JP2003110546A - Receiving data processing apparatus and method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a reception data processing device capable of achieving both easy access to reception time data and security against time data tampering. A tuner for receiving content, a timer for measuring time data, a generator for generating key data, a CPU for performing a predetermined operation using the time data and the key data, An encryption / decryption unit 5 for encrypting the content received by the tuner based on the calculation result, and a received data processing device having the HDD 10 record the encrypted data and time data encrypted thereby.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiving device for receiving broadcast contents, and more particularly to a received data processing device for encrypting and recording broadcast contents.

[0002]

2. Description of the Related Art Recently, a reception data processing device that handles broadcast contents as digital data has become widespread. Japanese Patent Laid-Open No. 2000-293936 discloses a recording device, a reproducing device, which can protect the copyright of a digital signal on a recording medium,
And a recording medium is disclosed, and in a digital signal recording device, a reproducing device and a recording medium for recording or reproducing a digital signal on a recording medium, a digital signal is recorded with a key obtained by performing a predetermined operation on the key data at the time of recording. Encrypted and recorded on a recording medium together with the key data, and at the time of reproduction, the reproduced digital signal is decrypted and output by the key obtained by performing the predetermined calculation on the key data reproduced from the recording medium. Achieved by

In this apparatus, the packet data recorded by the input / output circuit is output to the data encryption circuit. In the data encryption circuit, the input packet data is encrypted by the data key generated in the control circuit based on the keys generated by the device key generator and the block key generator,
This is output to the input / output control circuit. Then, in the input / output control circuit, a time stamp is applied to the packet data input based on the time data from the timing generation circuit,
This is output to the recording signal processing circuit. The recording signal processing circuit generates recording data including error correction code, ID data, sub-code, block key data used for encryption, etc. and generates a recording signal according to the recording mode judged by the control circuit. Then, the data is recorded on the tape by the rotary head.

By the way, when a receiver receives a broadcast, and this broadcast content is temporarily recorded by the receiver and then reproduced, the copyright holder limits the time during which the receiver can temporarily store and reproduce the broadcast content. The form used in the specification is becoming established, and at this time, the time when the content is broadcast and received and recorded needs to be recorded in the recording device of the receiver in association with the recorded content, and this time must not be tampered with.

However, in this conventional apparatus, although there is a device for encrypting and recording the reception recording time in order to prevent falsification, when reproducing the recorded content, the reception time data of the content to be reproduced is encrypted. Therefore, it is impossible to read the time data without decrypting the code each time, so that there is a problem that it takes too much time to access the time data.

[0006]

That is, since the above-mentioned prior art focuses on recording and recording the content on the medium in an encrypted manner, it is easy to access the reception time data of each part of the content and the reception time. There is a problem that it is not possible to achieve both the security against data tampering.

It is an object of the present invention to provide a received data processing device capable of easily accessing time data when a broadcast content is received by a receiver, and at the same time having high security against falsification of time data. I am trying.

[0008]

The present invention provides a receiving means for receiving contents, a time measuring means for measuring time data, a generating means for generating key source data, a time data measured by the time measuring means, and Arithmetic means for performing a predetermined arithmetic operation using the key source data generated by the generating means, and encryption means for encrypting the content received by the receiving means based on the arithmetic result obtained by the arithmetic means A receiving data processing device comprising: a recording unit that records the encrypted data encrypted by the encrypting unit and the time data measured by the time measuring unit.

The received data processing apparatus according to the present invention does not use the time data as it is for the encryption of the content, but uses the key source data and the time data to perform a predetermined operation to obtain an encryption key. Use it as data to encrypt content. As a result, even if the time data is stored in the hard disk together with the encrypted content data, the content data cannot be directly decrypted from the time data, so that the safety is not deteriorated. Therefore, it is possible to achieve both accessibility to time data and security against falsification.

Further, the present invention is a storage means for storing data including generation means for generating key source data, encrypted content, and time data associated with the content, and the storage means. A decryption for decrypting the encrypted content by performing a predetermined operation using the reading means for reading the data from the key, the key source data generated by the generating means, and the time data read by the reading means. The received data processing apparatus is characterized by comprising:

The reception data processing device according to the present invention enables the reception data processing device described above to decrypt and reproduce the encrypted content data while achieving both accessibility and security against tampering. Similarly, it is possible to achieve both accessibility and security.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A received data recording / reproducing apparatus of an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the outline of an embodiment of a received data recording / reproducing apparatus according to the present invention.

<Structure of Received Data Processing Device> In the received data recording / reproducing device according to the present invention shown in this figure, the tuner 1 first receives the broadcast content. The CPU 4 reads an instruction from the user from the remote controller 3. Upon receiving a recording instruction from the user, the CPU 4 reads the reception time from the current time timer 2, associates the reception time with the received content, and records the content in a hard disk drive (hereinafter, referred to as HDD) 10 as a file. However, as the time information, it is also preferable to use the time data included in the transmission packet in digital broadcasting instead of the time timer 2 in the system. The CPU 4 performs processing according to a flowchart described later to generate an encryption key, and the encryption / decryption device 5
The content is encrypted by and the encrypted content data is recorded in the HDD 10.

For some contents, the copyright holder has specified a time limit that allows viewing back 90 minutes before the start of broadcasting, for example. For example, when such content (program) is broadcast, the broadcast of the content (program) is started, and if the current time is within 90 minutes after the start of broadcasting, the content is traced back to the beginning of the content (program). However, if the current time is 100 minutes after the start of broadcasting, it means that the content (program) is allowed to be viewed from a position 10 minutes after the start. Therefore, it is necessary to obtain the reception recording time of the content for the partial portion of the content. The unit of this partial portion may be a video frame or a field, or a fixed time unit, for example, a 1 second unit.

The CPU 4 responds to a C instruction in response to a user instruction.
The PU 4 performs processing according to a flowchart described later, generates a decryption key if the relevant portion of the content to be played is within the playable time range,
The file is read from the HDD 10 and the encryption / decryption device 5
The content is decoded by means of the above, the data is decoded through the decoding device 7, the content is displayed by the display output device 7, and in the case of voice, this is reproduced.

When copying is possible, content data is output from the external output terminal 12 through the output IF (interface) 9.

When recording the content in the HDD 10, the recording time may be added to the content data itself, or a time data file may be generated in association with the content data and recorded as a file different from the content. Good.

Since the difference between the recording time point and the reproducing time point is important for copyright protection, which is the focus of the present application, the value of the current time timer 2 need not match the standard time of the world or Japan. Alternatively, the present time timer 2 may be realized by a counter that simply keeps time in the device.

FIG. 2 is a diagram showing an example of the contents of the time data file according to the present invention. Here, an example of the contents of the time data file is shown assuming that the contents are MPEG-compressed video. Each time one frame of video data is received, one line is added to the file. The line is
The picture number, data indicating the leading byte position of the picture, the type of the picture, and the time when the picture is received are indicated by the digits of hour, minute, second, and 1/30 second. The CCI field is copyright data, which means that CopyNever, CopyOnce, and Cop
The state of yFree is represented by 2 bits, and whether or not the time-limited storage / reproduction is permitted is represented by 1 bit. In this example, CopyNever allows the time-limited storage and reproduction.

In the example of FIG. 2, 2001, November, 22
In this example, the day starts at 1:00, 00 and 00 seconds. This data file is used in reproducing the content to obtain data as to when and when the portion of the content to be reproduced was received (broadcast or recorded). The picture number can be used for the same purpose. In this case, the recording start time of the content is recorded separately, the value is set to Ts, and the picture frequency is 29.98 Hz. Therefore, if the picture number is N, the reception time or recording time of the picture is Ts + N / 29.98 (seconds)
Is required as. The picture number is 1 from the beginning
Since it has a regularity that gradually increases, it is not necessary to record it.

One entry of the time file has a picture number of 4 bytes, a byte number of 7 bytes, and a type of 1 byte.
e, date 7 bytes, CCI 1 byte (3b of which)
20 bytes in total).

If the content position to be accessed is, for example, 10 seconds after the start of recording, it can be seen that it is 10 × 29.98 = about 300th picture. The 300th picture data has an entry at 300 × 20 bytes = 6000 bytes from the beginning of the time data file. By accessing the entry, the leading byte position of the picture, the picture type, the picture number, and the year / month / day time data can be obtained. Since these data are not encrypted, they can be used immediately after being read.

In the case of MPEG data, decoding cannot be performed unless the picture type at the beginning of reproduction is I. Therefore, 10
If the type of the second picture is not I, it is necessary to search for a picture with a picture type of I before and after that.

If these data are encrypted, it is necessary to obtain a decryption key for decrypting the data. However, if this time data file is encrypted using a different key for each part, It takes time to determine the part of the content to be accessed and obtain the key. However, in the present invention, there is no need to perform encryption, and there is no consumption of time for decryption.

Further, FIG. 3 is a diagram showing another example of the contents of the time data file according to the present invention. Each time one second of data such as video, audio, or data broadcast is received, one line is added to the file. One line indicates the data indicating the first byte position at that time, and the time when the picture is received by each digit of hour, minute, and second. In the example of FIG. 3, November 22, 2001, 1:00, 00, 00
It is an example starting from second. This data is
In reproducing the content, it is used to obtain data as to when and when the portion of the content to be reproduced is received (recorded).

For example, 2001, November, 22nd, 1st
If you try to read data from hour, 00 minutes, and 10 seconds, the beginning data of the time data file is 2001, 1
11th January, 22nd, 1 hour, 00 minutes, 00 seconds
By accessing the data in the row, the data regarding the data in the 10th second can be obtained. From the data on the 11th line, you can see the number of bytes from the beginning of the recorded data,
Then, the reception recording time can be confirmed.

One entry of the time file has a picture number of 4 bytes, a byte number of 7 bytes, and a type of 1 byte.
e, date 7 bytes, CCI 1 byte (3b of which)
15 bytes in total).

Further, FIG. 7 shows another example of the time data file. The file is composed of a recording start time and data indicating the position of each picture thereafter. 1 from the start of recording
If you try to start playback from 0 seconds, there is 1
It can be seen that 0 × 29.98 = about 300th picture. The 300th picture data has an entry at 300 × 20 bytes = 6000 bytes from the beginning of the time data file. By accessing the entry, the first byte position of the picture and the picture type,
You can get the picture number.

FIG. 8 shows another example of the contents of the time data file. Each time one second of data such as video, audio, or data broadcast is received, one line is added to the file. One line is data indicating the first byte position at that time,
The time when the picture is received is indicated by each digit of hour, minute, and second.

For example, 2001, November, 22nd, 1st
If you try to read data from hour, 00 minutes, and 10 seconds, the beginning data of the time data file is 2001, 1
11th January, 22nd, 1 hour, 00 minutes, 00 seconds
By accessing the data in the row, the data regarding the data in the 10th second can be obtained. From the data on the 11th line, it is possible to know the number of bytes from the beginning of the recorded data.

<Recording Process> Next, the recording process will be described with reference to FIG.
This will be described with reference to the flowchart of. The remote controller 3 issues a recording start instruction from the user to the CPU 4 to perform HDD recording.
Through (S11). In step S12, it is determined whether the content cannot be recorded and the content cannot be paused. The “pauseable” means “not permanent storage, but may be temporarily stored in the HDD of the receiver or the like for the purpose of temporarily shifting the viewing time by the user”. Here, this "temporary"
Is 90 minutes and will be described later.

If YES, it means that the recording is not possible, so step S13 is executed and the fact that the recording is not possible is displayed on the screen.

If the result of step S12 is NO, step S14 is executed to determine whether or not it is CopyFree. With CopyFree, since there is no particular restriction on copying, no processing for protection is required, and the process proceeds to step S15, a message indicating that recording is started is displayed, and recording is started. If the result of step S14 is NO, step S16 is executed, and it is checked whether or not a recording stop instruction is received from the user. If not, step S17 is executed.

There are two formats of the time data file: one for each picture and one for every fixed time. When creating for each picture, the beginning of the picture is detected. In the case of every fixed time, for example, in the case of every one second, in step S17, it is detected that the counting of time comes to the timing showing the break every one second. This may be performed by reading the current time from the current time timer 2 or simply counting 1 second.

In step S18, the present time is read from the present time timer 2.

The step S19 is executed to read the original data of the key from the key original data register 13, and the present time and the CCI value read previously are calculated to obtain the encryption key of the content. The operation may be exclusive OR, addition, or multiplication, but simple operation may be overlooked, so DES
Calculation such as is desirable. For example, key source data is bit-connected to the current time and CCI, unnecessary bits are discarded, and 56 bits are discarded.
The encrypted value is used as a key to perform an encryption operation. Here, it is preferable that the calculation process for obtaining the encryption key is performed at every predetermined time.
By doing so, it becomes possible to prevent illegal time even if the content is divided. Further, it is also preferable to perform this arithmetic processing for each predetermined video unit of the content, and by doing so, it is possible to prevent the time from being illegal even if the content is divided.

In step S20, the recorded content is encrypted using the encryption key obtained in step S19. The content encrypted in step S21 is recorded in the HDD 10.

At step S22, the byte number of the data for starting the encryption is obtained by using the previously obtained key, and the time data file of the format shown in FIGS. 2 and 3 is created.
It is recorded in the HDD 10.

In the above description, the common key source data is used for each received content, but it is also possible to use different key source data for each received content. In that case, the key source data register 13 may be composed of a random number generator so as to generate different key source data for each received content. Since the key source data used at the time of recording is also necessary at the time of reproducing, it is encrypted by the device unique key not shown in the HDD.
It is good to record at 10. By doing so, a different key can be used for each received content, and even if the key source data of one content is exposed, it is possible to prevent other contents from being decrypted.

On the contrary, the key source data register 13 is composed of a random number generator, the data generated here is regarded as encrypted key source data, and this is recorded in the HDD 10 and is stored in the HDD 10 and is unique to a device (not shown). Data decrypted with a key may be used as key source data.

At the time of reproduction, the encrypted key source data recorded in the HDD 10 may be read and decrypted with a device unique key (not shown), and this may be used as the key source data instead of the read value of the key source data register 13.

<Reproduction Process> Next, the reproduction process will be described with reference to FIG.
This will be described with reference to the flowchart of.

In step S31, the CPU 4 receives a reproduction start instruction from the user through the remote controller 3. In step S32, it is determined whether or not a reproduction end instruction is received from the user. If NO, the process proceeds to step S35.

In step S35, the reproduction designated position from the user is detected. Then, in step S36, the time data file is read and the data on the time data file at the designated position designated by the user is read.

The reproduction position can be designated by the user by direct designation of the recording time point, relative time from the recording start point, relative time from the current time, or the like.

When the designation by the user is designated in the form of directly indicating the recording time, the received recording data field of the time data file is searched. Further, particularly in the case of the time data file of the formats shown in FIGS. 7 and 8, the relative time from the reception recording start time described in the time data file of the designated time is obtained.

When using the relative time from the start of recording,
Further, a case where the designation by the user is based on the relative time from the start of recording will be described. It is assumed that this is, for example, the position 10 seconds after the start of recording. Refer to the time field of the first line of the time data file, and it is 10 × 29.98 =
It can be seen that it is the approximately 300th picture. The data of the 300th picture is 300x from the beginning of the time data file.
There is an entry at 20 bytes = 6000 bytes. By accessing the entry, the first byte position of the picture, the picture type, the picture number,
The date data can be obtained.

When the time data file is in the format shown in FIGS. 6 and 8, one line of data is 1 second, so that the location of 10 seconds is 11 seconds.
It can be obtained by accessing the line. In the case of the format shown in FIG. 6, since the recording time is written in the line,
By collating with this, it is possible to reconfirm whether it is within the reproducible range.

When the reproduction position designated by the user is designated by a time relative to the current time (for example, 10 minutes before the current time), the current time is first read from the current time timer 2 and then the current time is read. The recording time of the specified content to be reproduced is obtained by subtracting the specified time. Then, the reception record data field of the time data file is searched or the relative time from the reception record start time is obtained, and then the data at the designated position is read by the same method as described above.

Here, the time data file has been tampered with,
For example, if what was recorded three hours ago was changed to be recorded one hour ago, when the user tries to reproduce this, the user would normally "reproduce the content three hours ago". Where you have to specify,
The designation can be changed to "reproduce the content one hour ago". As a result, it cannot be correctly determined whether or not it is within the reproducible range in step S38 described later. Further, if the CCI field of the time data file is tampered with and is rewritten to CopyFree, this also makes it possible to cancel the check of the time range.

In the case of the formats shown in FIGS. 7 and 8, when the content length is changed by editing the content, the recording time cannot be correctly obtained for the portion whose length from the beginning has changed. There is. Since files are searched at relative positions, if there is content that started recording 3 hours ago, for example, 2 minutes after the start of the file,
When the content of time 57 minutes is edited or inserted by the file system operation, it means that the portion 2 minutes after the original content, that is, the portion recorded 2 hours and 58 minutes ago was recorded 1 minute before the present. The recording time cannot be determined correctly. In order to solve such a problem, the time is described in the partial part, and it is necessary to use the value to encrypt with the encryption key. The format of the time file shown in FIGS. 3 and 4 is valid. is there.

Next, in step S37, the present time is read from the present time timer 2. In step S38, the position designated by the user is compared with the current time to check whether the position is within 90 minutes.

In step S39, the time at the designated reproduction position, the CCI data, and the original data of the key read from the key original data 13 are calculated to obtain the decryption key. The calculation is the same as the method used at the time of recording.

If the time data file is falsified and the recording time or CCI value is changed, the decryption key in step S39 cannot be obtained correctly. As a result, it is possible to prevent unauthorized reproduction in the end.

In step S40, the content is decrypted with the decryption key obtained in step S39. The data format of the decrypted content is checked, and if the data is not correct, the CPU 4 "could not be decrypted correctly", or
Display a message such as "Data is corrupted" or "Database is corrupted" Device 6
It is preferable to display in.

When the recorded data is MPEG TS or PES, the header data exists at the beginning of the data, and therefore the method of checking the data format is such that there is a code that cannot be included in the contents. It is possible by checking the contradiction.

Finally, in step S41, the decrypted content is transmitted to the decoder 7 and the output IF (interface) 9.

According to the reproducing method described above, it is possible to prevent illegal reproduction even if the received recording time data is falsified.

(Structural diagram according to processing) FIG. 6 is an explanatory diagram of the structure of the present invention expressed along with the processing of data. In this figure, the recording process will be described first. Receive content from tuner 1. In step S17, the beginning of the picture is detected. At this timing, the current time timer 2 is read out, the key source data register 13 is read out, and an arithmetic key is calculated in step S19 to obtain an encryption key. The received content is encrypted by the encryption device 5 using this encryption key and recorded in the HDD 10.

Further, at the timing of detecting the picture head position, it is determined whether or not the recording data is the byte data, the time and the picture type are determined, and a time data file is created in step S22. This is also recorded in the HDD 10.

Next, regarding the reproduction process, the user instruction is received from the remote controller 3 from the remote controller 3, the time data file is read from the HDD 10, the time of the reproduction position designated by the user is compared with the time read from the current time timer 2, and reproduction is possible. Check if it is in range. If it is present, the time data file is searched, the original data of the key is read from the key original data register 13, an operation is performed in step S39 to obtain a decryption key, and the decryption device 5 decrypts the encrypted content of the HDD 10.

According to the recording method and the reproducing method described above, the received recording time can be referred immediately without encryption, and high security can be compensated. Therefore, it is possible to provide a reception data processing device capable of achieving both easy access to the reception time data and safety against falsification of the time data.

[0063]

As described in detail above, according to the present invention, the reception recording time can be recorded in the HDD or the like without being encrypted, and can be immediately known without the need of decryption for later reference. At the same time, by encrypting the content based on the key data obtained by the calculation result of the key source data and the time data, it is possible to secure high security at the same time.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of an embodiment of a received data recording / reproducing apparatus according to the present invention.

FIG. 2 is a diagram showing an example of contents of a time data file according to the present invention.

FIG. 3 is a diagram showing another example of contents of a time data file according to the present invention.

FIG. 4 is a flowchart illustrating a recording process of the received data recording / reproducing device according to the present invention.

FIG. 5 is a flowchart illustrating a reproduction process of the received data recording / reproducing device according to the present invention.

FIG. 6 is a block diagram showing the outline of another embodiment of the received data recording / reproducing apparatus according to the present invention.

FIG. 7 is a diagram showing another example of the contents of the time data file according to the present invention.

FIG. 8 is a diagram showing another example of the contents of the time data file according to the present invention.

[Explanation of symbols]

1… Tuner, 2… Current time timer, 3
User instruction unit 4 CPU, 5 Encryption / decryption unit 6
Display output device 7 ... Decoder, 10 ... HDD, 12 ...
Output IF

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Claims (9)

[Claims] 1. Receiving means for receiving contents, time measuring means for measuring time data, generating means for generating key source data, time data measured by the time measuring means, and key source data generated by the generating means. Calculating means for performing a predetermined calculation using, and an encrypting means for encrypting the content received by the receiving means based on the operation result obtained by the calculating means; A reception data processing device, comprising: a recording unit that records the encrypted data that has been encrypted and the time data that the time counting unit has timed. 2. The received data processing apparatus according to claim 1, wherein said encryption means encrypts and records said original key data generated by said generation means. 3. Storage means for generating key source data, storage means for storing data including encrypted content and time data associated with the content, and the storage means for storing the data. And a decryption unit for decrypting the encrypted content by performing a predetermined calculation using the key source data generated by the generation unit and the time data read by the readout unit. A received data processing device comprising: 4. The received data processing apparatus according to claim 1, wherein the encryption means reads the recorded encrypted data and decrypts it. 5. When the decrypting means decrypts the content, the determining means determines the validity of the content, and when the determining means determines that the content is not valid, displays that effect. 4. The reception data processing device according to claim 3, further comprising: 6. The received data processing apparatus according to claim 1, wherein the calculation means performs this calculation at every predetermined time. 7. The received data processing apparatus according to claim 1, wherein the calculation means performs this calculation for each predetermined video unit of the content. 8. A receiving step of receiving contents, a clocking step of clocking time data, a generating step of generating key source data, a time data clocked in the clocking step, and a key source data generated in the generating step. And an encryption step of encrypting the content received in the receiving step based on the operation result obtained in the operation step, and an encryption step in the encryption step. And a recording step of recording the encrypted data that has been encrypted and the time data measured in the time measuring step. 9. A generating step of generating key source data, a reading step of reading data including encrypted content and time data attached to the content, and the key generated in the generating step. A received data processing method, comprising: a decryption step of decrypting encrypted content by performing a predetermined operation using the original data and the time data read in the readout step. .