JP4423517B2 - Data processing apparatus, data processing method, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a data processing device, a data processing method, and a recording medium. In particular, for example, when data is broadcast by a satellite line or the like, a terminal (user) that can acquire the data can be easily obtained. The present invention relates to a data processing device, a data processing method, and a recording medium that can be restricted.
[0002]
[Prior art]
For example, when images and sounds are transmitted as digital data, it is possible to secure multiple channels in the same transmission band as when analog signals are transmitted, and to provide higher quality images and sounds. In the field of satellite broadcasting or satellite communication, systems that provide images and sounds as digital data are becoming widespread. For example, digital satellite broadcasting services such as SkyPerfecTV! And DirecTV in Japan, DirecTV in North America, and Canal Plus in Europe have started. Digitalization of broadcasting enables transmission costs per channel to be reduced, provision of programs and data handled by computers, etc., and provision of programs and images in conjunction with digitalization. Services are also spreading.
[0003]
In the digital satellite broadcasting service, digital data of images and sounds is converted into a format conforming to MPEG (Moving Picutre Experts Group) 2 and DVB (Digital Video Broadcasting) standard derived from MPEG 2, and further multiplexed. , Transmitted as radio waves. The radio wave is received by a satellite transponder, amplified, and other necessary processing is performed, and then transmitted to the ground.
[0004]
The transmission band of the transponder is, for example, as large as 30 Mbps (Mega bit per second). By using all of such a large transmission band, it is possible to distribute digital data with high quality and at high speed.
[0005]
However, generally, mainly for cost reasons, the transponder transmission band is often divided into multiple channels for use. In this case, even if the contents of the digital data transmitted by each channel are different, the receiving side receiving the digital data of each channel has a common mechanism, so that only a specific user receives provision of certain digital data. Therefore, a conditional access (CA) mechanism is required.
[0006]
That is, in particular, for example, when performing so-called data broadcasting, it is expected that the amount of data per program is small and the charging unit or charging form is complicated compared to the case of distributing images and sound, In order to cope with this, a conditional access mechanism capable of performing finer reception control is required. In addition, the limited reception mechanism is necessary to prevent leakage even when confidential information is distributed.
[0007]
In general, the conditional access mechanism is realized by encrypting a data stream to be distributed. As an encryption method, a common key encryption method (secret key encryption method) and a public key encryption method are known. In digital satellite broadcasting, the common key encryption method is often used because the processing load of encryption / decryption is lighter than that of the public key encryption method.
[0008]
In the common key encryption method, a code string that is the same as the encryption key and serves as a decryption key is delivered to a certain contractor A by some method, and the data is encrypted and distributed with the encryption key. The encrypted data is then difficult to analogize by reversely calculating the encryption key (decryption key) or the original data, and therefore user B who is not a contractor is encrypted. Even if the received data is received, it cannot be correctly restored to the original data. Further, the user A who is a contractor can restore the original data by decrypting the encrypted data with the decryption key passed by the contract. Therefore, the reception contract is equivalent to the delivery of the decryption key.
[0009]
[Problems to be solved by the invention]
By the way, for example, when the users A and C are contractors, when the contract with only the user A is terminated, or when the user A performs an illegal act, the encryption key used up to now is used. If the same decryption key as the changed encryption key is provided to only the user C, the user A who is no longer a contractor or who has performed an illegal act is encrypted with the new encryption key. It becomes impossible to restore the encrypted data, and the user C who is a valid contractor continues to normally restore the data encrypted with the new encryption key by decrypting with the new decryption key. can do.
[0010]
However, it is cumbersome to change the encryption key each time a user's contract is terminated or an illegal act is found, and to provide a legitimate contractor with the same decryption key as the changed encryption key. It is.
[0011]
The present invention has been made in view of such a situation, and makes it possible to easily limit users who can normally acquire (receive) data.
[0012]
[Means for Solving the Problems]
  The data processing apparatus of the present invention includes a destination,The registered entryEntry valid information indicating whether or not is valid andA key assigned to the destination registered in the entry, and key validity information indicating whether or not the key assigned to the destination registered in the entry is valid.Table with entries registeredAnd a table stored in the storage meansEntry with a destination that matches the destination of the data blockSearch forSearch means;It is determined whether the target entry is valid based on the entry valid information registered in the target entry that is an entry obtained as a result of the search by the search means, and the target entry is determined based on the key valid information registered in the target entry. Whether the key is validA determination means;When the determination means determines that the target entry is valid, when it is determined that the key of the target entry is valid, the key registered in the target entry is the data arranged in the data block. The decrypted data is output to the destination arranged in the data block, and when the determining unit determines that the target entry is not valid, the data is discarded, and the determining unit determines that the key of the target entry is not valid. Control the output of the data placed in the data block so that the data is discarded.Output control means.
[0014]
  Data encrypted with the key registered in the entry of interestDecoding means for decoding can be further provided.
[0018]
  Each entry in the table containsDestination registered in the entryTwo or more keys assigned to can also be registered.
[0019]
In each entry of the table, key validity information indicating whether or not the key is valid can be registered for each of two or more keys.
[0023]
The data processing apparatus of the present invention can be constituted by a one-chip IC (Integrated Circuit).
[0024]
  The data processing method of the present invention includes:In the storage means,Destination,The registered entryEntry valid information indicating whether or not is valid andA key assigned to the destination registered in the entry, and key validity information indicating whether or not the key assigned to the destination registered in the entry is valid.Table with entries registeredAnd a table stored in the storage means by the search meansEntry with a destination that matches the destination of the data blockSearch forA search step;The determination means determines whether the target entry is valid based on the entry valid information registered in the target entry, which is an entry obtained as a result of the search in the search step. Based on the key valid information registered in the target entry To determine whether the key of the entry of interest is validA determination step;When it is determined by the output control means that the target entry is valid in the determination step, when it is determined that the key of the target entry is valid, the data arranged in the data block is registered in the target entry. The decrypted data using the stored key is output to the destination arranged in the data block. If it is determined in the determination step that the target entry is not valid, the data is discarded, and the key of the target entry is determined in the determination step. Controls the output of data placed in a data block to discard data if it is determined not to be validOutput control step andIncludeIt is characterized by that.
[0025]
  The recording medium of the present invention includes a destination,The registered entryEntry valid information indicating whether or not is valid andA key assigned to the destination registered in the entry, and key validity information indicating whether or not the key assigned to the destination registered in the entry is valid.Table with entries registeredThe table stored in the storage meansEntry with a destination that matches the destination of the data blockSearch forA search step;It is determined whether the target entry is valid based on the entry valid information registered in the target entry that is an entry obtained as a result of the search in the search step, and the target entry is determined based on the key valid information registered in the target entry. Whether the key is validA determination step;In the determination step, when it is determined that the target entry is valid, when it is determined that the key of the target entry is valid, the key registered in the target entry is the data arranged in the data block. The decrypted data is output to the destination arranged in the data block, and when it is determined in the determination step that the target entry is not valid, the data is discarded, and in the determination step, it is determined that the key of the target entry is not valid. Control the output of the data placed in the data block so that the data is discarded.Output control step andContains programs that allow a computer to perform data processing includingIt is characterized by that.
[0026]
  In the data processing device, the data processing method, and the recording medium of the present invention,Entry validity information indicating whether the entry registered is valid, the key assigned to the destination registered in the entry, and whether the key assigned to the destination registered in the entry is valid And a table having entries registered with key valid information indicating the entry having a destination that matches the destination of the data block from the table stored in the storage means, and obtained as a result of the search It is determined whether the target entry is valid based on the entry valid information registered in the target entry that is an entry, and whether the key of the target entry is valid is determined based on the key valid information registered in the target entry. If the target entry is determined to be valid, the key of the target entry is determined to be valid. Data that has been decrypted using the key registered in the entry of interest is output to the destination placed in the data block, and if it is determined that the entry of interest is not valid, the data is discarded, If it is determined that the key of the target entry is not valid, the data is discarded.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of a broadcasting system to which the present invention is applied (a system is a logical collection of a plurality of devices, regardless of whether or not each component device is in the same housing). The example of a structure of the form is shown.
[0028]
In the embodiment of FIG. 1, the broadcasting system is composed of a transmission system 1, a satellite 2, a reception system 3, and a network 4. In FIG. 1, only one reception system (reception system 3) is shown in order to avoid making the figure complicated, but two or more reception systems can be provided.
[0029]
The transmission system 1 includes a control device 11, a data server 12, a transmission processing device 13, an antenna 14, a line connection device 15, and a cable 16, and includes the control device 11, the data server 12, the transmission processing device 13, and the line connection device. 15 are connected to each other via a cable 16 to constitute a LAN (Local Area Network).
[0030]
The control device 11 controls the data server 12 to supply the transmission processing device 13 with data to be distributed by satellite broadcasting. In addition, the control device 11 controls the line connection device 15 to acquire data to be distributed by satellite broadcasting from the external network 4 such as the Internet and supply it to the transmission processing device 13. Furthermore, the control device 11 controls various processes in the transmission processing device 13.
[0031]
The data server 12 stores data to be distributed by satellite broadcasting, and supplies necessary data to the transmission processing device 13 under the control of the control device 11.
[0032]
Under the control of the control device 11, the transmission processing device 13 packetizes the data supplied from the data server 12 or the line connection device 15 into, for example, an IP (Internet Protocol) packet, and further converts the IP packet into DVB data. Sections compliant with the broadcast specification, i.e., for example, EN 301 192 V1.1.1 (1997-12), DVB specification for data broadcasting ETSI (European Telecommunications Standards Institute) Multiprotocol Encapsulation Block data blocks called sections described by descriptors based on them. Then, the transmission processing device 13 divides the section into payloads of a predetermined length, and adds a header of a packet (hereinafter, appropriately referred to as a TS (Transport Stream) packet) constituting the MPEG2 transport stream to each payload. Thus, a packet similar to the TS packet is formed, and further necessary processing such as modulation and amplification is performed, and the resultant is transmitted from the antenna 14 as a satellite broadcast wave.
[0033]
In addition, the transmission processing device 13 is a terminal 24 constituting the reception system 3.₁, 24₂,... (Similar for terminals constituting the receiving system not shown in FIG. 1). Table-form encryption in which each MAC address is associated with an encryption key assigned to each MAC (Media Access Control) address. It has an encryption key table storage unit 13A that stores a key table. Note that the encryption keys assigned to each MAC address are basically all different. However, the same encryption key may be assigned to some MAC addresses.
[0034]
Here, the MAC address is an address system applied to IEEE (Institute of Electrical Electronics Engineers) 802.3, etc., and is a 48-bit value unique to each communication port, and is guaranteed not to overlap. . In the 48-bit MAC address, the upper 24 bits are a manufacturer (vendor) identification number registered / managed by IEEE, and the lower 24 bits are a device identification number managed by each vendor. It has become. According to the MAC address, each terminal 24 of the receiving system 3_i(I = 1, 2,...) Can be specified.
[0035]
According to the multi-protocol encapsulation described above, the terminal 24 that distributes the data arranged in the payload of the section to the section header (section header)._iAs the destination, the MAC address of the terminal is arranged. In the case where it is necessary to encrypt the data arranged in the payload of the section, that is, the IP packet here, the transmission processing device 13 sends the terminal 24 as the destination arranged in the header of the section._iThe encryption key assigned to the MAC address is read from the encryption key table stored in the encryption key table storage unit 13A, and the IP packet arranged in the payload of the section is encrypted with the encryption key. Yes.
[0036]
Note that the encryption key table may be in the same format as that of a key table included in the receiving device 22 that will be described later, which constitutes the receiving system 3, or may be in a different format. Here, the encryption key table is built in the transmission system 1, but the encryption key table is stored in, for example, a server (not shown) on the network 4 and, if necessary, the line It is also possible to read and use via the connection device 15.
[0037]
The line connection device 15 is composed of, for example, a modem, TA (Terminal Adapter), DSU (Digital Service Unit), and the like, and performs communication control via the network 4.
[0038]
The reception system 3 includes an antenna 21, a reception device 22, a line connection device 23, and a terminal 24.₁, 24₂,..., And a cable 25, a receiving device 22, a line connection device 23, and a terminal 24.₁, 24₂,... Are connected to each other via a cable 25, thereby constituting a LAN such as Ethernet (trademark).
[0039]
The receiving device 22 and the terminal 24₁, 24₂,... Can be configured by a computer, for example.
[0040]
Also, here, the receiving device 22 and the terminal 24₁, 24₂,... Are connected to each other via a cable 25 to form a LAN. However, the receiving device 22 and the terminal 24 are connected to each other.₁, 24₂,... Can be connected directly.
[0041]
Further, the receiving device 22 includes one terminal 24._iIt can be configured as a board that can be mounted in a slot of a computer.
[0042]
The receiving device 22 and the line connection device 23 can be configured by a single computer.
[0043]
The satellite broadcast wave transmitted from the transmission system 1 via the satellite 2 is received by the antenna 21, and the received signal is supplied to the receiving device 22. The receiving device 22 performs a process as described later on the received signal from the antenna 21, and the resulting data is sent to a predetermined terminal 24._iTo supply.
[0044]
The line connection device 23 is configured in the same manner as the line connection device 15 and performs communication control via the network 4.
[0045]
Terminal 24₁, 24₂,... Are configured by a computer, for example, and receive necessary data from the receiving device 22 to display, output, or store the data.
[0046]
Next, data transmission processing performed by the transmission system 1 will be described with reference to the flowchart of FIG.
[0047]
First, in step S1, the control device 11 makes a terminal 24._iWhether there is data to be transmitted is determined.
[0048]
Here, the control device 11 has a schedule table in which a schedule for transmitting data is described, and based on the schedule table, the terminal 24_iWhether there is data to be transmitted is determined. The terminal 24_iBy controlling the line connection device 23, it is possible to request data from the transmission system 1 via the network 4, and the control device 11 sends such a request to the network. 4, depending on whether or not the line connection device 15 receives the terminal 24_iWhether there is data to be transmitted is determined.
[0049]
In step S1, the terminal 24₁If it is determined that there is no data to be transmitted, the process proceeds to step S2, and the control device 11 determines whether to change the period.
[0050]
Here, in the transmission system 1, the encryption key described in the encryption key table in the encryption key table storage unit 13 is updated regularly or irregularly. A period during which encryption is performed using the obtained encryption key is referred to as an “even period”, and a period during which encryption is performed using an encryptor obtained by an odd number of updates is referred to as an “Odd period”. Therefore, although the Even period and the Odd period appear alternately, it is determined in step S2 whether it is time to change from the Even period to the Odd period or from the Odd period to the Even period.
[0051]
If it is determined in step S2 that the period is not to be changed, that is, if data encryption is to be continued using the encryption key used for encryption as it is, the process returns to step S1, and hereinafter, Similar processing is repeated.
[0052]
If it is determined in step S2 that the period is to be changed, that is, if the period is changed, that is, the Odd period when it is the Even period, and the Even period when it is the Odd period, the process proceeds to Step S3, and the control is performed. The device 11 updates the encryption key stored in the encryption key table to the encryption key generated last time in step S4, which will be described later, and thereafter uses the updated encryption key in the transmission processing device 13. Encryption.
[0053]
And it progresses to step S4, the control apparatus 11 produces | generates (or acquires) the encryption key used in the next period, supplies it to the transmission processing apparatus 13, makes it transmit as a decryption key, returns to step S1, Processing similar to that described above is repeated. The decryption key can be transmitted not only via the satellite 2 but also via the network 4.
[0054]
That is, if a new decryption key used in the next period is transmitted to the reception system 3 immediately before the start of the next period, the new decryption key is set in the reception system 3 at the start of the next period. May not be in time. Therefore, in this embodiment, a new encryption key used in the next period is distributed to the receiving system 3 in the period immediately before.
[0055]
On the other hand, in step S1, the terminal 24_iWhen it is determined that there is data to be transmitted, the control device 11 controls the data server 12 or the line connection device 15 to cause the transmission processing device 13 to supply the data to be transmitted. The transmission processing device 13 receives the data supplied from the data server 12 or the line connection device 15, packetizes it into an IP packet, and proceeds to step S5.
[0056]
In step S5, the transmission processing device 13 determines whether or not the IP packet needs to be encrypted. If the transmission processing device 13 determines that the IP packet does not need to be encrypted, the transmission processing device 13 skips steps S6 and S7. Proceed to S8.
[0057]
If it is determined in step S5 that the IP packet needs to be encrypted, the process proceeds to step S6, where the transmission processing device 13 sends the terminal 24 that is the destination of the IP packet._iThe encryption key assigned to the MAC address is read from the encryption key table, and the process proceeds to step S7. In step S7, the transmission processing apparatus 13 encrypts the IP packet with the encryption key read in step S6, and proceeds to step S8.
[0058]
In step S8, the transmission processing device calculates a CRC (Cyclic Redundancy Checking) code (or checksum) for the IP packet, uses the IP packet as a payload, places a CRC code at the end thereof, and at the head thereof. By arranging the section header, a section as shown in FIG. A stuffing byte is inserted between the payload and the CRC code as necessary.
[0059]
The section header is composed of 3 bytes (96 bits) as shown in FIG. Here, since the details of the section header are described in the above-mentioned EN 301 192 V1.1.1 (1997-12), the description thereof is omitted, but MAC addresses 1 to 6 in FIG. A 48-bit MAC address as a destination is arranged. Here, 8 bits from the most significant bit of the MAC address are arranged in MAC address 1, and the next higher 8 bits are arranged in MAC address 2. Similarly, 8 bits each of the MAC address are arranged in each of the MAC addresses 3 to 5, and the least significant 8 bits of the MAC address are arranged in the MAC address 6.
[0060]
After configuring the section, the transmission processing device 13 divides the section into payloads of a predetermined length, and adds the header of the TS packet that configures the MPEG2 transport stream to each payload, thereby classifying the section as a TS packet. Encapsulates the packet. Then, the transmission processing apparatus 13 proceeds to step S9, and the packet obtained as a result (this packet can be processed basically in the same manner as a TS packet, and henceforth referred to as a TS packet as appropriate). Then, necessary processing such as modulation and amplification is performed, and the satellite 14 transmits the satellite broadcast wave, and the process returns to step S1.
[0061]
In the section header shown in FIG. 3B, the 2-bit PSC (payload_scrambling_control) arranged in the 2nd bit of the 43rd and 44th bits from the head is, for example, data arranged in the payload of the section Is used as an encryption determination flag indicating whether or not is encrypted, and a period determination flag indicating whether the data is of the Even period or the Odd period.
[0062]
Specifically, for example, the lower bits of the PSC are used as an encryption determination flag, and are set to 1 when the data is encrypted, and set to 0 when the data is not encrypted. The upper bits of the PSC are used as a period determination flag, and are set to 0 in the Even period and 1 in the Odd period. However, the upper bits of the PSC can be used as an encryption determination flag, and the lower bits can be used as a period determination flag. Also, the assignment of the encryption determination flag 0 and 1 and the assignment of the period determination flag 0 and 1 can be reversed from those described above.
[0063]
Here, in the case of EN 301 192 V1.1.1 (1997-12), which is a DVB standard, PSC is 00B (B represents that the value placed before it is a binary number). Therefore, the encryption determination flag is set to 1 when the data is encrypted and is set to 0 when the data is not encrypted. This is desirable because it will not be contrary.
[0064]
As described above, in the broadcasting system of FIG._iSince the data is encrypted with the encryption key assigned to the unique MAC address, each terminal 24_iIn other words, it is possible to realize an ultimate limited reception mechanism called reception control.
[0065]
Note that a method for realizing a conditional access mechanism that performs fine reception control by assigning an encryption key to a unique value on the receiving side, such as a MAC address or an IP address, has been proposed by the present applicant. The details are disclosed in Japanese Laid-Open Patent Publication No. 10-215244. However, in the current situation where communication satellite broadcasting in Japan complies with the specification derived from DVB-SI (Digtal Video Broadcasting-Service Information / EN300 468), as described above, the MAC address is used. It will conform to.
[0066]
Next, FIG. 4 shows a configuration example of the receiving device 22 of FIG.
[0067]
The antenna 21 receives the satellite broadcast wave transmitted from the transmission system 1 via the satellite 2 and outputs the received signal to the front end unit 31. Under the control of the CPU 34, the front end unit 31 selects a signal of a predetermined channel from the received signal from the antenna 21, further demodulates the signal into a digital stream (IP_datagram_data_byte) of a TS packet, and demultiplexer 32. The demultiplexer 32 extracts a predetermined TS packet from the digital stream from the front end unit 31 and outputs it to a decoding LSI (Large Scale Integrated Circuit) 33 under the control of the CPU 34. That is, the demultiplexer 32 performs selection of TS packets based on PID (Packet Identification) arranged in the header of the TS packets constituting the digital stream from the front end unit 31, and only selects the selected TS packets. And output to the decoding LSI 33.
[0068]
The decryption LSI 33 is a one-chip LSI, and includes a filter 41, a decryptor 42, a key table storage unit 43, a checker 44, and a FIFO (First In First Out) buffer 45.
[0069]
Under the control of the CPU 34, the filter 41 inspects the data arranged in the payload of the section composed of the TS packets from the demultiplexer 32 as necessary, discards unnecessary TS packets, and creates the necessary TS. Only the packet is output to the decoder 42.
[0070]
The decoder 42 decrypts the data (in this case, the IP packet) arranged in the payload of the section composed of the TS packets from the filter 41 with the decryption key stored in the key table storage unit 43, and sends it to the checker 44. Output. Further, as described with reference to FIG. 2, when the encryption key is updated in the transmission system 1 and the updated encryption key is transmitted, the decryptor 42 decrypts the encryption key according to the control of the CPU 34. As a key, the stored contents of the key table storage unit 43 are updated. Therefore, here, the common key encryption method is used as the encryption method. However, a public key encryption method can be used as the encryption method.
[0071]
The key table storage unit 43 includes a terminal 24 connected to the receiving device 22 via the cable 25.₁, 24₂,... Stores a key table in which each MAC address and a decryption key assigned to each MAC address are registered in association with each other.
[0072]
Under the control of the CPU 34, the checker 44 performs error detection on the IP packet output from the decoder 42 by using the CRC code of the section in which the IP packet is arranged, so that the decoding in the decoder 42 is normal. It is determined whether or not it was performed. The IP packet processed by the checker 44 is supplied to the FIFO buffer 45. The FIFO buffer 45 temporarily stores the IP packet from the checker 44, and the stored IP packet is controlled under the control of the CPU 34. , Output to I / F (Interface) 35. As a result, the data rate of the IP packet is adjusted.
[0073]
The CPU 34 controls the front end unit 31, the demultiplexer 32, the decoding LSI 33, and the I / F 35. The I / F 35 receives the IP packet from the FIFO buffer 45 via the cable 25 according to the control of the CPU 34._iFunctions as an interface to supply
[0074]
Next, FIG. 5 shows a configuration example of a key table stored in the key table storage unit 43 of FIG.
[0075]
The key table is, for example, the terminal 24 connected to the cable 25.₁, 24₂,... Are made up of the same number of entries. In FIG. 5, the key table has N entries # 1 to #N. Therefore, in the present embodiment, the cable 25 has N terminals 24.₁Thru 24_NIs connected. The maximum number of key table entries is limited by the storage capacity of the key table storage unit 43 and the like.
[0076]
Each entry #i (I = 1, 2,..., N) includes a terminal 24._i48-bit MAC address MACaddress # i and an m-bit decryption key assigned to the MAC address (m is based on the encryption format used) are registered in association with each other. In the present embodiment, as described above, there are an Even period and an Odd period, and encryption is performed with different encryption keys in each period, so that each entry #i is encrypted in the Even period. Decryption key (hereinafter referred to as “Even decryption key” where appropriate) K for decrypting the encrypted data_{Even # i}And a decryption key for decrypting data encrypted in the Odd period (hereinafter referred to as an Odd decryption key as appropriate) K_{Odd # i}Are registered.
[0077]
Further, a Valid bit indicating whether the entry #i is valid (hereinafter referred to as an entry Valid bit as appropriate) is added to the head of the MAC address MACaddress # i of each entry #i. Also, the Even decryption key K of each entry #i_{Even # i}And Odd decryption key K_{Odd # i}In addition, a Valid bit indicating whether each is valid (hereinafter referred to as a decryption key Valid bit as appropriate) is added.
[0078]
Here, the entry valid bit and the decryption key valid bit represent, for example, that it is valid when it is 1, and that it is not valid when it is 0. However, the assignment of 0 and 1 for the entry valid bit and the decryption key valid bit can be reversed from the case described above.
[0079]
As described above, in the transmission system 1, the same decryption key as the new encryption key used in the next period is distributed to the reception system 3 in the period immediately before that. Therefore, in the Even period, the same decryption key (Odd decryption key) as the encryption key used in the next Odd period is distributed, and in the Odd period, the same decryption key as the encryption key used in the next Even period is distributed. The key (Even decryption key) is distributed. In the decryptor 42, the decryption key distributed in this way is set (for example, overwritten) in the key table under the control of the CPU 34. Therefore, in this case, the decryption key used in the next period is set in the key table until the end of the current period, and further, the decryption key change accompanying the change in the period does not involve the CPU 34. Since it is only necessary to switch the position (address) of the key table to be read by the decoder 42, it can be performed instantaneously.
[0080]
Next, the operation of the receiving device 22 in FIG. 4 will be described with reference to the flowchart in FIG.
[0081]
The antenna 21 receives the satellite broadcast wave transmitted from the transmission system 1 via the satellite 2, and the received signal obtained as a result is transmitted through the front end unit 31 and the demultiplexer 32, so that the digital signal of the TS packet is received. The stream is supplied to the decoding LSI 33.
[0082]
In the decoding LSI 33, a section composed of TS packets output from the demultiplexer 32 is supplied to the decoder 42 via the filter 41. The decoder 42 receives the section, and in step S11, sets the MAC address arranged in the section header in a variable MA as a built-in register.
[0083]
The decryptor 42 searches the MAC address entry that matches the variable MA by referring to the key table, that is, reads the MAC address registered in each entry #i in order from the entry # 1 of the key table. Then, the MAC address is compared (matched) with the variable MA, and in step S12, it is determined whether there is an entry with a MAC address that matches the variable MA. If it is determined in step S12 that there is no MAC address entry that matches the variable MA, that is, if the terminal having the MAC address arranged in the section header is not connected on the cable 25, the process proceeds to step S13. Proceeding, the decoder 42 discards the section supplied thereto and ends the process.
[0084]
If it is determined in step S12 that there is an entry with a MAC address that matches the variable MA, the process proceeds to step S14 with that entry as a target entry.
[0085]
In step S14, the decoder 42 determines whether the target entry is valid based on the entry Valid bit of the target entry. When it is determined in step S14 that the entry of interest is not valid, that is, when the entry Valid bit of the entry of interest is 0, the process proceeds to step S13, where the decoder 42 discards the section supplied thereto and performs processing. Exit.
[0086]
Therefore, even if a terminal having the MAC address arranged in the section header of the section supplied to the decoder 42 is connected on the cable 25, when the entry of the MAC address is not valid, the section Is not supplied to the terminal on the cable 25.
[0087]
If it is determined in step S14 that the entry of interest is valid, that is, if the entry Valid bit of the entry of interest is 1, the process proceeds to step S15, where the decoder 42 determines the PSC of the section header (FIG. 3 ( The lower bit of B)), that is, the encryption determination flag is referred to, and it is determined whether or not the data (IP packet) of the section payload is encrypted. If it is determined in step S15 that the encryption determination flag is 0, that is, if the IP packet arranged in the payload of the section is not encrypted, steps S17 and S18 are skipped and the process proceeds to step S19. The decryptor 42 outputs the unencrypted IP packet to the FIFO buffer 45 via the checker 44 and ends the process.
[0088]
Then, the IP packet stored in the FIFO buffer 45 is sent via the I / F 35 to the terminal 24 on the cable 25 specified by the MAC address in the section header of the section in which the IP packet is arranged._iTo be supplied.
[0089]
On the other hand, if it is determined in step S15 that the encryption determination flag is 1, that is, if the IP packet arranged in the payload of the section is encrypted, the process proceeds to step S16, and the decoder 42 The upper bit of the PSC (FIG. 3B) of the section header of the section, that is, the period determination flag is set in a variable EO as a built-in register, and the process proceeds to step S17.
[0090]
In step S17, the decoder 42 determines the period corresponding to the variable EO in the entry of interest whose MAC address matches the variable MA, that is, the Even period when the variable EO is 0, and the Odd period when it is 1. It is determined whether or not the decryption key Valid bit # (MA, EO) of the decryption key is valid. If it is determined in step S17 that the decryption key valid bit # (MA, EO) is not valid, that is, if the decryption key valid bit # (MA, EO) is 0, the process proceeds to step S13, where the decryptor 42 , The section supplied thereto is discarded, and the process ends.
[0091]
Therefore, even if the terminal having the MAC address arranged in the section header of the section supplied to the decoder 42 is connected on the cable 25 and the entry of the MAC address is valid, the period determination flag When the decryption key for the period represented by is not valid, the section is not supplied to the terminal on the cable 25.
[0092]
On the other hand, if it is determined in step S17 that the decryption key Valid flag # (MA, EO) is valid, that is, if the decryption key Valid bit # (MA, EO) is 1, the process proceeds to step S18 and decryption is performed. The unit 42 reads the decryption key Key (MA, EO) of the period corresponding to the variable EO in the entry of interest whose MAC address matches the variable MA from the key table, and uses the decryption key Key (MA, EO) to The IP packet arranged in the payload is decoded, and the process proceeds to step S19.
[0093]
In step S19, the decoder 42 outputs the decoded IP packet to the FIFO buffer 45 via the checker 44, and ends the process.
[0094]
Then, the IP packet stored in the FIFO buffer 45 is sent via the I / F 35 to the terminal 24 on the cable 25 specified by the MAC address in the section header of the section in which the IP packet is arranged._iTo be supplied.
[0095]
The process according to the flowchart of FIG. 6 is performed each time a section is supplied to the decoder 42.
[0096]
As described above, based on the entry Valid bit registered in the key table entry, it is determined whether or not the entry is valid, and the data output to the terminal is controlled. It is possible to easily limit users (terminals) that can receive the data.
[0097]
Furthermore, since the output of data is controlled based on the decryption key Valid bit of the key table, for example, for a certain terminal, reception of data only in either the Even period or the Odd period is received. It is possible to easily perform permission and prohibit reception of data in the other period.
[0098]
It should be noted that the entry valid bit and the decryption key valid bit can be set voluntarily in the receiving device 22, or based on information transmitted from the transmission system 1. is there.
[0099]
In this embodiment, the decryption key (including the encryption key) is assigned to the MAC address unique to the terminal. However, for example, the decryption key sets a terminal ID (Identification) unique to the terminal, for example. It is also possible to assign to the terminal ID. Furthermore, the decryption key can be assigned to each group ID by setting a unique group ID for each of a plurality of terminals. However, when assigning a decryption key to a MAC address, a fine limited reception mechanism as described above is used for digital satellite broadcasting in compliance with the DVB standard EN 301 192 V1.1.1 (1997-12). It can be easily incorporated into the framework.
[0100]
In this embodiment, the filter 41, the decoder 42, the key table storage unit 43, the checker 44, and the FIFO buffer 45 are configured by the one-chip decoding LSI 33. However, the filter 41, the decoder 42, The key table storage unit 43, the checker 44, and the FIFO buffer 45 can be configured as separate chips. However, if the filter 41, the decoder 42, the key table storage unit 43, the checker 44, and the FIFO buffer 45 are configured by the one-chip decoding LSI 33, the data decoding is completely hidden from the outside of the decoding LSI 33. Since it is performed in the form, security can be improved. Furthermore, the filter 41, the decoder 42, the key table storage unit 43, the checker 44, and the FIFO buffer 45 are configured by a one-chip decryption LSI 33 from the viewpoint of reducing the circuit mounting area and increasing the processing speed. Is desirable.
[0101]
In the present embodiment, the case of distributing data by digital satellite broadcasting has been described. However, the present invention is also applicable to, for example, the case of distributing data by multicast.
[0102]
Furthermore, in this embodiment, the two periods, the Even period and the Odd period, are provided. However, it is possible not to provide such a period, or to provide three or more periods. It is also possible. Similarly, the number of decryption keys registered in each entry of the key table can be only one, or three or more.
[0103]
In the present embodiment, data is distributed in a form that conforms to the DVB standard. However, data can also be distributed in a form that does not conform to the DVB standard.
[0104]
Next, the series of processes described above can be performed by hardware or software. When a series of processing is performed by software, a program constituting the software is installed in a general-purpose computer, a one-chip microcomputer, or the like.
[0105]
FIG. 7 shows a configuration example of an embodiment of a computer in which a program for executing the above-described series of processing is installed.
[0106]
The program can be recorded in advance in a hard disk 105 or a ROM 103 as a recording medium built in the computer.
[0107]
Alternatively, the program is stored temporarily on a removable recording medium 111 such as a floppy disk, a CD-ROM (Compact Disc Read Only Memory), an MO (Magneto optical) disc, a DVD (Digital Versatile Disc), a magnetic disc, or a semiconductor memory. It can be stored permanently (recorded). Such a removable recording medium 111 can be provided as so-called package software.
[0108]
The program is installed in the computer from the removable recording medium 111 as described above, or transferred from the download site to the computer wirelessly via a digital satellite broadcasting artificial satellite, LAN (Local Area Network), The program can be transferred to a computer via a network such as the Internet, and the computer can receive the program transferred in this way by the communication unit 108 and install it in the built-in hard disk 105.
[0109]
The computer includes a CPU (Central Processing Unit) 102. An input / output interface 110 is connected to the CPU 102 via the bus 101, and the CPU 102 allows the user to operate an input unit 107 including a keyboard, a mouse, and the like via the input / output interface 110. When a command is input by the above, a program stored in a ROM (Read Only Memory) 103 is executed accordingly. Alternatively, the CPU 102 also transfers from a program stored in the hard disk 105, a program transferred from a satellite or a network, received by the communication unit 108 and installed in the hard disk 105, or a removable recording medium 111 attached to the drive 109. The program read and installed in the hard disk 105 is loaded into a RAM (Random Access Memory) 104 and executed. Thus, the CPU 102 performs processing according to the above-described flowchart or processing performed by the configuration of the above-described block diagram. Then, the CPU 102 outputs the processing result from the output unit 106 configured with an LCD (Liquid Crystal Display), a speaker, or the like via the input / output interface 110, or from the communication unit 108 as necessary. Transmission and further recording on the hard disk 105 are performed.
[0110]
Here, in the present specification, the processing steps for describing a program for causing the computer to perform various processes do not necessarily have to be processed in time series in the order described in the flowcharts, but in parallel or individually. This includes processing to be executed (for example, parallel processing or processing by an object).
[0111]
Further, the program may be processed by one computer or may be distributedly processed by a plurality of computers. Furthermore, the program may be transferred to a remote computer and executed.
[0112]
【The invention's effect】
  According to the data processing device, the data processing method, and the recording medium of the present invention,Entry validity information indicating whether the entry registered is valid, the key assigned to the destination registered in the entry, and whether the key assigned to the destination registered in the entry is valid And a table having entries registered with key valid information indicating the entry having a destination that matches the destination of the data block from the table stored in the storage means, and obtained as a result of the search It is determined whether the target entry is valid based on the entry valid information registered in the target entry that is an entry, and whether the key of the target entry is valid is determined based on the key valid information registered in the target entry. If the target entry is determined to be valid, the key of the target entry is determined to be valid. Data that has been decrypted using the key registered in the entry of interest is output to the destination placed in the data block, and if it is determined that the entry of interest is not valid, the data is discarded, If it is determined that the key of the target entry is not valid, the data is discarded.Therefore, it is possible to easily limit users who can acquire data normally.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration example of an embodiment of a broadcasting system to which the present invention is applied.
FIG. 2 is a flowchart for explaining processing of the transmission system 1 of FIG. 1;
FIG. 3 is a diagram illustrating a format of a section and a section header.
4 is a block diagram illustrating a configuration example of the receiving device 22 in FIG. 1;
FIG. 5 shows a key table.
6 is a flowchart for explaining processing of the reception device 22 of FIG. 4;
FIG. 7 is a block diagram illustrating a configuration example of an embodiment of a computer to which the present invention has been applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission system, 2 Satellites, 3 Reception system, 4 Network, 11 Control apparatus, 12 Data server, 13 Transmission processing apparatus, 13A Encryption key table memory | storage part, 14 Antenna, 15 Line connection apparatus, 16 Cable, 21 Antenna, 22 Reception Equipment, 23 line connection equipment, 24₁, 24₂  Terminal, 31 front-end unit, 32 demultiplexer, 33 decoding LSI, 34 CPU, 35 I / F, 41 filter, 42 decoder, 43 key table storage unit, 44 checker, 45 FIFO buffer, 101 bus, 102 CPU, 103 ROM, 104 RAM, 105 hard disk, 106 output unit, 107 input unit, 108 communication unit, 109 drive, 110 input / output interface, 111 removable recording medium

Claims (7)

A data processing apparatus that processes data encrypted with a key assigned to a destination and a data block in which the destination of the data is arranged,
Entry valid information indicating whether the registered entry is valid, the key assigned to the destination registered in the entry, and whether the key assigned to the destination registered in the entry is valid Storage means for storing a table having entries in which key validity information indicating whether or not is registered ;
Search means for searching an entry having a destination that matches the destination of the data block from the table stored in the storage means ;
Based on the entry validity information registered in the entry of interest that is an entry obtained as a result of the search by the search means, it is determined whether the entry of interest is valid, and the key validity information registered in the entry of interest Determination means for determining whether or not the key of the entry of interest is valid ,
In the determination means, when it is determined that the target entry is valid, when it is determined that the key of the target entry is valid, the data arranged in the data block is the target entry. Output the data decrypted using the key registered in the data block to a destination arranged in the data block, and when the determination unit determines that the target entry is not valid, discards the data; Output control means for controlling the output of the data arranged in the data block so as to discard the data when the determination means determines that the key of the entry of interest is not valid. A data processing device. The data processing apparatus according to claim 1, further comprising decryption means for decrypting the encrypted data using the key registered in the entry of interest . The data processing apparatus according to claim 1 , wherein each entry of the table is registered with two or more keys assigned to a destination registered in the entry . 4. The data processing apparatus according to claim 3 , wherein key validity information indicating whether or not each of the two or more keys is valid is registered in each entry of the table. 5. The data processing apparatus according to claim 1, wherein the data processing apparatus is configured by a one-chip IC (Integrated Circuit). A data processing method of a data processing apparatus comprising a storage means, a search means, a determination means, and an output control means, wherein the destination of the data is arranged together with the data encrypted using the key assigned to the destination the data processing method for processing data blocks,
In the storage means, a destination, entry validity information indicating whether or not the registered entry is valid, a key assigned to the destination registered in the entry, and a destination assigned to the entry registered in the entry A storage step of storing a table having entries in which key validity information indicating whether the key is valid is registered ;
A search step of searching for an entry having a destination matching the destination of the data block from the table stored in the storage unit by the search unit ;
The determination means determines whether the attention entry is valid based on the entry valid information registered in the attention entry that is an entry obtained as a result of the search in the retrieval step, and is registered in the attention entry. A determination step of determining whether the key of the entry of interest is valid based on the key validity information ;
When it is determined by the output control means in the determining step that the attention entry is valid, the data arranged in the data block is determined when the key of the attention entry is determined to be valid. And outputting the data decrypted using the key registered in the target entry to a destination arranged in the data block, and when determining that the target entry is not valid in the determination step, Output control step for controlling the output of the data arranged in the data block so as to discard the data when the data is discarded and it is determined in the determination step that the key of the entry of interest is not valid data processing method which comprises and. A data process for processing a data block in which a destination of the data is arranged together with data encrypted using a key assigned to the destination ,
Entry valid information indicating whether the registered entry is valid, the key assigned to the destination registered in the entry, and whether the key assigned to the destination registered in the entry is valid A search step for searching for an entry having a destination that matches the destination of the data block from a table stored in storage means, the table including entries in which key validity information representing whether or not is registered;
Based on the entry valid information registered in the target entry that is an entry obtained as a result of the search in the search step, it is determined whether the target entry is valid, and the key valid information registered in the target entry is included in the key valid information registered in the target entry. A determination step for determining whether the key of the entry of interest is valid based on :
In the determination step, when it is determined that the target entry is valid, when it is determined that the key of the target entry is valid, the data arranged in the data block is the target entry. Output the data decrypted using the key registered in the data block to a destination arranged in the data block, and when the determination step determines that the target entry is not valid, discard the data; An output control step for controlling output of the data arranged in the data block so that the data is discarded when it is determined in the determination step that the key of the entry of interest is not valid ;
A recording medium on which is recorded a program that causes a computer to perform data processing .

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