WO2019167126A1 - Système de distribution de données de contenu, système de reproduction de contenu, procédé de distribution de données de contenu et programme - Google Patents

Système de distribution de données de contenu, système de reproduction de contenu, procédé de distribution de données de contenu et programme Download PDF

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Publication number
WO2019167126A1
WO2019167126A1 PCT/JP2018/007284 JP2018007284W WO2019167126A1 WO 2019167126 A1 WO2019167126 A1 WO 2019167126A1 JP 2018007284 W JP2018007284 W JP 2018007284W WO 2019167126 A1 WO2019167126 A1 WO 2019167126A1
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Prior art keywords
terminals
content data
distributed
pieces
restored
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PCT/JP2018/007284
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English (en)
Japanese (ja)
Inventor
崇 園田
栗原　洋介
航洋 竹之下
将仁 谷口
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株式会社ウフル
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Priority to PCT/JP2018/007284 priority Critical patent/WO2019167126A1/fr
Publication of WO2019167126A1 publication Critical patent/WO2019167126A1/fr

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    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F13/00—Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F21/00—Security arrangements for protecting computers, components thereof, programs or data against unauthorised activity
    • G06F21/60—Protecting data
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
    • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
    • H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
    • H04N21/2387—Stream processing in response to a playback request from an end-user, e.g. for trick-play

Definitions

  • the present invention relates to a content data distribution system, a content reproduction system, a content data distribution method, and a program used in the field of IoT (Internet of Things).
  • IoT Internet of Things
  • Patent Document 1 a technique for shortening the waiting time until the start of reproduction in video distribution is provided.
  • Patent Document 1 With the technology of Patent Document 1, it is impossible to produce content such as video and music only when the situation is limited.
  • the present invention provides a technique for restoring content data from distributed pieces when a plurality of terminals that have received any of the distributed pieces generated from the content data satisfy a predetermined condition.
  • the content data distribution system includes a generating unit that generates different n pieces (n is an integer of 2 or more) from content data according to a secret sharing method, and a hash of the n pieces of distributed pieces A calculation means for calculating each value, a distribution means for distributing one or more of the n distributed pieces to each of a plurality of terminals, and two or more of the plurality of terminals to the terminal.
  • the dispersed pieces were respectively obtained from the two or more terminals, a contents data distribution system having a restoring means for restoring the contents data based on the dispersion piece.
  • the content data distribution system is the content data distribution system according to the first aspect, wherein the generating means is based on any different k pieces (k is an integer of 2 or more and n or less). The n pieces of distributed pieces are generated so that the content data can be restored, and the determination unit is configured so that each of the acquired different hash values is identical to any one of the calculated hash values. In the content data distribution system, if there are k or more, the content data is determined to be recoverable.
  • the content data distribution system according to claim 3 of the present invention is the content data distribution system according to claim 1 or 2, wherein the acquisition unit acquires position information indicating the position of the terminal from the two or more terminals.
  • the determination means determines that the content data from the distribution piece is determined that the two or more terminals satisfy a predetermined condition when the positions indicated by the position information of the two or more terminals are within a predetermined range.
  • a content data distribution system for determining whether or not restoration is possible.
  • the content data distribution system according to claim 4 of the present invention is the content data distribution system according to claim 1 or 2, wherein the acquisition means accesses the predetermined device from the two or more terminals via a communication line. Access information indicating whether or not each of the two or more terminals is accessing the device based on the access information. It is a content data distribution system that determines whether or not the content data can be restored from the distributed piece, assuming that the terminal satisfies a predetermined condition.
  • a content reproduction system uses the distribution system according to any one of claims 1 to 4 and the content data restored by the distribution system to handle the content data.
  • a content playback system having playback means for playing back the content to be played.
  • the content data distribution method includes a step of generating different n pieces (n is an integer of 2 or more) of distributed pieces from content data according to a secret sharing method, and hash values of the n pieces of distributed pieces.
  • n is an integer of 2 or more
  • Each of the plurality of terminals, one or more of the n distributed pieces distributed to each of the plurality of terminals, and two or more of the plurality of terminals distributed to the terminals Obtaining each hash value of the distributed pieces, and when the two or more terminals satisfy a predetermined condition, based on the obtained hash value and the calculated hash value, Determining whether or not the content data can be restored from the distributed pieces distributed to two or more terminals, and determining that the content data can be restored
  • the dispersed pieces were respectively obtained from the two or more terminals, a contents data distribution method and a step of restoring the contents data based on the dispersion piece.
  • Each of the plurality of terminals, one or more of the n distributed pieces distributed to each of the plurality of terminals, and two or more of the plurality of terminals distributed to the terminals Obtaining each hash value of the distributed pieces, and when the two or more terminals satisfy a predetermined condition, based on the obtained hash value and the calculated hash value, Determining whether the content data can be restored from the distributed pieces distributed to two or more terminals, and determining that the content data can be restored.
  • FIG. 7 is a sequence diagram showing a flow of operations of the content reproduction system 9. The figure for demonstrating determination of the restoration possibility of content data. The figure which shows the example of the message displayed on the terminal 2. FIG. The figure for demonstrating the dispersion piece in a modification. The figure which shows the example of the content table 121 in a modification.
  • FIG. 1 is a diagram showing a configuration of a content reproduction system 9 according to the present embodiment.
  • the content reproduction system 9 includes a distribution system C, a plurality of terminals 2, and a communication line 3 that connects these terminals so that they can communicate with each other.
  • the distribution system C is a so-called cloud in which a plurality of distribution apparatuses 1 communicate with each other and share resources provided in each of them, and is a content data distribution system in the present invention.
  • the content data distribution system according to the present invention is a system that supplies content data to terminals that satisfy a predetermined condition. The distribution data generated based on the content data is distributed and the content data itself is distributed. You don't have to.
  • the plurality of distribution apparatuses 1 constituting the distribution system C may communicate with each other using, for example, an ad hoc mode in IEEE 802.11. Further, these distribution apparatuses 1 may communicate with each other via the communication line 3.
  • the plurality of terminals 2 are terminal devices each possessed by a user, such as a personal computer and a smartphone. Each of the terminals 2 is connected to the distribution system C via the communication line 3 and receives a distributed piece from the distribution device 1.
  • the communication line 3 is a line that connects the distribution apparatus 1 and the terminal 2 so as to communicate with each other, and is, for example, the Internet.
  • the communication line 3 may include a relay device such as a gateway or a router that relays communication with the distribution apparatus 1 or the terminal 2.
  • FIG. 2 is a diagram illustrating an example of the configuration of the distribution apparatus 1.
  • the distribution apparatus 1 includes a control unit 11, a storage unit 12, and a communication unit 13.
  • any of the plurality of distribution devices 1 may include the display unit 15 or the sound emitting unit 16.
  • the control unit 11 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), and a computer program (hereinafter simply referred to as a program) in which the CPU is stored in the ROM and the storage unit 12. Are read out and executed to control each part of the distribution apparatus 1.
  • a CPU Central Processing Unit
  • ROM Read Only Memory
  • RAM Random Access Memory
  • the communication unit 13 is a communication circuit connected to the communication line 3 by wire or wireless.
  • the communication unit 13 may have a function of directly connecting to another distribution device 1 by wire or wireless.
  • the distribution apparatus 1 exchanges information with the terminal 2 connected to the communication line 3 by the communication unit 13.
  • the display unit 15 has a display screen such as a liquid crystal display, and displays an image under the control of the control unit 11.
  • the image displayed by the display unit 15 may be a still image such as a photograph or an illustration, or may be a moving image that changes over time.
  • the sound emitting unit 16 is a speaker or the like that emits sound under the control of the control unit 11.
  • the delivery apparatus 1 does not need to have the display part 15 and the sound emission part 16, and may have only one among these.
  • the storage unit 12 is a storage unit such as a solid state drive or a hard disk drive, and stores various programs, data, and the like read by the CPU of the control unit 11.
  • the storage unit 12 includes a content table 121, a distributed fragment table 122, and a hash value table 123.
  • FIG. 3 is a diagram showing an example of the content table 121.
  • the content table 121 stores a content ID, which is identification information for identifying content, and data indicating the content (referred to as content data) in association with each other.
  • the storage unit 12 stores a plurality of contents using the content table 121.
  • the content is information created for, for example, art, education, entertainment, etc., and is expressed by a character string, an image, music, a movie, a video, or the like.
  • the control unit 11 reads the content data, displays the video on the display unit 15, and releases the sound to the sound emitting unit 16, thereby reproducing the video work, the music work, and the like.
  • the storage unit 12 does not have to store the content table 121.
  • FIG. 4 is a diagram showing an example of the dispersion piece table 122.
  • the distributed piece table 122 stores a plurality of distributed pieces generated based on content data in association with content IDs.
  • each of the plurality of dispersion pieces is associated with a dispersion piece ID which is identification information for identifying each of the plurality of dispersion pieces.
  • the plurality of dispersed pieces are configured so that the original content data cannot be restored even if they are each alone. That is, the original content data is not restored unless at least two distributed pieces are used.
  • FIG. 5 is a diagram illustrating an example of the hash value table 123.
  • the hash value table 123 stores each hash value of each dispersion piece in association with each dispersion piece ID. As shown in FIG. 5, the hash value table 123 may be associated with the content ID of the content data for each content data that is the basis of each distributed piece.
  • the hash value stored in the hash value table 123 is a value calculated from the dispersion piece identified by the corresponding dispersion piece ID, and is a value representing the dispersion piece.
  • the hash value has a smaller data amount than the original distributed piece.
  • the same hash value is always calculated from the same distributed piece. On the other hand, it is extremely rare that the same hash value is calculated from different dispersion pieces, and this is practically impossible.
  • This hash value is calculated by, for example, a cryptographic hash function such as MD5 (Message Digest AlgorithmS5) or SHA (Secure Hash Algorithm). And it is impossible to restore the original distributed piece from this hash value.
  • the hash value since the hash value is actually different for each original distributed piece, it functions as identification information for identifying the distributed piece. Therefore, in the distributed piece table 122, a hash value may be used instead of the distributed piece ID. In this case, the distribution piece table 122 may also serve as the hash value table 123.
  • FIG. 6 is a diagram illustrating an example of the configuration of the terminal 2.
  • the terminal 2 includes a control unit 21, a storage unit 22, a communication unit 23, an operation unit 24, a display unit 25, a sound emitting unit 26, and a positioning unit 27.
  • the control unit 21 includes a CPU, a ROM, and a RAM, and controls each unit of the terminal 2 when the CPU reads and executes a program stored in the ROM and the storage unit 22.
  • the storage unit 22 is a storage unit such as a solid state drive or a hard disk drive, and stores various programs, data, and the like read by the CPU of the control unit 21.
  • the communication unit 23 is a communication circuit connected to the communication line 3 by wire or wireless.
  • the terminal 2 exchanges information with the distribution device 1 connected to the communication line 3 by the communication unit 23.
  • the operation unit 24 includes operation buttons such as operation buttons, a keyboard, and a touch panel for giving various instructions.
  • the operation unit 24 receives an operation by the user and sends a signal corresponding to the operation content to the control unit 21.
  • the display unit 25 has a display screen such as a liquid crystal display, and displays an image under the control of the control unit 21.
  • a transparent touch panel of the operation unit 24 may be disposed on the display screen.
  • the sound emitting unit 26 is a speaker or the like that emits sound under the control of the control unit 21.
  • the positioning unit 27 is a device that measures the position of itself (terminal 2).
  • the positioning unit 27 is a receiver that receives navigation signals from a plurality of navigation satellites based on a global positioning satellite system (GNSS: Global Navigation Satellite System).
  • GNSS Global Navigation Satellite System
  • the positioning unit 27 may include a processor that measures (calculates) the position of the terminal 2 based on the received navigation signal.
  • the control unit 21 may measure the position of the terminal 2 using a plurality of navigation signals received by the positioning unit 27.
  • the means by which the positioning unit 27 measures the position is not limited to GNSS.
  • the positioning unit 27 measures the position of the terminal 2 by receiving a beacon transmitted from a beacon transmitter installed at a predetermined location and extracting information on a position included in the beacon. Also good.
  • the positioning unit 27 may cooperate with an entrance / exit system that manages entrance / exit in a predetermined area such as a station or a commercial facility by short-range wireless communication such as RFID (radio frequency identifier).
  • the positioning unit 27 may measure the position of the terminal 2 using the entry record written by the entry / exit system. That is, the positioning unit 27 measures whether or not the terminal 2 exists inside a predetermined area where entry / exit is managed by the entrance / exit system as position information of the terminal 2.
  • the positioning unit 27 may measure the position of the terminal 2 using position information provided from the base station.
  • the terminal 2 is not located within the determined range and communication with the distribution system C is not possible, the distribution system C is communicating with one of the distribution devices 1 itself. Thus, it can be determined that the terminal 2 is located within the determined range. In this case, the terminal 2 may not have the positioning unit 27.
  • FIG. 7 is a diagram illustrating a functional configuration of the distribution apparatus 1.
  • the communication line 3 and the communication unit 13 are omitted.
  • the control unit 11 of the distribution apparatus 1 reads out and executes a program stored in the storage unit 12, thereby generating a generation unit 111, a calculation unit 112, a distribution unit 113, an acquisition unit 114, a determination unit 115, and a restoration unit 116. Function as. Further, as shown in FIG. 7, when at least one of the display unit 15 and the sound emitting unit 16 is provided in the distribution device 1, the control unit 11 may function as the reproducing unit 117 by controlling them.
  • control unit 11 of one distribution device may be realized by the control unit 11 of one distribution device 1, but the control units 11 of the plurality of distribution devices 1 constituting the distribution system C communicate with each other to perform mutual computation functions. Alternatively, it may be realized by sharing resources such as storage contents of the storage unit 12.
  • the generation unit 111 reads content data corresponding to the specified content ID from the content table 121 of the storage unit 12, and generates n different pieces of distribution from the content data according to the secret sharing method.
  • n is an integer of 2 or more.
  • the distributed piece is data used to restore the content data. As described above, the generation unit 111 generates n distributed pieces so that the original content data is not restored unless at least two or more distributed pieces are used.
  • the calculating means 112 reads the dispersion pieces from the dispersion piece table 122 and calculates the hash values of these dispersion pieces.
  • the calculated hash value is stored in the hash value table 123 in association with the dispersion piece ID for identifying the original dispersion piece.
  • the distribution unit 113 distributes at least one of the n distributed pieces to each of the plurality of terminals 2.
  • the distribution unit 113 may select and distribute a distributed piece that cannot be predicted by the user of the terminal 2 using, for example, a pseudo random number sequence.
  • the distribution unit 113 may determine the number of distributed pieces to be distributed to the user's terminal 2 according to the user's instruction, payment amount, class assigned in advance, or the like.
  • the terminal 2 that has received the distributed piece from the distribution apparatus 1 stores the distributed piece in the storage unit 22 and calculates a hash value of the distributed piece.
  • the hash function used for this calculation is the same as the hash function used when the control unit 11 of the distribution apparatus 1 functions as the calculation unit 112. Therefore, the hash values calculated by the distribution apparatus 1 and the terminal 2 for the common distributed piece are the same value.
  • the obtaining unit 114 obtains the hash values of the distributed pieces distributed to the terminals 2 from two or more terminals 2 among the plurality of terminals 2.
  • the hash value acquired by the acquisition unit 114 is a hash value calculated in the terminal 2.
  • the acquisition unit 114 acquires position information indicating the position where the terminal 2 exists in association with the hash value described above from the terminal 2.
  • the determination unit 115 distributes to the terminals 2 based on the hash value acquired by the acquisition unit 114 and the hash value calculated by the calculation unit 112. It is determined whether or not the content data can be restored from the distributed pieces.
  • the determination unit 115 specifies the position of each of the terminals 2 based on the position information acquired by the acquisition unit 114 from two or more terminals 2. And the determination means 115 determines whether those terminals 2 are gathering in the predetermined place by determining whether those positions are in the determined range.
  • the determination unit 115 When determining that two or more terminals 2 are gathered at a predetermined place, the determination unit 115 stores the hash value acquired by the acquisition unit 114 from those terminals 2 and the hash value table 123 of the storage unit 12. Compare the hash value with Thereby, the determination unit 115 determines whether or not the original content data can be restored from the distributed pieces distributed to the terminals 2 gathered at the predetermined location.
  • n different distributed pieces generated from one piece of content data by the generation unit 111 have a property that the original content data cannot be restored unless all of them are prepared. Therefore, the determination unit 115 matches the different hash values acquired from the two or more terminals 2 described above with one of the n hash values associated with one content ID in the hash value table 123. When the number is n, it is determined that the original content data can be restored.
  • the restoration unit 116 acquires the respective distributed pieces from the two or more terminals 2 and restores the content data based on the distributed pieces.
  • Reproduction means 117 reproduces content corresponding to the content data using the restored content data.
  • the content data restored by the restoration unit 116 may be supplied (distributed) to the terminal 2 and used for content reproduction in the terminal 2.
  • the control unit 21 of the terminal 2 displays the video on the display unit 25 among the content indicated by the content data, and sends the sound to the sound emitting unit 26. By outputting the content, the content is reproduced.
  • the control unit 21 functions as a playback unit that plays back the content corresponding to the content data using the content data restored by the distribution system C.
  • FIG. 8 is a sequence diagram showing a flow of operations of the content reproduction system 9.
  • FIG. 8A shows the operation until the distributed piece is distributed from the distribution system C to the terminal 2
  • FIG. 8B shows the operation until the content data is restored and the content is reproduced.
  • the operations performed by the distribution system C shown below are performed by any one of the distribution devices 1 constituting the distribution system C, but the operations of each step are performed by different distribution devices 1 even if performed by the same distribution device 1. Also good.
  • the distribution system C reads, for example, content data indicating content produced by a certain artist from the storage unit 12 of any of the distribution apparatuses 1 constituting the content system C. N different dispersion pieces are generated based on (Step S101). Further, the distribution system C calculates the hash values of the generated n distributed pieces (step S102).
  • the distribution system C distributes one or more of the generated n distributed pieces to the terminals 2 possessed by the plurality of fans (users) of the artist described above (step S103).
  • the terminal 2 that has received one or more distributed pieces calculates a hash value of the distributed piece (step S104), and stores the calculated hash value and the original distributed piece in the storage unit 22 in association with each other (step S104). S105).
  • the terminal 2 performs positioning for measuring its own position (step S200).
  • the distribution system C acquires position information indicating its own position obtained by positioning by the plurality of terminals 2 and a hash value of the distributed piece (step S201).
  • the distribution system C determines whether or not these terminals 2 are gathered at a predetermined location based on the position information of the plurality of terminals 2, and when determining that they are gathered, the hash acquired from these terminals 2 The value is compared with the hash value stored in the distribution system C to determine whether the content data can be restored from the distributed pieces distributed to these terminals 2 (step S202).
  • FIG. 9 is a diagram for explaining determination of whether or not content data can be restored.
  • the distribution system C generates five different distributed pieces from the distributed piece D1 to the distributed piece D5 from one content data, and randomly distributes one of the distributed pieces. Delivered to the terminal 2. Seven users U1 to U7 each have a terminal 2, and any one of the dispersion pieces D1 to D5 is distributed to each of these terminals 2. Distributed pieces D1, D2, D3, D4, and D5 are distributed to terminals 2 owned by users U1, U2, U3, U4, and U5, respectively. Also, distributed pieces D2 and D1 are distributed to terminals 2 owned by users U6 and U7, respectively.
  • the distribution system C determines that the content data can be restored from the distributed pieces acquired from the terminals 2 possessed by these users.
  • the distribution system C can restore the content data. judge.
  • the dispersion piece D1 is not stored in any of the terminals 2 possessed by these users. That is, since all five different dispersion pieces are not prepared, the distribution system C determines that the content data cannot be restored.
  • the distribution system C may send information indicating the dispersion piece ID for identifying the dispersion piece that is lacking to the terminals 2 of all users constituting the group G3.
  • the terminal 2 that has received this information may display a message corresponding to the number of the dispersed pieces that are insufficient and the identification information.
  • FIG. 10 is a diagram illustrating an example of a message displayed on the terminal 2.
  • the five different dispersion pieces described above are associated with the five pieces constituting the puzzle shown in FIG. 10 in advance.
  • the user terminal 2 displays a character string representing a message “one piece is not enough!” Together with the image shown in FIG.
  • the image shown in FIG. 10 since only one piece at the lower right is displayed in a color different from the other four pieces, the user who sees this image knows which dispersion piece is lacking. .
  • the message displayed on the terminal 2 is not limited to that described above.
  • the message may display, for example, a picture of a musical instrument such as a piano, a drum, a guitar, or a bass, and express a lack of dispersed pieces by their colors.
  • this message may notify the user only of the fact that the distribution pieces necessary for restoring the content data are insufficient, and may not notify the user of the number of distribution pieces that are insufficient.
  • a user who gathered at the above-mentioned place and viewed the above-mentioned image can use other social networking services (social networking service, social networking service, etc.)
  • social networking service social networking service, etc.
  • a message such as “People who have a piece in the lower right, gather at the venue” can be called.
  • the distribution system C acquires the distributed pieces from these terminals 2 (step S203). Then, the distribution system C restores the content data based on the acquired plurality of dispersed pieces (step S204).
  • the distribution system C supplies the restored content data to each of the plurality of terminals 2 described above (step S205). These terminals 2 use the supplied content data to reproduce content corresponding to the content data (step S206).
  • step S206 may be performed in the distribution system C.
  • the distribution system C may not perform step S205.
  • ⁇ Modification 1> content such as video and music is played back only when a plurality of terminals 2 are gathered at a predetermined location, but the conditions for playing back the content are not limited to this. That is, the distribution system C only needs to be configured to reproduce content such as video and music only when two or more terminals satisfy a predetermined condition.
  • the acquisition unit 114 realized by the control unit 11 of the distribution apparatus 1 associates the hash value described above with each of the two or more terminals 2 and the terminal 2 accesses a predetermined apparatus via the communication line 3. You may acquire the access information which shows whether it is doing.
  • the determining unit 115 when it is determined that each of the terminals 2 is accessing the above-described device based on the access information acquired by the acquiring unit 114, the determining unit 115 satisfies the predetermined condition. It may be determined that If it is determined that the terminal 2 satisfies the predetermined condition, the determination unit 115 is distributed to the terminal 2 based on the hash value acquired by the acquisition unit 114 and the hash value calculated by the calculation unit 112. It may be determined whether or not the content data can be restored from the distributed pieces.
  • the generation unit 111 generates n distributed pieces that cannot be restored without using the original content data according to the secret sharing method. N pieces of distributed pieces may be generated so that the content data can be restored. In this case, the generation unit 111 may generate n distributed pieces from the content data using a so-called (k, n) threshold secret sharing method.
  • the (k, n) threshold secret sharing method is a secret sharing method using, for example, a Shamir polynomial or an exclusive OR.
  • the original content data can be decrypted from arbitrarily different k distributed pieces among the generated n distributed pieces, but arbitrarily different ( No information of the original content data can be obtained from k ⁇ 1) pieces of dispersion.
  • This k is an integer not less than 2 and not more than n.
  • the generation unit 111 may generate n distributed pieces so that the content data can be restored based on arbitrarily different k pieces (k is an integer of 2 or more and n or less). .
  • the determination unit 115 can restore the content data when the acquired plurality of different hash values match any one of the hash values calculated by the calculation unit 112 and there are k or more. Judge that there is.
  • the generation unit 111 may use the (k, L, n) threshold secret sharing method instead of the (k, n) threshold secret sharing method.
  • the original content data can be decoded from any of the k different distributed pieces, The original content data information cannot be obtained from any different (kL) distributed pieces.
  • the (k, L, n) threshold value secret sharing method information of the original content data is partially obtained from arbitrarily different (k ⁇ L + 1) to (k ⁇ 1) distributed pieces. Is obtained.
  • the generation unit 111 generates n distributed pieces so that the content data can be restored based on any two or more and n or less different distributed pieces.
  • the number of the dispersed pieces that can be restored when they are aligned does not have to be set to one.
  • FIG. 11 is a diagram for explaining a dispersion piece in this modification.
  • the generation unit 111 realized by the control unit 11 of the distribution apparatus 1 divides the content data into two or more different data (hereinafter referred to as divided data).
  • the content data is divided into six different pieces of divided data E1 to E6. These six pieces of divided data E1 to E6 are divided so that the original content data cannot be restored unless all of them are prepared.
  • the secret sharing method is used as a method for dividing content data, the different pieces of divided data obtained are pieces of information that do not make sense on their own. The security is ensured as compared with the case of using an algorithm that is considered to be safe.
  • the generation means 111 generates a dispersion piece identified by each dispersion piece ID as shown in FIG.
  • the dispersion piece D1 includes only the divided data E1, E2, and E3
  • the distribution piece D2 includes only the divided data E2, E3, and E4
  • the dispersion piece D3 includes only the divided data E3, E4, and E5.
  • the distributed piece D4 includes only the divided data E4, E5, and E6,
  • the distributed piece D5 includes only the divided data E1, E5, and E6.
  • the number of distributed pieces, the number of divided data, and the type and number of divided data included in each distributed piece are not limited to those shown in FIG.
  • the dispersion piece D1 and the dispersion piece D4 are gathered, all the six pieces of divided data E1 to E6 are obtained, so that the original content data can be restored.
  • the divided data E6 among the divided data E1 to E6 cannot be obtained. Therefore, as shown in FIG. 11, when generating dispersed pieces, the number of dispersed pieces that can be restored when they are aligned is not limited to one.
  • the distribution system C generates n different distributed pieces from one piece of content data.
  • the distribution system C generates encrypted data by encrypting the content data with the determined key data, and this key. N different distributed pieces may be generated from the data.
  • FIG. 12 is a diagram showing an example of the content table 121 in this modification.
  • the distribution system C individually generates key data that cannot be predicted by the user using, for example, a pseudo random number, for each piece of content data associated with the content ID, and performs encryption using the key data. Then, the distribution system C associates the key data used for encryption and the encrypted data generated by the encryption with the content ID.
  • the distribution system C generates n different distributed pieces from the key data and distributes one of them to the terminal 2.
  • the distribution system C acquires hash values of the distributed pieces distributed to the terminals 2 from the two or more terminals 2, and when the terminals 2 satisfy a predetermined condition, Based on the hash value calculated in the distribution system C, it is determined whether or not the original key data can be restored from the distributed pieces distributed to those terminals 2.
  • the distribution system C When determining that the original key data can be restored, the distribution system C obtains each distributed piece from the terminals 2 and restores the key data. The distribution system C reads the encrypted data from the content table 121 and applies the restored key data to restore the original content data.
  • the content data stored in the content table 121 may be deleted after the encrypted data is generated.
  • the key data stored in the content table 121 may be deleted after generating n distributed pieces from the key data.
  • the content data (content data in a narrow sense) of this modification can be said to be content data (content data in a broad sense) of the present invention in combination with key data.
  • the distribution apparatus 1 of this modification generates encrypted data by applying key data to content data (narrowly defined content data), and distributes n pieces of data from the key data (widely defined content data) according to a secret sharing method. It is possible to determine whether or not the content data can be restored from the obtainable distributed pieces by generating pieces and comparing the hash values calculated by the distribution device 1 and the terminal 2 for each of the pieces. When it is determined that the content data (in a narrow sense) is obtained by acquiring the distributed pieces, restoring the key data from the distributed pieces and applying the data to the encrypted data.
  • the process executed by the control unit 11 of the distribution apparatus 1 can be considered as a distribution method of content data (including distributed pieces generated from the content data). That is, according to the present invention, the generation unit generates different n pieces (n is an integer of 2 or more) from the content data according to the secret sharing method, and the calculation unit obtains the hash values of the n pieces.
  • the step of acquiring the hash value of each distributed piece distributed to the terminal and the determination means are calculated by the calculation means and the hash value acquired by the acquisition means when two or more terminals satisfy a predetermined condition.
  • the program executed by the control unit 11 of the distribution apparatus 1 is a recording medium readable by a computer device, such as a magnetic recording medium such as a magnetic tape and a magnetic disk, an optical recording medium such as an optical disk, a magneto-optical recording medium, or a semiconductor memory. Can be provided in a stored state.
  • the program may be downloaded via a communication line such as the Internet.
  • various devices other than the CPU may be applied as the control means exemplified by the control unit 11 described above. For example, a dedicated processor or the like is used.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Computer Security & Cryptography (AREA)
  • Software Systems (AREA)
  • General Health & Medical Sciences (AREA)
  • Bioethics (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Information Transfer Between Computers (AREA)

Abstract

L'invention concerne un système utilisé dans le domaine de l'Internet des objets (IoT), et plus spécifiquement un système de distribution destiné à reconstituer des données de contenu à partir d'une pluralité d'éléments de dispersion lorsqu'une pluralité de terminaux ayant respectivement reçu des éléments de dispersion arbitraires satisfait une condition prédéterminée. Un moyen 111 de génération génère, à partir de données de contenu, n éléments de dispersion différents les uns des autres selon un procédé de partage de secret. Un moyen 112 de calcul calcule les valeurs de hachage des éléments de dispersion respectifs. Un moyen 113 de distribution distribue un élément de dispersion arbitraire parmi la pluralité d'éléments de dispersion à chaque terminal d'une pluralité de terminaux 2. Un moyen 114 d'acquisition acquiert chacune des valeurs de hachage des éléments de dispersion à partir d'au moins deux terminaux. Lorsque les terminaux 2 satisfont une condition prédéterminée, un moyen 115 de détermination compare les valeurs de hachage acquises à partir des terminaux 2 aux valeurs de hachage calculées par le moyen 112 de calcul et détermine si les données de contenu peuvent être reconstituées. Lorsqu'il est déterminé que la reconstitution est possible, un moyen 116 de reconstitution reconstitue les données de contenu en acquérant les éléments de dispersion à partir des terminaux 2 respectifs.
PCT/JP2018/007284 2018-02-27 2018-02-27 Système de distribution de données de contenu, système de reproduction de contenu, procédé de distribution de données de contenu et programme WO2019167126A1 (fr)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008276686A (ja) * 2007-05-07 2008-11-13 Ricoh Co Ltd サーバ装置、情報処理装置、プログラムおよび記録媒体
JP2010198349A (ja) * 2009-02-25 2010-09-09 Ntt Docomo Inc データ暗号化システム、通信機器、及びデータ暗号化方法

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008276686A (ja) * 2007-05-07 2008-11-13 Ricoh Co Ltd サーバ装置、情報処理装置、プログラムおよび記録媒体
JP2010198349A (ja) * 2009-02-25 2010-09-09 Ntt Docomo Inc データ暗号化システム、通信機器、及びデータ暗号化方法

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HOSAKA, M. ET AL.: "On Constructions of Secret Sharing System Realizing Perfect Privacy via a Physical RNG and Integrity via Hash Values", J , (IEICE TECHNICAL REPORT, vol. 113, no. 479, 28 February 2014 (2014-02-28), pages 41 - 46, ISSN: 0913-5685 *

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