypted content data Cs. It cannot be decrypted.
Instead, when the authentication information input in S401 does not satisfy the predetermined condition, the scramble key decryptor 5 does not output the decrypted scramble key or the scramble key re-encryptor 53 is re-encrypted. A configuration in which a scramble key is not output may be used.

  As described above, the receiving device according to the present embodiment has a high protection capability for content data because the scramble key for decrypting the content data is encrypted in communication between the tuner card 51 and the host device 52. A receiving device that protects the copyright of the content data can be realized.

  The decryption key used by the scramble key decryptor 5 to decrypt the encrypted scramble key is a key provided to each tuner card by a company that outputs broadcast radio waves. The encryption key used by the scramble key re-encryptor 53 to re-encrypt the scramble key and the decryption key used by the scramble key re-decryptor 54 to re-decrypt the re-encrypted scramble key. Is a key arbitrarily determined only between the tuner card and the host device, or a key provided to each tuner card and host device by a company that outputs broadcast radio waves.

  The tuner card of the embodiment is an SDIO card. However, the present invention is not limited to this, and the tuner card may be an arbitrary IO card. Preferably, the tuner card is a general-purpose IO card, such as an SDIO card or a PC card. The host device is a device having a slot into which a general-purpose IO card is inserted, and is preferably a device having a general-purpose information processing function such as a PC, a mobile terminal, and a mobile phone.

  The present invention can be applied to, for example, a receiving apparatus that receives content data based on a digital broadcast signal.

FIG. 2 is a block diagram showing an outline of a configuration of a receiving apparatus according to Embodiment 1 of the present invention. FIG. 7 is a sequence diagram for explaining communication and operation between the tuner card and the host device according to the first embodiment of the present invention. FIG. 3 is a block diagram showing an outline of a configuration of a receiving apparatus according to Embodiment 2 of the present invention. FIG. 7 is a sequence diagram for explaining communication and operation between a tuner card and a host device in Embodiment 2 of the present invention. FIG. 9 is a block diagram showing an outline of the configuration of a receiving apparatus according to Embodiment 3 of the present invention. The sequence diagram explaining communication and operation | movement with the tuner card | curd and host apparatus in Embodiment 3 of this invention

Explanation of symbols

1, 31, 51 Tuner card 2, 32, 52 Host device 3 Antenna 4 Tuner 5 Scramble key decryptor 6 Host interface unit 7 Card interface unit 8 Separator 9 Content decoder 10 AV playback unit 33 Host authentication unit 34 Authentication Information storage unit 53 Scramble key re-encryptor 54 Scramble key re-decryptor

Claims (9)

A tuner that demodulates stream data including encrypted content and an encrypted scramble key from a broadcast wave;
A key decryptor for receiving the encrypted scramble key and decrypting the scramble key;
Sending the stream data to a host device, receiving the encrypted scramble key sent by the host device, sending it to the key decryptor, and receiving the decrypted scramble key outputted by the key decryptor A host interface section to send to the host device;
Tuner card with A host authentication unit that inputs authentication information from the host device via the host interface unit and determines whether the authentication information is predetermined information;
2. The tuner card according to claim 1, wherein the scramble key decrypted from the key decryptor is sent to the host device via the host interface unit only when the authentication information is predetermined information.   An encryption unit for encrypting the decrypted scramble key output from the key decryptor; and the host interface unit sends the re-encrypted scramble key output from the encryptor to the host device. The tuner card according to claim 1 or 2. A tuner that demodulates the stream data including the encrypted content from the broadcast wave and the encrypted scramble key, sends it to the host device, receives the encrypted scramble key sent from the host device, decrypts it, and sends it back A card interface unit that reads out the stream data and the decrypted scramble key from a card, and sends the encrypted scramble key to the tuner card;
A separator that separates and extracts the encrypted content and the encrypted scramble key from the stream data;
A content decryptor for decrypting the extracted encrypted content using the decrypted scramble key read from the tuner card via the card interface unit;
A host device comprising:   The host device according to claim 4, further comprising an authentication information generation unit that stores or calculates authentication information, and wherein the card interface unit transmits the authentication information to a tuner card. The tuner card receives and decrypts the encrypted scramble key sent from the host device, then encrypts it again and sends it back.
6. The host device according to claim 4, further comprising a decryptor that decrypts the re-encrypted scramble key and sends the decrypted scramble key to the content decryptor.   A receiving device comprising the tuner card according to claim 1 and the host device according to claim 4.   A receiving device comprising the tuner card according to claim 2 and the host device according to claim 5.   A receiving device comprising the tuner card according to claim 3 and the host device according to claim 6.

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