JPH03284058A - Transmission reception system for privacy information - Google Patents

Abstract

PURPOSE:To decode privacy information by reading received revision information even when a contractor uses any storage medium before or after update and selecting automatically a key used for the time. CONSTITUTION:A specific address, a key K1 corresponding thereto, an update number R1, a key K2 and an update number R1+1 are stored in a card (a) distributed to a recipient, and a specific address, a key K2 and the update number R1+1, a key K2 and an update number R1+2 are stored in an update card (b). Even when the cards (a), (c) are used for a period P2, since a receiver reads the update number R1+1 and selects the key K2 corresponding thereto, the transmission information is correctly decoded. Since the information is received even when the recipient uses the card (c) before and after update over a long period, the operability of the recipient is much simplified and the possibility of disabled reception due to erroneous loading of the card around the period of the update is precluded.

Description

[Detailed description of the invention] (a) Industrial application field The present invention is applicable to facsimile broadcasting, paid broadcasting, communication system 2, etc., in which information is scrambled and sent out, and confidential information is descrambled on the receiving side. system (′: related;

(b) Conventional technology Nowadays, in an era where information has value, paid broadcasting and communication systems that can be received only by the subscriber through consideration-based contracts have become effective business fields.For example, paid broadcasting and 15
Now, high-definition broadcasting using satellite broadcasting will also be available soon. In addition, related organizations are currently deliberating the technical conditions for the practical implementation of a paid system for TV multiplexed facsimile broadcasting.

These paid broadcasts are transmitted by scrambling the original image, video, audio, etc. signals on the transmitting side to ensure confidentiality, and the receiver, who is a contract member, descrambles the signals using the same scramble key as the transmitting side. A system is used that performs this process and restores images, etc. The system for disseminating this scrambled key to contract members includes a system in which magnetic cards or IC cards containing key information are distributed to contract members, and a system in which the pin code associated with the key is notified to contract members by means such as telephone or mail. and so on.

Among these, the present invention relates to a system using a portable storage medium such as a card.

(c) Problems to be solved by the invention In this system, the contract member inserts the card into the receiver, reads the key information into the receiver, and the receiver can descramble and restore data based on this key. .

However, in order to increase the security of information, it is desirable to update the scramble key at regular intervals, but in this case, the following needs to be considered.

When the key is updated, the updated card is distributed to the contractor, and after the update, the recipient needs to use the updated card to receive the card, but if the recipient forgets that the key has been updated. ,
There may be cases where the card cannot be restored correctly because the card before the update is used as is, or the updated card may be delayed for some reason and may not reach the recipient by the time the update is switched. In such a case, the subscriber may not be able to receive the desired pay program.

In view of the above points, the present invention provides a system in which the recipient can correctly restore and receive information on the receiving side, regardless of whether the recipient uses the card before or after the update, in the period before and after the key is updated.

(D) Means for Solving the Problems The present invention is such that the transmitting side scrambles the transmitted information using a scramble key that is sequentially updated at predetermined intervals and transmits it with confidentiality, and the receiving side uses the same information as the transmitting side. In a transmission/reception system that restores information by descrambling using a key, there is a transmission system that sends update information for the key used at the relevant time along with the scrambled information, and a transmission system that sends the updated information of the key used at the relevant time along with the scrambled information, and the key information before the update and the update. A key/update information reading means for reading the pre-updated and post-updated key information and update information from a storage medium in which subsequent key information and update information corresponding to each key are stored, and an updater for reading the update information from the received signal. A receiver comprising an information reading means, a key selection means for selecting a key corresponding to the updated information from the information obtained by the key/updated information reading means, and a descrambling processing means for performing descrambling processing based on the selected key. It is characterized by consisting of a system.

(e) Effects According to the configuration of the present invention, before and after the key is updated, the subscriber can read the received update information and store it based on this whether using the storage medium before or after the update. It is possible to automatically select the key used at the relevant time from the key-update information stored in the medium and restore the confidentiality information using this key. (F) Example First, to explain the outline of the example, the transmitting system manages the updating of scramble keys by assigning an update number (update information) to each key, and when transmitting each pay program, Update number information corresponding to the key being used is sent along with the scrambled program.

On the other hand, in the receiving system, the subscriber restores the card using the stored card based on the following specifications.

The card contains 1 and the time T for the key used during the period.
To the key updated in 1, both and more! Update number information for , and is stored, and this card is distributed to recipients by mail or the like. This update number is
For example, the initial value may be O, and the value may be sequentially incremented by 1 each time the key is updated, and the update number may be assigned as the update number. The receiving system refers to the update number sent along with the received program, selects the key with the corresponding update number from the two types of keys read from the card, and uses this selected key. The information is descrambled based on the information.

An embodiment of the present invention will be described below using a pay system for facsimile broadcasting as an example.

Technical standards regarding facsimile broadcasting were submitted to the Telecommunications Technology Council in February 1989. These technical standards are aimed at free broadcasting for the general public, and regarding paid broadcasting, the results of research conducted by the Facsimile Broadcast Utilization Technology Research Group of the Ministry of Posts and Telecommunications were reported in May of the same year, and further broadcasting technology development consultations were held. Technical specifications for the paid system are being discussed at the meeting. Facsimile broadcasting is one of the television multiplex broadcasts.
This is a system in which subcarriers obtained by digitally modulating facsimile signals (four-phase differential phase modulation method) are frequency-multiplexed with television audio signals, and are broadcast simultaneously with television programs. The facsimile signal is an image signal encoded in the same way as the wired G37 aximir, plus an error correction code as a countermeasure against transmission errors, and various controls for identifying facsimile broadcast programs and identifying the beginning and end of each program. The signal structure to which the signal is added (the frame matrix structure of the facsimile signal is shown in FIG. 4, the time series structure is shown in FIG. 5, and the structure of the program selection signal is shown in FIG. 6).

In paid systems, the image signal is scrambled, and only the subscriber can restore the image by descrambling it using the same key as the sender. As mentioned above, the scramble key is read by inserting a card distributed by the broadcaster into the receiver.

The card has an ID code (
For facsimile broadcasting, the specific address in Figure 6 corresponds to this), the key used during the period corresponding to this program, its update number, and the updated key and its corresponding update number are stored. There is.

The recipient receives the desired paid program by inserting the card into the receiver and making a program reservation.

A detailed explanation will be given below based on FIGS. 111 to 6.

FIG. 1 shows a block diagram of the transmitting system.

Reference numeral (1) denotes an encoding unit that performs one-dimensional encoding or two-dimensional encoding processing on an image signal similar to 63 facsimile.

(2) is a scrambling processing circuit that performs scrambling processing on the image signal (after encoding) input from the encoding unit (1), and scrambles the image signal (after encoding) based on the scramble key input from the scramble key generation unit (3). Perform processing.

As a method of scrambling processing, for example, a method of adding a PN (pseudo random) signal sequence generated based on a key to the original signal is used, but the method is not limited thereto. (8)
is an update number management unit that manages update numbers corresponding to scramble keys.

(4) is the program ID in the scrambled image signal.
This is a frame creation section that adds a code (specific address) and various other control signals to create a facsimile signal string having a frame structure (FIG. 5). The specific address and the update number of the key being used are assigned to a control signal called a program selection signal and sent out. Specifically, for example, the specific address of the program selection signal in FIG. 6 is used,
The update number uses the undefined part in the same figure.

The facsimile signal output from the 7-symbol generator (4) is further modulated using a 4-phase differential phase modulation method in the modulator (5), and then superimposed on the audio signal by frequency multiplexing in the multiplexer (6). The signal is then transmitted as a broadcast radio wave along with the video signal by the transmitter (7). FIG. 2 shows a block diagram of the receiving system. (11) is a channel selection/audio detection unit which selects a desired channel from the received television radio waves and further detects an audio carrier wave. (12) extracts the modulated signal of the facsimile signal from the voice detection signal, and
A demodulation section that performs demodulation using a differential phase modulation method outputs a demodulated digital signal string to a signal separation section (13). The signal separation unit (13) is a signal separation circuit that performs a series of digital processing such as synchronization and error correction on a digital signal string and separates an image signal and a control signal.

(14) is a control signal decoder that decodes the control signal, and when a program selection signal is input, it reads the specific address, key update number, etc. contained therein. (19) is a specific address comparison unit, which is a RAM that stores information on program reservation registration.
Referring to the program reservation table (15) consisting of Information on the flag, its specific address, and the update number input from the control signal decoder (14) is passed.

One of the main controls of the program reservation control section (16) is the registration of program reservations, and the reception subscriber operates the keys in the key manual section (7) and sends a magnetic card to the card league section (18). Program reservations are made by inserting a membership card (C) consisting of a card or the like.As mentioned above, the card (C)
The program's specific address and two types of scramble fa (
Program-related information consisting of the key used during the relevant period, the updated key KIJl (i is an integer), and the update numbers R1, R+ + 1 of each key is stored, and this reservation operation causes the receiver to make the reservation. A program reservation table storing the specified address and the corresponding key and time information is created and stored in the program reservation table storage section (J5). Here, you can use one or more cards that store information related to one program, or use cards that store information related to multiple programs (
By using one or more of C), it is possible to reserve multiple programs.

Further, when the match flag with the received specific address is input from the specific address comparison unit (19), the program reservation control unit (16) refers to the program reservation table (15), and
Select the key that matches the update number input from the specific address comparison section (19) out of the two types of keys corresponding to the specific address.
i! L, , This selected t=key is used to set a key for the descrambling processing unit (20). The descrambling processing unit (20) converts the signal separation circuit (13) based on this key.
) to descramble the scrambled image signal of the program having a predetermined specific address,
Further, a decoding section (21) performs -dimensional or two-dimensional encoding decoding, and a printer section (22) prints and records the image.

Note that if there is no key corresponding to the input update number, the process after descrambling is not performed.

Next, using FIG. 3, the card (C) in the above example
Figure 3 (a) shows the temporal change of the scramble key used for a facsimile broadcast program with a specific address on the transmitting side.
(time T, ~T,) is 1 for the key, period P2 (time T, ~7
゛,) is 1 for the key, and period P3 (time T, ~T>) is! To,
The update numbers corresponding to ~Kt for each key used are R3, R3+1, and R1+2, respectively.

Card a distributed to recipients in the present invention includes 9. A specific address, a corresponding key 1, an update number R1, and a key corresponding to the update number R, +1 are stored, and the update card b contains the specific address and key K.

and update number RI+1 and 111 K * and update number R,
+2 is attached.

Portrait 1. In the conventional method, as shown in Figure 3 (b), the card; +, 'i:''': is a specific address and key K. is stored in a specific address and key. Therefore, for example, card a'
If a card or card C° was used during period P2, it cannot be restored because the card reading block (acK, + or K) is different from the sender's key (key).

On the other hand, according to the system of the above embodiment, the system shown in FIG.
As in c), card a and card C are used in period P2,
However, since the receiver reads the update number R,+1 and selects the key corresponding to this, it is possible to restore correctly.

In addition, recipients can receive messages using either the pre-update card or the post-update card (C) over a fairly wide period of time.
The operability of the receiver becomes very simple, and the problem of inability to receive data due to incorrect card insertion, which may occur near the time of update, will be resolved. It is not limited to the above embodiments,
For example, a card can rarely use a storage medium, and the update number information (,1' may be some kind of identification symbol instead of a number; the update number information is included in the key information. Furthermore, the present invention is applicable to information transmission/reception systems other than 7A broadcasting.

(g) Effects According to the present invention, a correctly restored image can be received regardless of whether the storage medium used before or after the update is used before or after the subscriber 1+1 update, making it extremely easy to use. improves. In addition, it is possible to have a wide range of time for switching to an updated storage medium and the period for the carrier to send the data to the storage media subscriber, which improves convenience for recipients and operability for the carrier. The present invention is very effective.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a transmitting system in one embodiment of the present invention, FIG. 2 is a block diagram of a receiving system in the same embodiment, FIG. 3 is an explanatory diagram of the operation of the same embodiment and the conventional example, and FIG. 4 5 is a diagram explaining the facsimile signal configuration of facsimile broadcasting, and FIG. 5 is a time-series configuration diagram of the facsimile signal.
FIG. 6 is a configuration diagram of a program selection signal. (C) Card (storage medium), (14) Control signal decoding section, (18) Card reader section, (19)...
- Specific address comparison section.

Claims (1)

[Claims] (1) On the sending side, the transmitted information is scrambled using a scramble key that is updated sequentially at a predetermined period of time, and transmitted with confidentiality, and on the receiving side, the information is descrambled using the same key as on the sending side. In the transmitting/receiving system to be restored, a transmitting system that sends the updated information of the key used at the relevant time along with scrambled information, the key information before the update, the key information after the update, and corresponding to each key. key/update information reading means for reading the pre-update and post-update key information and update information from a storage medium storing the update information; update information reading means for reading the update information from the received signal; A method for transmitting and receiving confidential information, comprising a receiving system comprising a key selecting means for selecting a key from the information obtained by the key/update information reading means, and a descrambling means for performing a descrambling process based on the selected key. .