JP2001057023A - Electronic equipment having digital interface control function and deciphering function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To conduct a recording based on the copy status of desired contents without being affected by the copy status prior to the desired contents by transitioning a destination side electronic equipment to a recording standby condition when it is in a recording protection condition while fitting coding can not be conducted for the contents during a recording. SOLUTION: If it is in a status in which a copying is prohibited, audio and video signals of the contents are transitioned to a recording standby condition. Moreover, when it is in a copy capable status and a ciphering decoding process is required, a confirmation is made with the equipment of a source side and if it is O.K., a ciphering coding key is computed. If the confirmation fails, it is transitioned to a recording standby condition. During a recording, a checking is continuously made for the copy protection status of the contents. When it is changed to a copy capable status, the contents are immediately recorded when deciphering is not required.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic device having a digital interface control function and a decryption function, and more particularly to an electronic device connected by an IEEE 1394 serial data bus.

[0002]

2. Description of the Related Art In a digital AV system according to the prior art, a network is constructed by connecting electronic devices having a digital interface control function and a decryption function via a serial data bus. These connected electronic devices include a decryption function (AKE function system; Out)
Hentication and Key Excha
device equipped with an NRD (Integrated Rec.) which is a satellite broadcast receiving device.
Eve Decoder) or DV that is a recording device
HS (Digital Video Home System) and the like exist.

FIG. 3 shows a state in which devices provided with the IEEE 1394 interface and having a decryption function are connected by a serial data bus. Among them, an AKE function system constituting the decryption function is shown in FIG. , A specific device A, B connected via a bus, which has the same decryption function, and has a storage 11 for storing contents from a source device to a destination device, and a recognition and key exchange. Subsystem (Authentication and Key E)
xchange Subsystem; AKE function system) 12 and content decryption subsystem 13
And an IEEE 1394 interface 14 having a protocol for connecting to a source-side device via a bus.

The basic concept of the authentication and key exchange subsystem (AKE function system) 12 having such a configuration will be described. The content handled on the serial data bus is equipped with a system capable of encrypting and sending the content at the time of sending to protect the content. In order to input the encrypted data and display it on a monitor or to record on a recording device, the code must be decrypted. Only after decrypting the code can the original content be projected and recorded. The degree of encryption, that is, the copy protection status (Copy Protection Status)
Status) is, for example, DCTP (Digital).
Transmission Content Pro
EMI (Encryption)
Mode Indicator)
The degree to which copying should be performed is set. The type of the degree is copy free (Copy free).
Free), Copy Never (C)
copy One Generation (Copy One G) that can copy only one generation.
(energy), which are four types of No More Copies, which indicate that one generation is already copied once. In order to protect the content, information indicating the degree of encryption is marked on the content, and a receiving device (recording device in the embodiment) capable of externally inputting a signal is input. With this information of the content, it is instantaneously determined whether or not it is necessary to decrypt the content.

On the other hand, if it is necessary for the source device to encrypt and transmit the content in accordance with the encryption information of the content, the source device encrypts the content and transmits the content on the serial data bus (iLINK in the embodiment). If the input content is encrypted, the destination-side device (recording device in the embodiment) performs a process for decrypting the content together with the source-side device, and exchanges some necessary keys (Keys). Decrypt the code. For example, D
In TCP, there are three types of keys. Authentication key (Auto
Hentation Key) and exchange key (Ex)
changeKey) and the content key (Conte
nt Key). The authentication key is used to encrypt the exchange key and is established during authentication. The exchange key is a copy-write content stream (Cop)
Used to set up and manage the security of the Yield Content Stream. The last content key is used to encrypt and decrypt the exchanged content.

Next, a description will be given, with reference to the flow chart of FIG. 5, of a technique for decryption processing and recording in an electronic device having a digital interface control function and a decryption function in such a configuration.

First, it is determined whether or not there is a recording request to a destination-side device (in this case, a recording device) (step ST11).

When a recording request is issued, that is, when a trigger for recording execution is generated, or during recording, a serial data bus (iL
INK), the copy protection status of the Iso signal content (Copy Protection St).
atus) is checked (step ST12). If the status is a status that prohibits copying, the recording is not executed or the recording is stopped. If the recording is not completed, the copy protection status is checked. This is performed until the end of recording (step ST1).
3, ST14).

If the copy protection status of the input content is copy free, the input original content is recorded, and if the recording is not completed, the status contents are repeatedly checked (steps ST15, ST16, ST14). ).

In step ST15, if the copy protection status of the input content is a status that can be copied but must be decrypted, authentication is performed with the source device that is transmitting the input content. It is determined whether or not it is necessary to correct the password. If it is not necessary to perform the authentication again, it is determined whether or not the authentication is OK (steps ST17 and ST18).

If the authentication is OK, it is examined whether or not the decryption key needs to be updated. If the decryption key needs to be updated, a decryption key is calculated and sent to the decryption IC ( Step ST19).

In step ST18, if the authentication is not OK, authentication with the source side device is performed, and if this authentication is completed or if the authentication process fails even after five attempts, the recording execution is stopped. (Step ST21, S
T22, ST23, ST24). After stopping the recording,
Even if the copy protection status of the content input to the recording device changes to a copyable status, recording is not performed until the next recording execution trigger occurs.

In step 21, if the authentication processing with the source device is completed successfully, a content key is obtained, and a decryption key is sent to the decryption IC. (Steps ST22, ST25, ST2)
6, ST27).

[0014]

However, in an electronic device which can be connected via an IEEE 1394 serial data bus in the prior art, the encryption level (copy protection status) of the content must not be strongly copied. In general, if it is at a copyable level but cannot be decrypted for some reason when attempting to decrypt the electronic device, it is common practice not to perform the recording or to stop the recording. For example, a satellite broadcast receiver IRD (Inte
When a source device equipped with a tuner device such as a graded receiver decoder and a destination device which is a DVHS which is a recording / playback device are connected by an IEEE1394 serial data bus, the IRD makes a timer reservation to the DVHS. When recording is performed, the IRD is turned on at the reserved start time, receives the broadcast channel of the set program, and turns on the DVHS to perform the recording with the power turned on. I do.

A transition time is required for an electronic device to be turned on from power off or to transition from a stopped state to a recording state. In most cases, such an electronic device is tens of seconds from the reserved start time. It is designed so that power is turned on early and recording is started slightly before the set time. By doing so, recording can always be performed at the start time.

Here, for example, when a program or a commercial before a reserved program has a protection level at which copying is not possible, the start time of the reserved program is set shortly before the start time of the reserved program to ensure recording. Therefore, the copy protection of the content input to the recording device at the start of recording is read, and it is determined that copying is not possible.

In such a case, if the specification is to stop recording, it means that the program to be actually recorded is a program that can be copied but cannot be recorded.

For example, as shown in FIG. 6, in Europe (Germany) and the like, when recording is started by actually pressing the recording key instead of scheduled recording, several minutes are required to reliably record the program from the beginning. There is a tendency for users to start recording in advance, and even such a user detects uncopiable content at the time of executing recording several minutes ago, immediately stops recording, and even if a desired reserved program can be copied It will not be possible to record even content that is difficult.

As another example, as shown in FIG.
If a non-copyable content was already recorded but a copy-free program was later overwritten on a recording medium (for example, a tape) several times, it was copied between a certain program and a certain program. Impossible content may remain. When dubbing such a recording medium to another medium, even if it is attempted to perform the dubbing recording entirely, the recording is stopped when a portion that cannot be copied is detected. For the part that is earlier than the part where the uncopyable part is detected, the part that can be copied must be detected earlier and the recording must be newly started.

Further, if copy protection status information is exchanged via communication or the like, if a noise occurs for a moment and it is determined that copying is not possible, if the recording stop specification is used, automatic Cannot be recovered.

Therefore, when recording encrypted content, there is a problem to be solved in that the content can be recorded by decrypting the content to be actually recorded.

[0022]

In order to solve the above-mentioned problems, an electronic device having a digital interface control function and a decryption function according to the present invention comprises a network constructed by a plurality of electronic devices connected to a serial data bus. When the content in the source-side electronic device is transmitted to the destination-side electronic device and recording protection is performed such that the content cannot be decrypted, the destination-side electronic device is in a recording standby state. It is a transition.

The serial data bus is connected to an IEEE
The source-side electronic device is an IRD, and the destination-side electronic device is a recording device.

As described above, when recording, if the content cannot be decrypted, the state transits to the recording standby state, so that the copy status of the desired content is not affected by the copy status before the desired content. It will be possible to record based on that.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of an electronic device having a digital interface control function and a decryption function according to the present invention will be described with reference to the drawings. still,
The same components as those described in the related art will be described with the same reference numerals.

The configuration of an electronic device having a digital interface control function and a decryption function according to the present invention has the same configuration as that of FIG. 4 described in the related art. The following description focuses on those specific to the present invention.

In the present invention, when a trigger for recording execution occurs or during recording, the Iso signal of the serial data bus (in this embodiment, iLINK) input to (the recording device of) the destination-side device. Check the copy protection status of (isochronous signal) content. In this status, if the status is a copy prohibition status, both the audio and video signals of the input content are immediately shifted to the recording standby state. If the status indicates that copying is possible but decryption processing must be performed, authentication is performed with the source device that sends out the input content, and if OK, the decryption key is calculated. ,
If the authentication fails, a transition is made to the recording standby state. During the recording, the copy protection status of the content input to the recording device is continuously checked, and if the content is changed to a copyable one, the content is immediately recorded if decryption is unnecessary, and the content is encrypted. If decryption processing is required, authentication is performed with the source device that sends out the input content. If the authentication is OK, a decryption key is obtained by calculation, but if the authentication fails, a transition is made to the recording standby state.

The present invention of transitioning to the recording standby state for recording will be described in further detail with reference to the block diagram of FIG. 3 described in the prior art and the flowchart of FIG.

First, it is determined whether or not there is a recording request to the destination side device (step ST31).

When there is a recording request, that is, when a recording execution trigger is generated, or during a recording operation, a serial data bus (iL
INK), the copy protection status of the Iso signal content (Copy Protection St).
atus) (step ST32). When this status is a recording protection state in which copying is prohibited, the state transits to a recording standby state, and if recording is not completed, the copy protection status is repeatedly checked again until recording is completed (steps ST33 and ST34). .

If the copy protection status of the input content is copy free, the input original content is recorded, and if the recording is not completed, the status content is repeatedly checked (steps ST35, ST36, ST34). ).

In step ST35, if the copy protection status of the input content is a status that can be copied but the decryption process must be performed, authentication is performed with the source device that is transmitting the input content. It is determined whether or not the authentication needs to be corrected. If it is not necessary to perform the authentication again, it is determined whether or not the authentication is OK (steps ST37 and ST38).

If the authentication is OK, it is examined whether or not the decryption key needs to be updated. If the decryption key needs to be updated, a decryption key is calculated and sent to the decryption IC ( Step ST39).

In step ST38, if the authentication is not OK, the authentication with the source side device is performed, and if this authentication is completed, or if the recording protection state is unsuccessful even if the authentication processing has failed five times, To the recording standby state (steps ST41, ST42, ST43,
ST44).

In step 42, if the authentication process with the source device is completed successfully, the content key is obtained, the decryption key is sent to the decryption IC, and the decrypted content is recorded. If not, the copy protection status of the content is checked (steps ST45, ST46, ST47).

As described above, when recording is performed before the reserved content or the content to be recorded, when the recording protection state is set, the recording state is shifted to the recording standby state, so that the copy protection status before the desired content is not affected. . That is, as shown in FIG. 2, there is a program that wants to execute a reserved program,
The recording device records before the start time of the program reserved for executing the reserved program in a situation where the copy protection status is not copyable or the device that is trying to record cannot copy at that time. When started, the reserved program can be reliably recorded. The immediately preceding program is not limited to the same channel, and indicates a program that is being received when the recording device starts recording. The same applies to a case where the recording is executed before the start time of the program to be recorded, not limited to the scheduled recording.

As shown in FIG. 3, there are recording media for which dubbing is desired to be executed, and the recording media from which dubbing has been performed may have copy protection statuses that can be copied, and those that cannot be copied. Therefore, even when there is a mixture of characters, so-called "whole dubbing" can be executed in which only copyable items can be continuously copied.

[0038]

As described above, an electronic device having a digital interface control function and a decryption function according to the present invention can be used in a recording protection state such as a content that cannot be decrypted during recording. Makes a transition to the recording standby state, so that recording can be performed based on the copy status of the desired content without being affected by the copy status before the desired content, and the reserved recorded program can be reliably recorded. There is an effect that can be.

[Brief description of the drawings]

FIG. 1 is a flowchart in a case of transition to a recording standby state according to the present invention.

FIG. 2 is an explanatory diagram in which states of input content and the content recorded by a recording device in the case of performing the same scheduled recording are compared.

FIG. 3 is an explanatory diagram showing a comparison between input content of the recording device and recorded content of the recording device at the time of dubbing.

FIG. 4 is a block diagram showing a decryption function.

FIG. 5 is a flowchart of a related art in which recording is stopped when copying is prohibited.

FIG. 6 is an explanatory diagram showing a copy status when a reserved program is recorded in the related art.

FIG. 7 is an explanatory diagram showing a status of a copy at the time of repeatedly recording such as dubbing in the related art.

[Explanation of symbols]

11; content source destination storage; 12; authentication and key exchange subsystem; 13; content decryption subsystem; 14; IEEE 139
4 interfaces

Claims (3)

[Claims] An electronic device for constructing a network with a plurality of electronic devices connected to a serial data bus, wherein when content in a source electronic device is transmitted to a destination electronic device, decryption of the content is performed. An electronic device having a digital interface control function and a decryption function, wherein the destination-side electronic device transitions to a recording standby state when the recording protection state cannot be performed. 2. The method according to claim 1, wherein the serial data bus is an IEEE13.
The electronic device according to claim 1, wherein the electronic device has a digital interface control function and a decryption function. 3. The electronic device having a digital interface control function and a decryption function according to claim 1, wherein the source-side electronic device is an IRD, and the destination-side electronic device is a recording device.