CN101444096B - Encrypting device, decrypting device, license issuing device and content data generating method - Google Patents

Abstract

A content composed of a plurality of resources such as image, voice, and data broadcasting is respectively encrypted and transmitted, and the received encrypted data stream is distributed to each resource on the receiving side.

Description

Encrypting device, decrypting device, license issuing device and content data generating method

technical field

The present invention relates to an encryption device, a decryption device, a license issuing device and a content data generation method.

This application claims the priority of Japanese Patent Application No. 2006-137002 filed on May 16, 2006 and Japanese Patent Application No. 2006-137004 filed on May 16, 2006, and uses the contents thereof here.

Background technique

Conventionally, for example, Patent Document 1 describes a service providing system using broadcast waves and communication lines. In the prior art described in Patent Document 1, content is transmitted by broadcast waves, and a broadcast decoder activation signal for effectively functioning a broadcast decoder built in a terminal on the receiving side is transmitted through a communication line, whereby the received On the side, the broadcast decoder becomes active based on the broadcast decoder activation signal received through the communication line, and receives (views and listens to) content based on the broadcast wave.

However, in the above-mentioned prior art, even when content composed of a plurality of resources (video, audio, data, etc.) Effective, so can not provide a variety of service methods.

In recent years, digital broadcasting for mobile terminals has been put into practical use as a conventional technology related to mobile terminals. As an encryption method for program data in digital broadcasting for mobile terminals, considering the processing capability of mobile terminals, it is considered that data stream encryption with a light processing load is easier than the block encryption method generally used for content distribution such as the Internet. way is ideal. In the data stream encryption method, the states of the data stream encryption algorithms of both the encryption device and the decryption device are consistent, which is indispensable for normal decryption.

However, in digital broadcasting, due to a transmission error of the broadcast data, etc., if the transmission packet storing the stream encrypted data is lost, the states of the stream encryption algorithms of the encryption device and the decryption device become inconsistent, and decryption occurs. mistake.

Patent Document 1: Japanese Patent Laid-Open No. 2005-159457

Patent Document 2: Japanese Patent No. 3030341

Patent Document 3: Japanese Patent No. 3455748

Contents of the invention

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide an encryption device, a decryption device, and a license issuing device that can provide users with various service methods when content composed of a plurality of resources is provided by broadcast waves.

Another object of the present invention is to provide an encryption device, a decryption device, and a content data generation method of a data stream encryption method capable of strengthening resistance against loss of transmission data due to transmission errors.

In order to solve the above-mentioned problems, the present invention has, for example, the following aspects.

The encryption device according to claim 1 of the present invention is preferably an encryption device for providing content composed of a plurality of resources using broadcast waves, and includes: an encryption unit for encrypting each of the resources to be encrypted with each encryption key; and generating a data packet. a unit for generating a data packet respectively storing encrypted data or non-encrypted data of each resource; a sending unit for sending the data packet.

The license issuing device according to claim 2 of the present invention is preferably a license issuing device that, in a state where each of the resources to be encrypted is encrypted with each of the encryption keys for content composed of a plurality of resources, Providing a license for decrypting encrypted resources when provided using broadcast waves through a communication line, including: a storage unit that stores the license; a transmission unit that transmits the license in the storage unit; A combination of a license identifier and a decryption key; the license identifier indicating the broadcast range in which the license becomes valid; the decryption key is provided corresponding to each resource to be encrypted.

The decryption device according to claim 3 of the present invention is preferably a decryption device that, with respect to content composed of a plurality of resources, provides the content by broadcast waves in a state in which the respective resources to be encrypted are encrypted with respective encryption keys. , comprising: a broadcast receiving unit for receiving data packets by broadcast waves; a data packet distribution unit for distributing data packets with encrypted data according to different resources of encrypted objects according to the received data packets; a license receiving unit, The license is received through the communication line; the decryption unit uses each decryption key in the received license to decrypt the encrypted data in the data packet allocated according to the different resources of the encrypted object.

The decryption device according to claim 4 of the present invention is the decryption device, and preferably further includes a license holding unit for storing a license.

The decryption device according to claim 5 of the present invention is the decryption device described above, and preferably further includes a decryption control unit, and the decryption control unit controls decryption of the broadcast range in which the license is valid based on a license identifier in the license.

The decryption device according to claim 6 of the present invention is the above decryption device, and preferably further includes an accumulation unit that accumulates contents received by broadcast waves.

The decryption device according to claim 7 of the present invention is the above-mentioned decryption device, and preferably further includes a license obtaining unit that obtains a license valid for a broadcast range being received through a communication line.

The decryption device according to claim 8 of the present invention is the decryption device, and preferably further includes: a display unit for displaying on a display screen content that is being received or is scheduled to be received by broadcast waves; and a specifying unit for specifying the content clearly displayed on the display screen. Content: a license acquiring unit that acquires a license corresponding to the content specified by the specifying unit through a communication line.

The decryption device according to claim 9 of the present invention is the decryption device, preferably further comprising: a display unit for expressly displaying on a display screen the content being received or scheduled to be received by broadcast waves or the content accumulated in the accumulation unit; and a specifying unit, The content clearly displayed on the display screen is specified; and the license obtaining means acquires a license corresponding to the content specified by the specifying means through a communication line.

In the decryption device according to claim 10 of the present invention, it is preferable that the display unit clearly indicates on a display screen the presence or absence of a license corresponding to the content clearly indicated on the display screen.

According to the above aspects of the present invention, various service forms can be provided to users when content composed of a plurality of resources is provided using broadcast waves.

Moreover, in order to solve the above-mentioned subject, this invention has the following aspects, for example.

The encryption device according to the eleventh aspect of the present invention preferably includes: an initialization data packet generation unit, which generates an initialization data packet storing an initial value used in the initialization of the data stream encryption algorithm at an initialization interval of the data stream encryption algorithm; the encryption unit uses The initial value stored in the initialization data packet initializes the data stream encryption algorithm and encrypts the data stream; the encrypted data packet generation unit generates an encrypted data packet storing the encrypted data of the data stream; the sending unit sends the initialization data package and the encrypted data package.

In the encryption device according to claim 12 of the present invention, it is preferable that the initialization packet generating unit uses an initialization interval corresponding to a media type of encrypted data.

The encryption device according to claim 13 of the present invention is the encryption device, preferably, a plurality of the encryption units are provided; the initialization data packet generating unit stores the initial values of the encryption units in the initialization data packet.

The encryption device according to claim 14 of the present invention is the encryption device, and it is preferable that the initialization data packet and the encryption data packet are both transmission packets, and their types are different.

The decryption device according to claim 15 of the present invention preferably includes: a receiving unit that receives an initialization data packet and an encrypted data packet; a decryption unit that uses the initial value stored in the initialization data packet to initialize the data stream encryption algorithm, and The stream encrypted data saved in the encrypted data packet is decrypted.

The decryption device according to claim 16 of the present invention is the decryption device, and preferably a plurality of the decryption units are provided; the decryption unit decrypts the specified encrypted data of the data stream by using the specified initial value.

The decryption device according to claim 17 of the present invention is the decryption device, and preferably further includes a counting unit for counting the number of lost encrypted data packets; the decryption unit performs the decryption corresponding to the lost number idling.

The decryption device according to claim 18 of the present invention is the decryption device, preferably further corresponding to each of the decryption units, a counting unit for counting the number of losses of the encrypted data packets is provided; The number of losses corresponds to the decrypted idling.

In the decryption device according to claim 19 of the present invention, it is preferable that the decryption unit prevents idling of the decryption when the count range of the count unit is exceeded.

The decryption device according to claim 20 of the present invention is the decryption device, preferably, the initialization data packet and the encrypted data packet are both transmission packets, and their types are different.

The encryption device related to the 21st aspect of the present invention includes: an initialization data packet inserting unit, in the data packet string storing the content data of the data stream, according to the processing unit of each data stream content data, inserting and storing the initialization of the encryption algorithm in the data stream The initialization data packet of the initial value used in the initialization data packet; the encryption unit uses the initial value stored in the initialization data packet to initialize the data flow encryption algorithm, and performs the data flow encryption of the data flow content data; the sending unit sends and saves The encrypted data packet of the encrypted data stream content data and the initialization data packet.

In the encryption device according to claim 22 of the present invention, it is preferable that the initialization packet inserting unit inserts the initialization packet immediately before a packet storing a reference image frame.

In the encryption device according to claim 23 of the present invention, it is preferable that the reference picture frame is an I picture or an IDR picture.

The encryption device according to claim 24 of the present invention is the encryption device, and preferably, the initialization packet inserting unit inserts the initialization packet immediately before a packet storing a speech frame.

In the encryption device according to claim 25 of the present invention, it is preferable that the initialization packet inserting unit inserts the initialization packet immediately before the packet storing the ADTS header.

The encryption device according to claim 26 of the present invention is the encryption device, preferably, the initialization data packet inserting unit inserts the initialization data for each data unit of repeated broadcasting into a data packet string storing data broadcast content data. Bag.

The content data generating method according to claim 27 of the present invention is preferably the following content data generating method: use the initial value stored in the initialization data packet to initialize the data stream encryption algorithm, perform data stream encryption on the data stream content data, and store the data In the packet sequence of the stream content data, an initialization packet storing an initial value used for initializing the stream encryption algorithm is inserted for each processing unit of the stream content data.

In the content data generation method according to claim 28 of the present invention, in the content data generation method, it is preferable that the initialization packet is inserted immediately before a packet storing a reference image frame.

The content data generation method according to claim 29 of the present invention is the content data generation method, and preferably, the reference image frame is an I picture or an IDR picture.

In the content data generation method according to claim 30 of the present invention, the content data generation method preferably inserts the initialization packet immediately before a packet storing a voice frame.

In the content data generation method according to claim 31 of the present invention, in the content data generation method, it is preferable that the initialization packet is inserted immediately before the packet storing the ADTS header.

The content data generation method according to claim 32 of the present invention is the content data generation method, preferably inserting the initializing packet into the packet sequence storing the data broadcasting content data for each repeated data unit.

According to the above-mentioned aspects of the present invention, the data stream encryption method can be strengthened against loss of transmission data due to transmission errors or the like.

Moreover, in order to solve the above-mentioned subject, this invention has the following aspects, for example.

The encryption device according to claim 33 of the present invention is the encryption device. Preferably, the encryption unit encrypts each of the resources to be encrypted with each encryption key for the content composed of a plurality of resources; the encryption a data packet generating unit, generating a data packet respectively storing encrypted data or non-encrypted data of each resource; the sending unit sends the data packet generated by the encrypted data packet generating unit.

The encryption device according to claim 34 of the present invention is the encryption device, and preferably further includes an initialization packet generation unit, and the initialization packet generation unit generates and saves the data used in the initialization of the data stream encryption algorithm at the initialization interval of the data stream encryption algorithm. An initialization data packet of an initial value; the encryption unit uses the initial value stored in the initialization data packet to initialize a data stream encryption algorithm and perform data stream encryption.

In the encryption device according to claim 35 of the present invention, it is preferable that the initialization packet generating unit uses an initialization interval corresponding to a media type of encrypted data.

The encryption device according to claim 36 of the present invention is the encryption device. Preferably, a plurality of the encryption units are provided; and the initialization data packet generation unit stores the initial values of the encryption units in the initialization data packet.

The encryption device according to claim 37 of the present invention is the encryption device, preferably, the initialization data packet and the encryption packet are both transmission packets, and their types are different.

A thirty-eighth aspect of the present invention is a broadcasting system that provides content using broadcast waves, preferably including: an encryption unit that encrypts each content composed of a plurality of resources with each encryption key, and generates an encrypted file that stores the resources respectively. data or non-encrypted data packets, and send them; the license issuance unit sends the license for decrypting the encrypted data through the communication line; the decryption unit receives the data packets, and sends the license with the encrypted data The data packets are allocated according to the resource of the encrypted object, and the encrypted data is decrypted using the license received through the communication line; the license has a license indicating that the license becomes a valid broadcast range a combination of a certificate identifier and a decryption key corresponding to each of the resources to be encrypted; The encrypted data in the data packet distributed is decrypted.

Description of drawings

FIG. 1 is a block diagram showing the configuration of a broadcasting system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of the encryption device 100 shown in FIG. 1 .

FIG. 3 is a diagram showing a configuration example of a transport packet (TS packet) according to an embodiment of the present invention.

FIG. 4 is a diagram showing a configuration example of a license 200 provided by the license issuing device 2 shown in FIG. 1 .

FIG. 5 is a block diagram showing the configuration of the decryption device 300 shown in FIG. 1 .

FIG. 6 is a diagram showing a configuration example of the display screen 30 of the terminal device 3 shown in FIG. 1 .

7 is a data structure diagram of a broadcast signal for explaining a configuration example of an identifier for a combination of an encryption process and a decryption process according to an embodiment of the present invention.

8 is a data structure diagram of a descriptor example for explaining a configuration example of an identifier of a combination of an encryption process and a decryption process according to an embodiment of the present invention.

FIG. 9 is a block diagram showing the configuration of a decryption device according to another embodiment of the present invention.

FIG. 10 is a block diagram showing the configuration of an encryption device 1100 of a data stream encryption method according to Embodiment 2 of the present invention.

FIG. 11 is a diagram showing a configuration example of an initialization packet (IV packet) according to the embodiment.

FIG. 12 is a block diagram showing the configuration of a decryption device 1200 of a data stream encryption scheme according to Embodiment 2 of the present invention.

FIG. 13 is a block diagram showing the configuration of a decryption device 1220 of a data stream encryption scheme according to Embodiment 3 of the present invention.

FIG. 14 is a block diagram showing the configuration of a decryption device 1240 of a data stream encryption scheme according to Embodiment 4 of the present invention.

FIG. 15 is a block diagram showing the configuration of an encryption device 1120 of a data stream encryption method according to Embodiment 5 of the present invention.

FIG. 16 is an explanatory diagram for explaining an IV packet insertion operation according to Embodiment 5 of the present invention.

FIG. 17 is an explanatory diagram for explaining an IV packet insertion operation according to Embodiment 5 of the present invention.

Explanation of symbols:

1—broadcast station; 2—license issuing device; 3—terminal device; 4—communication network; 30—display screen; 31—image screen; 32—data broadcast screen; 100—encryption device; 110—encryption department; 111— Encryption process; 120—data packet generation unit; 130—sending unit; 200—license; 300—decryption device; 310—broadcast receiving unit; 320—data packet distribution unit; 330—decryption unit; 331—decryption process; 340— 350—license maintenance department; 360—license management department; 370—license acquisition control department; 600—accumulation department; 1100—encryption device; 1120—encryption device; IV data packet insertion unit; 1103—encryption unit; 1104—transmission unit; 1121—data analysis unit; 1200—decryption device; 1220—decryption device; 1240—decryption device; 1201—reception unit; 1204—decryption portion; 1221—count verification portion; 1241—count verification and decryption portion; 1102a—IV data packet insertion portion; 1130—I image; 1140—IV data packet; 1150— ADTS head; 1300—reproducing device; 1301—image reproducing unit; 1302—voice reproducing unit; 1303—data broadcasting display unit.

Detailed ways

Embodiment 1

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a broadcasting system according to an embodiment of the present invention. In FIG. 1 , a broadcasting station 1 has an encryption device 100 . The encryption device 100 encrypts content provided by broadcast waves. The license-issuing device 2 supplies a license for decrypting encrypted content provided in broadcast waves from the broadcasting station 1 through a communication line. The terminal device 3 has a decryption device 300 . The decryption device 300 decrypts encrypted content provided in broadcast waves from the broadcast station 1 using the license provided from the license-issuing device 2 .

The license issuing device 2 and the terminal device 3 have a communication function and are connected to a communication network 4 such as the Internet. The terminal device 3 may be a stationary terminal or may be a portable terminal. In the case of a portable terminal, it is connected to the Internet or the like through a mobile communication network. In addition, the terminal device 3 has a function of receiving broadcast waves.

FIG. 2 is a block diagram showing the configuration of the encryption device 100 shown in FIG. 1 . In FIG. 2, content is composed of a plurality of resources. Examples of types of resources include video, audio, data, and the like. All resources in the content may be encrypted, or there may be resources that are not encrypted. In the example of FIG. 2 , the content is composed of N resources_#1 to #N. Resources_#1 and #2 are encrypted, so they are encrypted, but resource_#N is not encrypted, so it is not encrypted. If specific examples are given, for content composed of video resources, audio resources, and data resources, it may be considered to encrypt video resources and audio resources, but not to encrypt data resources.

The encryption device 100 shown in FIG. 2 includes an encryption unit 110 , a packet generation unit 120 , and a transmission unit 130 . The encryption unit 110 may have a plurality of encryption processes 111 . Each encryption process 111 encrypts the resource to be encrypted with its own encryption key. In the example shown in FIG. 2 , resources_#1 and #2 to be encrypted are encrypted with encryption keys_#1 and #2 in each encryption process 111 . The encrypted data of each resource is input to the packet generation unit 120 . In addition, the resource_#N (non-encrypted data) that is not an encryption target is input to the packet generation unit 120 as it is.

The packet generation unit 120 generates a transport packet (TS packet) for storing encrypted data or non-encrypted data of each resource. FIG. 3 shows a configuration example of a TS packet. The TS packet in FIG. 3 conforms to ISO/IEC13818-1 (MPEG-2 system standard). In FIG. 3 , in the data_byte field, encrypted data is stored when it is an encrypted target resource, and non-encrypted data is stored when it is a non-encrypted target resource. In addition, the transport_scrambling_control field in the header holds a value representing an encryption target resource or a non-encryption target resource. Values "01", "10" and "11" of the transport_scrambling_control field indicate an encryption target resource. The value "00" of the transport_scrambling_comtrol field indicates that it is a non-encrypted object resource.

Also, in the case of an encryption target resource, the values "01", "10" and "11" of the transport_scrambling_control field identify the encryption process 111 that scrambles the resource. Therefore, according to the values "01", "10", and "11" of the transport_scrambling_control field, three encryption processes 111 can be identified. Here, the encryption process is paired with the decryption process on the decryption device side, but the decryption process on the decryption device side is specified with the values "01", "10", and "11" of the transport_scrambling_control field. In addition, in the case of using the transport_scrambling_control field, there can be three combinations of the encryption process and the decryption process, but an extension method for corresponding to a greater number of combinations will be described later.

The transmitting unit 130 transmits the TS packet sequence received from the packet generating unit 120 .

FIG. 4 is a diagram showing a configuration example of a license 200 provided by the license issuing device 2 shown in FIG. 1 . In FIG. 4, a license 200 is composed of a combination of a license identifier (license ID) and a decryption key. The license ID indicates that the license becomes a valid broadcast range. The broadcast range is defined, for example, by broadcast time, broadcast channel, content, resource, and the like. If specific examples are given, a specific broadcast channel at a specific broadcast time, specific content of a specific broadcast channel, or one or more specific resources of the specific content, etc., are considered as the broadcast range.

In the license 200, a decryption key combined with a license ID is provided corresponding to each encryption target resource. For example, in the example of FIG. 2 , the encryption target resources_#1, #2 are encrypted by the decryption keys_#1, #2, respectively. At this time, decryption keys_#1, #2 are set corresponding to each of the encryption target resources_#1, #2.

The license-issuing apparatus 2 has a storage unit that stores a license 200 . For example, the license 200 is stored as a database. Furthermore, the license-issuing apparatus 2 has a transmission unit that transmits the license 200 in the storage unit. This transmitting unit transmits the license 200 to the terminal device 3 via the communication network 4 .

In addition, the license issuing device 2 may be realized by dedicated hardware, or may be constituted by a computer system such as a server computer, and the functions of the license issuing device 2 may be implemented by executing a program for realizing each function of the license issuing device 2 .

FIG. 5 is a block diagram showing the configuration of the decryption device 300 shown in FIG. 1 . In FIG. 5 , broadcast receiving unit 310 receives TS packets using broadcast waves. At this time, the broadcast receiving unit 310 receives the broadcast channel designated by the user operation.

Based on the received TS packets, the packet allocation unit 320 allocates TS packets including encrypted data for different resources to be encrypted. For example, in the case of the TS packet shown in FIG. 3 , the TS packets whose values of the transport_scrambling_control field are "01", "10" and "11" store encrypted data that encrypts resources to be encrypted, but according to the value of the transport_scrambling_control field The values "01", "10" and "11" specify the decryption process to decrypt the encrypted data.

The decryption unit 330 may have a plurality of decryption processes 331 . For each decryption process 331, an identifier that distinguishes each of them is set. In each decryption process 331, the encrypted data of the encryption target resource distributed by the packet distribution unit 320 is input based on the identifier. Each decryption process 331 decrypts encrypted data using each decryption key supplied from the license management unit 360 . Each decrypted data is reproduced on the terminal device 3 . In addition, the non-encrypted data stored in the TS packet of the non-encrypted resource is reproduced on the terminal device 3 as it is.

The license receiving unit 340 receives the license 200 from the license issuing device 2 via the communication network 4 . The user can receive the license 200 by using the terminal device 3 by signing a contract to obtain the license 200 valid for a desired broadcast range using, for example, a license server on the Internet. In addition, the license 200 may be paid or free.

The license holding unit 350 stores the license 200 . According to this, a plurality of licenses 200 can be received and stored in advance, so the trouble of obtaining the license 200 every time viewing is omitted.

The license management unit 360 controls the decryption operation of the decryption unit 330 based on the license 200 . Based on the license ID in the license 200, the license management unit 360 specifies the broadcasting range in which the license 200 becomes valid. For example, by comparing the identification information included in the non-encrypted broadcast signal and the license ID, it is possible to determine the effective broadcast range.

In addition, depending on the device form of the terminal device 3, it is not necessary to provide all the decryption processes 331 corresponding to the license 200 in the decryption device 300, and only the decryption processes 331 corresponding to available services may be provided.

The license management unit 360 reads out the license 200 valid for the broadcast area being received from the license holding unit 350 , and supplies the decryption keys in the license 200 to the corresponding decryption processes 331 . Accordingly, the encrypted data of the decryption target resource included in the broadcast range is automatically decrypted.

The license acquisition control unit 370 acquires the license 200 through the communication network 4 . For example, the license acquisition control unit 370 accesses a license server on the Internet, and contracts to acquire the license 200 . In addition, a license server function may also be provided in the license issuing apparatus 2 . The license 200 that can be acquired by the license contract is received by the license receiving unit 340 . Regarding the acquisition of the license 200, two examples (cases 1 and 2) will be given and described below.

(case 1)

The license management unit 360 instructs the license acquisition control unit 370 to acquire the license 200 valid for the broadcast range being received in the license holding unit 350 when there is no license 200 valid for the broadcast range being received. Based on the acquisition instruction, the license acquisition control unit 370 attempts to acquire the license 200 valid for the broadcast range being received. Accordingly, the license 200 can be automatically acquired.

(case 2)

A display unit is provided on the display screen of the terminal device 3 to clearly indicate the contents being received or scheduled to be received by broadcast waves. For example, when the content has video assets and data assets, on the display screen 30 of the terminal device 3 illustrated in FIG. 6 , the video assets are displayed on the video screen 31 and the data assets are displayed on the data broadcast screen 32 . At this time, for example, a mark indicating the content being received or scheduled to be received by broadcast waves is displayed on the lower part of the video screen 31, so that the corresponding content can be clearly indicated. In addition, content that is being received or is scheduled to be received by broadcast waves can be known from content information in broadcast signals not to be encrypted, such as program-related information multiplexed on broadcast waves, content identifiers, and the like.

In addition, the display unit may clearly display the presence or absence of the license 200 corresponding to the content clearly displayed on the display screen of the terminal device 3 on the display screen. For example, by displaying a mark indicating the presence or absence of the license 200 in the lower portion of the video screen 31 in FIG. 6 , the presence or absence of the corresponding license 200 can be clearly indicated. The presence or absence of the license 200 can be determined by searching the license holding unit 350 .

In addition, specifying means for specifying content clearly displayed on the display screen of the terminal device 3 is provided.

For example, by selecting a mark displayed on the display screen with an operation key of the terminal device 3, the corresponding content can be specified.

The license acquisition control unit 370 attempts to acquire the license 200 corresponding to the specified content. According to this, the user can always acquire the license 200 when he wants to watch, and watch the desired content.

As described above, according to this embodiment, when providing content composed of a plurality of resources (video, audio, data, etc.) by broadcast waves, the broadcast station can set encryption or non-encryption in units of resources. Accordingly, selectable services can be provided in units of resources, and various service methods can be provided to users.

In addition, since the configuration of the decryption key included in the license can be flexibly set, various viewing forms of the content can be realized. For example, in a movie content composed of one video resource and two audio resources (such as Japanese audio and English audio), a license including each decryption key corresponding to the video resource and one audio resource (such as Japanese audio) is set. , and a license including each decryption key corresponding to the video resource and the other audio resource (for example, English audio), so that various types of licenses are set for one content, thereby providing users with various viewing forms .

In addition, the encryption device 100 and the decryption device 300 according to this embodiment may be realized by dedicated hardware, or may be composed of a memory, a CPU (central processing unit), etc., and the CPU executes a program for realizing the functions of each device, thereby realizing The function.

Next, a method of expanding the number of combinations of encryption processes and decryption processes (hereinafter referred to as "process groups") will be described.

In the method of identifying process groups using the value of the transport_scrambling_control field in the header of the TS packet shown in FIG. 3 described above, the process groups can be set to three. Furthermore, as a method of increasing the number of process groups, for example, a method of using the PMT data shown in FIG. 7 and the component descriptor shown in FIG. 8 is mentioned. Each data structure in FIG. 7 and FIG. 8 is defined by the standard specification "STD-B10" of the ARIB (Association of Radio Industries and Business).

The component descriptor shown in FIG. 8 can be stored in the descriptor area 2_500 in the PMT data shown in FIG. 7 . Furthermore, an identifier is stored in an undefined area 510 in this component descriptor. This area 510 has 4 bits, so a maximum of 16 identifiers can be set, and if one identifier indicates non-encryption, a maximum of 15 process groups can be identified with the remaining 15 identifiers.

In addition, the component descriptor is an existing descriptor, but it is also possible to define a new descriptor and use it. In this case, an arbitrary number of identifiers can be set, and the number of process groups can be further expanded.

As above, Embodiment 1 of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like within the range not departing from the gist of the present invention are also included.

For example, an accumulating means for accumulating contents received by broadcast waves may be provided in the decryption device. FIG. 9 shows a configuration example of the decryption device. In FIG. 9 , in the decryption device 300 shown in FIG. 5 , an accumulation unit 600 is further provided. In FIG. 9 , accumulation unit 600 stores and accumulates TS packets received by broadcast reception unit 310 . The packet distributing unit 320 reads TS packets from the accumulating unit 600, and distributes the TS packets containing encrypted data for different resources to be encrypted. According to this, when the user cannot view broadcast content in real time, the received content can be accumulated, decrypted and reproduced at any time, and can be viewed.

In addition, in the decryption device of FIG. 9 , the display means and designation means of the above-mentioned case 2 may be provided, and the license 200 corresponding to the content designated by the user may be acquired. In this case, the display means may clearly display on the display screen of the terminal device 3 the contents being received or scheduled to be received by broadcast waves or the contents accumulated in the accumulating unit 600 .

In addition, the present invention can be applied in various broadcasting systems. For example, it can be applied to a digital broadcasting system for mobile terminals. Accordingly, when content composed of a plurality of resources is provided by digital broadcasting, various service methods corresponding to the characteristics of the mobile terminal can be provided to the user.

In addition, as the encryption method in this embodiment, a data stream encryption method may be used, or a data block encryption method may be used.

[Embodiment 2]

FIG. 10 is a block diagram showing the configuration of an encryption device 1100 of a data stream encryption method according to Embodiment 2 of the present invention.

In FIG. 10, a header conversion unit 1101 performs header conversion of a transport packet (TS packet). The TS packet conforms to ISO/IEC13818-1 (MPEG-2 system standard). The header converter 1101 rewrites the value of the transport_scrambling_control field in the header of the TS packet. The values "01", "10" and "11" of the transport_scrambling_control field indicate that encryption is performed. The value "00" of the transport_scrambling_control field indicates that encryption is not performed.

The IV packet insertion unit 1102 generates an initialization packet (IV packet) at an initialization interval of the stream encryption algorithm, and the initialization packet (IV packet) stores an initial value (IV) used for initialization of the stream encryption algorithm. . Also, the IV packet inserting unit 1102 stores the key ID in the IV packet. There are two types of key IDs, "Current" and "Next". The key ID "Current" is an identifier of a key currently in use. The key ID "Next" is an identifier of a key to be used next. The IV packet insertion unit 1102 inserts the generated IV packet into the TS packet sequence output from the header conversion unit 1101 .

FIG. 11 shows a configuration example of an IV packet in this embodiment. In this embodiment, an IV packet is configured as a type of TS packet. In FIG. 11, the PID field in the header holds a value "0x889 (hexadecimal)" indicating that it is an IV packet. Also, the value of the transport_scrambling_control field is "00". That is, the IV packet is not encrypted. Also, in this example, the adaptation_field_control field is fixed at "01", and the adaptation_field is set to None.

Furthermore, in FIG. 11 , IV (iv), key IDs "Current" (id_current), and "Next" (id_next) are stored in the data_byte field. Also, a plurality of IVs can be stored (iv[n]; n is an integer of 0 or greater). When storing multiple IVs, a set of iv_tsc_flag[n] and iv[n] is formed. Each iv[n] is used in the initialization of the data stream encryption algorithm in each corresponding data stream encryption process.

Also, the initialization interval can be changed for every iv[n]. At this time, only iv[n] which is the initialization time is stored in the IV packet. The initialization interval corresponding to each iv[n] corresponds to each corresponding data stream encryption process. For example, an initialization interval corresponding to the media type of encrypted data is used. Examples of media types include audio, video, data, and the like.

In addition, in the example of FIG. 11, the unused area in the data byte field is filled with "0xff (hexadecimal)". In addition, "Cyclic Redundancy Check: CRC" (CRC_32) for error detection is stored in the data_byte field. Also, on the receiving side of the IV packet, when an error is detected as a result of the CRC check, the IV packet is discarded.

The encryption unit 1103 performs stream encryption on the TS packet sequence after IV packet insertion. The objects to be encrypted are TS packets whose values of the transport_scrambling_control field are "01", "10" and "11". In addition, the header of the TS packet is not encrypted. Also, for the IV packet, the value of the transport_scrambling_control field is "00", so encryption is not performed.

In this stream encryption process, when the encryption unit 1103 finds an IV packet (PID field value "0x889 (hexadecimal)") in the TS packet sequence, it reads the IV from the found IV packet. Then, the stream encryption algorithm is initialized using the read IV. That is, after the stream encryption algorithm is initialized at the position of the IV packet in the TS packet sequence, stream encryption is performed on the TS packets to be encrypted after the IV packet.

In the initialization of this stream encryption algorithm, key IDs "Current" (id_current) and "Next" (id_next) are read from the IV packet, and keys used for stream encryption are prepared.

In addition, the encryption unit 1103 may have multiple data stream encryption processes [n]. Each data stream encryption process [n] uses the corresponding IV(iv[n]) to initialize the data stream encryption algorithm. In addition, each stream encryption process [n] determines the TS packet to be encrypted according to the value of the PID field.

The encryption unit 1103 outputs the TS packet sequence including the IV packet and the encrypted TS packet to the transmission unit 1104 in the order obtained from the IV packet insertion unit 1102 .

The transmission unit 1104 transmits the TS packet sequence obtained from the encryption unit 1103 .

Next, a decryption device of the data stream encryption method according to Embodiment 2 will be described.

FIG. 12 is a block diagram showing the configuration of a decryption device 1200 of a data stream encryption method according to Embodiment 2 of the present invention.

In FIG. 12 , a receiving unit 1201 receives a TS packet transmitted from an encryption device 1100 . The receiving unit 1201 performs error detection and error correction processing on received TS packets.

At this time, the IV packet whose error is detected by the CRC check is discarded.

The packet distributing unit 1202 distributes the TS packets output from the receiving unit 1201 to the respective destinations based on the value of the PID field in the header. Here, the IV packet (the PID field value is “0x889 (hexadecimal)”) is output to the IV packet reading unit 1203 . Also, the encrypted TS packet (values "01", "10", and "11" of the transport_scrambling_control field) is output to the decryption unit 1204 corresponding to the field value. Also, other unencrypted TS packets are output from the decryption device 1200 as they are.

The IV packet reading unit 1203 reads the IV and key IDs "Current" (id_current) and "Next" (id_next) from the IV packet. Based on the read key IDs "Current" (id_current) and "Next" (id_next), a key used for decryption of the stream cipher is prepared. Then, the prepared key and IV are output to the decryption unit 1204 . Also, when a plurality of IVs (iv[n]) are stored in the IV packet, each iv[n] is output to the decryption unit 1204 having a corresponding stream decryption process [n].

The decryption unit 1204 acquires the encrypted TS packet from the packet distribution unit 1202, and decrypts the stream cipher.

In the decryption process of this stream cipher, the decryption unit 1204, upon acquiring the IV and the key from the IV packet reading unit 1203, initializes the stream encryption algorithm using the IV. Next, when the initialization is completed, the decryption process of the stream cipher is started using the key obtained from the IV packet reading unit 1203 . That is, at the position of the IV packet in the received TS packet sequence, after the stream encryption algorithm is initialized, the decryption of the stream cipher for the encrypted TS packets subsequent to the IV packet is performed.

The decryption unit 1204 outputs the decrypted TS packets to the playback device 1300 .

In the playback device 1300, the decrypted TS packets are played back. In the example shown in FIG. 12 , playback device 1300 includes image playback unit 1301 , audio playback unit 1302 , and data broadcast display unit 1303 . Decryption unit 1204 corresponding to image reproduction unit 1301 , audio reproduction unit 1302 , and data broadcast display unit 1303 is provided in decryption device 1200 . In the image reproduction unit 1301, the audio reproduction unit 1302, and the data broadcast display unit 1303, the TS packets output from the corresponding decryption unit 1204 are respectively reproduced. In addition, the configuration of the playback device 1300 shown in FIG. 12 is an example, and the type of media can be changed as appropriate.

According to the above-mentioned second embodiment, the state of the data stream encryption algorithm in the encryption process can be made consistent with the state of the data stream encryption algorithm in the decryption process through the IV packet. Therefore, even if the encrypted TS packet is lost due to a transmission error or the like, and the states of the stream encryption algorithms of both the encryption process and the decryption process temporarily become inconsistent, when the next IV packet is received, the encryption process and the decryption process both The state of the data stream encryption algorithm can also be consistent, and normal decryption can be resumed. According to this, in the data stream encryption method, it is possible to strengthen the tolerance against loss of transmission data due to transmission errors or the like.

[Embodiment 3]

FIG. 13 is a block diagram showing the configuration of a decryption device 1220 of a data stream encryption method according to Embodiment 3 of the present invention. In FIG. 13 , parts corresponding to those in FIG. 12 are assigned the same reference numerals, and description thereof will be omitted. In addition, since the encryption device is the same as that in Embodiment 2, description thereof will be omitted.

In Embodiment 3, as shown in FIG. 13 , a count verification unit 1221 is provided. Only the part related to the count verification unit 1221 is a point of change from the decryption device 1200 of FIG. 12 . The count check unit 1221 counts the number of lost encrypted TS packets.

A continuity_counter (continuity indicator) is inserted into the header of the TS packet. By detecting the continuity_counter, the number of lost TS packets can be counted. The count verification unit 1221 instructs the decryption unit 1204 to idle for decryption corresponding to the number of losses. The count verification unit 1221 instructs the count of the number of losses and the idling of decryption for each decryption unit 1204 .

The decryption unit 1204 idles the decryption process of the stream cipher according to the decryption idle instruction. In this idling, in a state where there is no encrypted data to be decrypted, decryption processing corresponding to the number of lost pieces is performed.

Accordingly, the state of the stream encryption algorithm is shifted by the number corresponding to the number of lost encrypted TS packets. As a result, even if the encrypted TS packet is lost, the states of the stream encryption algorithms of both the encryption process and the decryption process will not become inconsistent, and the states of the stream encryption algorithms of both the encryption process and the decryption process can continue to be consistent. According to this, in the data stream encryption method, it is possible to strengthen the tolerance against loss of transmission data due to transmission errors or the like.

In addition, the count checking unit 1221 does not instruct the idling of decryption when the number of losses exceeds the count range of the count function. This is because when the number of losses exceeds the count range, the idling of correct decryption cannot be performed. The count checking unit 1221 can determine that the number of lost objects exceeds the counting range of the counting function when losses continue for a certain interval or longer based on time information, for example.

Also, when the number of losses exceeds the counting range of the counting function, as in Embodiment 2, the state of the data stream encryption algorithm in both the encryption process and the decryption process can be made consistent by using the IV packet.

[Embodiment 4]

FIG. 14 is a block diagram showing the configuration of a decryption device 1240 of a data stream encryption method according to Embodiment 4 of the present invention. In this FIG. 14 , the parts corresponding to the parts in FIG. 12 are assigned the same reference numerals, and description thereof will be omitted. In addition, the encryption device is the same as that in Embodiment 2, and its description is omitted.

In Embodiment 4, as shown in FIG. 14 , the decryption unit 1204 in FIG. 12 is changed to a count checksum decryption unit 1241 . Only the portion related to the count check and decryption unit 1241 is a point of change from the decryption device 1200 of FIG. 12 . Also, the difference from Embodiment 3 is that the functions of the count verification unit 1221 in FIG. 13 are distributed to each decryption unit.

The count check and decryption unit 1241 counts the number of lost encrypted TS packets, and performs decryption idling corresponding to the lost number. In this idling, the number of decryption processes corresponding to the number of lost pieces is performed in a state where there is no encrypted data to be decrypted. In addition, when the number of losses exceeds the count range of the count function, no instruction is given to idle for decryption. For example, based on the time information, it can be determined that the number of lost objects exceeds the counting range of the counting function when losses continue for a certain interval or longer.

Accordingly, similar to Embodiment 3, even if the encrypted TS packet is lost, the states of the data stream encryption algorithms of both the encryption process and the decryption process will not become inconsistent, and the data stream encryption algorithms of both the encryption process and the decryption process will not become inconsistent. The state can continue to be consistent. Accordingly, in the data stream encryption method, it is possible to strengthen the tolerance against loss of transmission data due to transmission errors or the like.

In addition, when the number of losses exceeds the counting range of the counting function, similar to Embodiment 2, the states of the data stream encryption algorithms in both the encryption process and the decryption process can be made consistent by using the IV packet.

[Embodiment 5]

FIG. 15 is a block diagram showing the configuration of an encryption device 1120 of a data stream encryption method according to Embodiment 5 of the present invention. In FIG. 15 , parts corresponding to those in FIG. 10 are assigned the same reference numerals, and description thereof will be omitted. In addition, as the decryption device, the decryption device of any of the above-mentioned embodiments may be used, and description thereof will be omitted.

In Embodiment 5, as shown in FIG. 15 , a data analysis unit 1121 is provided. Only the part related to the data analysis unit 1121 is a point of change from the encryption device 1100 of FIG. 10 . The data analysis unit 1121 analyzes stream content data stored in TS packets. Through this analysis, the data analysis unit 1121 grasps the processing unit of the stream content data. The data analysis unit 1121 instructs the IV packet insertion unit 1102a to insert an IV packet for each processing unit of stream content data. The IV packet insertion unit 1102a inserts an IV packet at the timing instructed by the data analysis unit 1121 . Accordingly, an IV packet is inserted for each processing unit of stream content data.

Hereinafter, the IV packet insertion operation of this embodiment will be described in detail according to the type of stream content. In addition, here, as examples of streaming content, image content, audio content, and data broadcast content are cited.

(image content)

In the case of image content, an IV packet is inserted immediately before the TS packet storing the reference image frame. For example, in image coding methods such as MPEG-1/2/4, three types of images called I-picture (Intra-Picture), P-picture (Predictive-Picture), and B-Picture (Bi-directional Predictive-Picture) are generated. Among them, the I picture is a reference image frame, and is a frame used as a reference when decrypting an image. Therefore, in order to perform normal picture decryption, it is important to transmit I pictures normally. Therefore, as shown in FIG. 16, the IV packet 1140 is inserted immediately before the TS packet in which the I picture 1130 is stored. According to this, the encryption and decryption of the I picture start with the stream encryption algorithm initialized, so that the encrypted data of the I picture can be decrypted stably. Accordingly, it is possible to contribute to the realization of stable image content reproduction.

In addition, in image coding methods such as H.264, in addition to the above three types of images, a reference image frame called an IDR (Instantaneous Decoder Refresh) image is also generated. At this time, an IV packet may also be inserted immediately before the IDR frame.

(voice content)

In the case of audio content, an IV packet is inserted immediately before the TS packet storing the audio frame. For example, in digital broadcasting and the like, encoded speech data is transmitted in a frame having a header called ADTS (Audio DataTransport Stream). Since the audio frame starts from the ADTS header, the ADTS header serves as a reference when decrypting speech coded data. Therefore, as shown in FIG. 17 , the IV packet 1140 is inserted immediately before the TS packet holding the ADTS header 1150 . Accordingly, the data stream encryption algorithm is initialized immediately before the audio frame, and the encryption and decryption of the audio frame start while the data stream encryption algorithm is initialized, so that the encrypted data of the audio frame can be decrypted stably. Accordingly, it is possible to contribute to the realization of stable audio content playback.

(data broadcast content)

In the case of data broadcast content, an IV packet is inserted for every data unit (cyclic data) that is repeatedly broadcast. According to this, the stream encryption algorithm is initialized immediately before the cyclic data, and the cyclic data encryption and decryption are started with the stream cipher algorithm initialized, so that the encrypted data of the cyclic data can be decrypted stably. Accordingly, it is possible to contribute to the realization of stable playback of data broadcasting content.

As mentioned above, the embodiment of the present invention has been described with reference to the drawings, but the specific configuration is not limited to the present embodiment, and design changes and the like within the range not departing from the gist of the present invention are also included.

For example, the above-mentioned embodiments can be applied in a digital broadcasting system oriented to portable terminals. In this case, in digital broadcasting, even if the TS packet storing the stream encryption data is lost due to a broadcast data transmission error, etc., the state of the stream encryption algorithm on both the broadcast station side and the mobile terminal side becomes inconsistent, The receiving state of digital broadcasting becomes unstable for a while, and the state of data stream encryption algorithms on both the broadcasting station side and the portable terminal side can be made to be the same by using the subsequent IV packet, and the receiving state of digital broadcasting can be restored to a good state. status. Accordingly, it is possible to contribute to the improvement of the quality of digital broadcasting for mobile terminals.

In addition, the present invention can be applied in various broadcasting systems and communication systems.

Industrial availability

According to the present invention, in the case of providing content composed of a plurality of resources by broadcast waves, it is possible to provide users with various service methods. Furthermore, according to the present invention, in the data stream encryption method, it is possible to strengthen the tolerance against loss of transmission data due to transmission errors or the like.

Claims (14)

1. an encryption device, provide the content that is made of a plurality of resources with broadcast wave, comprising:

Ciphering unit is encrypted described each resource of cryptographic object with each encryption key;

The packet generation unit, the packet of enciphered data or the non-encrypted data of described each resource is preserved respectively in generation;

The initialization package generation unit generates the initialization package of the initial value that uses in the initialization of save data stream cipher algorithm with the initialization interval of traffic encryption algorithm;

The initialization package plug-in unit in the packet string that the described packet by save data stream content-data consists of, inserts described initialization package by the processing unit of each described data stream contents data; And

Transmitting element, it sends encrypted packets and the described initialization package of preserving the described data stream contents data after encrypting;

Described ciphering unit uses the initial value of preserving in described initialization package, and the data stream cipher algorithm is carried out initialization, and described data stream contents data are carried out traffic encryption.

2. license issuing device, for the content that is consisted of by a plurality of resources, require 1 described encryption device with each encryption key, described each resource of cryptographic object to be carried out under the state of encryption in right to use, be provided for by communication line the licence that the encrypt asset when utilizing broadcast wave to provide is decrypted, comprise:

Memory cell is stored described licence;

Transmitting element sends the licence in described memory cell;

Described licence is constituted by license identifier and decruption key;

Described license identifier represents that this licence becomes effective broadcasting area;

Each of described decruption key and cryptographic object resource is corresponding and be set up.

3. a decryption device, require 1 described encryption device with each encryption key, each resource of cryptographic object to be carried out utilizing broadcast wave that the content that is made of a plurality of resources is provided under the state of encryption in right to use, comprising:

Receiving element receives initialization package and encrypted packets;

The allocation of packets unit, it distributes the described encrypted packets with enciphered data according to the described packet that has received by the resource difference of cryptographic object;

The licence receiving element receives by communication line the licence that license issuing device claimed in claim 2 is issued;

Decrypting device, use the initial value of preserving in described initialization package, the data stream cipher algorithm is carried out initialization, with each described decruption key in the described licence that has received, the described enciphered data in the described packet that distributes by the resource difference of cryptographic object is decrypted.

4. decryption device according to claim 3,

The licence holding unit that also has the described licence of storage.

5. decryption device according to claim 3,

Also have the deciphering control unit, and should decipher control unit according to the described license identifier in described licence, control the deciphering that this licence becomes the described enciphered data that contains in effective broadcasting area.

6. decryption device according to claim 3,

Also have accumulative element, and this accumulative element accumulates the described content that receives with broadcast wave.

7. decryption device according to claim 3,

Also have licence and obtain the unit, and this licence is obtained the unit and obtained the effective described licence of broadcasting area in receiving by communication line.

8. decryption device according to claim 3,

Also have: display unit, express in display frame and utilize broadcast wave receiving or the predetermined described content that receives;

Designating unit specifies in the described content of expressing in described display frame;

Licence is obtained the unit, by communication line obtain with based on described licence corresponding to the described content of the appointment of described designating unit.

9. decryption device according to claim 6,

Also have: display unit, express in display frame utilize broadcast wave receiving or predetermined receive described in the described content that accumulates in perhaps described accumulative element;

Designating unit specifies in the described content of expressing in described display frame;

Licence is obtained the unit, by communication line obtain with based on described licence corresponding to the content of the appointment of described designating unit.

10. decryption device according to claim 8,

Described display unit is being expressed having or not of the described licence corresponding with the content expressed in described display frame in described display frame.

11. encryption device according to claim 1,

Described initialization package generation unit uses the initialization interval corresponding with the medium kind of encrypted data.

12. encryption device according to claim 1,

A plurality of described ciphering units are set;

Described initialization package generation unit is saved in each initial value of described ciphering unit in initialization package.

13. encryption device according to claim 1,

Described initialization package and described encrypted packets are all transmission package, and its kind is different.

14. a broadcast system possesses:

Encryption device claimed in claim 1;

License issuing device claimed in claim 2;

Decryption device claimed in claim 3.

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