JP2000217067A - Transmitter, recording and reproducing device and program recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmitter and a recording and reproducing device where no restriction on the configuration is caused, no high hardware/software cost is required, a reference clock is restored, and possibility of decoding encryption is not high even when much time is taken and to provide a program recording medium. SOLUTION: The recording and reproducing device is provided with an IEEE 1394 I/F 12 that receives AV data from the transmitter, having a transmission encryption means 4 that leaves a part of AV data including at least a program clock reference PCR as a plain text among AV data encrypted for transmission and having an IEEE 1394 I/F 3 that sends data to an IEEE 1394 bus I, with a reference clock generating means 17 that reads the PCR from the AV data received thereat and with a recording means that records the AV data on the basis of the reference clock.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus, a transmitting apparatus, and a program recording medium for handling copyright-protected data.

[0002]

2. Description of the Related Art When copyright-protected data is handled, encryption is performed during transmission, encryption is performed when recording data on a recording medium, and an internal bus or memory such as a PC (personal computer) is accessed. Devices that can do so are required to encrypt data for internal processing until just before data needs to be actually handled, such as decoding.

[0003] For transmission encryption, a DTPC method in the IEEE 1394 interface has been created, but no specific method has been determined for recording encryption and internal processing encryption.

A conventional recording / reproducing apparatus and a transmitting apparatus which handle copyright-protected data will be described with reference to FIG.

[0005] FIG. 13 shows a conventional method in which data is output from an IEEE 1394 interface and is decrypted for transmission and encrypted for recording when the data is input into the device. It is. here,
It is assumed that data is sent as MPEG2-TS.

[0006] The IEEE 1394 bus 1 is connected to each device and transfers data and commands between the devices. A plurality of devices of various types are connected to the IEEE 1394 bus 1. Here, a transmitting device and a recording / reproducing device are representative examples.

The transmitting device 37 receives a broadcast wave and transfers the received data to each device, such as an STB (satellite broadcast receiver) or a tuner. Transmission device 3
Reference numeral 7 denotes an IEEE 1394 I / F 3, a transmission encryption / decryption unit 4, a separation unit 5, a broadcast scramble decryption unit 6, a reception unit 7, an authentication unit 9, and a decryption unit 8.

[0008] The IEEE1394 I / F3 is an IEEE13
Outputs data and commands to bus 94, and outputs
Data and commands are input from the 1394 bus 1. The receiving means 7 is a means for receiving a broadcast wave sent from a broadcasting station and sending it to the broadcast scramble decoding means 6. The broadcast scramble decoding means 6 is means for decoding the scramble of the multiplexed stream received by the receiving means 6. The separating means 5 includes a broadcast scramble decoding means 6
Is a means for separating the multiplexed stream decrypted into the individual streams. The decoding unit 8 is a unit that decodes the individual streams separated by the separation unit 5 so as to output them to a monitor or a speaker. Transmission encryption / decryption means 4
Is a separating means 5 for transmitting to the IEEE 1394 bus 1.
Means for encrypting the data separated by. The authentication means 9 exchanges authentication with the device to which the data is to be transferred in response to an authentication request of the device. If the authentication is successful, the key for decrypting the data encrypted by the transmission encryption / decryption means 4 is used as the data. This is a means for transferring to the transfer destination device.

The recording / reproducing device 38 is an example of a device such as a PC which can access an internal bus and a memory.
This is a device for recording and reproducing data transmitted from the transmission device 37. The recording / reproducing device 38 is an IEEE1394I /
F12, transmission encryption / decryption means 39, recording encryption / decryption means 40, recording means 15, transmission authentication means 4
1. It comprises a recording authentication unit 42 and a reference clock generation unit 17.

The IEEE 1394 I / F12 is an IEEE 1394 I / F12.
Output data and command to 1394 bus 1
This is for inputting data and commands from the EE1394 bus 1. The authentication means for transmission 41 uses IEEE1394I /
This is a means for performing authentication with an external device such as the transmission device 37 via F12 and receiving a key for decrypting data that has been encrypted for transmission. The received key is for encryption / decryption for transmission. Is passed to the conversion means 39. The transmission encryption / decryption means 39 is means for decrypting the data encrypted for transmission using the key received from the transmission authentication means 41. The reference clock generating means 17
PCR (Program) existing in the packet of G2-TS
A clock of 27 MHz, which is a reference clock, is recovered from the m Clock Reference) and the arrival timing of the packet, and this reference clock is used when the recording unit 15 performs recording. The recording authentication unit authenticates the application software to be recorded / reproduced, and, when the authentication is successful, passes a key for decrypting the data encrypted by the recording encryption / decryption unit 40 to the application software. . Recording encryption /
The decryption means 40 is means for encrypting the data decrypted by the transmission encryption / decryption means 39 again for internal processing. The recording unit 15 is a unit that records data that has been encrypted for internal processing.

Next, the operation of the transmitting device 37 and the recording / reproducing device 38 having such a configuration will be described.

A broadcast wave transmitted from a broadcasting station is received by a receiving means 7 and scrambled by a broadcast scramble decoding means 6, and then a multiplex stream is separated into individual streams by a separation means 5. . Further, the individual streams output to the monitor and the speaker are decoded by the decoding means 8. The individual streams separated by the separation means 5 are passed to the transmission encryption / decryption means 4. Transmission encryption /
The data separated by the separating means 5 is encrypted by the decrypting means 4, and the data is encrypted by the IEEE 1394 I / F3.
Output to 394 bus 1. When there is an authentication request from the recording / reproducing device 38, the authenticating means 9 performs authentication with the transmitting authenticating means 41 of the recording / reproducing device, and when the authentication is successful, the transmitting encrypting / decrypting means 4 encrypts the data. The key for decrypting the decrypted data is passed to the transmission authentication means 41.

In the recording / reproducing device 38, IEEE 1
The 394 I / F 12 receives the data sent from the transmission device 37 and sends it to the transmission encryption / decryption means 39. The key to decrypt data encrypted for transmission is IEEE
When transmitted from the authentication unit 9 via the E1394 I / F3, the transmission authentication unit 41 transmits the key to the IEEE 139.
It is received via the 4 I / F 12 and passed to the transmission encryption / decryption means 39. The transmission encryption / decryption unit 39 receives the key from the transmission authentication unit 41 and decrypts the encrypted data. With reference to the decoded data, the reference clock generating means 17 generates a PCR (Program Clock) existing in the MPEG2-TS packet.
The clock of 27 MHz, which is the reference clock, is restored from k Reference) and the arrival timing of the packet. The recording means 15 uses this reference clock when recording this data.

[0014]

However, as shown in FIG. 13, in the prior art, the transmission encryption / decryption means 3 is used.
After 9, the data is decrypted up to the recording encryption / decryption means 40, and the data becomes plain text. Therefore, in the case of a PC or the like that can access the internal bus and the memory, there is a possibility that plaintext data can be used, which causes a problem in security.

[0015] To prevent this, IEEE 1394I
/ F12, the transmission encryption / decryption means 39, and the recording encryption / decryption means 40 are integrated in an LSI, which causes a problem in that the configuration is restricted.

In addition, the recording / reproducing device 38 has a problem that the block of the encryption / decryption means and the authentication means is required for transmission and recording, and the hardware / software cost is increased.

In order to solve these two points, a method is conceivable in which the encryption used for transmission is also used for recording. However, if the transmission encryption is simply used for the recording encryption, the following problems occur.

First, there is a problem that the reference clock cannot be restored because there is no part that has been decrypted. That is, in the MPEG2-TS data transmission, it is essential that the recording / reproducing apparatus restores the reference clock 27 MHz from the PCR present at a predetermined position in the packet and the arrival timing of the packet for recording / reproducing. This reference clock is not only the reference clock for the decoder, but also
Even in a recording device that does not include a decoder, it is essential to absorb jitter superimposed by recording. This PC
Since the portion including R is also encrypted when transmitted, if the transmission encryption is used as it is for recording, the PCR cannot be referenced and the reference clock cannot be restored. And no data can be recorded.

Further, if the data encrypted for transmission is recorded as it is, there is a problem that the encryption may be decrypted on the recording medium if it takes time. The encryption for transmission uses a key or the like that changes secretly from time to time, but all those having time-varying elements are stored in the recording medium or inside the device. That is, all the information for decrypting the transmission code is stored, so that the possibility of decryption increases.

According to the present invention, there is a problem in that the digital interface, the encrypting / decrypting means for transmission, and the encrypting / decrypting means for recording are integrated in an LSI, thereby causing restrictions on the configuration. The block of the decryption means and the block of the authentication means are required twice for transmission and recording, and the hardware / software cost is increased. Also, since there is no decrypted part, the restoration of the reference clock is not possible. Considering the problem that the encryption is possible and the problem that if the data encrypted for transmission is recorded as it is, the encryption may be broken if it takes time, there is no restriction on the configuration, and the hardware / software A transmitting device, a recording / reproducing device, and a program recording medium, which do not have a high cost, can restore a reference clock, and are not likely to be able to decrypt the code over time. The it is an object of the present invention.

[0021]

In order to solve the above-mentioned problems, a first present invention (corresponding to claim 1) uses an MPEG-TS transport packet to convert copyrighted AV data. When transmitting via the IEEE 1394 bus, at least PCR (Program Clock Reference) of the AV data encrypted for transmission.
(nce) in the transmission device, the transmission encryption means for transmitting the AV data to the IEEE 1394 bus, and a transmission encryption means for storing plain text without encryption. .

The second invention (corresponding to claim 2) provides:
The transmission apparatus according to the first invention, wherein the transmission encryption unit sets a flag indicating whether or not a plaintext portion is included in a CIP header.

A third aspect of the present invention (corresponding to claim 3) is:
The transmission device according to the second invention, wherein the flag is set using the remaining one bit of sy of the CIP header.

Further, a fourth invention (corresponding to claim 4) is:
The transmission encrypting means leaves only 192 bytes of the transport packets of the MPEG-TS transport packets including the PCR in plain text, and indicates EMI indicating copy management of the sy of the CIP header.
Is set to copy free (00).

The fifth invention (corresponding to claim 5) provides:
A second digital interface for receiving the AV data transmitted from the transmission device according to any one of the first to fourth inventions, and the at least PCR of the AV data received by the second digital interface.
And a recording means for recording the AV data based on the reference clock.

The sixth invention (corresponding to claim 6) provides:
The recording unit is configured to store the AV data in at least the PC
The recording / reproducing apparatus according to the fifth aspect of the present invention, wherein a portion including R is recorded as plain text.

A seventh aspect of the present invention (corresponding to claim 7) is:
The recording unit is configured to store the AV data in at least the PC
The recording / reproducing apparatus according to the fifth aspect of the present invention, wherein a portion including R is encrypted and recorded.

According to an eighth aspect of the present invention (corresponding to claim 8),
A second digital interface for receiving the encrypted AV data transmitted from a transmitting apparatus that transmits the claimed AV data via an IEEE 1394 bus using an MPEG-TS transport packet; Decoding means for decoding at least a portion of the AV data containing a PCR, reference clock generating means for generating a reference clock by reading the PCR of the AV data decoded by the decoding means, and a reference clock for the reference clock Recording means for recording the AV data on the basis of the above.

A ninth aspect of the present invention (corresponding to claim 9) is:
The recording and reproducing apparatus according to an eighth aspect of the present invention, wherein the recording means records the encrypted AV data output from the second digital interface.

The tenth invention (corresponding to claim 10)
The recording / reproducing apparatus according to the eighth aspect, wherein the recording means records the AV data decoded by the decoding means.

The eleventh invention (corresponding to claim 11)
When transmitting copyrighted AV data via an IEEE 1394 bus using an MPEG-TS transport packet, at least a PCR (Program Clock) of the AV data encrypted for transmission is used.
Reference), if there is a portion containing
Notifying means for notifying information of the position of the packet containing the CR and the PCR;
A first digital interface for sending to a bus.

The twelfth invention (corresponding to claim 12)
A second digital interface for receiving the AV data transmitted from the transmitting device according to the eleventh invention; and a detecting means for detecting a packet containing the PCR from the information notified by the notifying means. When,
Decoding means for decoding at least a portion of the packet including the PCR; reference clock generating means for reading the PCR to generate a reference clock; and recording means for recording the AV data based on the reference clock. A recording / reproducing apparatus characterized in that:

The thirteenth invention (corresponding to claim 13)
The recording apparatus according to the twelfth aspect, wherein the recording means records the encrypted AV data output from the second digital interface.

The fourteenth invention (corresponding to claim 14)
Is the recording / reproducing apparatus according to any one of the eleventh to thirteenth inventions, wherein the information is transmitted by an asynchronous command.

The fifteenth aspect of the present invention (corresponding to claim 15)
The invention according to a sixth, seventh or tenth invention, wherein the recording means performs encryption by adding a predetermined value to the encrypted AV data instead of the encryption method, and records the encrypted AV data. A recording / reproducing apparatus according to any one of the above.

The sixteenth invention (corresponding to claim 16)
The recording means changes and records an encrypted result of an encrypted portion using AV data of an unencrypted portion, instead of the encryption method. The recording / reproducing apparatus according to any one of the sixth, seventh and tenth aspects of the present invention.

The seventeenth invention (corresponding to claim 17)
Is the recording / reproducing apparatus according to the sixteenth aspect, wherein the change is an exclusive OR.

The eighteenth invention (corresponding to claim 18)
Comprises second decryption means for decrypting all of the encrypted AV data, wherein the recording means performs lighter encryption than the original encryption when recording the AV data. A recording / reproducing apparatus according to a fifth or eighth aspect of the present invention.

The nineteenth invention (corresponding to claim 19)
Is the recording / reproducing apparatus according to any one of the fifth to eighteenth aspects, wherein the portion including at least the PCR is an adaptation field control, a five flag, and a PCR.

According to a twentieth aspect of the present invention (corresponding to claim 20),
The recording / reproducing apparatus according to any one of claims 5 to 18, wherein the portion including at least the PCR is n bytes (n is a natural number) from the beginning of the transport packet of the MPEG-TS. is there.

According to a twenty-first aspect of the present invention (corresponding to claim 21),
The recording / reproducing apparatus according to the twentieth aspect, wherein the n bytes are 12 bytes.

According to a twenty-second aspect of the present invention (corresponding to claim 22),
20. The recording / reproducing apparatus according to claim 20, wherein the head is determined by a time stamp.

According to a twenty-third aspect of the present invention (corresponding to claim 23),
A program recording medium storing a program for causing a computer to execute all or a part of the functions of each component of the recording / reproducing device or the transmitting device according to any one of the first to twenty-second inventions. .

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the MPEG2 synchronization method will be described briefly.

The MPEG2 synchronization method requires the following two points. One is that information called a time stamp indicating when to decode and play should be added for each decoding / playback unit called video and audio access unit (one frame for video and one audio frame for audio). . Another is that a time reference is given to the time stamp by information called PCR.

The time stamp is like a tag for time management of decoding / reproducing processing attached to each access unit. There are two types of time stamps due to the MPEG audio coding scheme. One is PTS
(PresentationTime Stamp), which is time management information of reproduction output, and the other is DTS.
This is time management information called (Decoding Time Stamp).

The PCR is information for setting and correcting an STC (reference clock) value serving as a time reference to an intended value on the encoder side in an MPEG system decoding means including a video and audio decoder. In order to use PCR, in addition to its value, the accuracy of the timing of the byte (the time of arrival at the decoder) in the stream carrying the PCR value is also required. On the decoder side, the STC is required to set the value indicated by the PCR at the moment of the arrival of the last byte.

As described above, the PCR is essential not only for restoring the reference clock of the decoder, but also for absorbing the jitter superimposed by recording in the recording / reproducing apparatus 11 not including the decoder.

Next, the MPEG2-TS packet is transferred to the IEEE
A description will be given of a method of specifying a restoration time when transmitting data through the E1394 interface.

As shown at 22 in FIG.
Time stamp is attached to the 2-TS packet. With the time stamp, the receiving side can rearrange the packets in the correct order even if the arrival order of the packets slightly shifts. In the case of real-time data, the receiving side reproduces the data with reference to the time of the time stamp. Timestamp is 3
It is 2 bits (4 bytes). The time stamp is a value obtained by adding the maximum delay time as shown by δ in FIG. 7 to the absolute time of IEEE1394 read from the cycle time register. This value indicates the restoration time of the MPEG2-TS packet on the receiving side.

A 4-byte header with a time stamp is added to the beginning of an MPEG2-TS packet. MPE
Since the G2-TS packet is 188 bytes, the size of the packet actually transferred is 192 bytes.

The receiving node receives a 192 byte packet. The time the packet actually arrives at the receiving node may be different from the time stamped on the time stamp. This is because they may arrive earlier than the maximum delay time.

The receiving node checks the time stamp of the packet. When the time of the time stamp matches the value of the cycle time register of the receiving node, a 188-byte MPEG2-TS packet is recorded and reproduced. The method of specifying the restoration time has been described above.

Next, MPEG2-TS is transferred to IEEE 1394.
A method of creating a packet when performing the isochronous transfer will be described.

In the isochronous transfer mode, a data transfer rate is reserved for each channel. The size of data that can be sent in one cycle is fixed. However, depending on the cycle, no data may be sent at all. In this case, a dummy packet having no data is sent.

When data is sent in all cycles,
The same throughput as the reserved data transfer rate can be obtained. To secure an optimum data transfer rate, the size of data to be sent in one cycle must be optimized.

As shown at 25 in FIG.
192 bytes obtained by adding a 4-byte time stamp as shown at 26 to 188 bytes, which is the packet of 192 bytes, are divided into 24-byte units as shown at 27. When 24 bytes of data are transferred per cycle, 1.53 per second
6 Mbit data can be sent. Even if it is divided further, M
Since the encoding speed of PEG2 is generally 1.5 Mbit / sec or more, it has no meaning.

Specifically, the method of generating an isochronous packet is as follows.
It is divided into bytes X 8 data blocks. A plurality of data blocks are put together in an IEEE 1394 isochronous packet. The number N of data blocks included in one isochronous packet is 0, 1, 2, 4
Or a multiple of 8. In each case, the required transfer rate is NX 24 bytes X 8000 cycles X 8
Bit.

For example, an MP having an encoding speed of 4 Mbit / s
When transferring moving image data of EG2, the number of data blocks is set to four to secure a data transfer speed of 6.144 Mbit / sec.

As shown at 28 in FIG. 8, a CIP (Common Isochronous) precedes the data block.
(Packet) header. The header specifies the method of dividing the MPEG2-TS packet. The header information includes the following contents.

First, (1) there is a type of data format. When sending in MPEG2-TS packets, C
Declare “MPEG” and the type of data format in the IP header. There is also (2) a leading data block number. The lower 3 bits of the 8 bits indicate the number of the first block divided into eight. There is also (3) the size of a data block (24 bytes). (2) 19
There is a method of dividing a 2-byte data packet (in the case of MPEG, the data packet is divided into eight data blocks). In the field designated as "MPEG" in (1), the receiving node knows that an MPEG2-TS packet is transmitted in the isochronous transfer mode. The data format type packet is restored using the data block size of (3) and the information on the division method of the 192 byte data packet of (2).

In general, copyrighted data is transmitted after being encrypted. All 188 bytes except for the time stamp portion of the MPEG2-TS packet are encrypted. Therefore, the portion including the PCR has been conventionally encrypted.

The method of creating a packet has been described above.

FIG. 9 shows the structure of an MPEG2-TS packet. As is apparent from FIG. 9, the transport packet of 188 bytes includes an adaptation field control, 5 flags, and PCR in the first 12 bytes of the transport packet of the MPEG-TS. The end of the PCR is just 12 bytes from the beginning. The adaptation field control indicates the presence or absence of an adaptation field and the presence or absence of a payload in this packet. The 5 flag indicates whether data is contained in the five fields of PCR, OPCR, splice countdown, private data, and AF extension. Therefore, by referring to the adaptation field control and the 5 flag, it is possible to know whether or not the packet contains a PCR. That is, the presence or absence of a PCR can be known by referring to the first 12 bytes of the packet, and if there is a PCR, the value of the PCR can be referenced.

An embodiment of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, a first embodiment will be described.

In this embodiment, the transmitting apparatus
The portion including the PCR of the EG2-TS packet is sent as plaintext without encryption, and the recording / reproducing apparatus reads the portion including the PCR which is the plaintext, generates a reference clock based on the read portion, and further performs the original encryption. Will be described in the case of recording on a recording medium by changing the.

FIG. 1 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

In this embodiment, it is assumed that data is sent as MPEG2-TS.

The IEEE 1394 bus 1 is connected to each device and transfers data and commands between the devices. A plurality of devices of various types are connected to the IEEE 1394 bus 1. Here, a transmitting device and a recording / reproducing device are representative examples.

The transmitting device 2 is an STB (satellite broadcast receiver)
It receives broadcast waves and transfers the received data to each device, such as a TV or a tuner. The transmitting device 2
It comprises an IEEE 1394 I / F 3, a transmission encryption / decryption means 4, a separation means 5, a broadcast scramble decryption means 6, a reception means 7, an authentication means 9, a decryption means 8, and an encryption range setting means 10.

The IEEE 1394 I / F3 is an IEEE 1394 interface.
Outputs data and commands to bus 94, and outputs
Data and commands are input from the 1394 bus 1. The receiving means 7 is a means for receiving a broadcast wave sent from a broadcasting station and sending it to the broadcast scramble decoding means 6. The broadcast scramble decoding means 6 is means for decoding the scramble of the multiplexed stream received by the receiving means 6. The separating means 5 includes a broadcast scramble decoding means 6
Is a means for separating the multiplexed stream decrypted into the individual streams. The decoding unit 8 is a unit that decodes data compressed by the MPEG2 method in order to output the individual streams separated by the separating unit 5 to a monitor or a speaker. The transmission encryption / decryption means 4 is IE
This is a means for encrypting the data separated by the separating means 5 for transmission to the EE1394 bus 1. The authentication means 9 exchanges authentication with the device to which the data is to be transferred in response to an authentication request of the device. If the authentication is successful, the key for decrypting the data encrypted by the transmission encryption / decryption means 4 is used as the data. This is a means for transferring to the transfer destination device. The encryption range setting means 10 is a means for setting a range not to be encrypted so that a portion including the PCR can be referred to by the recording / reproducing apparatus.

The recording / reproducing apparatus 11 is an example of a device such as a PC which can access an internal bus and a memory.
This is a device for recording and reproducing data transmitted from the transmission device 2. The recording / reproducing device 11 is an IEEE1394 I / F
12, received packet processing means 13, encryption change means 14,
Recording means 15, authentication means 16, reference clock generating means 1
7 is comprised.

The IEEE 1394 I / F 12 is an IEEE 1394 interface.
Output data and command to 1394 bus 1
This is for inputting data and commands from the EE1394 bus 1. The received packet processing unit 13 is a unit that detects a portion including unencrypted PCR, reads the value of the PCR, sends it to the reference clock generation unit 17, and sends data to the encryption change unit 14. The cipher changing means 14
This is a means for changing the encryption for transmission by taking the exclusive OR of the encryption of the data passed from the reception packet processing means 13 with the data of the unencrypted part.
The reference clock generating means 17 is a means for restoring a 27 MHz clock which is a reference clock from the PCR present in the packet of the MPEG2-TS and the arrival timing of the packet, and using this reference clock when the recording means 15 performs recording. . The authentication means 16 uses the IEEE1394I /
Authentication is performed with the transmission device 2 via F12, and when the authentication is successful, a key for decrypting data is received from the transmission device 2 and between the transmission device 2 and application software that records and reproduces the data with the recording unit 15. This is a means for performing authentication and passing a key for decrypting data to the recording means 15 when the authentication is successful. The recording unit 15 is a unit that records the encrypted data using the reference clock recovered by the reference clock generation unit 17.

The reference clock generation means 17 is provided in FIG.
It is configured as follows. That is, the reference clock generating means 1
7 is a PLL (Phase) integrated with the reference clock.
(Locked Loop). That is, phase comparator 29, digital / analog converter 30, low-pass filter 31, voltage-controlled oscillator 32, counter 33
It consists of.

Next, the operation of this embodiment having such a configuration will be described.

The broadcast wave sent from the broadcasting station is received by the receiving means 7, the scramble is decoded by the broadcast scramble decoding means 6, and the multiplex stream is separated into individual streams by the separating means 5. . Further, the individual streams output to the monitor and the speaker are decoded by the decoding means 8. The individual streams separated by the separation means 5 are passed to the transmission encryption / decryption means 4.

The encryption range setting means 10 sets the range to be encrypted by the transmission encryption / decryption means 4 so that the PCR can be referred to by the recording / reproducing apparatus. That is, as shown in FIG. 11, the 12-byte data after the SPH (time stamp) is not encrypted as the partial resolution range. This part includes the adaptation field control, the five flags, and the PCR. Since a part of the data is not encrypted, even if the data is not once decrypted as in the conventional technique, the P field can be obtained from the adaptation field control and the 5 flag.
The presence or absence of CR can be determined, and if there is a PCR, the value of the PCR can be read.

Since encryption / decryption is performed in units of 8 bytes, it is easier to perform 16-byte decryption than 12-byte decryption. Therefore, the plain text may be 16 bytes instead of the 12 bytes after the SPH.

The data separated by the separation means 5 is encrypted only in the range set by the encryption range setting means 10. That is, only the encrypted data portion in FIG. 11 is encrypted. And the packet is IEEE1394 I / F
3 to the IEEE 1394 bus 1. When there is an authentication request from the recording / reproducing device 11, the authentication unit 9
Performs authentication with the authentication means 16 of the recording / reproducing apparatus,
When the authentication is successful, a key for decrypting the data encrypted by the transmission encryption / decryption means 4 is passed to the authentication means 9.

In the recording / reproducing apparatus 11, the IEEE 1
The 394 I / F 12 receives the data sent from the transmitting device 2 and sends it to the received packet processing means 13. The key for decrypting the data encrypted for transmission is IEEE13
When sent from the authentication means 9 via the I / F 3, the authentication means 16 converts the key into the IEEE 1394 I / F 1.
Receive via 2. The authentication unit 16 further performs authentication in response to a request from the application software for recording by the recording unit 15, and passes the key for decrypting data to the application software when the authentication is successful. The reception packet processing means 13 refers to the data of 12 bytes from the beginning of the transport packet of the MPEG2-TS to check the presence or absence of PCR from the value of the adaptation field control and 5 flags.
Read the value of CR. However, whether or not the start of the transport packet of the MPEG2-TS can be determined by referring to the SPH flag in the CIP header. Since the part containing the PCR remains in plain text,
The presence or absence of PCR and the value of PCR can be easily checked. The value of the PCR is sent to the reference clock generator 17. The received packet processing means 13 is an MPEG2-T
The data in which the 12 bytes from the beginning of the S transport packet remain in plaintext are sent to the cipher changing means 14. The reference clock generating means 17 restores a 27 MHz reference clock from the PCR and the arrival timing of the packet, and sends it to the recording means. The cipher changing means 14 is configured to
The recording means 1 changes the encryption for transmission by taking the exclusive OR of the 12-byte part from the beginning of the G2-TS transport packet and the encrypted part.
Send to 5. The recording means 15 performs recording using the reference clock generated by the reference clock generation means 17.

When the encryption range is determined on the transmitting side in this way, it is necessary to inform the recording / reproducing apparatus 11 that the packet is different in encryption from normal encryption. To do this, one of the following processes may be performed. That is, 0x4 is added to the first byte of MPEG2-TS.
We can tell if 7 exists. MPEG
The first byte of 2-TS is always 0x47 when not encrypted, but becomes 0x4 by being encrypted.
It is no longer seven. Therefore, the received packet processing means 1
In step 3, it is sufficient to determine whether the first byte of the MPEG2-TS is 0x47. As another method, the remaining one bit of Sy of the CIP header can be used as a flag indicating whether or not it is partially encrypted. Using the remaining one bit of Sy, the encryption range setting means 10 of the transmitting device 2 sets whether or not the data is partially encrypted, and sets the received packet processing means 13 of the recording / reproducing device 11.
Can refer to this flag. Another method is P
For the packet including the CR, all 192 bytes of the MPEG2-TS transport packet are left in plaintext, and the 2 bits (EMI) indicating copy management in the SIP of the CIP header of the plaintext packet are set to 00 (copy free). = No encryption), a special flag can be made unnecessary. That is, the encryption range setting means 10 of the transmission device 2 uses the MPEG2-T
By setting the encryption range so that all 192 bytes of the S transport packet are plaintext, the recording / reproducing apparatus 11 can read the PCR.

In this way, since the encryption for transmission is recorded in the recording means 15 without being decrypted, the plaintext portion does not appear, and there is no restriction on the configuration such as LSI. In addition, since the authentication means and the encryption / decryption means are not required twice, the cost of hardware / software is not increased, the reference clock can be restored without any problem, and the encryption for transmission can be performed. Since the data encrypted for transmission by the encryption changing means 14 is not recorded as it is, but the encryption method is changed, it is possible to reduce the possibility of the transmission encryption being decrypted over time. I can do it.

The transmission encryption / decryption means 4 and the encryption range setting means 10 according to the present embodiment correspond to claim 1 of the present invention.
It is an example of the transmission encryption means described in the description, and
The EEE1304 I / F3 is the first device according to claim 1 of the present invention.
The IEEE 1394 I / F 12 of the present embodiment is an example of the second digital interface according to claim 2 of the present invention, and the cipher changing means 14 and the recording means 15 of the present embodiment It is an example of the recording means of claim 13 of the invention.

Further, the cipher changing means of the present embodiment
The present invention is not limited to the method in which the encryption for transmission is changed by taking the exclusive OR of the plaintext part of the data and the encrypted part. An operation other than the exclusive OR of the plaintext portion and the encrypted portion may be used, or the encryption may be changed without using the data of the plaintext portion. In short, the encryption of the encrypted part may be changed using the plaintext part, or the encryption of the encrypted part may be changed without using the plaintext part.

Further, the authentication means 16 of the present embodiment is not limited to the means for authenticating the transmission software and the application software for recording data in the recording means 15 for internal processing. If the device cannot access the internal bus or the memory, the authentication for the internal processing need not be performed.

Further, the method of setting the encryption range by the encryption range setting means 10 according to the present embodiment is described in MPEG2-T
The 12 bytes from the beginning of each transport packet of S may be in plaintext, or only the packet containing PCR among the transport packets of MPEG2-TS may be those in which the 12 bytes from the beginning remain in plaintext. .

(Embodiment 2) Next, a second embodiment will be described.

In the present embodiment, in the transmitting apparatus, MP
The portion including the PCR of the EG2-TS is sent as plaintext without encryption, and the recording / reproducing apparatus reads the portion including the PCR which is a plaintext, generates a reference clock based on the read portion, and encrypts the portion in the plaintext. A case will be described in which encryption is performed and the original encryption is changed to be recorded on a recording medium.

FIG. 2 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

In the present embodiment, it is assumed that data is sent as MPEG2-TS as in the first embodiment.

The transmitting apparatus 2 of the present embodiment is the same as that of the first embodiment, and the description is omitted. Further, the recording / reproducing apparatus 11 of the present embodiment differs from the first embodiment in that a partial encryption unit 18 is provided.

The partial encryption means 18 is a means for encrypting the PCR portion of the packet sent from the transmission device 2 which is in plain text, but encrypts this portion.

Next, the operation of this embodiment will be described focusing on the differences from the first embodiment.

After receiving the data transmitted from the transmitting device 2 and generating a reference clock by the reference clock generating means 17 and receiving data from the received packet processing means 13, the partial encryption means 18 The 12-byte data in the partial resolution range is encrypted. Encryption changing means 14
Receives data from the partial encryption unit 18 and changes the encryption applied for transmission. Unlike the first embodiment, since there is no plaintext portion in this case, the encryption method is changed by adding a predetermined value to the encrypted portion. And it records on a recording means.

When the encryption range is determined on the transmission side in this way, it is necessary to inform the recording / reproducing apparatus 11 that the packet has a different encryption method from the normal encryption. To do this, one of the following processes may be performed. That is, 0x4 is added to the first byte of MPEG2-TS.
We can tell if 7 exists. MPEG
The first byte of 2-TS is always 0x47 when not encrypted, but becomes 0x4 by being encrypted.
It is no longer seven. Therefore, the received packet processing means 1
In step 3, it is sufficient to determine whether the first byte of the MPEG2-TS is 0x47. As another method, the remaining one bit of Sy of the CIP header can be used as a flag indicating whether or not it is partially encrypted. Using the remaining one bit of Sy, the encryption range setting means 10 of the transmitting device 2 sets whether or not the data is partially encrypted, and sets the received packet processing means 13 of the recording / reproducing device 11.
Can refer to this flag. Another method is P
For the packet including the CR, all 192 bytes of the MPEG2-TS transport packet are left in plaintext, and the 2 bits (EMI) indicating copy management in the SIP of the CIP header of the plaintext packet are set to 00 (copy free). = No encryption), a special flag can be made unnecessary. That is, the encryption range setting means 10 of the transmission device 2 uses the MPEG2-T
By setting the encryption range so that all 192 bytes of the S transport packet are plaintext, the recording / reproducing apparatus 11 can read the PCR.

In this way, since the encryption for transmission is recorded in the recording means 15 without being decrypted, the plaintext portion does not appear, and there is no restriction on the configuration such as LSI. In addition, since the authentication means and the encryption / decryption means are not required twice, the cost of hardware / software is not increased, the reference clock can be restored without any problem, and the encryption for transmission can be performed. Since the data encrypted for transmission by the encryption changing means 14 is not recorded as it is, but the encryption method is changed, it is possible to reduce the possibility of the transmission encryption being decrypted over time. I can do it.

It should be noted that the transmission encryption / decryption means 4 and the encryption range setting means 10 according to the present embodiment correspond to claim 1 of the present invention.
It is an example of the transmission encryption means described in the description, and
The EEE1394 I / F3 is the first device according to claim 1 of the present invention.
The IEEE 1394 I / F 12 according to the present embodiment is an example of the second digital interface according to the second embodiment of the present invention, and the partial encryption unit 18 and the encryption change unit 14 according to the present embodiment. The recording means 15 is an example of the recording means according to claim 4 or 12 of the present invention.

Further, the cipher changing means of the present embodiment
The present invention is not limited to changing the encryption by adding a predetermined value. In short, any method can be used as long as the encryption can be changed.

Further, the authentication means 16 of the present embodiment is not limited to the means for authenticating the transmission software and the application software for recording data in the recording means 15 for internal processing. If the device cannot access the internal bus or the memory, the authentication for the internal processing need not be performed. Further, the method of setting the encryption range by the encryption range setting means 10 of the present embodiment is as follows.
The first 12 bytes of each transport packet of MPEG2-TS may be in plain text,
PCR of each transport packet of EG2-TS
However, only the first 12 bytes of the packet including the packet may be left as plain text.

(Embodiment 3) Next, a third embodiment will be described.

In the present embodiment, the transmitting device is the same as the conventional technology, and encrypted data is transmitted for transmission.
A case will be described in which the recording / reproducing device decodes the portion including the PCR of the MPEG2-TS, reads the portion including the PCR, generates a reference clock based on the read portion, and records the encrypted data for transmission on the recording medium. .

FIG. 3 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

In the present embodiment, it is assumed that data is sent as MPEG2-TS as in the first embodiment.

The transmitting apparatus 2 according to the present embodiment is the same as the transmitting apparatus according to the prior art, and the description is omitted.

The recording / reproducing device 11 is an example of a device capable of accessing an internal bus or a memory, such as a PC.
This is a device for recording and reproducing data transmitted from the transmission device 2. The recording / reproducing device 11 is an IEEE1394 I / F
12, a recording unit 15, an authentication unit 16, a reference clock generation unit 17, and a partial decoding unit 18. IEEE
The E1394 I / F 12 outputs data and commands to the IEEE 1394 bus 1, and outputs the data and commands to the IEEE 1394 bus 1.
Input data and commands. The partial decoding unit 18 is a unit that decodes a 12-byte portion from the beginning of the transport packet of the MPEG2-TS, and passes it to the reference clock generation unit 17. The reference clock generation means 17 outputs the P clock existing in the MPEG2-TS packet.
CR (Program Clock Reference)
e) recovers the reference clock of 27 MHz from the packet arrival timing and uses the reference clock when the recording unit 15 performs recording. The authentication unit 16 authenticates with the transmission device 2 via the IEEE 1394 I / F 12, receives a key for decrypting data from the transmission device 2 when the authentication is successful, and records and reproduces the data with the recording unit 15. This is a means for performing authentication with application software to be executed and passing a key for decrypting data to the recording means 15 when the authentication is successful. The recording unit 15 is a unit that records the encrypted data using the reference clock recovered by the reference clock generation unit 17.

Next, the operation of this embodiment will be described.

The operation of the transmitting device 2 is the same as that of the prior art, and the encrypted data is output to the IEEE 1394 bus 1.

In the recording / reproducing apparatus 11, the IEEE 13
The authentication unit 16 issues an authentication request to the transmission device 2 via the 94 I / F 12. If the authentication is successful, the authentication unit 9 of the transmission device 2 passes the key for decrypting the data to the authentication unit 16. Further, the authentication unit 16 performs authentication with the application software in response to the request of the application software to be recorded by the recording unit 15, and passes the key for decrypting the encrypted data when the authentication is successful. The partial decoding unit 18 decodes only 12 bytes from the beginning of the MPEG2-TS transport packet. That is, the part of the partial decomposition range shown in FIG. 11 is decoded. Note that since encryption / decryption is performed in units of 8 bytes, it is easier to perform 16-byte decryption than 12-byte decryption. Therefore, decoding may be performed for 16 bytes instead of 12 bytes. This 12-byte portion is passed to the reference clock generating means 17. The reference clock generation means 17 determines the presence or absence of a PCR of this packet from the adaptation field control and the portion of the 5 flag, and reads the value of the PCR if there is a PCR.
A reference clock of 27 MHz is restored from the value of R and the arrival timing of the packet and sent to the recording means. I
The IEEE 1394 I / F 12 sends the encrypted data to the recording unit 15, and the recording unit 15 records the data based on the reference clock generated by the reference clock generation unit 17.

In this way, since the encryption for transmission is only partially decrypted and recorded in the recording means 15, a plain text portion hardly appears, and a configuration such as LSI is adopted. There are no restrictions, and authentication means and encryption /
There is no need for double decoding means, hardware / software cost is not increased, and the reference clock can be restored without any problem.

Note that the partial decoding means 18 of this embodiment
Is an example of a decoding means according to claim 5 of the present invention, and the IEEE1394 I / F12 of this embodiment is an example of a second digital interface according to claim 5 of the present invention.

Further, the authentication means 16 of the present embodiment is not limited to the means for authenticating for transmission and the application software for recording data in the recording means 15 for internal processing. If the device cannot access the internal bus or the memory, the authentication for the internal processing need not be performed.

(Embodiment 4) Next, a fourth embodiment will be described.

In the present embodiment, the transmitting device is the same as the conventional technology, and transmits encrypted data for transmission.
A case will be described in which the recording / reproducing device decodes the portion including the PCR of the MPEG2-TS, reads the portion including the PCR, generates a reference clock based on the read portion, changes the encryption of the data, and records the data on the recording medium.

FIG. 4 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

In the present embodiment, it is assumed that data is sent as MPEG2-TS as in the first embodiment.

[0117] The transmitting device 2 of the present embodiment is the same as the transmitting device of the prior art, so that the description is omitted.

The recording / reproducing device 11 is an example of a device capable of accessing an internal bus or a memory, such as a PC.
This is a device for recording and reproducing data transmitted from the transmission device 2.

The recording / reproducing apparatus 11 according to the present embodiment
An encryption changing unit 14 is added to the recording / reproducing apparatus of the embodiment. What is recorded by the recording means 15 is data output from the encryption changing means 14.

Next, the operation of the present embodiment will be described.

The operation of the transmitting apparatus 2 is the same as that of the conventional technique, and the encrypted data is output to the IEEE 1394 bus 1.

In the recording / reproducing apparatus 11, the IEEE 13
The authentication unit 16 issues an authentication request to the transmission device 2 via the 94 I / F 12. If the authentication is successful, the authentication unit 9 of the transmission device 2 passes the key for decrypting the data to the authentication unit 16. Further, the authentication unit 16 performs authentication with the application software in response to a request of the application software to be recorded by the recording unit 15, and passes the key for decrypting the encrypted data when the authentication is successful. The partial decoding unit 18 decodes only 12 bytes from the beginning of the MPEG2-TS transport packet. That is, the part of the partial decomposition range shown in FIG. 11 is decoded. Since encryption / decryption is performed in units of 8 bytes, 16-byte decryption can be more easily performed than 12-byte decryption. Therefore, decoding may be performed for 16 bytes instead of 12 bytes. This 12-byte portion is passed to the reference clock generating means 17. The reference clock generation means 17 determines the presence or absence of a PCR of this packet from the adaptation field control and the 5 flag portion, reads the value of the PCR if there is a PCR,
A reference clock of 27 MHz is restored from the value of R and the arrival timing of the packet and sent to the recording means. The cipher changing unit 14 receives the plaintext data of 12 bytes from the partial decrypting unit 18, performs an exclusive OR operation on the plaintext portion and the encrypted portion, and
Pass to 5. The recording means 15 includes a reference clock generating means 17
This data is recorded based on the reference clock generated in the step (1).

In this manner, since the encryption for transmission is recorded in the recording means 15 with almost no decryption, almost no plaintext portion appears, and there are also restrictions on the configuration such as LSI. Without the need for duplicate authentication and encryption / decryption means,
The cost of hardware / software is not increased, the reference clock can be restored without any problem, and the encryption for transmission is not recorded as it is for the data encrypted for transmission by the encryption changing means 14, but the encryption is performed. Is changed, it is possible to reduce the possibility that the encryption for transmission is decrypted over time.

The partial decoding means 18 of the present embodiment
Is an example of the decryption means according to claim 5 of the present invention, and the IEEE1394 I / F12 of this embodiment is an example of the second digital interface according to claim 5 of the present invention, The changing means 14 and the recording means 15 are examples of the recording means according to claim 13 of the present invention.

Furthermore, the cipher changing means of the present embodiment
The present invention is not limited to the method in which the encryption for transmission is changed by taking the exclusive OR of the plaintext part of the data and the encrypted part. An operation other than the exclusive OR of the plaintext portion and the encrypted portion may be used, or the encryption may be changed without using the data of the plaintext portion. In short, the encryption of the encrypted part may be changed using the plaintext part, or the encryption of the encrypted part may be changed without using the plaintext part.

Further, the authentication means 16 of the present embodiment is not limited to the means for authenticating the transmission software and the application software for recording data in the recording means 15 for internal processing. If the device cannot access the internal bus or the memory, the authentication for the internal processing need not be performed.

(Embodiment 5) Next, a fifth embodiment will be described.

In this embodiment, in the transmitting apparatus, P
The recording / reproducing device is notified of the presence / absence of the portion including the CR using asynchronous transfer, the encrypted data for transmission is transmitted, and the presence / absence of PCR notified from the transmitting device is detected by the recording / reproducing device. MPE only in certain cases
A case will be described in which a portion including the PCR of the G2-TS is decoded, a portion including the PCR is read, a reference clock is generated based on the read portion, and data encrypted for transmission is recorded on a recording medium.

FIG. 5 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

Here, it is assumed that data is sent as MPEG2-TS as in the first embodiment.

The transmitting apparatus 2 according to the present embodiment has a notifying unit 19 added to the transmitting apparatus according to the prior art. Notification means 1
Reference numeral 9 denotes a unit for notifying the recording / reproducing apparatus 11 whether or not a PCR is included in the MPEG2-TS packet separated by the separation unit 5 using an asynchronous packet.

The recording / reproducing device 11 is an example of a device that can access an internal bus or a memory, such as a PC.
This is a device for recording and reproducing data transmitted from the transmission device 2, and is a device in which a detection means 20 is added to the third embodiment.

The detecting means 20 is provided by the notifying means 1 of the transmitting device 2.
PC of MPEG2-TS packet sent from PC9
This is a means for detecting the presence or absence of R.

Next, the operation of the present embodiment will be described.

When an MPEG2-TS packet is sent from the transmitting device 2, the notifying means 19 sends the PCR of the packet.
Notify if there is. The recording / reproducing device 11 detects the information on the presence or absence of the PCR notified from the notifying unit 19
Is detected at The detection result is transmitted to the partial decoding unit 18.
Only when there is a PCR, the partial decoding means 18 decodes only 12 bytes of the MPEG2-TS packet. Note that since encryption / decryption is performed in units of 8 bytes, it is easier to perform 16-byte decryption than 12-byte decryption. Therefore, 16 bytes may be decoded instead of 12 bytes. The rest is the same as the third embodiment.

In this way, since the encryption for transmission is only partially decrypted and recorded in the recording means 15, a plaintext portion hardly appears, and a configuration such as an LSI is adopted. There are no restrictions, and authentication means and encryption /
There is no need for double decoding means, hardware / software costs are not increased, and the reference clock can be restored without any problem. Since only the part including the PCR is decoded, decoding is performed. The time required for conversion can be reduced.

The IEEE 1394I of the present embodiment
/ F3 is an example of the first digital interface according to claim 8 of the present invention.
The 94 I / F 12 is an example of the second digital interface according to claim 9 of the present invention, and the partial decoding means 18 of the present embodiment is an example of the decoding means according to claim 9 of the present invention.

Further, the authentication means 16 of the present embodiment is not limited to the means for performing authentication for transmission and authentication for application software for recording data in the recording means 15 for internal processing. If the device does not have access to the internal bus or memory, authentication for internal processing need not be performed.

(Embodiment 6) Next, a sixth embodiment will be described.

In the present embodiment, the transmitting device is the same as the conventional technology, and transmits encrypted data for transmission.
In the recording / reproducing apparatus, the P of the MPEG2-TS packet
The part containing the CR is decoded, the part containing the PCR is read, and a reference clock is generated based on the part.
A case where a 2-TS packet is decrypted, lightly encrypted, and then recorded on a recording medium will be described.

FIG. 6 shows a transmitting apparatus and a recording / reproducing apparatus according to the present embodiment.

In the present embodiment, it is assumed that data is sent as MPEG2-TS as in the first embodiment. It is assumed that the encryption method used in the present embodiment is of a type in which data is subjected to a process of feeding back and repeating an encryption process.

The transmitting apparatus 2 of the present embodiment is the same as the transmitting apparatus of the prior art, and the description is omitted.

The recording / reproducing apparatus 11 is an example of a device such as a PC which can access an internal bus and a memory.
This is a device for recording and reproducing data transmitted from the transmission device 2.

The recording / reproducing apparatus 11 of the present embodiment has a fourth
Partial decoding means 1 of the part of the recording / reproducing apparatus of the embodiment
8 is obtained by adding a decryption means 43 in place of the encryption change means 14 and an encryption means 21 in place of the encryption change means 14.

The decoding means 43 is means for decoding all data, as in the conventional technique. The encrypting means 21 is means for decrypting the data once decrypted by the decrypting means 43 once and performing a lighter encryption.

Next, the operation of the present embodiment will be described.

The operation of the transmitting device 2 is the same as that of the prior art, and the encrypted data is output to the IEEE 1394 bus 1.

In the recording / reproducing apparatus 11, the IEEE 13
The authentication unit 16 issues an authentication request to the transmission device 2 via the 94 I / F 12. If the authentication is successful, the authentication unit 9 of the transmission device 2 passes the key for decrypting the data to the authentication unit 16. Further, the authentication unit 16 performs authentication with the application software in response to the request of the application software to be recorded by the recording unit 15, and passes the key for decrypting the encrypted data when the authentication is successful. The decoding means 43 decodes all MPEG2-TS packets. The reference clock generating means 17 determines whether or not there is a PCR of this packet from the adaptation field control and the 5-flag portion using the decoded data, and reads the value of the PCR if there is a PCR.
A reference clock of 27 MHz is restored from the value of R and the arrival timing of the packet and sent to the recording means. The encryption unit 21 receives the plaintext data from the decryption unit 43 and encrypts it. Here, it is assumed that the data to be decrypted by the decrypting means 43 is encrypted by eight repetitions as shown in FIG. Then, the encrypting unit 21 performs encryption four times by using the same encryption method as that decrypted by the decrypting unit 43. That is, encryption for recording is performed lighter than encryption for transmission. The encryption means 21 repeats the data four times and transfers the encrypted data to the recording means 15. The recording means 15 records this data based on the reference clock generated by the reference clock generation means 17.

By doing so, the reference clock can be restored without any problem, and the encryption method is changed by using light encryption instead of recording the encrypted data for transmission. So
It is possible to reduce the possibility that the encryption for transmission is decrypted over time.

The IEEE 1394I of the present embodiment
/ F12 is an example of the second digital interface according to claim 5 of the present invention, and the decoding means 43 of the present embodiment is an example of the decoding means according to claim 5 of the present invention.
The decrypting means 43 of the present embodiment also serves as the second decrypting means of the present invention, and the encrypting means 21 and the recording means 15 of the present embodiment serve as the second decrypting means of the present invention. It is an example of a recording unit.

Further, although the decrypting means 43 and the encrypting means 21 of the present embodiment are divided into separate blocks for the sake of explanation, since the same encrypting method is used, the encrypting / decrypting means is used. As a single block. In this case, since the plaintext portion does not appear, there is no need for a restriction on the configuration such as implementation of an LSI, and there is no need to duplicately use the authentication means and the encryption / decryption means. The cost does not increase.

Further, the authentication means 16 of the present embodiment is not limited to the means for authenticating the transmission software and the application software for recording data in the recording means 15 for internal processing. If the device cannot access the internal bus or the memory, the authentication for the internal processing need not be performed.

Furthermore, the number of repetitions of encryption in this embodiment is eight for transmission and four for recording, but is not limited to this. In short, it is only necessary that the encryption for transmission has a larger number of times of encryption than the encryption for recording.

It is to be noted that all or some of the functions of each component of the transmission device or the recording / reproducing device of the present invention may be realized using dedicated hardware, or may be realized by software using a computer program. No problem.

Furthermore, a program recording medium in which a program for causing a computer to execute all or a part of the functions of each component of the transmitting device or the recording / reproducing device of the present invention also belongs to the present invention.

[0157]

As is apparent from the above description, the present invention has no restrictions on the configuration, does not have a large hardware / software cost, and can restore the reference clock.
It is possible to provide a transmitting device, a recording / reproducing device, and a program recording medium that are not likely to be decrypted even if time is taken.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a transmitting device and a recording / reproducing device when a portion including a PCR is recorded in plain text according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a transmitting device and a recording / reproducing device in a case where a portion including a PCR transmitted in plain text is encrypted and recorded according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a configuration of a transmitting apparatus and a recording / reproducing apparatus when a recording / reproducing apparatus according to a third embodiment of the present invention decodes a part including a PCR and records data output from an interface.

FIG. 4 is a block diagram showing a configuration of a transmitting device and a recording / reproducing device in a case where a recording / reproducing device according to a fourth embodiment of the present invention decodes a part including a PCR and records the decoded data.

FIG. 5 is a block diagram showing a configuration of a transmitting device and a recording / reproducing device when a transmission device and a recording / reproducing device are notified of the presence / absence of a part including a PCR according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a transmitting apparatus and a recording / reproducing apparatus when performing encryption with a smaller number of repetitions than in a transmission encryption and recording according to a sixth embodiment of the present invention.

FIG. 7 shows an MPEG2-TS packet being converted to IEEE 139.
FIG. 9 is a diagram showing a method of specifying a restoration time when transmitting data through four interfaces.

FIG. 8 is a diagram showing a method for generating an isochronous packet.

FIG. 9 is a diagram showing the structure of an MPEG2-TS packet.

FIG. 10 is a diagram showing a configuration of a reference clock generation unit according to the first to sixth embodiments of the present invention.

FIG. 11 is a diagram showing the position of a part including PCR.

FIG. 12 is a diagram illustrating positions where encryption is performed when encryption is performed with a smaller number of repetitions than the transmission encryption according to the sixth embodiment of the present invention.

FIG. 13 is a diagram showing a configuration of a conventional transmitting device and a recording / reproducing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IEEE1394 bus 2 Transmission device 3 IEEE1394I / F 4 Transmission encryption / decryption means 5 Separation means 6 Broadcast scramble decoding means 7 Receiving means 8 Decoding means 9 Authentication means 10 Encryption range setting means 11 Recording / reproducing apparatus 12 IEEE1394I / F 13 Received packet processing means 14 Encryption changing means 15 Recording means 16 Authentication means 17 Reference clock generation means 18 Partial encryption means 19 Notification means 20 Detection means 21 Encryption means

Claims (23)

[Claims] Claims 1. A copyrighted AV data is stored in an MPEG format.
-IEEE1 using transport packets of TS
When transmitting via the 394 bus, at least a PCR (Program) of the AV data encrypted for transmission is used.
A transmission device comprising: a transmission encryption unit for storing a portion including a clock reference in plain text without encryption; and a first digital interface for transmitting the AV data to an IEEE 1394 bus. 2. The transmission apparatus according to claim 1, wherein the transmission encryption unit sets a flag in the CIP header to indicate whether or not a plaintext portion is included. 3. The transmitting apparatus according to claim 2, wherein the flag is set using the remaining one bit of sy of a CIP header. 4. The transmission encrypting means comprises an MPEG-T
Only the 192 bytes of the transport packets of the S transport packets, including the PCR, are left in plaintext, and the EMI indicating the copy management of the sy of the CIP header is set to copy free (00). The transmitting device according to claim 1, wherein 5. A second digital interface for receiving the AV data transmitted from the transmission device according to claim 1, and a second digital interface for receiving the AV data received by the second digital interface. From the portion containing at least PCR,
A recording / reproducing apparatus comprising: a reference clock generating means for reading a CR to generate a reference clock; and a recording means for recording the AV data based on the reference clock. 6. The recording / reproducing apparatus according to claim 5, wherein said recording means records the portion including at least the PCR of the AV data as plain text. 7. The recording / reproducing apparatus according to claim 5, wherein the recording unit encrypts and records the portion including the at least PCR of the AV data. 8. The method of converting the copyrighted AV data into MPEG data.
-IEEE1 using transport packets of TS
A second digital interface that receives the encrypted AV data transmitted from a transmitting device that transmits the data via a 394 bus; a decryption unit that decrypts at least a portion of the AV data that includes a PCR; PCR of the AV data decoded by the decoding means
1. A recording / reproducing apparatus comprising: a reference clock generating means for generating a reference clock by reading the AV data; and a recording means for recording the AV data based on the reference clock. 9. The recording device according to claim 7, wherein the recording unit outputs the encrypted AV data output from the second digital interface.
The recording / reproducing apparatus according to claim 8, wherein data is recorded. 10. The recording / reproducing apparatus according to claim 8, wherein the recording unit records the AV data decoded by the decoding unit. 11. The AV data for which copyright is claimed is
IEEE using transport packets of G-TS
When transmitting via the 1394 bus, at least PCR (Program) of the AV data encrypted for transmission is used.
When there is a portion including a ClockReference), there is provided a notifying means for notifying information of a packet containing the PCR and a position of the PCR, and a first digital interface for sending the AV data to an IEEE1394 bus. Transmitting device. 12. A second digital interface for receiving the AV data transmitted from the transmitting apparatus according to claim 11, and said PC based on said information notified by said notifying means.
Detecting means for detecting a packet containing R; decoding means for decoding at least a portion of the packet including the PCR; reference clock generating means for reading the PCR to generate a reference clock; Recording means for recording the AV data based on the recording data. 13. The recording means according to claim 11, wherein said encrypted A output from said second digital interface is encrypted.
13. The recording / reproducing apparatus according to claim 12, wherein V data is recorded. 14. The recording / reproducing apparatus according to claim 11, wherein the information is sent by an asynchronous command. 15. The recording means according to claim 6, wherein said recording means performs encryption by adding a predetermined value to said encrypted AV data instead of said encryption method. Or the recording / reproducing device according to any one of 10 above. 16. The recording means changes an encryption result of an encrypted portion using the AV data of the unencrypted portion, instead of the encryption method,
The recording / reproducing apparatus according to claim 6, wherein recording is performed. 17. The recording / reproducing apparatus according to claim 16, wherein the change is an exclusive OR. 18. Second decryption means for decrypting all of the encrypted AV data, wherein the recording means performs lighter encryption than the original encryption when recording the AV data. 6. The method according to claim 5, wherein
Or the recording / reproducing apparatus according to 8. 19. The recording / reproducing apparatus according to claim 5, wherein the portion including at least the PCR is an adaptation field control, a 5-flag, and a PCR. 20. The portion containing at least PCR,
N from the top of the MPEG-TS transport packet
6. A byte (n is a natural number).
19. The recording / reproducing apparatus according to any one of claims 18 to 18. 21. The recording / reproducing apparatus according to claim 20, wherein the n bytes are 12 bytes. 22. The recording / reproducing apparatus according to claim 20, wherein the head is determined by a time stamp. 23. A program storing a program for causing a computer to execute all or a part of the functions of each component of the recording / reproducing apparatus or the transmitting apparatus according to claim 1. recoding media.