JP2001223686A - Broadcast receiver suitable for restricted reception system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadcast receiver that can allow a receiver main body to discriminate whether an IC card loaded to the receiver main body has a prescribed secret processing function, without providing a confidentiality processing function to the receiver body. SOLUTION: A comparison section 10 compares a value Y sent from a broadcast station, having a value Z resulting from processing the value X sent from the broadcast station by an IC card 30 and returning it to the receiver body 20, so as to discriminate whether the IC card 30 loaded to the receiver main body 20 has a function of processing an encryption system of the prescribed restricted reception system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadcast receiver adapted to a conditional access system.

More specifically, the present invention relates to a broadcast receiver conforming to a conditional access system, which is suitable for judging the processing function of an IC card loaded in a receiver main body on the receiver main body side. .

[0003]

2. Description of the Related Art Conventionally, a receiver of a conditional access system generally includes a descrambler for restoring a scrambled and broadcasted signal such as video and audio as a part related to security processing, There is a related information processing unit that processes information called related information for controlling the information processing. At this time, the relationship between the receiver main body and the part that performs the security processing may be largely as shown in FIG.

In FIG. 2, ant is a receiving antenna,
tunr is a tuner, desc is a descrambler, pr
oc is a related information processing unit, dec is a video / audio decoder,
disp is a display unit.

[0005] FIG. 2A shows a case where the part for performing the security processing is embedded in the receiver main body, which is highly secure in that it does not have an interface for outputting a signal being processed to the outside. If the part is decrypted, it is necessary to update it including the receiver itself.

FIG. 2B shows a case where the descrambler is included in the receiver main body, but the related information processing section for controlling the descramble is a module detachable from the receiver main body. That is, program information (Entitlement Control Message, hereinafter referred to as ECM) and individual information (Entitlement Mana
gement Massage (hereinafter abbreviated as EMM), decrypts the encryption of related information, determines whether or not it can be received, and generates a scramble key (denoted as Ks in the drawing). This is the case where the security module is in the form of a module.
An IC card with a built-in CPU according to the ISO standard is often used.

[0007] When the security of the related information encryption system cannot be maintained, the configuration of B is used in accordance with the ISO standard IC.
Only the card portion needs to be updated, but if the security of the portion for descrambling the signal cannot be maintained, the receiver body needs to be replaced.

FIG. 2C shows a case where the module including the signal descrambler is detachable from the receiver body. Since the interfaced signal is faster than B, C is called the high-speed CA interface system and B is called the low-speed CA interface system.
C is standardized in Europe and the like as a highly secure system since the scramble key Ks does not appear at the interface portion as in the case of B. However, as for the number of contacts of the module, B has 8 pins, while C has a multi-contact card of, for example, 68 pins.

By the way, in the case of B, the descrambling method is standardized and made public, but security is maintained by changing the scramble key Ks as a descrambling parameter. In this system, the interface between the IC card and the receiver main unit is standardized, and processing related to security is performed inside the IC card that is not accessible from the outside. Can be excluded.

As a result, the receiver body can be freely manufactured by each manufacturer without entering into a confidentiality contract with the developer of the conditional access system, and the cost of the receiver body can be reduced by mass production. Promotion of accompanying dissemination, etc. becomes possible.

[0011]

By the way, in the case of the receiver of the conditional access system according to the configuration B described above (see FIG. 2), the IC card loaded in the receiver main body is used for a signal to be broadcast. It must be able to handle the conditional access system used, for example, the encryption system for related information.

However, physically, the receiver main body has the ISO
If the IC card conforms to the standard, it can be loaded. Therefore, it is necessary to immediately determine that an IC card that can correctly process the received broadcast signal is loaded, and to show the viewer if the IC card is incorrect. is there.

However, as a method of determining a function of a device that performs secret processing such as an IC card from the receiver side, conventionally, a signal for confirming the function is provided to the receiver body side with the secret function. The method of generating by holding was used.

However, in this method, the receiver main body has an IC.
It is necessary to have a secret function related to at least a part of the secret processing in the card, and as described above, the receiver body can be freely manufactured without having a secret part. Will not meet the purpose.

Accordingly, an object of the present invention is to provide
The receiver itself can determine whether the IC card loaded in the receiver has the intended secret processing function, without giving the receiver itself a secret processing function. It is to provide a broadcast receiver which has been improved.

[0016]

In order to achieve the above object, a broadcast receiver according to the present invention is a broadcast receiver compatible with a conditional access system, comprising: a first code and a first code; Receiving means for receiving a second code obtained by conversion by a method that cannot be detected by a third party on the broadcast station side, and having a form detachable from the receiver main body, An IC card for inputting a second code, wherein the IC card sends a third code obtained as a result of performing a conversion process based on an internal program of the IC card to the receiver main body; And a notifying means for notifying that the IC card is not compatible with the conditional access system if the result of comparison by the comparing means does not match. It is provided.

Here, the conversion process performed based on the internal program of the IC card is an inverse conversion process with respect to the conversion process performed on the broadcasting station side, and the result obtained by the inverse conversion process is the same as the first code. If they are the same, it is possible not to make a notification that they do not conform to the conditional access system.

Further, a block cipher system or a stream cipher system can be used as conversion processing performed on the broadcast station side and in the IC card.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In one embodiment of the present invention, it is determined whether or not an IC card loaded in a receiver main body has a secret processing function by providing secret information to the receiver main body. In order to do so, we send secret information from the broadcaster side,
After receiving the information, the receiver body transfers the information to the IC card, and makes the above determination using the response result and the information received from the broadcast station side.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a configuration diagram showing a receiver main body and an IC card to which the present invention is applied.

In the figure, ANT is a receiving antenna. 2 is a tuner, 4 is a descrambler, 6 is a video
Audio decoder, 8 is a buffer memory, 10 is a comparator, 1
Reference numeral 2 denotes a different card notification unit, and reference numeral 20 denotes a receiver main body. 22, a response processing unit; 24, a related information processing unit; and 30, an IC card.

The receiver main unit 20 receives a program signal transmitted from a broadcasting station and processed by a predetermined conditional access system and information for controlling reception (related information). , And X and Y are newly included. For example, the value X is a value obtained as a result of performing a secret process performed on the value Y in the broadcasting station.

In the receiver main unit 20, the value Y among the values received and reproduced via the tuner 2 is stored in the buffer memory 8 in the receiver main unit 20 as it is, and the value X is loaded into the receiver main unit 20. Is transferred to the IC card 30. It is necessary to load an IC card 30 for performing a process corresponding to the secret process performed by the broadcasting station into the receiver main body 20 adapted to the conditional access system.
When the value X is transferred in advance, an arithmetic function capable of returning the value X to the value Y is incorporated. Therefore,
When the receiver main unit 20 transfers the received value X to the response processing unit 22 of the IC card 30, the value Z output as the calculation result of the response process is stored in the buffer memory 8 of the receiver main unit 20 first. The comparison unit 10 determines whether or not the value is equal to the value Y, and determines whether or not the IC card 30 has a function of performing the same secret processing as that of the broadcast station.

Here, as the relationship between the value X and the value Y, the two can be related using various encryption methods.
For example, a block cipher system or a stream cipher system can be used as conversion processing performed on the broadcast station side and in the IC card. Also, a company that creates an internal processing program for the IC card 30 and issues the card,
Since the broadcasting station that sends out the information of the value X and the value Y only needs to know the relationship between the value X and the value Y, it can be used without a so-called encryption method.

However, in order to maintain the security against the determination / identification processing to which the present invention is applied, a third party can easily estimate the relationship between the value X and the value Y by observing the broadcast signal. It is important not to be.

In order to perform the above identification according to the present invention,
For example, the BS digital broadcasting conditional access system (BS-CA
S system) standard (refer to the Radio Industries and Industry Association's standard “BS digital broadcasting limited reception system” (ARIB STD-B25))
Can be realized by adding the following functions.

(A) A value X and a value Y are included in a signal to be broadcast.
Is newly provided and transmitted. (A) Among the commands sent from the receiver main body 20 to the IC card 30, an appropriate command such as one requiring a response from the authorized IC card 30 is transmitted including the value X. (C) The response from the IC card 30 to the command of (a), including the value Z resulting from processing the value X by the IC card 30, is returned to the receiver main body 20. (D) When the value Y is different from the value Z, the receiver main body 20 performs a process for notifying, for example, that the IC card 30 does not support the broadcast signal. In the present embodiment, the process for this notification is performed by the different card notification unit 12.

[0029]

As described above, according to the present invention, whether the secret processing function in the IC card 30 loaded in the receiver main unit matches the secret processing function in the information transmitted from the broadcasting station or not. The mechanism for determining whether or not to perform the determination can be easily and easily realized without including a secret part in the receiver main body.

Therefore, according to the broadcast receiver to which the present invention is applied, it is possible to manufacture independently without entering into a confidentiality contract with a business operator for developing and operating the limited reception system to be used. , A special effect can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a diagram illustrating a relationship between a receiver main body and a part performing a security process in a broadcast receiver using a conditional access system.

[Explanation of symbols]

 ANT receiving antenna 2 tuner 4 descrambler 6 video / audio decoder 8 buffer memory 10 comparison unit 12 different card notification unit 20 receiver body 22 response processing unit 24 related information processing unit 30 IC card

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C064 BA01 BC06 BC20 BC22 CB08 5J104 AA07 BA03 EA22 KA02 NA35 NA38 NA40 PA04 PA05 9A001 BB06 EE03 LL03

Claims (3)

[Claims] 1. A broadcast receiver adapted to a conditional access system, comprising: a first code and a first code obtained by converting the first code by a broadcast station by a method that cannot be detected by a third party. Receiving means for receiving the second code; and an IC card having a form detachable from the receiver main body for inputting the received second code.
An IC card that sends a third code obtained as a result of performing a conversion process based on an internal program of the card to the receiver main body, a comparing unit that compares the third code with the first code, A notification unit for notifying that the IC card is not compatible with the conditional access system when the result of comparison by the comparison unit does not match, wherein the broadcast adapted to the conditional access system is provided. Receiving machine. 2. The broadcast receiver according to claim 1, wherein the conversion process performed based on the internal program of the IC card is a reverse conversion process to a conversion process performed on a broadcast station side. If the obtained result is the same as the first code, the broadcast receiver not adapted to the conditional access system is not notified, and the broadcast receiver adapted to the conditional access system is not provided. 3. The broadcast receiver according to claim 1, wherein a block cipher system or a stream cipher system is used as conversion processing performed on the broadcast station side and in the IC card. Broadcast receiver.