JP2011045100A - Apparatus and method for outputting information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus that prevents "Copy One Generation" content or the like from being copied to infinite number of storage media without limitation, and protects profits of a copyright holder. <P>SOLUTION: When copy-controlled digital information is output to external devices connected to a plurality of output circuits 315A, 315B, a control circuit 311 limits the number of external devices to be authenticated, thereby limiting the total number of external devices to which the copy-controlled digital information is output, within a predetermined value. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an information output apparatus and an information output method for outputting digital information such as video and audio.

When information such as video and audio is handled as digital information, there is an advantage that there is no or very little quality degradation in the information transmission process and recording / reproduction process. But a good copy of the information
If a lot of copies are made around the copyright holder's custody and the copy is repeated,
There is a problem that profits are not returned to the copyright holder.

Patent Document 1 discloses a method of attaching 2-bit copy control information to information. Depending on the intention of the copyright owner or the information creator, this can be done with one of three options: “Copy Never”, “Copy Authorization” (Copy Free), or “Copy One Generation”. By selecting, the operation of the recording apparatus is controlled. The recording device does not perform the recording operation if “copy prohibited”, and performs the recording operation if “copy authorization”. If “one-generation copy authorization” is specified, the control information is rewritten with information “No More Copies” (No More Copies), and then the recording operation is performed.

US Pat. No. 5,896,454

The matter disclosed in the above prior art defines the operation on the recording apparatus side when the given information is supplied to the recording apparatus. However, there is the following problem in the handling of information that is "Copy one generation only" (Copy One Generation).

  The reason for "Copy One Generation" instead of "Copy Once" is an effective way to limit the number of connected recording devices or the number of copies. Because there was no. Accordingly, if the number of recording devices is equal, recording can be performed on an infinite number of recording media, which is substantially the same as “copy authorization”, and the profits of the copyright holder are impaired. This problem is not mentioned in the above mentioned literature.

  In view of the above problems, the object of the present invention is to prevent unlimited copying on an unlimited number of recording media when copying is restricted as in “Copy One Generation”. It is to provide a method and apparatus for protecting the interests of copyright holders.

In the information output device that outputs digital information to an external device, the object includes a plurality of output circuits that output the digital information, and a control circuit that controls the plurality of output circuits.
The control circuit limits the total number of external devices that output the digital information among external devices connected to a plurality of output circuits by limiting the number of authentications with external devices. Can be achieved. Further, in the digital information output apparatus capable of mounting a plurality of output circuits, the digital information output device includes a control circuit that controls the plurality of output circuits, and the control circuit restricts the number of authentications with external devices by limiting the number of authentications. This can be achieved by limiting the total number of external devices that output the digital information among the external devices connected to the output circuit within a predetermined number. Further, in an information output method for outputting digital information from a plurality of output circuits to an external device, the digital information is detected by detecting the total number of external devices that have been authenticated among the external devices connected to the plurality of output circuits. This can be achieved by limiting the total number of external devices that output a value within a predetermined number.

As described above, according to the present invention, an apparatus and a method for protecting the interests of the copyright holder can be provided.

1 is a block diagram showing a first embodiment of an entire system to which an information output apparatus of the present invention is applied. The block diagram which shows the structural example of the information provision station 1 in FIG. The block diagram which shows the structural example of the receiver 3 (information output device) in FIG. The figure which shows the flowchart of the connection of the apparatus in 1st Embodiment. The block diagram which shows 2nd Embodiment of the information output device of this invention. The block diagram which shows 3rd Embodiment of the information output device of this invention. The figure which shows the flowchart of the connection of the apparatus in 3rd Embodiment. The block diagram which shows 4th Embodiment of the information output device of this invention. The block diagram which shows 5th Embodiment of the information output device of this invention. The block diagram which shows 6th Embodiment of the information output device of this invention. The block diagram which shows 7th Embodiment of the information output device of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the entire system to which the present invention is applied will be described.

FIG. 1 is a block diagram showing a first embodiment of the entire system in which the information output apparatus of the present invention is used. Information broadcast from an information providing station 1 such as a broadcast station is received by the receiving device 3 through the relay station 2, and the first recording / reproducing device 4, the second recording / reproducing device 6A, and the third recording / reproducing device 6 are received.
B is recorded and reproduced and viewed on the display 5. In this case, the receiving device 3 corresponds to an information output device in the present invention, and the recording / reproducing devices 6A and 6B correspond to external devices.

The information providing station 1 such as a broadcasting station transmits the signal radio wave modulated by the information via the relay station 2 such as a broadcasting satellite. In addition, transmission by cable, transmission by telephone line, transmission by terrestrial broadcasting, and the like may be used. The receiving device 3 on the receiving side receives the signal and demodulates it, and then records it on the first recording / reproducing device 4, the second recording / reproducing device 6A, and the third recording / reproducing device 6B as necessary. Also, the display 5 views the received information content directly or the information reproduced by the first to third recording / reproducing apparatuses 4, 6A, 6B.

Here, it is assumed that the first recording / reproducing apparatus 4 is based on a digital recording system built in the receiving apparatus 3. For example, a hard disk can be used as the recording medium. The recording / reproducing apparatus incorporated in the receiving apparatus may be a medium that cannot be removed because the information storage period is relatively short. Here, the second recording / reproducing apparatus 6A and the third recording / reproducing apparatus 6B are externally attached to the receiving apparatus 3. The recording medium may be a removable medium such as a magnetic tape or an optical disk in addition to a hard disk.

If the copy control information attached to the broadcast information is “copy authorization”, it can be recorded in any of the first to third recording / reproducing apparatuses 4, 6A, 6B. ,
If it is “copy prohibited” or “copy permission for only one generation”, recording is restricted as described later.

Although the example of FIG. 1 has three recording / reproducing apparatuses, the present invention is not limited to this. That is, the present invention can be applied regardless of the number of devices or whether they are built-in or external. The present invention is not applied only to a system for recording / reproducing received information. Of course, when reproducing packaged software in which information is recorded in advance, simply receiving information currently being broadcast and outputting it to the display 5, or reproducing information from a hard disk of a PC (Personal Computer), etc. It can also be applied to the case of outputting to the outside of the apparatus via the network.

When a removable recording medium in which information is recorded in advance, for example, package software, is provided, the reproduction operation and the like in the second recording / reproducing apparatus 6A to which the information is attached, for example, is performed. In this case, the information providing station 1 and the relay station 2 are excluded, but the present invention can also be applied.

Information is often exchanged between devices using digital signals. For example, the receiving device 3 and the display 5 may be connected using analog signals. In some cases, the luminance and the two color difference signals are used for connection, and in the case of a PC, the RGB signals are used for connection.

FIG. 2 is a block diagram showing a configuration example of the information providing station 1 in FIG. Information such as video / audio generated by the source generation unit 11 including a camera, a recording / playback apparatus, and the like is compressed by the encoding circuit 12 by the MPEG method or the like so that it can be transmitted in a smaller occupied band. When protection such as copy restriction is necessary, transmission encryption is performed by the scramble circuit 13. After being modulated into a signal suitable for transmission by the modulation circuit 14, the transmission antenna 15
For example, it is emitted as a radio wave toward the relay station 2 such as a broadcasting satellite. At this time, the management information adding circuit 16 adds the copy control information described above. Further, for example, request information from the receiving side in video on demand is input to the input terminal 17 via a telephone line or the like, and information to be transmitted is determined in response to the request information.

In many cases, a plurality of pieces of information are multiplexed in a radio wave signal to be transmitted by a method such as time division or spread spectrum. In this case, there are a plurality of systems of the source generation unit 11 and the encoding circuit 12, and a multiplex circuit for multiplexing a plurality of information is placed between the encoding circuit 12 and the scramble circuit 13.

FIG. 3 is a block diagram illustrating a configuration example of the receiving device 3 in the system of FIG. In the figure, a solid line indicates a flow of main information such as received video and audio, and a broken line indicates a flow of control signal information between components. A case where the first recording / reproducing apparatus 4 is built in the receiving apparatus 3 is shown.

First, the configuration of the present embodiment will be described along the flow of main information such as video and audio indicated by a solid line. For example, radio waves from a relay station such as a broadcasting satellite are input to the RF / IF conversion circuit 301. Here, radio waves in the RF band are frequency-converted to IF band (Intermediate Frequency)
In addition, the signal is in a certain band independent of the reception channel, and the modulation operation performed for transmission by the demodulation circuit 302 is demodulated. Further, the error correction circuit 303 detects and corrects the code error generated during transmission, and then the descramble circuit 304 releases the transmission cipher. Thereafter, the data is sent to the first and second demultiplexing circuits 305 and 307. The demultiplex circuits 305 and 307 separate only desired information from a plurality of information multiplexed on one channel. The reason for providing two demultiplex circuits is not only to enable so-called back program recording, but also to remove information that is not recorded and add information for recording in the first demultiplex circuit 305. is there. For example, items that do not need to be recorded, such as weather forecasts and program broadcast schedules, are removed here.

The output of the first demultiplexing circuit 305 is supplied to the first recording / reproducing apparatus 4 and also to the input / output circuits 315A and 315B. The input / output circuits 315A and 315B are connected to the second recording / reproducing device 6A and the third recording / reproducing device 6B via the input / output terminals 306A and 306B, respectively. The input / output circuits 315A and 315B are bi-directional input / output interfaces, for example, and exchange information to be recorded / reproduced with the second and third recording / reproducing apparatuses 6A and 6B, for example, with digital data. In general, connection according to the IEEE 1394 standard is often used. Further, a USB (Universal Serial Bus) connection frequently used in a PC may be used, or a wireless LAN (Local Area Network) or the like may be used for a wireless connection.
The number of input / output circuits 315A and 315B is not limited to this, and a larger number of input / output circuits 315A and 315B may be provided, or a plurality of input / output interfaces having different specifications may be used.

In the first to third recording / reproducing apparatuses 4, 6A, 6B, a recording operation is performed according to copy control information attached to information to be recorded. If the copy control information indicates “Copy Never” or “No More Copies”, no recording is performed. If it is "Copy one generation only" (Copy One Generation), rewrite this as "No more copies" (No More Copies) and record. If it is “Copy Authorization” (Copy Free), recording is performed as it is. As a special case, when recording is temporarily recorded with a limited playback period while it is Copy Never, or when information is moved under the condition that the original information source cannot be reproduced while being No More Copies Recording operations such as

In the second demultiplexing circuit 307, information sent from the descrambling circuit 304, information reproduced by the first recording / reproducing device 4, or input / output circuits 315A, 315B
The information reproduced by the second and third recording / reproducing devices 6A and 6B is input via the, and desired information is selected and separated from these. In the next decoding circuit 308, decompression processing is performed for data compression by the MPEG method or the like performed before transmission, and output terminals 309 and 310 are output.
Sent to an external device. The output terminals 309 and 310 may be either digital output or analog output, and the former can be used separately for digital output and the latter for analog output. The number of output terminals may be one.

Next, the configuration in FIG. 3 will be described along control signals indicated by broken lines. The control circuit 311
From the RF / IF conversion circuit 301 to the first and second demultiplexing circuits 305 and 30.
7. Control signals are exchanged between the decoding circuit 308 and the components reaching the input / output circuits 315A and 315B, and the entire receiving apparatus 3 is controlled to perform a desired operation. The information management circuit 312 supplies management data for performing control to the control circuit 311 upon request. For example, reception contract information is managed here. When the user designates a channel to be viewed, this designation is input from the input terminal 314 and sent to the control circuit 311 via the command input circuit 313. The control circuit 311 requests the reception contract information from the information management circuit 312. When it is determined that there is a contract with the channel designated by the user, a control signal is sent to each of the above-described components, and a control operation such as instructing a reception operation of the corresponding channel is performed.

When the first recording / reproducing device 4 is built in the receiving device 3, the input terminal 314 is used.
The recording / reproducing operation is performed according to the user's instruction input from. For this reason, the output of the command input circuit 313 is supplied. This control signal may be supplied from the control circuit 311.

Next, copy control information added to received information or added at the time of output from an input / output circuit will be described. As the copy control information, for example, 3-bit information as shown in Table 1 is used.

CCI is 2-bit information. When it is “00”, it represents “Copy Authorization”.
"10" indicates "Copy one generation only" (Copy One Generation) and "01"
"No More Copies", that is, information that can be copied for only one generation is copied, and "11" is "Copy prohibited" (Copy Never) ). Note that “No More Copies” is not used when broadcasting or the like. When the CCI is other than “00”, the information is protected when an illegal copy is made by encrypting and transmitting at the time of output. EPN is 1-bit information. When this information is “0”, it indicates that there is no copy restriction, but it is encrypted and transmitted. This protects information from unauthorized use other than copying on legitimate recording devices.

Next, the limitation on the number of copies that is a feature of the present invention will be described. In order to limit the number of copies, the number of devices connected to all input / output terminals may be limited. That is, the total number N of the number of devices connected to the input / output circuit 315A and the number of devices connected to the input / output circuit 315B is managed by the control circuit 311 and the number is a predetermined limit number Nm ( For example, Nm = 62)
Restrict to:

FIG. 4 shows a flowchart of device connection in the input / output circuit 315A or 315B. When there is a connection request (S101) from the device to be connected, the input / output circuit 315A,
315B inquires the control circuit 311 about the number N of currently connected devices (S10).
2). If N is less than the limit number Nm (S103), authentication with the device is performed (S1).
04). In the authentication, for example, determined information is sent to the counterpart device, and it is determined whether or not the device is legitimate by a response to the information (S105). If the authentication is successful, it is determined that the partner device is a legitimate device, and the encryption key is passed to the partner device (S106). The number N of connections managed by the control circuit 311 is updated (S107). When N is not less than Nm (S103), or when authentication is not successful (S105), the connection is discarded without passing the encryption key to the partner device (S105).
108). Accordingly, even if a device that is not permitted to connect receives information, the encrypted information cannot be decrypted because the device does not have a decryption key.

Note that the connection request (S101) may be an authentication request. In this case, the number N of devices that are authenticated is managed. Further, instead of passing the encryption key (S106), information for generating a shared key may be passed.

Normally, the authentication process is performed by an input / output circuit. Therefore, in the case of only one input / output circuit, authentication may be performed by the input / output circuit and the number of connections may be managed. However, when there are multiple input / output circuits, the number of connections in each input / output circuit is as follows. Can manage, but cannot manage the total number of connections. Even in such a case, the number of devices connected to all the input / output circuits can be managed by managing the number of connections in the control circuit 311.

As described above, even when a plurality of input / output circuits are provided, the number of copies can be limited by limiting the number of connected devices. Note that the plurality of input / output circuits may be interfaces having different specifications, or of course, may be interfaces dedicated to output. In addition, the control circuit 311 may be performed including authentication processing.

The management of the number N of connections may be performed only when information to be protected indicated by the copy control information is output. This may be performed in all cases where the information needs protection, but may be performed only when outputting Copy One Generation information, for example, if the purpose is to limit the number of copies. In addition, it may be performed for all devices connected to all input / output circuits, but if only the input / output circuit that outputs the information to be protected or only the recordable device is managed,
It can be managed more accurately. In the case of outputting a plurality of types of information, each information may be managed independently.

FIG. 5 is a block diagram showing a second embodiment of the information output apparatus of the present invention. The information signal source 71 comprises an information receiving device, an information reproducing device, or the like, and sends information to the input / output circuits 72A to 72D.
To send it to an external device. As an example, the input / output circuits 72A and 72B are IEEE13.
The 94 standard, the input / output circuit 72C is a USB standard, and the input / output circuit 72D is an interface via a wireless network. The control circuit 73 is the same as the control circuit 311 in FIG. As described above, even when a plurality of input / output circuits having different specifications are provided, the number of copies can be limited by limiting the number of devices connected to the whole by the control circuit 73 as in the case of FIG. .

The input / output circuits 72A and 72B have the same interface, but when output from circuits with different identification IDs, the input / output circuits 72A and 72B are independent outputs, and processing such as connection is performed in each input / output circuit. In addition, even in the case of transmission using the same interface but different transmission methods (transmission protocols), the number of connected devices is controlled by the control circuit when control is performed independently by each transmission method. 73 may be managed.

FIG. 6 is a block diagram showing a third embodiment of the information output apparatus of the present invention. In this embodiment, a bus bridge 74 that relays between different buses is interposed. In this case, it is necessary to consider the number of devices connected via the bus bridge 74. The bus bridge 74 may relay a bus with the same specification, or may relay a bus with a different specification.

FIG. 7 shows a flowchart of connection of devices when a bus bridge 74 as in the embodiment of FIG. 6 is interposed. When there is a connection request from the device to be connected (S111), the input / output circuits 72A to 72D inquire the control circuit 73 about the number N of currently connected devices (S112). Next, the device to be connected is authenticated (S113). At this time, as in the case of FIG. 4 (S103), it may be confirmed whether N is less than the limit number Nm. If the authentication is successful, it is determined that the counterpart device is a legitimate device (S114), and then it is confirmed whether the counterpart device is a bus bridge (S115). If it is not a bus bridge (S120), if N is less than the limit number Nm, the encryption key is passed to the partner device (S121).
Simultaneously with the completion of the connection, the control circuit 73 is notified that the connection has been made, and the number N of connections managed by the control circuit 73 is updated (S122). If the counterpart device is a bus bridge, the number Nb connected via the bus bridge is acquired from the bus bridge (S116).
. If N + Nb is equal to or less than Nm (S117), the encryption key is transferred to the partner device (S1).
18) At the same time as completing the connection, the control circuit 73 is notified that the connection has been made, and the number N of connections managed by the control circuit 73 is updated to N + Nb. If N + Nb exceeds Nm (S120), the connection is discarded (S123). Note that the connection via the bus bridge may be limited to a range not exceeding Nm.

FIG. 8 is a block diagram showing a fourth embodiment of the information output apparatus of the present invention. here,
For example, an information signal source 71 such as a PC device, a control circuit 73, and input / output circuits 72A to 72D.
Is connected via the internal bus 75 and is removable. Here, the internal bus 75 may connect all the circuits to one bus, or by using a plurality of internal buses, for example, the information signal source 71 is connected to the control circuit 73 via the first bus, Input / output circuits 72A-72
D may be connected to the control circuit 73 via the second bus.

In this embodiment, first, it is necessary to check whether or not the input / output circuits 72A to 72D that are mounted are regular, that is, whether they correspond to the connection number limit. Therefore, the control circuit 73 authenticates the mounted input / output circuits 72A to 72D, and encrypts and sends information from the information signal source 71 to the successfully input / output circuit. This prevents information from being output via an input / output circuit other than the regular input / output circuit. Further, a common key may be shared between the regular input / output circuit and the information signal source 71 without performing authentication. The number of connections may be limited by the same procedure as in FIG. 4 or FIG.

FIG. 9 is a block diagram showing a fifth embodiment of the information output apparatus of the present invention. 80A-8
0D is a key management unit that manages the encryption key, and 82 is a connection number management unit that manages the number N of connections.
When there is a connection request or an authentication request from a device to be connected, the input / output circuits 72A, 72
B, 72C or 72D inquires the control circuit 73 about the number N of devices currently connected or authenticated. If N is less than the limit number Nm, authentication is performed with the device, and if the authentication is successful, it is determined that the counterpart device is a legitimate device, and the key management units 80A, 80B, 80C are determined.
Alternatively, information for generating an encryption key or a shared key managed by 80D is passed to the counterpart device, and at the same time as the connection is completed, the control circuit 73 is notified that the connection has been made. The number of connected connections N is updated. Thus, the key management units 80A, 80B, 8
In 0C or 80D, the key to be encrypted is managed by each input / output circuit, and the number N of connections is managed by the control circuit 73, so that different encryption keys are used in each input / output circuit. Even when the encryption method or the authentication method is used, the number of connections can be managed.

FIG. 10 is a block diagram showing a sixth embodiment of the information output apparatus of the present invention. Reference numeral 81 denotes a key management unit that manages encryption keys. When there is a connection request or an authentication request from a device to be connected, the input / output circuit 72A, 72B, 72C or 72D requests the control circuit 73 for authentication. The control circuit 73 checks the number N of currently connected or authenticated devices. If N is less than the limit number Nm, the control circuit 73 authenticates with the device. If the authentication is successful, the partner device is a legitimate device. It is determined that there is, and the information for generating the encryption key or shared key managed by the key management unit 81 is passed to the counterpart device, and the connection number N is updated at the same time as completing the connection.
In this way, by managing the encryption key and the number N of connections in the control circuit 73, authentication and key management can be performed with a single circuit even when a plurality of input / output circuits are provided.

FIG. 11 is a block diagram showing a seventh embodiment of the information output apparatus of the present invention. 83A,
83B is information of the information signal source 71, 84A and 84B are the number of connections NA for each information,
Connection number management units 85A and 85B for managing the NB are key management units for managing encryption keys for the respective information. The information 83A and 83B are, for example, received information on different channels, received information, information reproduced from the reproduction device, and the like. When a plurality of types of information such as information A and information B are output from the information signal source 71, the number of copies can be limited for each information by managing the number of connections for each information.

Of course, even when a plurality of types of information are output, management may be performed only with the total number of connections. In this case, the number of connections is limited more than necessary, but it is not necessary to manage which information is output where, and the management process can be simplified. Than this,
When copying is restricted as in “Copy authorization for only one generation”, it is possible to prevent unlimited copying on an unlimited number of recording media.

1. Information providing station 2. Relay station 3. Receiving device (information output device)
4... First recording / reproducing device 5... Display 6 A... Second recording / reproducing device 6 B... Third recording / reproducing devices 306 A, 306 B, 309, 310. · Input / output terminal 308 ··· Decoding circuits 311 and 73 ··· Control circuits 315A, 315B, 72A to 72D ··· Input / output circuit 71 ··· Information signal source 74 ··· Bus bridge 75 ... Internal buses 80A to 80D, 81, 85A, 85B ... Key management units 82, 84A, 84B ... Number of connection management units 83A, 83B ... Information

Claims (17)

In an information output device that outputs digital information to an external device,
A plurality of output circuits for outputting the digital information to a connected external device;
A control circuit for controlling the plurality of output circuits,
The control circuit restricts the number of authentications with the external device, so that the total number of external devices that output the digital information among the external devices connected to the plurality of output circuits is within a predetermined number. An information output device characterized by being limited to be. The information output apparatus according to claim 1, wherein the plurality of output circuits include output circuits having different output specifications. 2. The control circuit according to claim 1, wherein the control circuit limits the total number of external devices that output the digital information to be within a predetermined number when the digital information to be output is information that needs to be protected. Information output device. 4. The control circuit according to claim 3, wherein when the digital information to be output is information whose copy is restricted, the control circuit limits the total number of external devices that output the digital information within a predetermined number. Information output device. In an information output device that mounts a plurality of output circuits and outputs digital information from the output circuits to an external device,
A control circuit for controlling the plurality of output circuits;
The control circuit restricts the number of authentications with the external device, so that the total number of external devices that output the digital information among the external devices connected to the plurality of output circuits is within a predetermined number. An information output device characterized by being limited to be. 6. The information output apparatus according to claim 5, wherein the plurality of output circuits include output circuits having different output specifications. 6. The control circuit according to claim 5, wherein the control circuit limits the total number of external devices that output the digital information within a predetermined number when the output digital information is information that needs to be protected. Information output device. 8. The control circuit according to claim 7, wherein when the digital information to be output is information whose copy is restricted, the control circuit limits the total number of external devices that output the digital information within a predetermined number. Information output device. The control circuit is capable of outputting the digital information only when the mounted output circuit is an output circuit capable of limiting the total number of external devices within a predetermined number. 5. The information output device according to 5. In an information output method for outputting digital information from a plurality of output circuits to an external device,
Detect the total number of external devices that have been authenticated among the external devices connected to the multiple output circuits,
An information output method, wherein the total number of external devices that output the digital information is limited within a predetermined number. 11. The plurality of output circuits include output circuits having different output specifications.
Information output method described in 1. 11. The information output method according to claim 10, wherein when the digital information to be output is information that needs protection, the total number of external devices that output the digital information is limited to a predetermined number or less. 2. The apparatus according to claim 1, wherein when the digital information to be output is information whose copy is restricted, the total number of external devices that output the digital information is limited to be within a predetermined number.
The information output method according to 0. 2. The information output apparatus according to claim 1, wherein the digital information is output by being encrypted with the same encryption key from the plurality of output circuits. 2. The information output apparatus according to claim 1, wherein the digital information is output after being encrypted with different encryption keys from the plurality of output circuits. 6. The information output apparatus according to claim 5, wherein the digital information is output by being encrypted with the same encryption key from the plurality of output circuits. 6. The information output apparatus according to claim 5, wherein the digital information is output by being encrypted with different encryption keys from the plurality of output circuits.

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