JP5476155B2 - Content processing apparatus and content moving method thereof - Google Patents

Description

  The present invention relates to a content processing apparatus and a content transfer method thereof, and in particular, data encrypted according to a certain standard (for example, SAFIA which is an iVDR encryption standard) and another standard (for example, a DCTP-IP standard). The present invention relates to a content processing apparatus suitable for use in digital TVs, recorders, and the like that transmit between devices based on the above, and a content movement method thereof.

  In recent years, it has become common for content such as video and audio to be handled as digital data and displayed and reproduced by a user information processing apparatus. Digital data has the advantage that there is no degradation in quality upon copying, but on the other hand, since illegal copying is easily performed, a copyright protection mechanism is required.

  Such a copyright protection mechanism is called a copy guard technique, and various standards have been proposed. As an encryption technique for transmitting a digital video signal, there is DTCP (Digital Transmission Content Protection). . In DTCP, each device has an ID, uses public key cryptography or common key cryptography to perform mutual authentication, and if it is determined that content protection is possible on both sides, the encryption key is exchanged and the content is encrypted. Send and receive. Further, DTCP-IP is a standard that enables DTCP to be used for communication on an IP network. This DTCP-IP is assumed to be used for connection of AV devices in the home based on DLNA (Digital Living Network Alliance). The implementation of DTCP-IP is described in detail in Non-Patent Document 1.

  On the other hand, there is iVDR (Information Versatile Disk for Removable usage) as a standard for a removable hard disk for recording digital data. In SAFIA (Security Architecture For Intelligent Attachment device), which is a copyright protection standard corresponding to iVDR, a rule is defined in which recorded data is divided into blocks within a certain playback time and is encrypted and stored with an encryption key. It has been.

  In a content processing apparatus that supports iVDR, such as a recorder, when moving content or the like, the SAFIA is usually used, and the same data exists at the source and destination for a certain fixed time. It is only allowed, preventing illegal copying and increasing security. It should be noted that the outline of iVDR can be known from Non-Patent Document 2.

Hitachi, Ltd., Intel Corporation, Matsushita Electric Industrial Co., Ltd., Sony Corporation, Toshiba Corporation, "DTCP Volume 1 Supplement E Mapping DTCP to IP Revision 1.2 (Informational Version)", [online], June 15, 2007, Digital Transmission Licensing Administrator (DTLA), [Search February 1, 2010], Internet <URL: http://www.dtcp.com/data/info%2020070615%20DTCP%20V1SE%201p2.pdf> iVDR Consortium Personal Page Home, [online], iVDR Consortium, [Search February 1, 2010], Internet <URL: http://www.ivdr.org/jp/>

  As described above, when copying and moving content protected by SAFIA between iVDR-compatible devices on a home IP network, it is necessary to process the content according to the DTCP-IP standard. In DTCP-IP, when content movement through the network ends and content protection (encryption) at the content receiving device ends, “transmission” from the content receiving device to the transmitting device. Issue a commitment request that means "Please disable it because you received it." At this time, it is stipulated in the DTCP-IP standard that the device on the content transmission side responds with the content invalidated within a predetermined time, for example, within one second after receiving this request. Effective means for invalidating the content is not erasing the content but invalidating the key that is encrypting the content. However, SAFIA stipulates that content must be blocked and each must be encrypted within a predetermined time, for example, every 60 seconds, using a different key.

  Since the content key is stored in the tamper-resistant area on the HDD, it takes about several hundreds of milliseconds to access the key. For this reason, for example, in the case of content of 2 hours, 120 keys are invalidated on the transmission side when the content is moved, so that it takes time to invalidate the key for about 12 seconds. Therefore, if the content invalidation process is performed after receiving the commitment request on the content receiving side, the response of the commitment becomes long, and there is a problem that the DTCP-IP standard cannot be observed. When the response of the content commitment becomes too late, the content receiving side reissues the commitment request to the content transmitting side. In addition, it is considered that there is no response to the content commitment, the content receiving side is not validated, and the processing may be interrupted.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a technique capable of improving convenience when moving content between a plurality of devices. In particular, to improve the responsiveness when moving content encrypted with a certain standard (SAFIA, iVDR encryption standard) to another device via a network based on another standard. A suitable technique is provided.

  The content processing apparatus according to the present invention is stored in an external storage device such as an HDD, and the content is divided into blocks and encrypted with an encryption key corresponding to each block, and the encryption key is also stored in the external storage device.

  For example, based on the DTCP-IP standard, when moving content to another content processing device, the content block stored in the external storage device and the encryption key corresponding to each block are stored in the main storage device. Transfer, decrypt, and transfer the decrypted content to another content processing apparatus.

  At that time, when all the encryption keys corresponding to the respective blocks stored in the external storage device are transferred to the main storage device, the untransferred content is divided by the number of encryption keys. Then, in order to decrypt each of the divided data and transfer the decrypted one divided data to another content processing device, in response to transferring one divided data to the other content processing device, Delete one encryption key on the external storage device.

  Further, prior to deleting the encryption key, the encryption key stored in the external storage device such as the HDD is backed up in the FLASH memory, and stored in the FLASH memory when the transfer of the divided data is interrupted due to a failure. The written encryption key is written back to an external storage device such as an HDD.

  In this way, when the content processing source content processing device receives a content migration commitment request from the content migration destination content processing device, all the encryption keys on the external storage device have been deleted. Therefore, a response to the commitment request can be returned promptly.

  In addition, since the divided data that has been subdivided is transferred, one transfer does not take time, and communication on the TCP / IP protocol is not interrupted.

  Furthermore, if a backup of the encryption key is stored in the FLASH memory, data is not lost when the content is moved, so that the safety of the data can be improved.

  According to the present invention, it is possible to improve convenience when moving content between a plurality of devices. In particular, it is possible to improve the responsiveness when moving the content on the network according to a standard different from the encryption standard for the content.

It is a block diagram which shows the hardware structural example of the content processing apparatus which concerns on 1st embodiment of this invention. It is a figure which shows the relationship between the encryption key and content in the content movement process which concerns on 1st embodiment of this invention, and a content processing apparatus. It is a figure which shows the relationship between the encryption key and content in the content movement process which concerns on 1st embodiment of this invention. It is a flowchart which shows the procedure when performing a content movement process from the content processing apparatus (transmission side) which concerns on 1st embodiment of this invention to a content processing apparatus (reception side) (the 1). It is a flowchart which shows the procedure at the time of performing a content movement process from the content processing apparatus (transmission side) which concerns on 1st embodiment of this invention to a content processing apparatus (reception side) (the 2). It is a flowchart which shows the procedure when performing a content movement process from the content processing apparatus (transmission side) which concerns on 1st embodiment of this invention to a content processing apparatus (reception side) (the 3). It is a block diagram which shows the hardware structural example of the content processing apparatus which concerns on 2nd embodiment of this invention. It is a figure which shows the relationship between the encryption key and content in the content movement process which concerns on 2nd embodiment of this invention, and a content processing apparatus. It is a flowchart which shows the procedure when performing a content movement process from the content processing apparatus (transmission side) which concerns on 2nd embodiment of this invention to a content processing apparatus (reception side) (the 1). It is a flowchart which shows the procedure when performing a content movement process from the content processing apparatus (transmission side) which concerns on 2nd embodiment of this invention to a content processing apparatus (reception side) (the 2). It is a flowchart which shows the procedure when performing a content movement process from the content processing apparatus (transmission side) which concerns on 2nd embodiment of this invention to a content processing apparatus (reception side) (the 3).

  Embodiments according to the present invention will be described below with reference to FIGS. 1 to 7C.

Embodiment 1
A first embodiment according to the present invention will be described below with reference to FIGS. 1 to 4C.

First, the configuration of the content processing apparatus according to the first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a block diagram illustrating a hardware configuration example of the content processing apparatus according to the first embodiment of the present invention.

  The content processing device (transmission side) 10 is, for example, a digital television receiver or a recorder, which corresponds to the iVDR standard, and the content is encrypted and processed according to the SAFIA standard. The content processing apparatus (reception side) 20 is also a similar device, and in the present embodiment, description will be made with the role sharing between the transmission side and the reception side.

  As shown in FIG. 1, the content processing device (transmission side) 10 includes a CPU 1, a main storage device 2, an HDD (Hard Disk Drive) 3, a network I / F device 4, and an encryption / decryption device 5. The configuration of the content processing apparatus 10 includes, for example, a component for realizing a tuner function, a component for realizing a recording function, and a component for realizing a user interface other than the functions described in this embodiment. Omitted.

  CPU1 controls each part of the content processing apparatus 10, and runs the program for implement | achieving the content movement process of this embodiment.

  The main storage device 2 is composed of a semiconductor memory, and holds programs and data executed by the CPU 1.

  An HDD (Hard Disk Drive) 3 is a device that stores information on a magnetic disk, and stores contents and programs. Further, the HDD 3 of the present embodiment conforms to the iVDR specification, and may be a built-in type (iVDR built-in type) or a removable type (iVDR cartridge type). Further, the HDD 3 conforming to the iVDR specification has a tamper-resistant structure area that protects against information theft.

  The network I / F device 4 is a device that handles a network interface between devices, whereby the content processing device (transmission side) 10 and the content processing device (reception side) 20 communicate with each other using the TCP / IP protocol. To do. The physical medium of the network may be an Ethernet (registered trademark) cable or may be wireless.

  The encryption / decryption device 5 performs data encryption / decryption processing according to the AES (Advanced Encryption Standard) standard. The AES standard is a common key encryption method adopted by the US government.

Next, a procedure for performing content movement processing from the content processing apparatus (transmission side) to the content processing apparatus (reception side) according to the first embodiment of the present invention will be described with reference to FIGS. 2 to 4C.
FIG. 2 is a diagram showing the relationship between the encryption key, the content, and the content processing device in the content movement processing according to the first embodiment of the present invention.
FIG. 3 is a diagram showing the relationship between the encryption key and the content in the content movement processing according to the first embodiment of the present invention.
FIG. 4A to FIG. 4C are flowcharts showing a procedure when content movement processing is performed from the content processing apparatus (transmission side) to the content processing apparatus (reception side) according to the first embodiment of the present invention.

  According to the iVDR standard, content is divided into N (N is an integer of 1 or more), encrypted with different encryption keys, and stored in the HDD 3. Here, the i (i = 1,..., N) -th content is written as CONT [i], and the corresponding encryption key is written as KEY [i].

  First, as shown in FIG. 4A, there is exchange of content size and encryption key between the content processing device (transmission side) 10 and the content processing device (reception side) 20, and transmission / reception information is exchanged. Yes, both sides complete preparations for content transmission / reception (S01, R01).

  Next, the parameter i is set to 1 (S02).

  Next, KEY [i] of the HDD 3 is transferred to the main storage device 2 (A01, S03 in FIG. 2). This is a preparation for decrypting the content in a later process.

  Next, i and N are compared (S04), and if i <N, the process goes to S06 and S05. Note that S05 and S06 are asynchronous processes.

  When i <N, CONT [i] is transferred to the main storage device 2 (A02), KEY [i] and CONT [i] are input to the encryption / decryption device 5 (A03, A04), and CONT [ i] is decrypted (A06, S06).

  The CONT [i] decrypted in S06 is further input to the encryption / decryption device 5 (A06) and encrypted according to the DTCP standard (A07, S07).

  Next, the amount of untransferred content is compared with a predetermined amount (S08). Here, the predetermined amount is a size that does not hinder the subsequent processing after S10 when the block of CONT [i] encrypted in S07 is transferred. Specifically, if at least n bytes are sent in one TCP / IP packet communication, the predetermined amount is n × N + (number of bytes of CONT [i] encrypted in S07).

  When the amount of untransferred content> a predetermined amount, the CONT [i] data encrypted in S07 is transmitted from the content processing device (transmission side) 10 to the content processing device (reception side) 20 (S09).

  When the amount of untransferred content ≦ a predetermined amount, CONT [i] encrypted in S07 is not transmitted.

  On the other hand, if i <N, i is incremented by 1 (S05), the process returns to S03, and these processes are repeated. Here, in S03, the encryption key KEY [i + 1] stored in the main storage device 2 in the i-th process is overwritten and updated when the next i + 1-th process is performed. The That is, the encryption key KEY [i] is deleted every time the decryption process of CONT [i] is completed.

  When i = N in S04, the non-transfer table is divided into N (S10 in FIG. 4B). Here, the jth (j = 1,..., N) th of the divided content is denoted as L_CONT [j]. The division is performed so that the size of each of the N divided data is equally divided as much as possible.

  In FIG. 3, transmission of CONT [1] to CONT [N-3] from the content processing apparatus (transmission side) 10 to the content processing apparatus (reception side) 20 is complete, and untransferred is indicated by CONT [ N-2], CONT [N-1], and CONT [N] are shown as examples. In this untransferred block, CONT [N-2] has already been decrypted, and CONT [N-1] and CONT [N] have not been decrypted yet and remain encrypted.

  Next, j = 1 is set (S11).

  Then, KEY [j] on the HDD 3 is deleted (S12).

  Next, when L_CONT [j] is included in CONT [k] and the block of CONT [k] is not decoded, L_CONT [j] is decoded with KEY [k] on the main storage device 2. (S13). That is, L_CONT [j] and KEY [k] are input to the encryption / decryption device 2 to obtain decoded L_CONT [j]. In the example of FIG. 3, when L_CONT [j] is included in CONT [N−1] and CONT [N], they are decoded by KEY [N−1] and KEY [N], respectively.

  Next, L_CONT [j] is input to the encryption / decryption device 5 and encrypted according to the DTCP standard (S14).

  Then, L_CONT [j] encrypted in S14 is transmitted from the content processing apparatus (transmission side) 10 to the content processing apparatus (reception side) 20 (S15).

  Next, j and N are compared (S16). If j <N, j is incremented by 1 (S17), and the process returns to S12 to repeat these processes.

  In this way, before each L_CONT [j] is sent, KEY [j] is deleted, and then L_CONT [j] is transferred from the content processing apparatus (transmission side) 10 to the content processing apparatus (reception side). When data is transmitted at once and then the encryption key on the HDD 3 is deleted, TCP-IP communication is not performed during that time, and the content processing apparatus (reception side) 20 This is because a packet retransmission request is made to the content processing apparatus (transmission side) 10.

  In S16, when j = N, the process proceeds to S18. In S18, the remaining encryption key KEY [i] (encryption key corresponding to the last content) stored in the main storage device 2 in S03 is deleted after confirming that there is no content to be decrypted.

  When the content processing apparatus (reception side) 20 confirms that the reception of the content is completed (R02), a commitment request is made to the content processing apparatus (transmission side) 10 based on the DTCP-IP standard (R03). ).

  Then, the content processing apparatus (transmission side) 10 confirms the consistency of the transmitted content from the commitment request parameters (S19), and if OK, a commitment request response is made (S20).

  Finally, when a response to the commitment request is received, the content processing device (transmission side) 10 decrypts the content based on the DTCP standard, and the content processing device (reception side) 20 plays and stores (necessary) Is encrypted by iVDR standard).

  As described above, the feature of this embodiment is that when the commitment request R03 is made from the content processing apparatus (reception side) 20 to the content processing apparatus (transmission side) 10, all the encryption keys on the HDD are deleted. In other words, since the content on the transmission side is invalidated, the period from the commitment request R03 to the response S20 of the commitment request can be shortened.

[Embodiment 2]
Hereinafter, a second embodiment according to the present invention will be described with reference to FIGS. 5 to 7C.

  In the first embodiment, no consideration is given to the process of recovering the content on the transmission side when the content transmission process is interrupted. In the present embodiment, when the content transmission process is interrupted, a process for recovering the content is performed.

First, the configuration of the content processing apparatus according to the second embodiment of the present invention will be described with reference to FIG.
FIG. 5 is a block diagram showing a hardware configuration example of the content processing apparatus according to the second embodiment of the present invention.

  Compared with the content processing apparatus of the first embodiment, a FLASH memory 6 accessed from the CPU 1 is added. This is for backing up the encryption key, as will be described later. Since the encryption key is temporarily stored, it is desirable that the FLASH memory 6 also has tamper resistance.

Next, a procedure for performing content movement processing from the content processing apparatus (transmission side) according to the second embodiment of the present invention to the content processing apparatus (reception side) will be described with reference to FIGS. 6 to 7C.
FIG. 6 is a diagram showing the relationship between the encryption key, the content, and the content processing apparatus in the content movement processing according to the second embodiment of the present invention.
FIG. 7A to FIG. 7C are flowcharts showing a procedure for performing content movement processing from the content processing apparatus (transmission side) to the content processing apparatus (reception side) according to the second embodiment of the present invention.

  Unlike the first embodiment, as shown in FIG. 7B, all the encryption keys transferred from the HDD 3 to the main storage device are stored in the FLASH memory 6 before the processing of S10 (A10 in FIG. 6). , S20). In the first embodiment, the encryption key KEY [i] stored in the main storage device 2 is overwritten with the next encryption key KEY [i + 1] each time the decryption process is performed (S03 in FIG. 4A). In this embodiment, in S03 ′ of FIG. 7A, the main storage device 2 stores all the encryption keys without overwriting the encryption key KEY [i]. Then, all the encryption keys stored in the main storage device 2 are stored in the FLASH memory 6 in S20 of FIG. 7B.

  After the process of storing the encryption key in the FLASH memory 6 in S20, all the encryption keys corresponding to the content for which the decryption process has been completed are deleted in S21. Further, the remaining encryption keys not deleted here are deleted from the main storage device after confirming that there is no content to be decrypted in S18.

  Then, as shown in FIG. 7B, after S15, it is determined whether the transfer process is interrupted (S40). When the transfer process is interrupted, the encryption key stored in the FLASH memory 6 is used. Then, the deleted encryption key of the HDD 3 is restored via the main storage device 2 (S41). If it is interrupted during the transfer process of the encrypted L_CONT [j] in S15, KEY [1] to KEY [j] should have been deleted from the HDD 3.

  Then, all the encryption keys stored in the FLASH memory 6 are deleted (S42).

  In this embodiment, since the encryption key is stored in the FLASH memory 6 in S20, all the encryption keys stored in the FLASH memory 6 are deleted even when the transfer process of L_CONT [N] is completed. (S50).

  In this embodiment, even if the transfer process is interrupted due to a failure in the content processing apparatus (reception side) 20 or the communication path, the encryption key on the HDD 3 is used by the encryption key on the backed up FLASH memory 6. Since the content can be revived, loss of content can be prevented and safety can be improved.

10 ... content processing device (transmission side), 20 ... content processing device (reception side),
DESCRIPTION OF SYMBOLS 1 ... CPU, 2 ... Main storage device, 3 ... HDD (Hard Disk Drive), 4 ... Network I / F device, 5 ... Encryption / decryption device, 6 ... FLASH memory.

Claims (6)

In a content processing device that stores content in an external storage device encrypted with an encryption key,
The stored content is divided into blocks and encrypted with an encryption key corresponding to each block, and the encryption key is also stored in the external storage device,
When moving content to another content processing device,
The content block stored in the external storage device and the encryption key corresponding to each block are transferred to the main storage device, the content block is decrypted, and the decrypted content block is transferred to another When transferring to a content processing device:
When all the encryption keys corresponding to the respective blocks stored in the external storage device are transferred to the main storage device, the blocks of untransferred content are divided by the number of encryption keys, and the respective divisions are performed. data decode, when transferring the one of the divided data decoded in the content processing apparatus, in response to transferring the one of the divided data to the content processing apparatus, on the external storage device A content processing apparatus, wherein one encryption key is deleted. The content processing apparatus according to claim 1 , further comprising a second external storage device,
The stored encryption key before Symbol first external storage device, all stored in the second external storage device,
When the process of transferring the decrypted one piece of divided data to another content processing device is interrupted, the encryption key stored in the second external storage device is written to the first external storage device. A content processing apparatus characterized by being returned. The first storage device is an HDD (Hard Disk Drive), and the second storage device is
3. The content processing apparatus according to claim 2 , wherein the content processing apparatus is a FLASH memory. In a content transfer method of a content processing apparatus for storing content encrypted in an external storage device with an encryption key,
By executing the process of deleting the encryption key of the content in parallel with the process of moving the content to another content processing device,
In the mobile content movement method of Turkey content processing apparatus to complete the deletion of the encryption key of the content before receiving the notification indicating the movement completion of the content from the content processing apparatus of the content destination,
The content is divided into blocks, encrypted with an encryption key corresponding to each block, and stored in the external storage device together with the encryption key;
Transferring a block of content stored in the external storage device and an encryption key corresponding to each block to a main storage device;
Decrypting the block of content with the encryption key;
Transferring the decrypted block of content to another content processing device, and
Dividing all the untransferred contents by the number of encryption keys when all the encryption keys corresponding to the respective blocks stored in the external storage device are transferred to the main storage device;
Decoding each segmented data;
When transferring one piece of decrypted data to another content processing apparatus, one encryption key on the external storage device is assigned in correspondence with transferring one piece of divided data to another content processing apparatus. And a content moving method of the content processing apparatus . 5. The content moving method according to claim 4 , further comprising:
Storing all the encryption keys stored in the first external storage device in the second external storage device;
When the process of transferring the one piece of decrypted data to another content processing device is interrupted, the encryption key copied to the second external storage device is written to the first external storage device. And a step of returning the content. The first storage device is an HDD (Hard Disk Drive), and the second storage device is
6. The content moving method of the content processing apparatus according to claim 5, wherein the content moving method is a FLASH memory.

Images