JP2022088741A - Scrambling device and scrambling method - Google Patents

Abstract

To provide a scrambling device to encrypt content information using an ECM generated in an external device, in which an ECM and the content information can be output according to standards for a CAS (Conditional Access System).SOLUTION: A scrambling device 101 includes: a scrambling section which receives an ECM (Entitlement Control Message) including a scramble key, the ECM being sent repeatedly from an ECM transmitter, and encrypts content information using the scramble key included in the ECM; and an output section which outputs the content information encrypted by the scrambling section and the ECM including the scramble key on the scrambling section. That is used to encrypt the content information in the scrambling section. The output section outputs the ECM at timing delayed by predetermined time from output timing of the content information encrypted by using the corresponding scramble key.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to scrambling devices and scrambling methods.

Conventionally, a technique related to CAS (Conditional Access System) for managing contents distributed by digital broadcasting has been developed.

For example, JLabs SPEC-035 2.1 version, "Advanced Cable Voluntary Broadcasting Operation Specifications", Japan Cable Laboratories, December 25, 2018 (Non-Patent Document 1), various matters related to CAS. The standard is disclosed. That is, Non-Patent Document 1 discloses that when the scramble key of the ES (Elementary Stream) to which the ECM (Entility Control Message) is applied is changed, the ECM is updated prior to the change of the scramble key. ing. Further, Non-Patent Document 1 discloses that when the scramble key is changed, the even key is changed to the odd key, and the odd key is changed to the even key in this order, and the same key is not continuously changed.

JLabs SPEC-035 2.1 Edition, "Advanced Cable Voluntary Broadcasting Operation Specifications", Japan Cable Laboratories, December 25, 2018

In a scramble device that encrypts content information using an ECM generated in an external device, a technique capable of outputting the ECM and the content information in accordance with the standards related to CAS is desired.

The present disclosure has been made to solve the above-mentioned problems, and an object thereof is a scramble device for encrypting content information using an ECM generated in an external device, in which the ECM and the content information are in accordance with the standards related to CAS. It is to provide a scrambling device and a scrambling method capable of producing an output.

The scramble device of the present disclosure is a scramble device that receives ECM including a scramble key and encrypts content information repeatedly transmitted from the ECM transmission device, and the ECM is an even key and an odd key as the scramble key. The even key and the odd key are updated alternately, and the ECM management unit that receives the ECM and the scramble key included in the ECM received by the ECM management unit are used. A scramble unit that encrypts the content information, the content information encrypted by the scramble unit, and an output unit that outputs the ECM including the scramble key used for encrypting the content information in the scramble unit. The output unit outputs the ECM at a timing delayed by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key.

The scramble device of the present disclosure is a scramble device that receives ECM including a scramble key and encrypts content information repeatedly transmitted from the ECM transmission device, and the ECM is an even key and an odd key as the scramble key. The even key and the odd key are updated alternately by using the ECM management unit that receives the ECM and the scramble key included in the ECM received by the ECM management unit. A scramble unit that encrypts the content information, the content information encrypted by the scramble unit, and an output unit that outputs the ECM including the scramble key used for encrypting the content information in the scramble unit. The ECM management unit detects the update of the scramble key included in the received ECM, and includes an acquisition unit for acquiring cycle information indicating an update cycle, which is a cycle in which the scramble key is updated. The unit is encrypted at the timing when the time obtained by subtracting the predetermined time from the update cycle indicated by the cycle information acquired by the acquisition unit has elapsed from the timing when the update of the scramble key is detected by the ECM management unit. The scramble key used for encryption is switched between the even key and the odd key.

The scramble method of the present disclosure is a scramble method in a scramble device that repeatedly transmits an ECM including a scramble key and encrypts content information, and the ECM is an even key as the scramble key. And the odd key, the even key and the odd key are updated alternately, and the content information is encrypted using the step of receiving the ECM and the scramble key included in the received ECM. Including the step of outputting the ECM including the encrypted content information and the scramble key used for encrypting the content information, the step of outputting the content information and the ECM is used for encryption. Encryption using the same scramble key by creating a relative time difference between the switching timing for switching the scramble key between the even key and the odd key and the update timing of the scramble key in the output ECM. The same encryption period, which is the period during which the output of the content information is continued, is included in the ECM including the key used, which is the scramble key used for encrypting the content information to be output in the same encryption period. It starts from a predetermined time before the update timing of the scramble key different from the used key.

One aspect of the present disclosure can be realized not only as a scramble device provided with such a characteristic processing unit, but also as a semiconductor integrated circuit that realizes a part or all of the scramble device, or a process in the scramble device. Can be realized as a program for executing the steps of It can be realized as a method in which processing is a step, or it can be realized as a program for causing a computer to execute a processing step in a broadcasting system.

According to the present disclosure, in a scramble device that encrypts content information using an ECM generated in an external device, the ECM and the content information can be output in accordance with the standards related to CAS.

FIG. 1 is a diagram showing a configuration of a broadcasting system according to the first embodiment of the present disclosure. FIG. 2 is a diagram showing an example of a scramble key included in the ECM transmitted by the ECM transmission device according to the first embodiment of the present disclosure. FIG. 3 is a diagram showing a format of TS packets in the broadcasting system according to the first embodiment of the present disclosure. FIG. 4 is a diagram showing a configuration of a scrambler according to the first embodiment of the present disclosure. FIG. 5 is a diagram showing an example of format conversion by the ECM detection unit in the scrambler according to the first embodiment of the present disclosure. FIG. 6 is a diagram showing the format of section data in the broadcasting system according to the first embodiment of the present disclosure. FIG. 7 is a diagram showing a scramble key used by the scramble unit in the scramble device according to the first embodiment of the present disclosure to encrypt a TS packet. FIG. 8 is a diagram showing an example of a timing chart showing the update timing of the scramble key received and transmitted in the scramble device according to the first embodiment of the present disclosure and the scramble key used for encrypting the content information. FIG. 9 is a flowchart defining an example of an operation procedure when the scramble device according to the first embodiment of the present disclosure performs scrambling processing. FIG. 10 is a flowchart defining an example of an operation procedure when the scramble device according to the first embodiment of the present disclosure performs scrambling processing. FIG. 11 is a diagram showing a configuration of a scrambler according to a second embodiment of the present disclosure. FIG. 12 is a diagram showing an example of a timing chart showing the update timing of the scramble key received in the scramble device according to the second embodiment of the present disclosure and the scramble key used for encrypting the content information. FIG. 13 is a diagram showing an example of a timing chart showing the update timing of the scramble key received and transmitted in the scramble device according to the second embodiment of the present disclosure and the scramble key used for encrypting the content information. FIG. 14 is a flowchart defining an example of an operation procedure when the scramble device according to the second embodiment of the present disclosure performs scrambling processing.

First, the contents of the embodiments of the present disclosure will be listed and described.

(1) The scramble device according to the embodiment of the present disclosure is a scramble device that receives ECM including a scramble key repeatedly transmitted from the ECM transmission device and encrypts the content information, and the ECM is the above-mentioned ECM. The scramble key includes an even key and an odd key, and the even key and the odd key are updated alternately, and are included in the ECM management unit that receives the ECM and the ECM received by the ECM management unit. Includes a scramble unit that encrypts the content information using the scramble key, the content information encrypted by the scramble unit, and the scramble key used for encrypting the content information in the scramble unit. The output unit includes an output unit for outputting the ECM, and the output unit outputs the ECM at a timing delayed by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key.

In this way, by configuring the ECM to be output at a timing delayed by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key, for example, the update timing of the ECM transmitted from the ECM transmission device can be changed. At the same time, by changing the switching timing of the scramble key used for encrypting the content information, the scramble key used for encrypting the content information can be switched at a timing predetermined time before the update timing of the output ECM. Therefore, even when the update timing of the ECM transmitted from the ECM transmission device is changed, the ECM and the content information can be output according to the standard regarding CAS. Therefore, in the scramble device that encrypts the content information by using the ECM generated in the external device, the ECM and the content information can be output according to the standard regarding CAS.

(2) Preferably, the ECM management unit detects the update of the scrambled key contained in the received ECM, and the scramble unit detects the update of the scrambled key by the ECM management unit. The scrambled key used for encryption is switched between the even key and the odd key.

With such a configuration, the scramble key used for encrypting the content information can be switched flexibly in response to the update of the update timing of the ECM transmitted from the ECM transmission device.

(3) The scramble device according to the embodiment of the present disclosure is a scramble device that receives ECM including a scramble key repeatedly transmitted from an ECM transmission device and encrypts content information, and the ECM is the above-mentioned ECM. The scrambled key includes an even key and an odd key, and the even key and the odd key are updated alternately, and are included in the ECM management unit that receives the ECM and the ECM that is received by the ECM management unit. Includes a scramble unit that encrypts the content information using the scramble key, the content information encrypted by the scramble unit, and the scramble key used for encrypting the content information in the scramble unit. The ECM management unit includes an output unit that outputs the ECM and an acquisition unit that acquires cycle information indicating an update cycle that is a cycle in which the scramble key is updated, and the ECM management unit includes the scramble key included in the received ECM. The scramble unit has subtracted the predetermined time from the update cycle indicated by the cycle information acquired by the acquisition unit from the timing when the update of the scramble key is detected by the ECM management unit. At the timing when the time has elapsed, the scramble key used for encryption is switched between the even key and the odd key.

In this way, scramble used for encryption at the timing when the update of the scramble key included in the ECM received from the ECM transmission device is detected and the time obtained by subtracting the predetermined time from the update cycle indicated by the acquired cycle information has elapsed. Even if the update cycle of the ECM transmitted from the ECM transmitter is changed by the configuration for switching the key, for example, the content information is encrypted according to the update cycle after the change of the ECM indicated by the cycle information acquired in advance. By changing the switching timing of the scramble key used for the ECM, the scramble key used for encrypting the content information can be switched at a timing predetermined time before the update timing of the ECM. Therefore, even when the update timing of the ECM transmitted from the ECM transmission device is changed, the ECM and the content information can be output according to the standard regarding CAS. Therefore, in the scramble device that encrypts the content information by using the ECM generated in the external device, the ECM and the content information can be output according to the standard regarding CAS.

(4) The scramble method according to the embodiment of the present disclosure is a scramble method in a scramble device that repeatedly receives an ECM including a scramble key and encrypts content information, which is repeatedly transmitted from the ECM transmission device, and is the ECM. Includes an even key and an odd key as the scramble key, and the even key and the odd key are updated alternately, and the step of receiving the ECM and the scramble key included in the received ECM are used. The content information is encrypted using and the ECM including the encrypted content information and the scramble key used for encrypting the content information is output, and the content information and the ECM are output. In the step, the same is performed by creating a relative time difference between the switching timing for switching the scramble key used for encryption between the even key and the odd key and the update timing of the scramble key in the ECM to be output. The scramble key used for encrypting the content information output in the same encryption period during the same encryption period, which is the period during which the output of the content information encrypted using the scramble key continues. It starts from a predetermined time before the update timing of the scramble key different from the used key in the ECM including the used key.

In this way, in the scramble device that receives the ECM repeatedly transmitted from the ECM transmission device and encrypts the content information, the same encryption period is set from the update timing of the scramble key different from the used key in the ECM including the used key. ECM and content information can be output according to the standards related to CAS by the method starting from a predetermined time before. Therefore, in the scramble device that encrypts the content information by using the ECM generated in the external device, the ECM and the content information can be output according to the standard regarding CAS.

(5) Preferably, in the step of receiving the ECM, the update of the scramble key included in the received ECM is detected, and in the step of outputting the content information and the ECM, the encryption is performed at the switching timing. In the step of switching the scramble key used for the conversion to the scramble key different from the scramble key updated immediately before the even key and the odd key, and outputting the content information and the ECM, the update The time difference is created by delaying the timing by a predetermined time from the switching timing.

By such a method, even if the update timing of the ECM transmitted from the ECM transmission device is changed, the ECM and the content information can be output according to the standard regarding CAS, so that the ECM received from the ECM transmission device can be output. Content information can be encrypted flexibly in response to changes in the update timing of.

(6) Preferably, the scramble method further includes a step of acquiring cycle information indicating an update cycle, which is a cycle in which the scramble key is updated, and in a step of receiving the ECM, the received ECM is used. In the step of detecting the update of the included scramble key and outputting the content information and the ECM, at the switching timing, the scramble key used for encryption is immediately before the even key and the odd key. In the step of switching to the updated scramble key and outputting the content information and the ECM, the switching timing is obtained by subtracting the predetermined time from the update cycle indicated by the acquired cycle information from the update timing. The time difference is created by delaying the time.

By such a method, even if the update cycle of the ECM transmitted from the ECM transmission device is changed, the content information is encrypted according to the update cycle after the change of the ECM indicated by the cycle information acquired in advance, for example. By changing the switching timing of the scramble key used for, the ECM and content information can be output in accordance with the standards related to CAS, so the content information can be encrypted flexibly in response to changes in the ECM update timing received from the external device. Can be done.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated. In addition, at least a part of the embodiments described below may be arbitrarily combined.

<First Embodiment>
[Configuration and basic operation]
FIG. 1 is a diagram showing a configuration of a broadcasting system according to the first embodiment of the present disclosure. With reference to FIG. 1, the broadcasting system 401 includes an ECM transmission device 201, an EMM (Enterprise Management Message) transmission device 202, a scramble device 101, an encoder device 111, a remax device 121, and a plurality of STBs (Set Tops). Box) 301 is provided. A CAS module (not shown) is connected to the STB301.

For example, the ECM transmission device 201 and the encoder device 111 are provided at different locations from each other. More specifically, the ECM transmission device 201 and the EMM transmission device 202 are provided in the program distribution center 251. The encoder device 111, the scramble device 101, and the remax device 121 are provided in the cable television station 151. The STB301 is provided in the subscriber's house 351. The STB301 includes a cable television broadcast receiving device (not shown).

The program distribution center 251 distributes the content to the subscriber's house 351 via the cable TV station 151. The program distribution center 251 collectively manages the contents and the contract information for each subscriber's house 351.

The ECM transmission device 201 generates an ECM including information about a program which is an example of content, a scramble key for encrypting content information such as video information and audio information, and various control information. The ECM includes an even key KE and an odd key KO as scrambled keys, and the even key KE and the odd key KO are updated alternately. For example, the even-numbered key KE and the odd-numbered key KO are alternately updated at each update timing UT according to the update cycle UC. The update cycle UC is, for example, 8 seconds.

The ECM transmission device 201 encrypts the generated ECM using the work key, and transmits the encrypted ECM to the scramble device 101. More specifically, the ECM transmission device 201 generates section data including encrypted ECM, and generates a plurality of TS packets containing information in which the generated section data is divided into a plurality of parts, for example, one or a plurality of IPs (Internet). Protocol) Included in a packet and transmitted to the scrambler 101 via the IP transmission network 211. In the IP transmission network 211, IP packets are transmitted according to the IP protocol.

FIG. 2 is a diagram showing an example of a scramble key included in the ECM transmitted by the ECM transmission device according to the first embodiment of the present disclosure.

With reference to FIG. 2, for example, the ECM transmission device 201 repeatedly transmits the ECM to the scramble device 101 with a predetermined period PC. Specifically, the ECM transmission device 201 repeatedly transmits ECM_E1 including the odd key KO1 and the even key KE2 by the predetermined cycle PC in the period from the update timing UT1 to the next update timing UT2, and from the update timing UT2 to the next. In the period up to the update timing UT3, the ECM_E2 including the even key KE2 and the odd key KO3 is repeatedly transmitted by the PC at a predetermined cycle, and in the period from the update timing UT3 to the next update timing UT4, the odd key KO3 and the even key KE4 are included. ECM_E3 is repeatedly transmitted by a PC at a predetermined cycle. The predetermined period PC is, for example, 100 milliseconds. The ECM transmission device 201 may be configured to repeatedly transmit the ECM to the scramble device 101 on an irregular basis.

With reference to FIG. 1 again, the EMM transmission device 202 generates an EMM including contract information for each subscriber's house 351 and a work key for decrypting the encrypted ECM. The EMM transmission device 202 encrypts the generated EMM using a master key set so that it can be decrypted by the CAS module at the subscriber's house 351 that has made a viewing contract for the program. The EMM transmission device 202 transmits the EMM encrypted using the master key to the scramble device 101. More specifically, the EMM transmission device 202 generates section data including encrypted EMM, and the generated section data is divided into a plurality of TS packets, for example, into one or a plurality of IP packets. Including, it is transmitted to the scramble device 101 and the remax device 121 via the IP transmission network 211.

The cable television station 151 scrambles or encrypts the content information, and transmits the encrypted content information to the STB 301 of the subscriber's house 351.

More specifically, the encoder device 111 acquires content information from the program distribution center 251 as a content operator, and encodes the acquired content information to encode the acquired content information into a plurality of TSs including information in which the content information is divided into a plurality of pieces. Generate a packet. The encoder device 111 includes the generated plurality of TS packets in, for example, one or a plurality of IP packets and transmits the scrambled device 101.

The scramble device 101 receives the ECM including the scramble key repeatedly transmitted from the ECM transmission device 201, and encrypts the content information. More specifically, the scramble device 101 receives an IP packet from the encoder device 111 and acquires a TS packet from the received IP packet.

Further, the scramble device 101 receives an IP packet from the EMM transmission device 202 via the IP transmission network 211, and acquires the EMM from the TS packet included in the received IP packet. The scramble device 101 acquires a work key from the EMM by decrypting the acquired EMM using the master key. The scramble device 101 updates the work key stored in the CAS module described later with the work key acquired from the EMM.

Further, the scramble device 101 receives an IP packet from the ECM transmission device 201 via the IP transmission network 211, and acquires an ECM from the TS packet included in the received IP packet. The scramble device 101 acquires the scramble key from the ECM by decrypting the acquired ECM using the work key stored in the CAS module.

The scramble device 101 scrambles and outputs the TS packet acquired from the IP packet received from the encoder device 111. More specifically, the scramble device 101 encrypts the TS packet using the acquired scramble key. The scramble device 101 includes the encrypted TS packet and a plurality of TS packets including information obtained by dividing the ECM into a plurality of encrypted TS packets into, for example, one or a plurality of IP packets and transmits the encrypted TS packet to the remax device 121. do.

FIG. 3 is a diagram showing a format of TS packets in the broadcasting system according to the first embodiment of the present disclosure. With reference to FIG. 3, the TS packet has a data length of 188 bytes and includes a header, an adaptation field, and a payload. The headers are a synchronization byte, a transport error indicator, a payload unit start indicator, a transport priority, a PID (Packet Identity), a transport scramble control, an adaptation field control, and a continuity index, that is, CC (Continuity). Includes the Counter) value.

The PID is an identifier of the TS packet. The PID is an identifier represented by 13 bits and is set to a value corresponding to the content of the payload of the TS packet. The payload unit start indicator is 1-bit data indicating whether or not the information contained in the payload is started from the payload. The CC value is a 4-bit counter value that indicates the continuity of TS packets and is incremented for each TS packet having the same PID. The transport scramble control is a 2-bit control that indicates whether the information contained in the payload is encrypted, and whether the information contained in the payload is encrypted using the even key KE or the odd key KO. It is data.

With reference to FIG. 1 again, the remax device 121 receives an IP packet from the EMM transmission device 202 via the IP transmission network 211. Further, the remax device 121 receives an IP packet from the scramble device 101.

The remax device 121 generates an RF (Radio Frequency) band broadcast signal by modulating the received IP packet by a predetermined modulation method. The remax device 121 transmits the generated broadcast signal to the subscriber's house 351 via the cable television network 311.

The STB 301 in the subscriber's house 351 receives the broadcast signal transmitted from the remax device 121 via the cable television network 311. The STB301 acquires encrypted content information, ECM and EMM by demodulating the received broadcast signal. The STB301 acquires a work key by decrypting an EMM using a CAS module, acquires a scramble key by decrypting an ECM using the acquired work key, and decodes content information using the acquired scramble key. Scramble or decrypt. The STB301 transmits the decoded content information to a TV monitor (not shown). The TV monitor plays a program based on the content information received from STB301.

[Scramble device]
FIG. 4 is a diagram showing a configuration of a scrambler according to the first embodiment of the present disclosure. With reference to FIG. 4, the scramble device 101 includes an ECM management unit 10, an EMM management unit 20, an acquisition unit 30, a scramble unit 40, an output unit 50, a storage unit 60, and a CAS module 70. .. The ECM management unit 10 includes an ECM detection unit 11, a key output unit 12, and an ECM decoding unit 13. The work key is stored in the CAS module 70. The storage unit 60 may be provided outside the scramble device 101.

(Acquisition department)
The acquisition unit 30 acquires cycle information indicating the update cycle UC in the ECM transmitted by the ECM transmission device 201. The acquisition unit 30 stores the acquired cycle information in the storage unit 60.

For example, the acquisition unit 30 receives an IP packet including periodic information from the ECM transmission device 201 via the IP transmission network 211 periodically or irregularly. The acquisition unit 30 acquires periodic information from the received IP packet, and stores the acquired periodic information in the storage unit 60.

Alternatively, the operator at the cable television station 151 receives notification of the update cycle UC from the program distribution center 251 periodically or irregularly. The operator performs an operation of inputting the notified update cycle UC to the scramble device 101 using a keyboard or a mouse. The reception unit (not shown) in the scramble device 101 receives an input operation by the operator and outputs cycle information indicating the update cycle UC to the acquisition unit 30. The acquisition unit 30 receives the cycle information from the reception unit and stores the received cycle information in the storage unit 60.

(ECM Management Department)
The ECM management unit 10 receives the ECM transmitted from the ECM transmission device 201. The ECM management unit 10 outputs the scramble key included in the received ECM to the scramble unit 40. As described above, the ECM includes an even-numbered key KE and an odd-numbered key KO as scrambled keys, and the even-numbered key KE and the odd-numbered key KO are alternately updated, for example, at each update timing UT.

More specifically, the ECM detection unit 11 in the ECM management unit 10 receives an IP packet from the ECM transmission device 201 via the IP transmission network 211, and acquires a TS packet from the received IP packet. When the ECM detection unit 11 determines that a part of the section data including the ECM is stored in the payload of the TS packet by referring to the PID or the like in the acquired TS packet, the ECM detection unit 11 outputs the TS packet. Output to 50.

Further, the ECM detection unit 11 converts the data format of the TS packet into the data format of the section data.

FIG. 5 is a diagram showing an example of format conversion by the ECM detection unit in the scrambler according to the first embodiment of the present disclosure. With reference to FIG. 5, the section data has a data length of up to 1024 bytes or up to 4096 bytes, for example. The section data is generated in the ECM transmission device 201, divided into a plurality of TS packets having a data length of, for example, 188 bytes, and included in the IP packet for transmission. The section data includes a field of a header part, a field of a data part, and a field of CRC (Cyclic Redundancy Check) 32.

The ECM detection unit 11 reconstructs the section data including the encrypted ECM generated in the ECM transmission device 201 by combining the data stored in the payload of the TS packet.

FIG. 6 is a diagram showing the format of section data in the broadcasting system according to the first embodiment of the present disclosure. With reference to FIG. 6, the header part in the section data includes a table identifier, a section syntax instruction, a section length, a table identifier extension, a version number, a current next instruction, a section number, and a final section number. include.

The table identifier indicates the table to which the section data belongs. The value of the table identifier is "0x82" or "0x83" when the table to which the section data belongs is an ECM, that is, when the ECM is stored in the data unit. Here, the numbers starting with "0x" mean that the numbers after "0x" are represented by hexadecimal numbers. The version number indicates the version number of the table. The value of the version number is updated with the update of the scramble key included in the ECM stored in the data unit.

The ECM detection unit 11 acquires the encrypted ECM from the data unit of the reconstructed section data, and outputs the acquired ECM to the ECM decoding unit 13.

The ECM decoding unit 13 receives the ECM from the ECM detection unit 11 and decodes the received ECM using the work key stored in the CAS module 70. The ECM decoding unit 13 outputs the scrambled key, that is, the even key KE and the odd key KO included in the decoded ECM to the key output unit 12.

The key output unit 12 receives the even-numbered key KE and the odd-numbered key KO from the ECM decoding unit 13, and outputs either the received even-numbered key KE or the odd-numbered key KO to the scramble unit 40.

The ECM management unit 10 detects the update of the scramble key included in the received ECM. For example, the ECM detection unit 11 detects the update of the scramble key included in the ECM stored in the data unit of the section data based on the information stored in the header unit of the reconstructed section data.

As an example, the ECM detection unit 11 detects the update of the scramble key included in the ECM stored in the data unit of the section data based on the value of the version number of the reconstructed section data. More specifically, each time the section data is reconstructed, the ECM detection unit 11 acquires the value of the version number from the reconstructed section data, and from the acquired version number value and the section data reconstructed immediately before. By comparing with the acquired version number value, the change of the version number is detected.

When the ECM detection unit 11 detects a change in the version number of the section data, it determines that the scramble key included in the ECM stored in the section data has been updated, and detects the change in the version number, which is the detection timing DT. The detection information indicating the above is output to the key output unit 12.

The key output unit 12 receives the detection information from the ECM detection unit 11 and acquires the cycle information from the storage unit 60. The key output unit 12 outputs a scramble key to be output to the scramble unit 40 as an even number key at the timing when the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC indicated by the cycle information has elapsed from the detection timing DT indicated by the detection information. Switch between KE and odd key KO.

(EMM Management Department)
The EMM management unit 20 receives an IP packet from the EMM transmission device 202 via the IP transmission network 211, and acquires a TS packet from the received IP packet. When the EMM management unit 20 determines that a part of the section data including the EMM is stored in the payload of the TS packet by referring to the PID or the like in the acquired TS packet, the EMM management unit 20 and the ECM decoding unit 13 Similarly, the data format of the TS packet is converted into the data format of the section data.

The EMM management unit 20 reconstructs the section data including the encrypted EMM generated in the EMM transmission device 202 by combining the data stored in the payload of the TS packet.

The EMM management unit 20 acquires an encrypted EMM from the field of the data unit of the reconstructed section data, and decodes the acquired EMM using, for example, a master key assigned in advance from the program distribution center 251. To obtain the work key from EMM. The EMM management unit 20 updates the work key stored in the CAS module 70 with the work key acquired from the EMM.

(Scramble part)
The scramble unit 40 encrypts the content information by using the scramble key included in the ECM received by the ECM management unit 10.

More specifically, the scramble unit 40 receives an IP packet from the encoder device 111, and encrypts the TS packet included in the received IP packet by using the scramble key received from the key output unit 12.

FIG. 7 is a diagram showing a scramble key used by the scramble unit in the scramble device according to the first embodiment of the present disclosure to encrypt a TS packet. FIG. 7 shows the update timing of the ECM and the switching timing of the scramble key used for encryption, which are defined in the standard described in Non-Patent Document 1.

With reference to FIG. 7, in the above standard, the update cycle UC is defined as a period T1 starting from the nth update timing UTn and a period T2 from the end time of the period T1 to the (n + 1) th update timing UT (n + 1). It is stipulated that the content information is encrypted using the same scramble key in the period starting from the period T2 and the update timing UT (n + 1). Here, n is an integer of 1 or more. Further, in the above standard, it is stipulated that the period T1 is set to be larger than 7600 milliseconds, the period T2 is set to be larger than zero seconds, and the sum of the period T1 and the period T2 is set to be larger than 8000 milliseconds.

Hereinafter, the scrambled key to be used in the period T1 is also referred to as a current key, and the scrambled key to be used in the period T2 is also referred to as a next key.

The scramble unit 40 encrypts the TS packet using the current key in the period T1 and encrypts the TS packet using the next key in the period T2 according to the standard regarding the switching of the scramble key. The details of switching the scramble key used for encryption in the scramble unit 40 will be described later. The scramble unit 40 outputs the encrypted TS packet to the output unit 50.

(Output section)
The output unit 50 outputs the content information encrypted by the scramble unit 40 and the ECM including the scramble key used for encrypting the content information in the scramble unit 40.

More specifically, the output unit 50 takes the encrypted TS packet received from the scramble unit 40 and the TS packet received from the ECM detection unit 11 in which a part of the section data including the ECM is stored. It is multiplexed in the axial direction, and each TS packet after multiplexing is transmitted to the remax device 121.

The scramble device 101 outputs the content and the ECM so that the duration of the encryption key used for the output content, that is, the scramble key is within the duration of the encryption key in the output ECM. More specifically, the output unit 50 is encrypted including the content information so that the period for outputting the content information encrypted using the scramble key is included in the period for outputting the ECM including the scramble key. The TS packet and the TS packet in which a part of the section data including the ECM is stored are multiplexed and transmitted to the remax device 121.

<Scramble key switching process>
FIG. 8 is a diagram showing an example of a timing chart showing the update timing of the scramble key received and transmitted in the scramble device according to the first embodiment of the present disclosure and the scramble key used for encrypting the content information.

With reference to FIG. 8, the scramble unit 40 subtracts a predetermined time Tb from the update cycle UC indicated by the cycle information acquired by the acquisition unit 30 from the detection timing DT in which the update of the scramble key is detected by the ECM management unit 10. At the timing ST when the time Ta has elapsed, the scramble key used for encryption is switched between the even key KE and the odd key KO.

More specifically, the ECM detection unit 11 in the ECM management unit 10 detects that the scramble key included in the ECM received from the ECM transmission device 201 has been updated at the nth update timing UTn, and sets the detection timing DTn. The indicated detection information is output to the key output unit 12. The detection timing DTn is the same timing as the update timing UTn, or the timing immediately after the update timing UTn.

The key output unit 12 receives the detection information from the ECM detection unit 11, and the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC indicated by the cycle information in the storage unit 60 elapses from the detection timing DTn indicated by the received detection information. At the timing ST (n + 1), the scramble key to be output to the scramble unit 40 is switched between the odd key KO and the even key KE. For example, the predetermined time Tb is equal to the length of the period T2 described above. As described above, in the timing ST (n + 1), ST (n + 2), ST (t + 3) ..., The key output unit 12 outputs the scramble key to the scramble unit 40 between the odd-numbered key KO and the even-numbered key KE. Switch. Hereinafter, the timing ST is also referred to as a switching timing ST.

For example, the key output unit 12 switches the scramble key output to the scramble unit 40 to the scramble key updated immediately before among the even-numbered key KE and the odd-numbered key KO at the switching timing ST. More specifically, in the switching timing ST, the key output unit 12 updates the scramble key output to the scramble unit 40 at the detection timing DT immediately before the switching timing ST among the even key KE and the odd key KO. Switch to the scrambled key.

Specifically, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 at the switching timing ST2 to the even-numbered key KE2 updated at the detection timing DT1 immediately before the switching timing ST2. Further, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 at the switching timing ST3 to the odd-numbered key KO3 updated at the detection timing DT2 immediately before the switching timing ST3. Further, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 in the switching timing ST4 to the even-numbered key KE4 updated in the detection timing DT3 immediately before the switching timing ST4.

The scramble unit 40 encrypts the TS packet using the scramble key received from the key output unit 12, so that the scramble key used for encryption is set between the odd-numbered key KO and the even-numbered key KE at the switching timing ST. Switch with.

As a result, the scramble unit 40 has the even-numbered key KE and the odd-numbered key KO included in the ECM received by the ECM management unit 10 in the target period TXn starting from the switching timing STn, which is a predetermined time before the nth update timing UTn. Encrypt content information using either one. Further, the scramble unit 40 is the ECM management unit 10 in the target period TX (n + 1) following the target period Tn, which starts from the switching timing ST (n + 1) predetermined time before the (n + 1) th update timing UT (n + 1). The content information is encrypted using either the even key KE or the odd key KO included in the ECM received by.

Specifically, for example, the key output unit 12 outputs to the scramble unit 40 at the switching timing ST2 in which the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC 1 has elapsed from the detection timing DT1 corresponding to the update timing UT1. The scramble key is switched from the odd key KO1 to the even key KE2. More specifically, the key output unit 12 outputs the odd key KO1 included in the ECM_E1 received from the ECM compound unit 13 to the scramble unit 40 during the period from the detection timing DT1 to the switching timing ST2, and from the switching timing ST2. During the period up to the update timing UT2, the even key KE2 included in the ECM_E1 received from the ECM compound unit 13 is output to the scramble unit 40.

Further, for example, the key output unit 12 outputs a scramble key to be output to the scramble unit 40 at the switching timing ST3 in which the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC from the detection timing DT2 corresponding to the update timing UT2 has elapsed. Switch from the even key KE2 to the odd key KO3. More specifically, the key output unit 12 outputs the even-numbered key KE2 included in the ECM_E2 received from the ECM compound unit 13 to the scramble unit 40 during the period from the detection timing DT2 to the switching timing ST3, and from the switching timing ST3. During the period up to the update timing UT3, the odd key KO3 included in the ECM_E2 received from the ECM compound unit 13 is output to the scramble unit 40.

Further, for example, the key output unit 12 outputs a scramble key to be output to the scramble unit 40 at the switching timing ST4 in which the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC from the detection timing DT3 corresponding to the update timing UT3 has elapsed. Switch from the odd key KO3 to the even key KE4. More specifically, the key output unit 12 outputs the odd key KO3 included in the ECM_E3 received from the ECM compound unit 13 to the scramble unit 40 during the period from the detection timing DT3 to the switching timing ST4, and from the switching timing ST4. During the period up to the update timing UT4, the even key KE4 included in the ECM_E3 received from the ECM compound unit 13 is output to the scramble unit 40.

The scramble unit 40 encrypts the TS packet using the odd key KO1 received from the key output unit 12 in the period from the detection timing DT1 to the switching timing ST2, and in the target period TX2 from the switching timing ST2 to the switching timing ST3, the scramble unit 40 encrypts the TS packet. The TS packet is encrypted using the even key KE2 received from the key output unit 12, and the TS packet is encrypted using the odd key KO3 received from the key output unit 12 in the target period TX3 from the switching timing ST3 to the switching timing ST4. In the target period TX4 from the switching timing ST4 to the switching timing ST5, the TS packet is encrypted using the even key KE4 received from the key output unit 12.

As described above, the scramble device 101 according to the first embodiment of the present disclosure creates a relative time difference between the switching timing ST and the scramble key update timing UT in the output ECM. More specifically, the scramble device 101 creates the time difference by delaying the switching timing ST by a time Ta later than the update timing UT. By creating the time difference, the scramble device 101 uses the target period TX, which is the period during which the output of the content information encrypted using the same scramble key continues, for encrypting the content information output in the target period TX. It starts at a timing within the output continuation period, which is the period during which the output of the ECM including the scrambled key is continued. The target period TX is an example of the same encryption period. More specifically, the scramble device 101 creates the time difference, so that the target period TX is the key used in the ECM including the key used which is the scramble key used for encrypting the content information output in the target period TX. The scramble key update timing different from UT is started from Tb before a predetermined time. Specifically, for example, the scramble device 101 creates the time difference so that the target period TX3 includes the odd key KO3 which is the key used for encrypting the content information output in the target period TX3. Update timing of even-numbered key KE in ECM_E3 ECM_E3, ECM_E4 including even-numbered key KE4, which is a key used for encrypting content information output in target period TX4, starting from a predetermined time Tb before UT3. The update timing of the odd-numbered key KO in UT4 is started from Tb before a predetermined time.

That is, in the scramble device 101 according to the first embodiment of the present disclosure, the switching timing ST (n + 1) in which the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC from the detection timing DTn corresponding to the update timing UTn has elapsed. In, the scramble key used for encryption is switched between the even key KE and the odd key KO. Thereby, according to the above-mentioned standard for switching the scramble key, the content information is encrypted using the current key included in the ECM received from the ECM transmitting device 201 and transmitted to the remax device 121 in the period T1, and the next update timing is performed. In the period T2 starting from a predetermined time before UT (n + 1), the content information can be encrypted by using the next key included in the ECM that is received from the ECM transmission device 201 and transmitted to the remax device 121.

Here, as the scramble device 101 according to the comparative example, for example, the update cycle UC of the ECM is calculated based on two consecutive detection timing DTs, and the time obtained by subtracting the predetermined time Tb from the calculated update cycle UC from the detection timing DTn. At the switching timing ST (n + 1) after Ta has elapsed, it is conceivable that the scramble key used for encryption is switched between the even key KE and the odd key KO. However, in such a configuration, when the update cycle UC of the ECM transmitted from the ECM transmission device 201 is changed, it may not be possible to switch the scramble key used for encrypting the content information according to the above-mentioned standard.

Specifically, in the scramble device 101 according to the comparative example, the update cycle UC of the ECM transmitted from the ECM transmission device 201 is changed, for example, the (n + 1) th update of the ECM is from the original update timing UT (n + 1). Even when the ECM is updated at the early timing UTm, the update cycle UC calculated from the detection timing DTn is predetermined as in the case where the (n + 1) th update of the ECM is performed at the original update timing UT (n + 1). At the switching timing ST (n + 1) when the time Ta obtained by subtracting the time Tb has elapsed, the scramble key used for encryption is switched between the even key KE and the odd key KO. As a result, the scramble key cannot be switched at a timing before a predetermined period Tb before the actual update timing UTm, and a period larger than zero seconds cannot be secured as the period T2.

On the other hand, in the scramble device 101 according to the first embodiment of the present disclosure, the acquisition unit 30 acquires cycle information indicating an update cycle, which is a cycle in which the scramble key is updated. The ECM management unit 10 detects the update of the scramble key included in the received ECM. The scramble unit 40 has a time Ta obtained by subtracting a predetermined time Tb from the update cycle UC indicated by the cycle information acquired by the acquisition unit 30 from the detection timing DTn which is the timing when the update of the scramble key is detected by the ECM management unit 10. At the elapsed switching timing ST (n + 1), the rumble key used for encryption is switched between the even key KE and the odd key KO.

With such a configuration, when the update cycle UC of the ECM transmitted from the ECM transmission device 201 is changed, for example, cycle information indicating the changed update cycle UC is acquired in advance, and the changed update cycle UC is set. Based on this, the scramble key used for encrypting the content information can be switched at the timing according to the above-mentioned standard. Therefore, in the scramble device 101 that encrypts the content information using the ECM generated by the ECM transmission device 201, which is an external device, the content flexibly responds to the change of the update cycle UC of the ECM received from the ECM transmission device 201. Information can be encrypted.

[Operation flow]
Each device in the broadcasting system according to the first embodiment of the present disclosure includes a computer including a memory, and an arithmetic processing unit such as a CPU in the computer includes a part or all of each step of the following flowchart and sequence. The included program is read from the memory and executed. The programs of these plurality of devices can be installed from the outside. The programs of these plurality of devices are distributed in a state of being stored in a recording medium.

FIG. 9 is a flowchart defining an example of an operation procedure when the scramble device according to the first embodiment of the present disclosure performs scrambling processing.

With reference to FIG. 9, first, the scrambler 101 acquires periodic information (step S102).

Next, the ECM transmitted from the ECM transmission device 201 is received. More specifically, the scramble device 101 receives an IP packet from the ECM transmission device 201 via the IP transmission network 211, and acquires a TS packet from the received IP packet. Then, the scramble device 101 reconstructs the section data including the encrypted ECM by combining the data stored in the payload of the TS packet, and acquires the encrypted ECM from the reconstructed section data. (Step S104).

Next, the scramble device 101 encrypts the content information by using the scramble key included in the acquired ECM. More specifically, the scrambler 101 decodes the acquired ECM using the work key stored in the CAS module 70. Then, the scramble device 101 receives the IP packet from the encoder device 111, and encrypts the TS packet including the content information included in the received IP packet by using the scramble key included in the decoded ECM (step S106). ).

Next, the scramble device 101 outputs the encrypted content information and the ECM including the scramble key used for encrypting the content information. More specifically, the scramble device 101 multiplexes the encrypted TS packet and the TS packet containing a part of the section data including the ECM used for encryption in the time axis direction, and after multiplexing. Each TS packet is transmitted to the remax device 121 (step S108).

FIG. 10 is a flowchart defining an example of an operation procedure when the scramble device according to the first embodiment of the present disclosure performs scrambling processing. FIG. 10 shows the details of step S106 of the flowchart shown in FIG.

With reference to FIG. 10, first, the scramble device 101 listens for the update of the scramble key included in the ECM transmitted from the ECM transmission device 201 (NO in step S202), and the scramble key included in the ECM is updated. (YES in step S202), the encryption is performed at the switching timing ST (n + 1) at which the time Ta obtained by subtracting the predetermined time Tb from the update cycle UC indicated by the cycle information has elapsed from the detection timing DTn that detected the update of the scramble key. The scramble key used for conversion is switched between the even key KE and the odd key KO. That is, the scramble device 101 delays the switching timing ST by a time Ta later than the update timing UT to create a relative time difference between the switching timing ST and the scramble key update timing UT in the output ECM (step S204).

Next, the scramble device 101 waits for the next update of the scramble key included in the ECM transmitted from the ECM transmission device 201 (NO in step S202).

In the broadcasting system 401 according to the first embodiment of the present disclosure, the ECM transmission device 201, the EMM transmission device 202, and the encoder device 111 include the TS packet in one or a plurality of IP packets via the IP transmission network 211. However, the configuration is such that transmission to the scramble device 101 is performed, but the present invention is not limited to this. At least one of the ECM transmission device 201, the EMM transmission device 202, and the encoder device 111 is configured to include the TS packet in the ASI signal, which is an ASI (Asynchronous Serial Interface) type signal, and transmit the TS packet to the scramble device 101. There may be.

Further, in the scramble device 101 according to the first embodiment of the present disclosure, the key output unit 12 has a predetermined time from the detection timing DT indicated by the detection information received from the ECM detection unit 11 and the update cycle UC indicated by the cycle information. In the switching timing ST, which is the timing when the time Ta after deducting Tb has elapsed, the scramble key to be output to the scramble unit 40 is switched between the even key KE and the odd key KO. do not have. The key output unit 12 may be configured to switch the scramble key to be output to the scramble unit 40 between the even-numbered key KE and the odd-numbered key KO in the switching timing ST based on a timing other than the detection timing DT.

Next, other embodiments of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

<Second embodiment>
This embodiment is a scramble that outputs the ECM at a timing delayed by a predetermined time from the output timing of the content information encrypted by using the corresponding scramble key, as compared with the scramble device 101 according to the first embodiment. With respect to device 102. Except for the contents described below, the scrambler device 101 according to the first embodiment is the same.

[Configuration and basic operation]
FIG. 11 is a diagram showing a configuration of a scrambler according to a second embodiment of the present disclosure. With reference to FIG. 11, the scramble device 102 includes an ECM management unit 80 instead of the ECM management unit 10 as compared with the scramble device 101 according to the first embodiment. The ECM management unit 10 includes an ECM detection unit 11, a key output unit 82, an ECM decoding unit 13, and a delay control unit 84.

The ECM detection unit 11 in the ECM management unit 10 receives an IP packet from the ECM transmission device 201 via the IP transmission network 211, and acquires a TS packet from the received IP packet. When the ECM detection unit 11 determines that a part of the section data including the ECM is stored in the payload of the TS packet by referring to the PID or the like in the acquired TS packet, the ECM detection unit 11 delay-controls the TS packet. Output to unit 84.

Further, the ECM detection unit 11 reconstructs the section data including the encrypted ECM generated in the ECM transmission device 201 by combining the data stored in the payload of the TS packet. For example, the ECM detection unit 11 detects the update of the scramble key included in the ECM stored in the data unit of the section data based on the information stored in the header unit of the reconstructed section data. When the ECM detection unit 11 detects a change in the version number of the section data, the ECM detection unit 11 outputs detection information indicating the detection timing DT, which is the timing at which the change in the version number is detected, to the key output unit 82.

The key output unit 82 receives the detection information from the ECM detection unit 11 and switches the scramble key to be output to the scramble unit 40 between the even-numbered key KE and the odd-numbered key KO in the detection timing DT indicated by the received detection information.

The scramble unit 40 receives an IP packet from the encoder device 111, and encrypts the TS packet included in the received IP packet by using the scramble key received from the key output unit 82. The scramble unit 40 outputs the encrypted TS packet to the output unit 50.

The delay control unit 84 receives a TS packet from the ECM detection unit 11, performs delay processing on the received TS packet, and outputs the received TS packet to the output unit 50. More specifically, the delay control unit 84 holds the TS packet received from the ECM detection unit 11 at Tb for a predetermined time, and then outputs the TS packet to the output unit 50.

The output unit 50 uses the TS packet after the delay processing in which a part of the section data including the ECM received from the delay control unit 84 is stored, and the scramble key included in the ECM received from the scramble unit 40. The encrypted TS packet is multiplexed in the time axis direction, and each TS packet after multiplexing is transmitted to the remax device 121.

<Scramble key switching process>
FIG. 12 is a diagram showing an example of a timing chart showing the update timing of the scramble key received in the scramble device according to the second embodiment of the present disclosure and the scramble key used for encrypting the content information.

With reference to FIG. 12, the scramble unit 40 sets the scramble key used for encryption between the even key KE and the odd key KO in the detection timing DTn, which is the timing when the scramble key update is detected by the ECM management unit 10. Switch.

More specifically, the ECM detection unit 11 in the ECM management unit 10 detects that the scramble key included in the ECM received from the ECM transmission device 201 has been updated at the nth update timing UTn, and sets the detection timing DTn. The indicated detection information is output to the key output unit 12.

The key output unit 82 receives the detection information from the ECM detection unit 11 and switches the scramble key to be output to the scramble unit 40 between the odd-numbered key KO and the even-numbered key KE. That is, the key output unit 82 switches the scramble key to be output to the scramble unit 40 between the odd-numbered key KO and the even-numbered key KE, for example, in the switching timing ST which is the timing immediately after the detection timing DT.

For example, in the switching timing ST, the key output unit 12 switches the scramble key output to the scramble unit 40 to a scramble key different from the scramble key updated immediately before among the even key KE and the odd key KO. More specifically, in the switching timing ST, the key output unit 12 updates the scramble key output to the scramble unit 40 at the detection timing DT immediately before the switching timing ST among the even key KE and the odd key KO. Switch to a scrambled key that wasn't there.

Specifically, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 to the even-numbered key KE2 that was not updated in the detection timing DT2 at the switching timing ST immediately after the detection timing DT2. Further, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 to the odd key KO3 that was not updated in the detection timing DT3 at the switching timing ST immediately after the detection timing DT3. Further, for example, the key output unit 12 switches the scramble key output to the scramble unit 40 to the even-numbered key KE4 that was not updated in the detection timing DT4 at the switching timing ST immediately after the detection timing DT4.

As described above, the key output unit 82 switches the scramble key to be output to the scramble unit 40 between the odd-numbered key KO and the even-numbered key KE in the switching timing ST immediately after the detection timing DTn corresponding to the update timing UTn.

The scramble unit 40 encrypts the TS packet using the scramble key received from the key output unit 82, so that the scramble key used for encryption is set between the odd-numbered key KO and the even-numbered key KE at the detection timing DTn. Switch.

FIG. 13 is a diagram showing an example of a timing chart showing the update timing of the scramble key received and transmitted in the scramble device according to the second embodiment of the present disclosure and the scramble key used for encrypting the content information.

With reference to FIG. 13, the output unit 50 outputs the ECM at a timing delayed by Tb by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key.

More specifically, as described above, the delay control unit 84 holds the TS packet containing a part of the section data including the ECM received from the ECM detection unit 11 at Tb for a predetermined time, and then the output unit 50. Output to.

On the other hand, the key output unit 82 outputs the scrambled key received from the ECM decoding unit 13 to the scramble unit 40 without performing delay processing.

Then, the scramble unit 40 outputs the TS packet encrypted using the scramble key received from the key output unit 82 to the output unit 50 without performing delay processing. That is, the scramble unit 40 outputs the encrypted TS packet to the output unit 50 without holding the Tb for a predetermined time like the delay control unit 84.

The output unit 50 multiplexes the TS packet received from the delay control unit 84 and the TS packet received from the scramble unit 40 in the time axis direction, and transmits each multiplexed TS packet to the remax device 121.

As a result, focusing on the ECM transmitted from the scramble device 102 to the remax device 121 and the scramble key used for encrypting the content information transmitted from the scramble device 102 to the remax device 121, the remax device from the scramble device 102. The scramble key used for encrypting the content information can be switched at a timing Tb before a predetermined time Tb from the nth update timing UTn of the ECM transmitted to 121.

As described above, the scramble device 102 according to the second embodiment of the present disclosure creates a relative time difference between the switching timing ST and the scramble key update timing UT in the output ECM. More specifically, the scramble device 102 creates the time difference by delaying the update timing UT of the scramble key in the output ECM by a predetermined time Tb from the detection timing DT. By creating the time difference, the scramble device 102 uses the target period TX, which is the period during which the output of the content information encrypted using the same scramble key continues, for encrypting the content information output in the target period TX. It starts at a timing within the output continuation period, which is the period during which the output of the ECM including the scrambled key is continued. More specifically, the scramble device 101 creates the time difference, so that the target period TX is the key used in the ECM including the key used which is the scramble key used for encrypting the content information output in the target period TX. The scramble key update timing different from UT is started from Tb before a predetermined time.

That is, in the scramble device 102 according to the second embodiment of the present disclosure, the output unit 50 delays the ECM by a predetermined time Tb from the output timing of the content information encrypted using the corresponding scramble key. Output. As a result, according to the above-mentioned standard for switching the scramble key, the content information is encrypted using the current key included in the ECM transmitted to the remax device 121 in the period T1, and the content information is encrypted for a predetermined time from the next update timing UT (n + 1). In the period T2 starting from the front, the content information can be encrypted by using the next key included in the ECM transmitted to the remax device 121.

With such a configuration, even if the update cycle UC of the ECM transmitted from the ECM transmission device 201 is changed, the switching timing of the scramble key used for encrypting the content information is changed according to this change. Therefore, ECM and content information can be output according to the above-mentioned standards. Therefore, in the scramble device 102 that encrypts the content information using the ECM generated by the ECM transmission device 201, which is an external device, the content flexibly responds to the change of the update cycle UC of the ECM received from the ECM transmission device 201. Information can be encrypted. Further, since the scramble device 102 according to the second embodiment of the present disclosure does not need to acquire periodic information, the configuration can be simplified as compared with the scramble device 101 according to the first embodiment. ..

FIG. 14 is a flowchart defining an example of an operation procedure when the scramble device according to the second embodiment of the present disclosure performs scrambling processing. FIG. 14 shows the details of step S108 of the flowchart shown in FIG.

With reference to FIG. 14, first, the scramble device 102 holds the ECM including the scramble key used for encrypting the content information at Tb for a predetermined time (step S302).

Next, the scramble device 102 outputs the ECM at a timing delayed by Tb by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key. More specifically, the scramble device 102 has a time axis of a TS packet containing a part of section data including an ECM held at Tb for a predetermined time and a TS packet encrypted by using the scramble key included in the ECM. It is multiplexed in the direction, and each TS packet after multiplexing is transmitted to the remax device 121. That is, the scramble device 102 delays the scramble key update timing UT in the output ECM by a predetermined time Tb later than the detection timing DT, so that the switching timing ST is relative to the scramble key update timing UT in the output ECM. Make a time difference (step S304).

It should be considered that the above embodiments are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The above description includes the features described below.
[Appendix 1]
A scramble device that receives ECM containing a scramble key and encrypts content information, which is repeatedly transmitted from the ECM transmitter.
The ECM includes an even key and an odd key as the scramble key, and the even key and the odd key are updated alternately.
The ECM management unit that receives the ECM and
A scramble unit that encrypts the content information using the scramble key included in the ECM received by the ECM management unit, and a scramble unit.
It includes the content information encrypted by the scramble unit and an output unit that outputs the ECM including the scramble key used for encrypting the content information in the scramble unit.
The output unit outputs the ECM at a timing delayed by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key.
The scramble unit is a scramble device that encrypts the content information acquired from an encoder device provided at a place different from the place where the ECM transmission device is provided.

10, 80 ECM management unit 11 ECM detection unit 12, 82 Key output unit 13 ECM decoding unit 20 EMM management unit 30 Acquisition unit 40 Scramble unit 50 Output unit 60 Storage unit 70 CAS module 84 Delay control unit 101, 102 Scrambler 111 Encoder Equipment 121 Remax equipment 151 Cable TV station 211 IP transmission network 201 ECM transmission equipment 202 EMM transmission equipment 210 ECM generation unit 220 transmission unit 251 Program distribution center 301 STB
311 Cable TV network 351 Subscriber home 401 Broadcasting system

Claims (6)

A scramble device that receives ECM (Enterprise Control Message) containing a scramble key and is repeatedly transmitted from an ECM transmitter and encrypts content information.
The ECM includes an even key and an odd key as the scramble key, and the even key and the odd key are updated alternately.
The ECM management unit that receives the ECM and
A scramble unit that encrypts the content information using the scramble key included in the ECM received by the ECM management unit, and a scramble unit.
It includes the content information encrypted by the scramble unit and an output unit that outputs the ECM including the scramble key used for encrypting the content information in the scramble unit.
The output unit is a scramble device that outputs the ECM at a timing delayed by a predetermined time from the output timing of the content information encrypted using the corresponding scramble key. The ECM management unit detects the update of the scramble key included in the received ECM, and detects the update.
The scramble device according to claim 1, wherein the scramble unit switches the scramble key used for encryption between the even key and the odd key at the timing when the update of the scramble key is detected by the ECM management unit. .. A scramble device that receives ECM containing a scramble key and encrypts content information, which is repeatedly transmitted from the ECM transmitter.
The ECM includes an even key and an odd key as the scramble key, and the even key and the odd key are updated alternately.
The ECM management unit that receives the ECM and
A scramble unit that encrypts the content information using the scramble key included in the ECM received by the ECM management unit, and a scramble unit.
An output unit that outputs the content information encrypted by the scramble unit, and the ECM including the scramble key used for encrypting the content information in the scramble unit.
It is provided with an acquisition unit for acquiring cycle information indicating an update cycle, which is a cycle in which the scramble key is updated.
The ECM management unit detects the update of the scramble key included in the received ECM, and detects the update.
The scramble unit is at a timing when the time obtained by subtracting the predetermined time from the update cycle indicated by the cycle information acquired by the acquisition unit has elapsed from the timing when the update of the scramble key is detected by the ECM management unit. , A scramble device that switches the scramble key used for encryption between the even key and the odd key. A scrambling method in a scrambling device that receives ECM including a scramble key and encrypts content information repeatedly transmitted from the ECM transmitting device.
The ECM includes an even key and an odd key as the scramble key, and the even key and the odd key are updated alternately.
The step of receiving the ECM and
The step of encrypting the content information using the scrambled key included in the received ECM and outputting the encrypted content information and the ECM including the scrambled key used for encrypting the content information. Including,
In the step of outputting the content information and the ECM, the switching timing for switching the scramble key used for encryption between the even key and the odd key is relative to the update timing of the scramble key in the ECM to be output. By creating a time difference, the same encryption period, which is the period during which the output of the content information encrypted using the same scramble key continues, is encrypted in the same encryption period. A scramble method that starts from a predetermined time before the update timing of the scrambled key different from the used key in the ECM including the used key that is the scrambled key used in the above. In the step of receiving the ECM, the update of the scramble key included in the received ECM is detected, and the update is detected.
In the step of outputting the content information and the ECM, at the switching timing, the scramble key used for encryption is different from the scramble key updated immediately before the even key and the odd key. Switch to the key,
The scramble method according to claim 4, wherein in the step of outputting the content information and the ECM, the time difference is created by delaying the update timing by a predetermined time from the switching timing. The scramble method further includes a step of acquiring cycle information indicating an update cycle, which is a cycle in which the scramble key is updated.
In the step of receiving the ECM, the update of the scramble key included in the received ECM is detected, and the update is detected.
In the step of outputting the content information and the ECM, at the switching timing, the scramble key used for encryption is switched to the scramble key updated immediately before the even key and the odd key.
In the step of outputting the content information and the ECM, the time difference is created by delaying the switching timing from the update timing by a time obtained by subtracting the predetermined time from the update cycle indicated by the acquired cycle information. The scrambling method according to claim 4.

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