JP2006080870A - Receiving device, recording device, reproducing device, and recording / reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a receiving apparatus capable of quickly searching for an I picture necessary for digest reproduction without having to read out all TS stored in an accumulating apparatus.
Key data information extraction means for extracting key data information corresponding to the key data from reception data including a stream corresponding to the scrambled content and key data for descrambling the stream. And table generation means for generating a table for associating the key data information extracted by the key data information extraction means with the stream.
[Selection] Figure 1

Description

  The present invention relates to a receiving device, a recording device, a reproducing device, and a recording / reproducing device, and more particularly to a receiving device suitable for generating data necessary for performing summary reproduction of content received by the receiving device, and recording the data. The present invention relates to a recording apparatus, a reproducing apparatus that reproduces content based on the data, and a recording / reproducing apparatus.

  A conventional receiving apparatus corresponding to server-type broadcasting receives content transmitted from a transmitting apparatus and an encrypted key (content key, scramble key, etc., hereinafter, the encrypted key is also referred to as an encryption key). The content or the like is stored in the storage device. When performing summary playback of the content, the content key and the scramble key stored in the storage device are used to descramble the content, and I pictures corresponding to the content are sequentially played back (for example, Non-patent document 1 and Non-patent document 2).

Standard number “ARIB STD-B25”, Standard name “Access control system in digital broadcasting”, Radio Industry (ARIB), 4.1 edition (revised date: June 5, 2003), year of formulation Date: October 26, 1999 Tomonari Nishimoto, Akiyo Baba, Shinya Kurioka, Seiichi Namba, “Access Control Method for Content in Server-Based Broadcasting”, The Journal of the Institute of Image Information and Television Engineers, The Institute of Image Information and Television Engineers, July 1, 2004, Volume 58 No. 7, p. 1003-p. 1008

  However, in the conventional receiving apparatus, a TS (Transport Stream) and an encryption key corresponding to the received content are sequentially stored in the storage apparatus. Therefore, when the content stored in the storage device is summarized and reproduced, the TS and the encryption key stored in the storage device are all read out in a short time, the encryption key is decrypted, and the TS is descrambled. It is necessary to search for an I picture necessary for reproduction.

  As a result, when the TS is read in a short time and the I picture is searched, the operation load on the receiving device and the storage device becomes very high. In particular, when the summary playback and other processing (content reception, recording, etc.) are performed at the same time, the operation load becomes high, causing a video break and the like, making smooth summary playback difficult. .

  Further, in order to perform smooth summary reproduction, it is necessary to increase the number of I pictures to be decoded per unit time. However, when all TSs are read as described above, the performance of the storage device and the reception device is reduced. Due to the limit, there is a limit in increasing the number of I pictures to be decoded per unit time.

  Accordingly, an object of the present invention is to provide a receiving apparatus that can quickly search for I pictures necessary for digest reproduction without having to read out all TS stored in a storage apparatus.

  A receiving apparatus according to the present invention extracts a key data information corresponding to the key data from reception data including a stream corresponding to the scrambled content and key data for descrambling the stream. Data information extracting means, and table generating means for generating a table that associates the key data information extracted by the key data information extracting means with the stream.

  According to the receiving apparatus of the present invention, it is possible to quickly search for I pictures necessary for digest playback without descrambling all TS stored in the storage apparatus.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing the configuration of the recording / reproducing apparatus in the first embodiment. The recording / reproducing apparatus includes a receiving apparatus 101 and a storage apparatus 4. Further, the security module 2 is connected to the recording / reproducing apparatus via an interface (not shown).

  The receiving apparatus 101 receives a scrambled TS from a tuner (not shown). The TS includes data corresponding to content (hereinafter also referred to as a stream), a key (encryption key) encrypted by a transmitter (not shown), and the like. A thick arrow in FIG. 1 indicates a stream flow. Here, the encryption key will be described.

  For example, in server-type broadcasting described in ARIB STD-B25 (Non-Patent Document 1), a scramble key Ks for scrambling the stream, a work key Kw set for each content provider, and set for each security module. A master key Km and a unique key Km ′, which are unique keys, and a content key Kc for realizing content-based viewing control are provided. Note that the scramble key Ks is a common key method that uses the same key for encryption and decryption, and is set to be different in seconds. The content key Kc is stored together with the scrambled stream, and is encrypted with the unique key Km ′ at the time of storage.

  These keys are then encrypted and transmitted by another key at the transmitter. For example, the work key Kw is encrypted with the master key Km and transmitted by the EMM. In the following description, another key Kb encrypted with one key Ka is assumed to be Kb · E (Kb). Therefore, the work key Kw encrypted with the master key Km is Kw · E (Km). Also, the EMM or ECM that transmits the encryption key is defined as EMM (Ka · E (Kb)) and ECM (Ka · E (Kb)), respectively.

  The TS input to the receiving apparatus 101 is input to the limited reception related information separating unit 5 in the receiving apparatus 101. The conditional access related information separation unit 5 separates EMM (Kw · E (Km)) and EMM (Kw · E (Km ′)) from the TS and outputs them to the EMM processing unit 7 in the security module 2. Further, data other than EMM (Kw · E (Km)) and EMM (Kw · E (Km ′)) is output to the information reproducing unit 6 for limited reproduction.

  The EMM processing unit 7 decrypts Kw · E (Km) with the master key Km preset in the security module 2 and sends the work key Kw to the ECM processing unit 8 for limited reception or the ECM-Kc processing unit 9 for limited playback. Output. Further, the EMM processing unit 7 decodes the EMM (Kw · E (Km ′)) and outputs it to the ECM-Kc processing unit 9 for limited reproduction. 2 is a schematic diagram schematically showing decoding of Kw · E (Km) in the EMM processing unit 7, and FIG. 3 schematically shows decoding of Kw · E (Km ′) in the EMM processing unit 7. It is the schematic diagram shown. Further, D in FIGS. 2 and 3 means “Decrypt”, that is, decryption.

  The conditional access ECM processing unit 8 reproduces the content corresponding to the received TS at the same time as reception, and the ECM-Kw (Ks · E (Kw)) separated by the conditional access related information separation unit 5. And Ks · E (Kw) is decrypted with the work key Kw output from the EMM processing unit 7. FIG. 4 is a schematic diagram schematically showing Ks · E (Kw) decoding in the conditional access ECM processing unit 8. The scramble key Ks obtained by the decryption is output to the descrambler 3. The descrambler 3 descrambles the stream input from the limited playback information separation unit 6 with the scramble key Ks and outputs the descrambled stream to the decoder unit 23. The decoder unit decodes the descrambled stream and outputs it to a display unit (not shown).

  On the other hand, when recording a content (stream) on the recording / reproducing apparatus, the limited reproduction ECM-Kc processing unit 9 transmits the content key Kc separated from the TS by the limited reproduction information separating unit 6. Kc · E (Kw) in EMC (Kc · E (Kw)) is decrypted with the work key Kw output from the EMM processing unit 7, and the content key Kc obtained by the decryption is output from the EMM processing unit 7. Encrypt with the unique key Km ′. FIG. 5 is a schematic diagram schematically showing decryption and encryption of the content key Kc in the ECM-Kc processing unit 9 for limited playback. Further, E in FIG. 5 means “Encrypt”, that is, encryption.

  Then, the encrypted Kc · E (Km ′) is transmitted to the ECM storage unit 10 for Kc transmission by ECM. Then, the ECM accumulation unit 10 for Kc transmission records ECM (Kc · E (Km ′)). The work key Kw and the unique key Km ′ are stored in a storage unit (not shown) provided in the security module.

  When storing the stream, the limited reproduction information separating unit 6 outputs the stream from which the ECM (Kc · E (Kw)) is separated to the limited reproduction ECM-Kc detection unit 13. The limited playback ECM-Kc detection unit 13 detects whether or not the input TS includes the ECM-Kc, and the detection result (presence / absence of the ECM-Kc) and the input TS are added to the TS information header addition unit. 15 is output. Here, ECM-Kc is an ECM that transmits Ks · E (Kc) obtained by encrypting a scramble key Ks with a content key Kc in a transmitter.

  The time counter 20 outputs a time stamp corresponding to the time when the TS input to the TS information header adding unit 15 is received by the receiving apparatus 101 to the TS information header adding unit 15.

  The TS information header adding unit 15 adds a header including the presence / absence of the ECM-Kc input from the limited playback ECM-Kc detection unit 13 and the time stamp input from the time counter 20 to the TS. Append. Then, the TS with the header added is output to the recording buffer 11.

  When the TS is stored in the storage device 4, the TS is transferred in units of one block composed of a predetermined number n of TSs. Therefore, the recording buffer 11 holds the TS until a predetermined number of TSs constituting one block are prepared. 6 is a schematic diagram schematically showing a block composed of a predetermined number n of TSs (hereinafter also referred to as TS blocks). In FIG. 6, h is the TS information header adding unit 15. Indicates the header added to TS. In addition, the predetermined number n is appropriately set based on the performance of the storage device 4 when designing the recording / reproducing apparatus.

  When a predetermined number n of TSs are arranged in the recording buffer 11, a TS block is output from the recording buffer 11 to the table generating unit 40 by a control unit (not shown). The table generation unit 0 stores information related to ECM-Kc included in the input TS block (for example, the presence or absence of ECM-Kc in the TS block, the address of the storage device in which the ECM-Kc is recorded, etc.). -A Kc storage location table is generated.

  FIG. 7 is a block diagram illustrating a configuration of the table generation unit 40 according to the first embodiment. The TS block output from the recording buffer 11 is input to the storage device interface unit 43 (hereinafter referred to as storage device I / F 43).

  The storage device I / F 43 includes a time stamp detection unit 44, an ECM-Kc detection unit 45, and a TS output unit 46. The time stamp 44 detects a time stamp from the header added to the first TS in the input TS block, and outputs the time stamp to the ECM-Kc storage position table generation unit 41.

  The ECM-Kc detection unit 45 detects whether any of the TSs constituting the input TS block includes the ECM-Kc, and outputs the detection result to the ECM-Kc storage location table generation unit 41. Specifically, the presence / absence of the ECM-Kc is detected by referring to information indicating the presence / absence of the ECM-Kc included in the header added to the TS constituting the TS block. Therefore, if at least one TS among the TSs constituting the TS block has ECM-Kc, the detection result is “ECM-Kc present”.

  The TS output unit 46 outputs the TS block to the storage device 4 so that the input TS block is recorded at the address of the storage medium (not shown) in the storage device 4 specified by the write address management unit 42. To do. When the address is output to the TS output unit 46, the address is also output to the ECM-Kc storage location table generation unit 41.

  The ECM-Kc storage position table generation unit 41 receives the time stamp input from the time stamp detection unit 44, the detection result input from the ECM-Kc detection unit 45 (presence / absence of ECM-Kc), and the input from the write address management unit 42. The address is stored in the ECM-Kc storage location table in association with the TS block.

  FIG. 8 is a schematic diagram schematically showing the ECM-Kc storage position table. In FIG. 8, a block number indicates the number of an input TS block, and an address, the presence / absence of ECM-Kc, and a time stamp are stored in association with the block number. When the ECM-Kc storage location table corresponding to the content is completed, the ECM-Kc storage location table is output to the ECM-Kc storage location table storage unit 17 in the storage device 4 and stored. The TS block is output from the TS output unit 46 to the stream storage unit 12 and stored at the address specified by the write address management unit 42.

  In order to obtain the scramble key Ks used for storing the content received by the receiving apparatus 101, creating and storing the ECM-Kc storage location table corresponding to the content, and descrambling the content as described above. Necessary ECM (Kc · E (Km ′)) is accumulated.

  Next, a case will be described in which the content recorded in the storage device 4 is summarized and reproduced in the recording / reproducing apparatus. In the recording / reproducing apparatus, when a user performs an operation for performing summary reproduction, a signal for performing summary reproduction is input to the ECM-Kc reading control unit 18 from a control unit (not shown).

  The ECM-Kc read control unit 18 reads the ECM-Kc storage location table from the ECM-Kc storage location table storage unit 17 and identifies the TS block including the ECM-Kc. Then, the stream storage unit 12 is instructed to output the identified TS block.

  Based on an instruction from the ECM-Kc read control unit 18, the TS block output from the stream storage unit 12 is held by the reproduction buffer 13. The reproduction award buffer 13 sequentially outputs TSs constituting the TS block to the TS information header deletion unit 19 under the control of a control unit (not shown). The TS information header deletion unit 19 deletes the header added by the TS information header addition unit 15 from the input TS, and outputs it to the limited playback ECM-Kc separation unit 14.

  When the input TS includes ECM-Kc, the limited playback ECM-Kc separation unit 14 separates the ECM-Kc and outputs it to the limited reception ECM-Kc processing unit 9. Also, the stream from which the ECM-Kc is separated is output to the descrambler 3.

  The conditional access ECM-Kc processing unit 9 reads the ECM (Kc · E (Km ′)) corresponding to the content to be summarized and reproduced from the ECM storage unit 10 for Kc transmission and uses the stored unique key Km ′. Decrypt Kc · E (Km ′) to obtain the content key Kc. Then, by using the content key Kc, Ks · E (Kc) included in the ECM-Kc input from the limited playback ECM-Kc separation unit 14 is decrypted to obtain a scramble key Ks. Then, the scramble key Ks is output to the descrambler 3. FIG. 9 is a schematic diagram schematically showing decryption until the scramble key Ks is obtained in the conditional access ECM-Kc processing unit 9.

  The descrambler 3 uses the scramble key Ks input from the conditional access ECM-Kc processing unit 9 to de-scramble the stream input from the limited playback ECM-Kc separation unit 14. Then, the descrambled stream is output to the I picture extraction unit 21.

  The I picture extraction unit 21 extracts an I picture from the input stream, and outputs the I picture to the decoder 23 according to the reproduction speed (summary rate) designated by the double speed control unit 22. Then, the decoder 23 decodes the input I picture and outputs it to a display unit (not shown). By the above operation, summary reproduction is performed by the recording / reproducing apparatus.

  In the server-type broadcast described in Non-Patent Document 1, the case where summary reproduction is performed by specifying the reproduction start position at a relative time from a predetermined position of content using segment metadata is also defined. However, in the recording / reproducing apparatus according to the first embodiment, the ECM-Kc read control unit 18 refers to the type stamp stored in the ECM-Kc storage position table, thereby specifying the reproduction position specified by the segment metadata. Can be quickly searched and the necessary ECM-Kc can be accessed, so that a quick random access can be realized and a smooth summary reproduction can be realized.

  As described above, according to the recording / reproducing apparatus in the first embodiment, the ECM-Kc storage location table can be generated by the receiving apparatus 101 provided in the recording / reproducing apparatus. It is not necessary to descramble all TSs stored in.

  More specifically, in the conventional apparatus, the ECM-Kc having the scramble key Ks necessary for descrambling the stream is stored in the storage apparatus without being managed. Therefore, the ECM-Kc is searched. For this reason, it is necessary to read all TS stored in the storage device for each TS block. Therefore, even TS blocks that do not include ECM-Kc have been read. That is, there is a waste of search time, and a wasteful load is applied to the storage device and the power is consumed wastefully.

  However, in the recording / reproducing apparatus in the first embodiment, the TS block including the ECM-Kc can be identified and read in advance by referring to the ECM-Kc storage position table. Therefore, it is possible to reduce the time required for the search and realize smooth summary reproduction. In addition, the load on the storage device and the power consumption can be reduced.

  In the first embodiment, the case where the presence / absence of ECM-Kc is stored in the ECM-Kc storage location table for each TS block has been described. However, whether each TS constituting the TS block includes ECM-Kc or not. May be stored in the ECM-Kc storage position table.

  In the first embodiment, the TS information header deletion unit 19 only deletes the header added to the TS, but the TS information header deletion unit 19 includes the ECM-Kc in the input TS. It may be determined with reference to the header added to the TS, and only the TS including the ECM-Kc may be output to the limited playback ECM-Kc separation unit 14.

Embodiment 2. FIG.
FIG. 10 is a block diagram showing the configuration of the recording / reproducing apparatus in the second embodiment. In FIG. 10, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The limited playback information separating unit 6 outputs the TS after separating the ECM (Kc · E (kw)) to the second descrambler 25. The second descrambler 25 descrambles the input TS and outputs it to the first I picture detection unit 26. Note that the scramble key Ks necessary for scrambling in the second descrambler 25 is decrypted by the conditional access ECM processing unit 8 in the same manner as when the content corresponding to the received TS is reproduced simultaneously with reception, Input to the second descrambler 25.

  The first I picture detection unit 26 detects whether or not there is an I picture in the input TS, and outputs the detection result to the TS information header addition unit 15. The TS information header adding unit 15 includes the presence / absence of an I picture input from the I picture detection unit 26, the presence / absence of an ECM-Kc (output of the ECM-Kc detection unit 13 for limited reception reproduction), and the time stamp output by the time counter. Is added to the TS output from the ECM-Kc detection unit 13 for limited reception and reproduction and output to the recording buffer 11. The TS held in the recording buffer 11 is output to the table generating unit 50 for each block.

  FIG. 11 is a block diagram illustrating a configuration of the table generation unit 50 according to the second embodiment. In FIG. 11, the second I picture detection unit 52 detects an I picture in the input TS block based on the header, and outputs the detection result to the I picture storage position table generation unit 53. Further, the time stamp and the address are input to the I picture storage position table generation unit 53 from the time stamp detection unit 44 and the write address management unit 42 as in the first embodiment.

  Then, the I picture storage position table generation unit 53 generates an I picture storage position table as shown in FIG. 12, stores the address, the presence / absence of the I picture, and the time stamp, and stores the I picture storage position table in the storage device. 4 to the I picture storage position table storage unit 28. The ECM-Kc storage location table is generated in the ECM-Kc storage location table generation unit 41 as in the first embodiment, and is output to the ECM-Kc storage location table storage unit 17. As described above, the reception device 102 generates two tables, and the two tables are recorded in the storage device 4 together with the stream.

  Next, a case where summary reproduction is performed will be described. In the recording / reproducing apparatus, when a user performs an operation for performing summary reproduction, a signal for performing summary reproduction is input from an unillustrated control unit to the ECM-Kc readout control unit 18 and the I picture readout control unit 29. The

  The ECM-Kc read control unit 18 refers to the ECM-Kc storage position table, specifies the storage position (address) of the ECM-Kc, and transmits the TS including the ECM-Kc from the stream storage unit 12 to the reproduction buffer. 13 to output. On the other hand, the I picture read control unit 29 refers to the I picture storage position table, and the I picture closest to the storage position after the storage position (address) of the ECM-Kc specified by the ECM-Kc read control unit 18 Is stored, and a TS including the I picture is output from the stream storage unit 12. Note that the number of I pictures specified by the I picture read control unit 29 is set according to the playback speed (summary rate) specified by the double speed control unit 22.

  The TS including the I picture specified by the I picture read control unit 29 is input to the first descrambler 3 via the TS information header deletion unit 19 and the limited playback ECM-Kc separation unit 14. The TS is descrambled using the scramble key Ks decrypted by the limited playback ECM-Kc processing unit 9 and output to the decoder unit 23 in the same manner as in the first embodiment.

  As described above, according to the recording / reproducing apparatus in the second embodiment, the receiving apparatus 102 generates an ECM-Kc storage position table, and further generates an I picture storage position table. It becomes possible to carry out more easily and quickly.

  In the recording / reproducing apparatus according to the second embodiment, smooth summary reproduction can be realized by quickly accessing the I picture using the segment metadata.

Embodiment 3 FIG.
FIG. 13 is a block diagram showing the configuration of the recording / reproducing apparatus in the third embodiment. In FIG. 10, the same components as those described in the first embodiment or the second embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The I picture position information extraction unit 30 extracts I picture position information previously added to the TS at the transmitter as metadata or a file from the input TS, and stores the I picture position information table storage unit in the storage device 4. To 31. The I picture position information is stored in the I picture position information table storage unit 31. Note that the I picture position information is a table in which relative time information from a predetermined point in the content, such as the time from the beginning of the content, and the I picture number are associated with each other.

  Next, a case where summary reproduction is performed will be described. In the recording / reproducing apparatus, when a user performs an operation for performing summary reproduction, a signal for performing summary reproduction is input from an unillustrated control unit to the ECM-Kc readout control unit 18 and the I picture readout control unit 29. The

  The I picture read control unit 29 refers to the I picture position information table and specifies the position of the I picture in the content based on time information from the beginning of the content. Further, the ECM-Kc read control unit 18 refers to the ECM-Kc storage position table (specifically, the time stamp in the ECM-Kc storage position table) and immediately before the time information corresponding to the position of the I picture. The storage position of the stored ECM-Kc is specified. Then, based on the specified ECM-Kc, the scramble key Ks is obtained as described in the first embodiment or the second embodiment.

  Next, in order to read out the I picture, the I picture read control unit 29 refers to the ECM-Kc storage position table, and uses the relative time information of the I picture read out from the I picture position information table, immediately before the relative time. The storage position (address) of the stored block is specified, and the corresponding block is output from the stream storage unit 12 in the storage device 4. The block output from the stream storage unit 12 is descrambled by the descrambler 3 and output to the decoder 23.

  As described above, according to the recording / reproducing apparatus in the third embodiment, the receiving apparatus 103 generates the ECM-Kc storage position table, extracts the I picture position information, and stores it in the recording apparatus. Thus, it is possible to more easily and quickly detect an I picture when generating a summary.

  In the recording / reproducing apparatus according to the third embodiment, smooth summary reproduction can be realized by quickly accessing the I picture using the segment metadata.

  In the first or second embodiment, when summary playback is performed from the top of the content stored in the storage device 4, the ECM-Kc storage location table is referred to and the content is closest to the top of the content. It is sufficient to specify ECM-Kc and perform summary playback. However, when summary playback is performed while the content is being played back, the I picture closest to the position on the currently playing TS can be played back. In addition, it is necessary to specify ECM-Kc.

  For example, in the ARIB standard, the interval between I pictures in a stream is defined as 0.5 seconds. Therefore, for example, in the case of the second embodiment, when the summary playback is performed from the middle of the playback of the content when the interval between the I pictures is 0.5 seconds, the next I picture is first stored in the I picture position information table. More specifically, the ECM-Kc corresponding to the position immediately before is temporally specified by the ECM-Kc storage position table, and the TS block including the ECM-Kc is output from the stream storage unit 12.

  Next, the TS block including the I picture specified from the I picture position information table is output from the stream storage unit 12. For subsequent I-picture accesses, the ECM-Kc corresponding to the position immediately preceding the position 0.5 × N seconds ahead of the I-picture head position output from the previous stream storage unit 12 is stored in the ECM-Kc storage position table. The TS block including the I picture 0.5 × N seconds ahead of the I picture head position output from the stream storage unit 12 and then output from the stream storage unit 12 is output by the TS block including the ECM-Kc. Is output.

  Then, when the I picture is located at a position 0.5 × N seconds ahead from the position on the TS that is currently reproduced, it is possible to avoid reproducing the I picture from the middle. Here, N is a value set by a double speed instruction from the double speed control unit 22.

  When the ECM-Kc and the I picture are associated with each other, the recording / reproducing apparatus according to the first to third embodiments reads the ECM-Kc from the storage device with reference to the ECM-Kc storage position table. Thus, the I picture can be searched easily and quickly, and smoother summary reproduction can be performed.

It is a block diagram which shows the structure of the recording / reproducing apparatus in Embodiment 1 of this invention. It is the schematic diagram which showed typically decoding of Kw * E (Km) in the EMM process part. It is the schematic diagram which showed typically decoding of Kw * E (Km ') in the EMM process part. It is the schematic diagram which showed typically decoding of Ks * E (Kw) in the ECM process part 8 for conditional access. It is the schematic diagram which showed typically decoding and encryption of the work key Kw in the ECM-Kc process part 9 for limited reproduction. It is the schematic diagram which showed typically the block (henceforth TS block) comprised by predetermined number n TS. 3 is a block diagram illustrating a configuration of a table generation unit 40 according to Embodiment 1. FIG. It is the schematic diagram which showed typically the ECM-Kc storage position table. FIG. 5 is a schematic diagram schematically showing decryption until the scramble key Ks is obtained in the conditional access ECM-Kc processing unit 9. It is a block diagram which shows the structure of the recording / reproducing apparatus in Embodiment 2 of this invention. 10 is a block diagram illustrating a configuration of a table generation unit 50 according to Embodiment 2. FIG. It is the schematic diagram which showed typically the I picture storage location table. It is a block diagram which shows the structure of the recording / reproducing apparatus in Embodiment 3 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Demultiplexer, 2 Security module, 3,25 Descrambler, 4 Accumulator, 5 Limited reception related information separation unit, 6 Limited playback information separation unit, 7 EMM processing unit, 8 Limited reception ECM processing unit, 9 Limited playback ECM-Kc processing unit, 10 Kc transmission ECM storage unit, 11 recording buffer, 12 streams, 13 playback buffer, 14 limited playback ECM-Kc separation unit, 15 TS information header addition unit, 17 ECM-Kc storage Position table, 18 ECM-Kc read control unit, 19 TS information header deletion unit, 20 Time counter, 21 I picture extraction unit, 22 Double speed control unit, 23 Decoder, 24 Playback time designation unit, 26 I picture extraction unit, 28 I Picture storage position table, 29 I picture read control unit, 30 I picture Position information extraction unit, 31 I picture position information table, 41 ECM-Kc storage position table generation unit, 42 Write address management unit, 43, 51 Storage device interface unit, 44 Time stamp detection unit, 45 ECM-Kc detection unit, 46 TS output unit, 40, 50 table generation unit, 52 I picture detection unit, 53 I picture storage position table generation unit, 101, 102, 103 Receiving device.

Claims (4)

Key data information extraction means for extracting key data information corresponding to the key data from received data including a stream corresponding to the scrambled content and key data for descrambling the stream;
A receiving device comprising table generating means for generating a table that associates the key data information extracted by the key data information extracting means with the stream. A receiving device according to claim 1;
A recording apparatus comprising: the table generated by the table generation means; and an accumulation means for accumulating the stream. A recording apparatus according to claim 2;
Means for reading out the key data and a stream corresponding to the key data based on the table stored in the storage means of the recording device;
A recording / reproducing apparatus comprising: descrambling means for descrambling the stream using the key data. Means for reading a table recorded in the recording apparatus according to claim 2;
Means for reading out the key data and a stream corresponding to the key data based on the table;
A playback device comprising: descrambling means for descrambling the stream using the key data.

Images