JP5190427B2 - Authentication processing circuit - Google Patents

Description

  The present invention relates to an authentication processing circuit, a transmitter, and an authentication processing method and program, and in particular, a circuit, a transmitter, and a method for authenticating a content data transmission destination in accordance with an HDCP (High-bandwidth Digital Content Protection) system. And the program.

  In recent years, an interface for transmitting digital content data including AV (Audio & Visual) data from a playback device such as a DVD (Digital Versatile Disk) player, DVD recorder, STB (Set Top Box) to an image receiving device such as a display. For example, HDMI (High Definition multimedia interface) and DVI (Digital Visual Interface) are mainly used.

  In such an interface, it is essential to install a function corresponding to the HDCP system. Here, the HDCP system is a copyright protection technology that generally encrypts and transmits a digital signal and prevents content data from being illegally copied. In the following description, an interface equipped with a function corresponding to the HDCP system may be referred to as an HDCP compatible interface.

  On the other hand, the playback device authenticates the image receiving device in accordance with the HDCP method, and transmits the encrypted content data to the image receiving device via the HDCP compatible interface when the authentication is successful. As a transmission method at this time, a TDMS (Transition Minimized Differential Signaling) method is generally employed, and a digital signal is transmitted between the reproduction device and the image receiving device without being compressed.

  Hereinafter, an outline of an authentication process defined in the HDCP system (hereinafter, sometimes referred to as an HDCP authentication process) will be described. In the following description, a device that is a content data transmission source and leads authentication, such as the above-described playback device, may be referred to as a transmitter. On the other hand, an apparatus that is a transmission destination of content data and is a subject of authentication by a transmitter, such as the above-described image receiving apparatus, may be referred to as a receiver (receiver). A device that relays content data from a transmitter to a receiver and is subject to authentication by the transmitter, such as an AV amplifier, may be referred to as a repeater.

  The HDCP authentication process is roughly divided into the following first to third authentication processes. Here, only the first and third authentication processes are performed between the transmitter and the receiver. On the other hand, all of the first to third authentication processes are performed between the transmitter and the repeater.

[First authentication process]
This process is generally a process for exchanging authentication data between a transmitter and a receiver or a repeater.

  First, the transmitter starts outputting content data in accordance with the TDMS method via the HDCP compatible interface. Then, the transmitter waits for a predetermined time (hereinafter referred to as an authentication start waiting time) for the output of the content data to stabilize, and then starts exchanging authentication data with the receiver or the repeater.

  Specifically, the transmitter transmits a secret key AKSV (KSV is an abbreviation of “Key Selection Vector”) and a pseudo-random value An held by itself to the receiver or the repeater. In response to this, the receiver or repeater returns a secret key BKSV held by itself and a REPEATER bit indicating whether or not it is a repeater to the transmitter.

  Then, the transmitter uses the ciphertext function common to the receiver or the repeater to determine whether or not the authentication data has been successfully exchanged from its own authentication data and the received authentication data (in each device in advance). Information R0 for collating (whether or not the assigned valid authentication data has been exchanged) is generated. On the other hand, the receiver or the repeater uses the ciphertext function to check whether the transmitter successfully exchanges the authentication data from its own authentication data and the received authentication data. R0 ′ is generated.

  At this time, the transmitter waits for a predetermined time (hereinafter referred to as R0 ′ generation waiting time) for the generation of the information R0 ′ to be completed in the receiver or the repeater. Here, the R0 ′ generation waiting time is normally set to 100 msec.

  After the R0 ′ generation waiting time elapses, the transmitter acquires information R0 ′ from the receiver or the repeater. Then, the transmitter compares the information R0 generated by itself with the acquired information R0 ′. As a result, when both pieces of information match, the transmitter determines that the authentication data has been successfully exchanged. Thereafter, when the authentication data is exchanged with the receiver (when the REPEATER bit does not indicate a repeater), the transmitter executes the following third authentication process. On the other hand, when the authentication data is exchanged with the repeater (when the above REPEATER bit indicates the repeater), the transmitter executes the following second authentication process.

[Second authentication process]
This process is generally a process for causing a repeater to collect and report authentication data of all receivers connected to the repeater.

  After the first authentication process, the transmitter waits for completion of collection of secret keys KSVs from all receivers connected to the relay in the relay. More specifically, the transmitter waits for a predetermined time (hereinafter referred to as READY bit reception waiting time) to receive the READY bit indicating completion of collection of the secret key KSVs from the repeater. Here, the READY bit reception waiting time is normally set to 5000 msec.

  If the READY bit is received before the READY bit reception waiting time elapses, the transmitter further receives a list of secret keys KSVs from the repeater. Then, the transmitter performs a hash operation on the received list using a hash function common to the repeater. On the other hand, prior to transmission of the READY bit, the repeater performs a hash operation on the collected list of secret keys KSVs using the hash function. The transmitter acquires the hash calculation result V ′ from the repeater.

  The transmitter compares the hash calculation result V obtained by its own hash calculation with the hash calculation result V ′ acquired from the repeater. As a result, when both hash calculation results match, the transmitter determines that the list of secret keys KSVs is a valid list. Further, the transmitter compares the list with a “revocation list” including a secret key KSV of a violating device that has been discovered in the past and impersonates an HDCP-compatible device and attempts to illegally decrypt the content data encryption. . As a result, when the same secret key KSV is not included in both lists, the transmitter executes the following third authentication process.

[Third authentication process]
This process is a process for confirming whether or not the content data is normally encrypted.

  After the first or second authentication process described above, the transmitter generates information Ri for verifying the integrity of each frame forming the content data by using a ciphertext function common to the receiver or the repeater. To do. On the other hand, the receiver or the repeater uses the ciphertext function to generate information Ri ′ for causing the transmitter to verify the integrity of each frame forming the received content data. The transmitter acquires information Ri ′ from the receiver or the repeater at every certain timing (usually every 128 frames).

  The transmitter compares the information Ri generated by itself with the information Ri ′ acquired from the receiver or the repeater. As a result, if the two pieces of information do not match, the transmitter determines that synchronization has been lost, and stops the encryption of the content data and also stops the execution of the HDCP authentication process.

  By the way, the manufacturer must be certified in the HDCP compliance test that the developed transmitter, receiver, or repeater operates in compliance with the HDCP system. However, the HDCP compliance test is merely an inspection of basic operations. For this reason, there is a case where the HDCP authentication process fails even when devices that have been certified are connected to each other.

For the purpose of reduction of such cases, "HDMI plugfest (plug Festa)" event for the connection verification called have been held regularly. As a failure factor of the HDCP authentication process in the “HDMI plugfest”, the above-described various waiting time differences are often detected between the transmitter and the receiver or the repeater. The difference in waiting time occurs because the understanding of the standard differs between the transmitter developer and the receiver or repeater developer, and the time value is not specified in the standard. To do.

  For example, the time value of the authentication start waiting time is not defined in any of the HDCP standard document, the HDMI standard document, and the HDCP compliance test specification. The time value of the R0 ′ generation wait time is normally defined as 100 msec in the HDCP standard. The time value is interpreted as a maximum of 100 msec or a minimum of 100 msec. Everything will be different. Similarly, the interpretation of the time value of the READY bit reception waiting time (usually 5000 msec in the HDCP standard) is different for each developer.

  A related technique for dealing with this problem is described in Patent Document 1, for example.

  FIG. 7 shows a configuration of the disk reproducing apparatus 10 described in Patent Document 1. The disc playback device 10 is connected to the image receiving device 30 via the HDMI cable 20. Here, the HDMI cable 20 is for a data line 21 for transmitting content data 40 and a DDC (Display Data Channel, a channel for transmitting / receiving various control information between the playback device 10 and the image receiving device 30) as shown in the figure. Control line 22 and a hot plug line 23 used for connection detection of the HDMI cable 20.

  Further, the disk playback device 10 decodes the HDMI connector 11 for connecting the HDMI cable 20, the disk access unit 12 for accessing the disk 50, and the read data from the disk 50, and the audio data 60 and the video data. 70, and a transmitter 14x for transmitting content data 40 composed of audio data 60 and video data 70 via the HDMI connector 11.

  Further, the transmitter 14x sends the content data 40 via the HDMI connector 11 when the authentication processing circuit 100x authenticates the receiver 32 constituting the image receiving device 30 and the authentication processing circuit 100x succeeds in authentication. An HDMI transmission circuit 200, a timer 300 for timing the authentication start waiting time, and a memory 400 used as a work area of the authentication processing circuit 100x. Here, the authentication processing circuit 100x is connected to the HDMI transmission circuit 200 via the I2C bus as shown in the figure, and transmits / receives various control information for DDC via the HDMI transmission circuit 200. Further, the authentication processing circuit 100x detects the connection of the HDMI cable 20 (that is, the connection of the receiver 32) by monitoring the input voltage from the hot plug line 23.

  As shown in FIG. 8, the memory 400 stores in advance a table 410 in which the number of authentication attempts 411 in the authentication processing circuit 100x is associated with the authentication start waiting time 412. This table 410 indicates that a time value of 200 msec should be set at the first authentication attempt, a time value of 1000 msec should be set at the second authentication attempt, and a time value of 2000 msec should be set at the third authentication attempt.

  As shown in FIG. 9, the authentication processing circuit 100x includes an authentication processing unit 701, a dummy data generation unit 702, a hot plug detection unit 703, a scramble unit 704, a transmission processing unit 705, and a reception processing unit 706. And a determination unit 707, a waiting time setting unit 708, and a central control unit 709 that controls these blocks 701 to 708.

  The authentication processing unit 701 executes the HDCP authentication process described above. The dummy data generation unit 702 generates dummy data serving as a start trigger for the HDCP authentication process. The hot plug detection unit 703 monitors the input voltage from the hot plug line 23 and detects the connection of the receiver 32. The scramble unit 704 encrypts the content data 40. The transmission processing unit 705 transmits the dummy data and an EDID (Extended Display Identification Data) request to the receiver 32. The reception processing unit 706 receives EDID from the receiver 32. The determination unit 707 determines the resolution of the content data 40 and the dummy data based on the specification information such as the resolution and aspect ratio related to the display device 33 (see FIG. 7) included in the EDID. Also, the determination unit 707 determines the type of HDCP-compatible interface (the type of connector whose connection has been detected) in response to connection detection by the hot plug detection unit 703. Furthermore, the determination unit 707 determines the transmission rate of the content data 40 and the dummy data based on the determination result.

  The waiting time setting unit 708 searches the table 410 for the authentication start waiting time 412 using the number of authentication trials 411 received from the central control unit 709 as a key. In addition, the waiting time setting unit 708 gives the authentication start waiting time 412 obtained by the search to the central control unit 709.

  The central control unit 709 determines whether or not the authentication processing unit 701 can succeed in authentication, and counts the number of authentication trials 411. In addition, the central control unit 709 controls the timer 300 by using transmission of dummy data as a trigger, and thereby measures the authentication start waiting time 412. Furthermore, the central control unit 709 causes the authentication processing unit 701 to execute HDCP authentication processing when the authentication start waiting time 412 has elapsed.

  Returning to FIG. 7, the image receiving apparatus 30 includes an HDMI connector 31, a receiver 32 that receives the content data 40 via the connector 31, a display of the video data 70 in the content data 40, and an output of the audio data 60. It is comprised with the display apparatus 33 which performs (reproduction | regeneration).

  Among these, the receiver 32 includes an HDMI receiving circuit 601 that receives the content data 40 via the HDMI connector 31, a video / audio processing unit 602 that separates the audio data 60 and the video data 70 from the content data 40, and these A control unit 603 such as a CPU (Central Processing Unit) that controls the blocks 601 and 602 of the control unit 602 and a memory 604 used as a work area of the control unit 603 are provided. Here, the control unit 603 is connected to the HDMI receiving circuit 601 via the I2C bus as shown in the figure, and thus transmits and receives various control information for DDC via the HDMI receiving circuit 601. Further, the control unit 603 outputs a predetermined voltage to the hot plug line 23 in accordance with the connection of the HDMI cable 20 to the HDMI connector 31.

  Hereinafter, operations of the transmitter 14x and the receiver 32 will be described with reference to FIGS.

  As shown in FIG. 10, the hot plug detection unit 703 in the transmitter 14 x constantly monitors the input voltage from the hot plug line 23. When the HDMI connectors 11 and 31 are connected by the HDMI cable 20, the hot plug detection unit 703 detects the input of the voltage signal from the control unit 603 in the receiver 32 (step S1).

  At this time, the central control unit 709 in the transmitter 14x initializes the value of the temporary variable CT for counting the number of authentication trials 411 to “1” (step S2). Then, the central control unit 709 controls the transmission processing unit 705 to transmit an EDID request to the receiver 32 (step S3).

  When receiving the EDID request (step T1), the control unit 603 in the receiver 32 reads out the EDID of the display device 33 stored in advance in the memory 604 and transmits it to the transmitter 14x (step T2).

  The reception processing unit 706 in the transmitter 14x receives EDID (step S4). The determination unit 707 that has detected this determines the type of the HDCP-compatible interface (step S5). In this example, the determination unit 707 determines that the type is HDMI, and determines the transmission rate of the content data 40 and the dummy data to a rate according to HDMI (step S6). Further, the determination unit 707 determines the resolution of the content data 40 and the dummy data based on the specification information included in the EDID (Step S7).

  At this time, the central control unit 709 instructs the dummy data generation unit 702 to generate dummy data in accordance with the resolution determined by the determination unit 707. Further, the central control unit 709 controls the transmission processing unit 705 to transmit dummy data to the receiver 32 (step S8).

  When receiving the dummy data (step T3), the control unit 603 in the receiver 32 waits for reception of the secret key AKSV and the pseudorandom value An described in the first authentication process.

  On the other hand, the central control unit 709 in the transmitter 14x gives the variable CT to the waiting time setting unit 708 as the number of authentication trials 411. The waiting time setting unit 708 searches the table 410 for the authentication start waiting time 412 using the variable CT as a key. Now, since the variable CT = “1”, the time value 200 msec corresponding to the first authentication attempt is searched as the authentication start waiting time 412. The waiting time setting unit 708 gives the authentication start waiting time 412 = “200 msec” to the central control unit 709. The central control unit 709 causes the timer 300 to count the authentication start waiting time 412 (step S9) and waits for the authentication start waiting time 412 to elapse (step S10).

  When the authentication start waiting time 412 elapses, the central control unit 709 causes the authentication processing unit 701 to transmit the secret key AKSV and the pseudorandom value An to the receiver 32. As a result, the first and third authentication processes are performed by the cooperative operation of the transmitter 14x and the receiver 32 (steps S11 and T4).

  As a result, when the authentication processing unit 701 succeeds in the authentication of the receiver 32, the central control unit 709 controls the scrambler 704 and the HDMI transmission circuit 200, and encrypts the content data 40 and transmits it to the receiver 32. (Step S13). The video / audio processing unit 602 in the receiver 32 that has detected the reception of the content data 40 decodes the content data 40 to obtain the audio data 60 and the video data 70. Then, the video / audio processing unit 602 causes the display device 33 to display the video data 70 and output the audio data 60 (steps T5 and T6).

  On the other hand, when the authentication processing unit 701 fails to authenticate the receiver 32, the central control unit 709 determines whether or not the variable CT ≧ “3” is satisfied (step S14). Now, since the variable CT = “1”, the central control unit 709 increments the variable CT by “1” (step S15), and returns to the above step S8.

  Thus, after waiting for the authentication start waiting time 412 = “1000 msec” corresponding to the second authentication attempt in the above steps S10 and S11, the HDCP authentication process is re-executed in the above step S12. . As a result, when the authentication of the receiver 32 is successful, the content data 40 is transmitted to the receiver 32 in step S13 described above. On the other hand, when the authentication of the receiver 32 fails again, the HDCP authentication process is re-executed after waiting for the authentication start waiting time 412 = “2000 msec” corresponding to the third authentication attempt. If the receiver 32 fails to authenticate even after the third HDCP authentication process is executed (that is, if the variable CT ≧ “3” is established in step S14), the transmitter 14x transmits the content data 40 Is not sent and the process is terminated.

  As described above, increasing the authentication start waiting time is one factor that makes the HDCP authentication process successful.

JP 2008-219796 A

  However, the transmitter 14x has a problem that the execution efficiency of the HDCP authentication process is low. This is because the transmitter 14 x determines the authentication start waiting time 412 according to the number of authentication attempts 411. When the receiver that has been successfully authenticated is disconnected and then reconnected, the HDCP authentication process repeats failures for the number of trials that have resulted in the success. This repeated failure occurs every time the receiver is reconnected.

  The above problem also occurs when the repeater is the execution target of the HDCP authentication process.

  An authentication processing circuit according to an aspect of the present invention authenticates a receiver that is a destination of content data or a relay that relays the content data to the receiver in accordance with the HDCP method, and succeeds in the authentication. An authentication unit that increases the waiting time for the authentication until the authentication, a storage unit that stores the identification information of the receiver or the repeater that has succeeded in the authentication, and the waiting time that is used when the authentication is successful . The authentication unit uses the stored waiting time when re-authentication of the receiver or repeater corresponding to the identification information.

  In addition, a transmitter according to an aspect of the present invention includes the authentication processing circuit and a transmission circuit that transmits the content data to a receiver or a repeater that has succeeded in the authentication via an HDCP-compatible interface. .

  An authentication processing method according to an aspect of the present invention includes an authentication processing method for authenticating a receiver that is a destination of content data or a relay that relays the content data to the receiver in accordance with the HDCP method. provide. In this authentication processing method, the waiting time for the authentication is increased until the authentication is successful, and the identification information of the receiver or repeater that has succeeded in the authentication and the waiting time used in the success are stored in association with each other. The stored waiting time is used when the receiver or repeater corresponding to the identification information is re-authenticated.

  Furthermore, an authentication processing program according to an aspect of the present invention provides a computer that authenticates a receiver that is a destination of content data or a relay that relays the content data to the receiver in accordance with the HDCP method. A process for increasing the waiting time for the authentication until the authentication is successful, a process for storing the identification information of the receiver or the relay that has succeeded in the authentication, and the waiting time used for the success in association with each other, and When the receiver or repeater corresponding to the identification information is re-authenticated, the process using the stored waiting time is executed.

  That is, in the present invention, the waiting time used at the time of success is used in the re-authentication associated with the reconnection of the receiver or the repeater once successfully authenticated. For this reason, at the time of reconnection of the receiver or the repeater, the HDCP authentication process can be completed once without failure.

  According to the present invention, the execution efficiency of HDCP authentication processing can be greatly improved. Further, with improvement in execution efficiency, it becomes possible to reduce power consumption, required resource amount, and the like during HDCP authentication processing.

It is the block diagram which showed the structural example of the authentication process circuit and transmitter which concern on embodiment of this invention. It is the figure which showed one structural example of the table used for the authentication processing circuit which concerns on embodiment of this invention. It is the block diagram which showed the structural example of the authentication part used for the authentication processing circuit which concerns on embodiment of this invention. It is the flowchart figure which showed one example of operation | movement of the authentication process circuit and transmitter which concern on embodiment of this invention. It is the figure which showed the other structural example of the table used for the authentication processing circuit which concerns on embodiment of this invention. It is the flowchart figure which showed the other example of operation | movement of the authentication process circuit and transmitter which concern on embodiment of this invention. It is the block diagram which showed the structural example of the transmitter which concerns on the related technique of this invention. It is the figure which showed the structural example of the table used for the authentication process circuit which concerns on the related technology of this invention. It is the block diagram which showed the structural example of the authentication process circuit which concerns on the related technology of this invention. It is the flowchart figure which showed the operation example of the authentication process circuit and transmitter which concern on the related technique of this invention. It is the flowchart figure which showed the operation example of the receiver which concerns on the related technique of this invention.

  Embodiments of an authentication processing circuit according to the present invention and a transmitter to which the authentication processing circuit is applied will be described below with reference to FIGS. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary for the sake of clarity.

  As shown in FIG. 1, the transmitter 14 according to the present embodiment can be applied to a disc reproducing apparatus 10 instead of the transmitter 14 x shown in FIG. 7. The transmitter 14 includes an authentication processing circuit 100, an HDMI transmission circuit 200, a timer 300, a memory 400, and a nonvolatile memory 500 similar to those in FIG.

  The transmitter 14 can transmit the content data 40 via various HDCP compatible interfaces such as DVI, UDI (Unified Display Interface), GVIF (Giga-bit Video Interface), etc., not limited to HDMI. In this case, instead of the HDMI transmission circuit 200, a transmission circuit suitable for each interface may be provided. In addition, the audio data 60 and the video data 70 may be input to the transmitter 14 from various devices without being limited to the disk device (the disk 50, the disk access unit 12, and the AV decoder 13).

  Further, the authentication processing circuit 100 includes an authentication unit 110 and a storage unit 120.

  Among these, the authentication unit 110 controls the timer 300 to measure the waiting time for the HDCP authentication process and uses the memory 400 as a work area. In addition, the authentication unit 110 sets the receiver 32 serving as the transmission destination of the content data 40 or the relay device that relays the content data 40 to the receiver 32 as the execution target of the HDCP authentication process. Furthermore, the authentication unit 110 increases the waiting time until the authentication of the receiver 32 or the repeater is successful.

  On the other hand, the storage unit 120 stores the identification information 511 of the receiver or repeater successfully authenticated by the authentication unit 110 in association with the waiting time 512 used at the time of success in the nonvolatile memory 500. For example, as illustrated in FIG. 2, the storage unit 120 forms a table 510 in which the identification information 511 and the authentication start waiting time 512 a described above are associated with each other in the nonvolatile memory 500. For the identification information 511, the unique information (vendor information, product information, etc.) of the receiver or repeater included in the EDID can be used as it is. In this case, no modification occurs in the signal system that transmits between the transmitter 14 and the receiver 32.

  Further, the authentication unit 110 uses the waiting time 512 when re-authentication of the receiver or the relay corresponding to the identification information 511 (that is, reconnection of the receiver or the relay that has been successfully authenticated once).

  As a result, the authentication unit 110 can end the HDCP authentication process for the receiver or the repeater that has been successfully authenticated once without failing thereafter. Further, since the identification information 511 and the waiting time 512 are stored in the non-volatile memory 500, even if the power supply to the transmitter 14 is temporarily stopped and then restarted, the authentication unit 110 receives the authentication once successfully received. The HDCP authentication process for the receiver or repeater can be completed once without failure.

  As shown in FIG. 3, the authentication unit 110 includes a central control unit 111, an authentication processing unit 701 similar to that in FIG. 9, a dummy data generation unit 702, a hot plug detection unit 703, a scramble unit 704, and a transmission processing unit 705. The reception processing unit 706 and the determination unit 707 can be used for simple configuration.

  Here, the central control unit 111 generally executes the processes shown in the following (A) to (C) as processes peculiar to the present embodiment.

(A) Write processing of identification information 511 and waiting time 512 to nonvolatile memory 500 or read processing of identification information 511 and waiting time 512 from nonvolatile memory 500 under the control of storage unit 120.
(B) The identification information included in the EDID received from the receiver or the repeater is compared with the identification information 511 read from the nonvolatile memory 500. The process of determining whether or not the receiver or repeater has been successfully authenticated once.
(C) A process for waiting for the waiting time 512 to elapse or a process for causing the authentication processing unit 701 to wait for the waiting time 512 to elapse.

  Next, operations of the authentication processing circuit 100 and the transmitter 14 will be described. First, an operation example (1) in the case where the table 510 shown in FIG. 2 is formed in the nonvolatile memory 500 will be described with reference to FIG. To explain. An operation example (2) when the table 510a shown in FIG. 5 is formed in the nonvolatile memory 500 will be described with reference to FIG. The operation of the receiver 32 (or repeater) is the same as that in FIG.

[Operation example (1)]
As shown in FIG. 4, in this operation example, the processes shown in steps S16 to S23 are executed in place of the steps S2, S9, S10, S14, and S15 shown in FIG.

  Specifically, when the connection of the receiver 32 or the repeater is detected in the hot plug detection process shown in step S1, the central control unit 111 in the authentication processing circuit 100 sets the authentication start waiting time. An initial time value 800a (for example, “200 msec”) is set in the temporary variable WTa to be used (step S16). Then, the central control unit 111 controls the transmission processing unit 705 and the reception processing unit 706, thereby executing the EDID reception processing shown in steps S3 and S4. Further, the central control unit 111 controls the dummy data generation unit 702 and the determination unit 707, thereby executing the dummy data setting process shown in steps S5 to S7.

  Thereafter, the central control unit 111 determines whether or not the identification information included in the EDID received from the receiver 32 or the repeater is stored in the nonvolatile memory 500 (step S17).

  Now, assuming that the receiver 32 or the repeater is connected to the transmitter 14 for the first time, the central control unit 111 determines that the identification information included in the EDID is not stored in the nonvolatile memory 500. At this time, the central control unit 111 controls the dummy data generation unit 702 and the transmission processing unit 705, thereby executing the dummy data transmission process shown in step S8. The central control unit 111 controls the timer 300 and waits for the time indicated by the variable WTa (initial time value 800a) to elapse (step S18). After the elapse of the time indicated by the variable WTa, the central control unit 111 controls the authentication processing unit 701, and thus causes the authentication processing unit 701 to perform the cooperative operation with the receiver 32 or the repeater shown in step S11 above. The HDCP authentication process is executed.

  As a result, when the authentication processing unit 701 succeeds in the authentication of the receiver 32 or the repeater in step S12, the central control unit 111 determines whether or not the variable WTa ≠ initial time value 800a is satisfied (step S12). S19). Now, since the variable WTa = initial time value 800a is established, the central control unit 111 controls the scramble unit 704 and the HDMI transmission circuit 200, thereby executing the transmission process of the content data 40 shown in step S13 above. .

  On the other hand, when the authentication processing unit 701 fails to authenticate the receiver 32 or the repeater, the central control unit 111 determines whether or not the variable WTa ≧ upper limit time value 900a (for example, 2000 msec) is satisfied (step S20). ). Since the variable WTa <the upper limit time value 900a is now established, the central control unit 111 increases the variable WTa by a predetermined increment time value 1000a (for example, 200 msec) (step S21). The central control unit 111 waits for the elapse of the time indicated by the increased variable WTa via the above steps S8 and S18, and then proceeds to the above step S11. Re-execute processing.

  As a result, when the authentication of the receiver 32 or the repeater is successful, the variable WTa ≠ initial time value 800a is established in the above step S19, so that the central control unit 111 controls the storage unit 120, thereby The identification information 511 (identification information included in the EDID) and the waiting time 512a (the time indicated by the variable WTa) are written in the nonvolatile memory 500 (step S22). Then, the central control unit 111 proceeds to the above step S13 and executes the transmission process of the content data 40.

  Thus, the non-volatile memory 500 stores the identification information 511 of the receiver or repeater that has been successfully authenticated, and the authentication start waiting time 512a that was used when the authentication was successful.

  In addition, when the receiver or the repeater that has been successfully authenticated is reconnected, the central control unit 111 stores the same identification information 511 as the identification information included in the EDID in the nonvolatile memory 500 in step S17 described above. It is determined that At this time, the central control unit 111 sets the authentication start waiting time 512a stored in the nonvolatile memory 500 to the variable WTa (step S23).

  As a result, the reconnected receiver or repeater is authenticated by one HDCP authentication process without failure.

  If it is determined in step S20 that the variable WTa ≧ the upper limit time value 900a is satisfied, the central control unit 111 does not execute the transmission process of the content data 40 and ends all the processes. For this reason, it is possible to avoid excessive execution of HDCP authentication processing for a receiver or repeater that cannot be successfully authenticated.

  In this operation example, the authentication start waiting time 512a is set as the control target. However, the authentication processing circuit 100 can set the above-described R0 ′ generation waiting time or the READY bit reception waiting time as the control target. In this case, the authentication processing circuit 100 stores the R0 ′ generation waiting time or the READY bit reception waiting time upon successful authentication in the nonvolatile memory 500, and the stored R0 ′ generation waiting time or the READY bit reception waiting time. May be used during the HDCP authentication process.

[Operation example (2)]
In this operation example, the authentication unit 110 in the authentication processing circuit 100 associates the identification information 511 with the authentication start waiting time 512a and the READY bit reception waiting time 512b in the nonvolatile memory 500 as shown in FIG. The storage unit 120 is controlled to form the table 510a.

  Correspondingly, as shown in FIG. 6, in addition to the processing shown in FIG. 4, the authentication unit 110 executes the processing shown in steps S24 to S28, and replaces the above S19 and S22 with step S29. And the process shown to S30 is performed.

  Specifically, after the initial setting process of the variable WTa shown in step S16 above, the central control unit 111 in the authentication processing circuit 100 sets the initial variable WTb used for setting the READY bit reception waiting time to the initial variable WTb. A time value 800b (for example, “5000 msec”) is set (step S24). During the second authentication process described above, the variable authentication processing unit 701 waits for the time indicated by the variable WTb to receive the READY bit indicating completion of collection of the secret key KSVs from the repeater.

  As a result, when the authentication processing unit 701 fails to authenticate the repeater in step S12, the central control unit 111 determines the failure factor (step S26).

  When the failure factor is the variable WTa (that is, when the authentication start waiting time is short), the central control unit 111 increases the time value indicated by the variable WTa in the above steps S20 and S21, and performs the above steps S8 and S18. It waits for the passage of time indicated by the variable WTa after the increase. Thereafter, the central control unit 111 proceeds to step S11 described above, and causes the authentication processing unit 701 to re-execute the HDCP authentication processing.

  On the other hand, when the failure factor is the variable WTb (that is, when the READY bit reception waiting time is short), the central control unit 111 determines whether or not the variable WTb ≧ the upper limit time value 900b (for example, 6000 msec) is satisfied. (Step S27). As a result, when the variable WTb <the upper limit time value 900b is satisfied, the central control unit 111 increases the variable WTb by a predetermined increment time value 1000b (for example, 200 msec) (step S28). As a result, the HDCP authentication process shown in step S11 is performed again using the time indicated by the increased variable WTb.

  As a result, when the authentication of the repeater is successful in step S12, the central control unit 111 determines whether the variable WTa ≠ initial time value 800a or the variable WTb ≠ initial time value 800b is satisfied (step S29). ).

  When variable WTa ≠ initial time value 800a or variable WTb ≠ initial time value 800b holds, central control unit 111 determines that the authentication of the repeater has succeeded due to an increase in authentication start waiting time or READY bit reception waiting time. Then, the central control unit 111 controls the storage unit 120, and thus stores the identification information 511 (identification information included in EDID), the waiting time 512 a (the time indicated by the variable WTa), and the waiting time 512 b ( (Time indicated by variable WTb) is written (step S30).

  As described above, the non-volatile memory 500 stores the identification information 511 of the repeater that has been successfully authenticated, and the authentication start waiting time 512a and the READY bit reception waiting time 512b that are used at the time of the success.

  When the repeater that has been successfully authenticated is reconnected, the central control unit 111 stores the same identification information 511 as the identification information included in the EDID in the non-volatile memory 500 in step S17 described above. Is determined. At this time, the central control unit 111 sets the authentication start waiting time 512a stored in the non-volatile memory 500 to the variable WTa and receives the READY bit stored in the non-volatile memory 500 in the variable WTb in step S23 described above. A waiting time 512b is set (step S25).

  As a result, the reconnected repeater is authenticated by one HDCP authentication process without failure.

  If it is determined in step S27 that the variable WTb ≧ the upper limit time value 900b is satisfied, the central control unit 111 ends all the processes in the same manner as in step S20. For this reason, the effect of avoiding excessive execution of HDCP authentication processing for a repeater that cannot succeed in authentication is obtained for both the authentication start waiting time and the READY bit reception waiting time.

  In this operation example, the authentication start waiting time 512a and the READY bit reception waiting time 512b are controlled, but the authentication processing circuit 100 can also control the R0 ′ generation waiting time described above. In this case, when the authentication processing circuit 100 determines that the cause of the authentication failure is that the R0 ′ generation waiting time is short, the authentication processing circuit 100 increases the R0 ′ generation waiting time, and when the authentication to the nonvolatile memory 500 is successful. The R0 ′ generation waiting time may be stored and the stored R0 ′ generation waiting time may be used during the HDCP authentication process.

  Similarly, the authentication processing circuit 100 can also control the waiting time that can be added in the future as the HDCP specification changes.

  Note that the present invention is not limited to the above-described embodiments, and it is apparent that various modifications can be made by those skilled in the art based on the description of the scope of the claims. For example, each process of the authentication processing circuit 100 described in the above embodiment can be provided as a program for causing a computer to execute. In this case, it is preferable to store the program in a storage medium such as a memory so that the processor in the computer can execute the program. Alternatively, the program may be provided as a plug-in to firmware incorporated in an existing playback device or transmitter.

DESCRIPTION OF SYMBOLS 10 Disc reproducing apparatus 11, 31 HDMI connector 12 Disc access part 13 AV decoder 14 Transmitter 20 HDMI cable 21 Data line 22 Control line 23 Hot plug line 32 Receiver 40 Content data 50 Disc 60 Audio data 70 Video data 100 Authentication processing circuit 110 Authentication unit 111 Central control unit 120 Storage unit 200 HDMI transmission circuit 300 Timer 400 Memory 500 Non-volatile memory 510, 510a Table 511 Identification information 512 Wait time 512a Authentication start wait time 512b READY bit reception wait time 701 Authentication processing unit 702 Dummy data Generation unit 703 Hot plug detection unit 704 Scramble unit 705 Transmission processing unit 706 Reception processing unit 707 Determination unit 800a, 00b initial time value 900a, 900b upper limit time value 1000a, 1000b incremental time value WTa, WTb variable

Claims (1)

A receiver that is a destination of content data or a relay that relays the content data to the receiver is authenticated in accordance with an HDCP (High-bandwidth Digital Content Protection) method, and the authentication is performed until the authentication is successful. An authentication unit that increases the waiting time according to
A storage unit that stores the identification information of the receiver or repeater that has succeeded in the authentication and the waiting time that was used when the authentication succeeded; and
An authentication processing circuit in which the authentication unit uses the stored waiting time when re-authentication of a receiver or a relay corresponding to the identification information.

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