JPH02246553A - Information transmission system - Google Patents

Abstract

PURPOSE:To prevent information from leaking halfway on a line and to improve the secrecy by using information whose contents change momentarily like time information as an enciphering key. CONSTITUTION:A secret connecting device 6 which is connected to the modular plug of a telephone set 1 is connected to a center 7 through a PB(push-button) signal type subscriber line 40 and a pay telephone network exchange 5 and the secret connecting device 6 and center 7 enciphers time information into enciphering keys and send data out through the subscriber line 40 and pay telephone network exchange 5. The information whose contents change momentarily like time information are used as the enciphering key. Consequently, data is prevented from leaking halfway on the communication line and the secrecy is improved.

Description

[Detailed Description of the Invention] C. Industrial Application Field] The present invention relates to an information transmission system in which a terminal and a center exchange data via a communication line. The present invention relates to a confidential information transmission system that encrypts and transmits data in order to prevent data from being stolen.

[Conventional technology]

2. Description of the Related Art Conventionally, as an example of this type of information transmission system, a "personal related information storage and processing system" disclosed in Japanese Patent Application Laid-Open No. 62-231332 has been known. In this disclosed information transmission system, a terminal device provided for each member and a center are connected via a communication line. and,
The center is equipped with a file in which personal information such as the name and address of each member is registered in advance, while each member has a file in which the member's individual identification information (membership number) and PIN information are stored. A management card is provided. When data containing the membership number and PIN information stored in this information management card is sent from the terminal device to the center via a communication line, in order to prevent the contents of the data from being stolen during the communication line. , the above data is encrypted and sent. At the center, the information processing unit (CPU) of the center processes this encrypted data (ciphertext) sent from the terminal device.
The terminal is decrypted to obtain the original data, and the membership status of the terminal is confirmed by the password information in the obtained original data.

The encryption performed in this system uses the terminal SQ number as the encryption key. That is, the terminal SQ number is added to the data to be sent, and the added data is sent as ciphertext. Here, the terminal SQ number is a number that changes each time the terminal uses the center, but it goes without saying that the number is always the same between the center and the terminal.

[Problem to be solved by the invention]

In the conventional information transmission system described above, the data exchanged between the terminal and the center is encrypted, so confidentiality is maintained to a certain extent. could have been stolen.

Therefore, an object of the present invention is to provide an information transmission system with better confidentiality.

[Means to solve the problem]

An information transmission system according to the present invention is an information transmission system in which a terminal and a center exchange data via a communication line.
It is characterized by encrypting information whose content changes from moment to moment, such as time information, as an encryption key and transmitting it.

[For production]

Since the encryption key uses information whose content changes from moment to moment, such as time information, it is possible to prevent data from leaking during the communication line and provides superior confidentiality compared to conventional information transmission systems. It can be said that there are.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, a personal information system to which an information transmission system according to an embodiment of the present invention is applied includes a secure connection device 6 as a terminal device and a center 7. The secure connection device 6 of this embodiment is prepared at the 6th meeting, and the telephone (place)
1 modular (modular jack 1a and modular
(consisting of plug 1b), as shown in Figure 1.
Connect the modular plug 2o of the secure connection device 6 to the modular jack 1a of the telephone l, and connect the modular jack 3o of the secure connection device 6 to the modular plug l of the telephone all.
It is used by connecting to b. Note that a facsimile (FAX) may be used instead of the telephone 1.

The secure connection device 5T6 connected to the modular telephone hall in this way is connected to the center 7 via the subscriber telephone line 40 in the Pa (button button) signal format and the public network exchange 5.
It is connected to the. Therefore, the subscribed@talk line 40 and the public network exchange 5 are used as communication lines that allow data to be exchanged between the secure connection device if6 and the center 7. In this embodiment, each of the secure connection device 6 and the center 7 encrypts the data using time information as an encryption key, and sends the data via the subscriber telephone line 4o and the public network exchange 5, as will be described later. are doing.

2nd FI! Referring to J, each member using the secure connection device 6 has a magnetic card (MC) distributed in place of a business card.
I own 2. This magnetic card 2 has the name written (in this example, Abe Yamada) in the same way as a normal business card.
Not only are the company name, job title, address of the company, and telephone number printed thereon, but also a magnetic recording band 21 consisting of three areas 211, 212, and 213 is provided.

Area 211 has a membership number unique to the notation format.
2 is a written telephone number, and area 213 is magnetically recorded with the year and month of validity of this card. Therefore, as will be detailed later, this business card (magnetic card 2
), the other member who received the card can use his or her own secure connection device 6 to automatically dial the recipient of this business card. This automatic dialing is called RC dialing.

Referring to FIG. 3, each member using the secure connection device 6 also possesses a membership card 3 consisting of a RAM card (RC) 3. The RAM card 3 has an integrated circuit (IC) section 319, and a power supply terminal and an information access lead terminal 318 connected to a RAM card reader/writer to be described later are connected to the tenth section 319. This membership card includes
In addition to the person listed, a membership number 311 and expiration date 313 are printed. This membership number 311 and expiration date 313
are the magnetic recording band 21 of the magnetic card 2 described above, respectively.
The contents are the same as the membership number and effective eye opening magnetically recorded in areas 211 and 213.

Referring to FIG. 4, in the IC section 319 of the RAM card 3, there is a memory including an area file 4. The area file 4 contains a membership number 421 with the same content as that recorded in the area 211 of the magnetic recording band 21 of the magnetic card 2, an expiration date 423 with the same content as that recorded in the area 213, and a predetermined information for the member concerned. I remember the password number 424 agreed upon between Center 7. In addition, the area file 4 stores area numbers 410 indicating 100 areas from '00'' to '99#, and each area contains telephone numbers 412 of other members, member numbers, etc. 4
11, and name 414 are stored. Therefore, the area file 4 of the membership card can store the telephone numbers, membership numbers, names, etc. of up to 100 other members. Also, by using this membership card and his/her own confidential connection device 6, the member can obtain the area number 4 as described in detail later.
10 manually, this input area number 41
It is possible to automatically dial other members whose names are recorded in 414 in the area corresponding to 0. This automatic dialing is called RC dialing.

Referring again to FIG. 1 along with FIGS. 5 and 6, the secure connection device 6 has a mode switch 601 for switching between the secure connection device 6 and the telephone 1. In FIG. When the mode switch 601 is turned to the (C) side, the secure connection device 6 is connected to the telephone line 40, and when it is turned to the (T) side, the telephone 1 is connected to the telephone line 40. Line control detection sending unit 602
is the (C) side of the mode switch 601 and the PB oscillator 60.
3, and has the functions of a network control unit (NCU), a PB signal detection circuit, and a PB signal transmission circuit. The magnetic card reader 604 is for reading the contents of the above-mentioned magnetic card 2 (FIG. 2), and is provided with a slit for this purpose. The RAM card reader/writer 605 reads the contents of the RAM card 3 (FIG. 3) mentioned above, and
This is for writing to the card 3. Clock circuit 606 generates time information. This time information is used as an encryption key for encrypting data sent to the center 7, as described above and detailed later. As will be described later, the center 7 also has a clock circuit, but the time information generated by the clock circuit of the center 7 and the time information generated by the clock circuit 606 of the secure connection device 6 always match in content.
That is, it is necessary that synchronization is achieved. Otherwise, the transmitted encrypted data (ciphertext) cannot be faithfully decrypted. Since various methods are already known as this synchronization method, their explanation will be omitted here.

A display (DISP) 607 is for displaying information (data). Press the PB dial 608 to select the P that corresponds to the pressed number (including # and *).
This is for causing the B-times signal PB oscillator 603 to oscillate. Reference numerals 609 and 613 are a connection button and a secret button, respectively, and how to use these buttons will be explained in detail in the operation description given later. The center telephone number memory 610 is for storing the telephone number of the center 7, and is housed in a back lid 614 secured with screws. The center telephone number memory 610 of this embodiment is of a rotary switch type, and is set in advance to the telephone number of the center 7 (211-9999 in this embodiment) using a screwdriver. A central processing unit (CPU) 612 is for controlling the above-mentioned devices connected via the memory bus 611. The battery 615 is a power source for the secure connection device 6, and when the battery 615 is not inserted into the secure connection device 6, the plug of the power cord 616 is inserted into a socket (not shown) to connect the The power source can also be used as a power source for the secure connection device 6.

Referring to FIG.
1. The PB oscillator 702 and the clock circuit 703 are
PB oscillator 603 of the above-mentioned secure connection device 6, respectively.
and the clock circuit 606. The center file 706 stores information similar to that stored in the area file 4 shown in FIG. 4, classified by member number 421. The CPU 704 is connected to the memory bus 70
The line control detection sending unit 701 connected via 5;
It is for controlling the PB oscillator 702, clock circuit 703, and center file 706.

The operation of this embodiment will be described below with reference to the operation flows shown in FIGS. 7 to 11.

First, the qualification confirmation mode will be explained with reference to FIG.

(1) Qualification confirmation mode First, in order to use the secure connection device 6, the member (user) equipped with the secure connection device 6 removes the modular of the telephone 1, and plugs the secure connection device 6 into the modular plug. 20
and insert the modular jack 30 into the modular jack 1a and modular plug 1b of the electrical appliance 1, respectively, and turn the mode switch 601 to the (C) side (step Sl).

Next, the member sets the RAM card 3 in the RAM card reader/writer 605 (setting RC(3) in step S2). In addition, if the member passes the magnetic card 2 through the slit of the magnetic card reader 604 in this step S2 (MC(2) in step S2 is the slit), the ninth
Moving on to the MC dial, which will be explained later with reference to the figure.

The member presses the confidential button 613 (Y in step S3)
, presses the connection button 608 (step S4). CPU6
12 detects this, the line control detection sending unit 602
After starting up and making a "calling connection" to the public network exchange 5, read the telephone number (211-9999) of the center 7 stored in the center telephone number memory 610, and check the read contents. This causes the PB oscillator 603 to oscillate a PB double signal, and automatically dials the telephone number (211-9999) of the center 7 to the public network exchange 5 (step S5). Incidentally, if the secret button 613 is not pressed in step S3 (N in step S3), the process moves to the RC dial which will be explained later with reference to FIG.

As a result, the line control detection sending unit 701 of Centaph
"Automatic response". When the CPU 612 confirms this via the line control detection and sending unit 602, the display 607
``Connection OKJ'' is displayed (Y in step S6). When the user sees this, the user enters his/her PIN number on the PB dial 6.
08 (step S7). Next, CPU61
2 is the RAM card reader/writer 605.
Read the membership number 421, PIN 424, and expiration date 423 in the area file 4 in the IC section 319 of the M card 3 (step S8), and find that the expiration date 423 is after the current month and is the input PIN - PIN 424. (Step S9) Here, if the expiration date 423 is before the current month, or the entered PIN ≠ PIN 424
(N in step S9), the CPU 612
Display 60 indicates that AM card 3 cannot be used.
7 and disconnects the secure connection device 6 from the center 7 (step 510).

On the other hand, if the expiration date 423 is after the current month and the input PIN number - PIN 424 (Y in step S9)
, the CPU 612 receives the year, month, date, and
Read the time information of hours and minutes (YY-MM-DD-HHφNN, for example, 15:20 on December 1, 1988),
Using this time information as an encryption key, the data consisting of the membership number 421 and the password 424 is encrypted and sent to the center 7 via the line control detection and sending unit 602, the telephone line 40, and the public network exchange 5 (step 511). As a specific example of this encryption, the member number 421 is "2516".
, if the time information is "6312011520", add these together (2516'+'6312011520°
-"631201436"), resulting in "631201
436" as encrypted data (ciphertext).

Having received this ciphertext, the CPU 704 of the center 7 decrypts the ciphertext using the clock information of the clock circuit 703 as a decryption key, reads the member number 421 and the corresponding password 424 in the center file 706, and decodes them. Decrypted area file 4 member number 421 and password 42
4 (step 512). As a specific example of this decoding, clock information of the clock circuit 703 is transmitted to the confidential connection device 6.
"6312011, which is equal to the time information of the clock circuit 606 of
520", the ciphertext for member number 421 is "631".
By subtracting this from ``201436'', the original information (``2516'' for member number 421) can be obtained (6312014).
36"-6312011520"-'2516")
.

As a result of the comparison in step S12, the member number 421 in the RAM card 3 - the member number 421 in the center file 706
When the CPU 704 confirms that the password is 424 in the RAM card 3 and the password 424 in the center file 706 (Y in step 513),
KJ is determined, and the confirmation OKJ is encrypted using the clock information of the clock circuit 703 as an encryption key and sent to the secure connection device 6.

When the secure connection device 6 receives this ciphertext, the CPU 6
12 decrypts this ciphertext using the clock information of the clock circuit 606 as a decryption key, and displays "Confirmation Complete" on the display 607 (step 514).

In the above, an example has been described in which the membership card consists of the RAM card 3 and the RAM card 3 is set in the RAM card reader/writer 605 to confirm the qualification. However, when the membership card consists of a magnetic card, Of course, by passing this magnetic card through the slit of the magnetic card reader 604, qualifications can be similarly verified.

Next, using a telephone (facsimile) will be explained with reference to FIG.

(2) Use of Telephone (FAX) After confirming the qualifications described above, when attempting to send or receive information by telephone or facsimile to the center 7 (Telephone in step S15)
(FAX), the user must press the mode switch 60.
1 to the (T) side, the telephone or facsimile can be used (step 516).

By the way, as mentioned above, the RAM card 3 has a fourth
Area file 4 shown in the figure is stored. this is,
Since it is used for RC dialing, which will be explained later in (5), it must be kept current at all times.

Further, the same contents as the area file 4 are also stored in the center file 706 of the center 7, as described above. The contents of the center file 706 are always
By contacting us by mail or facsimile from Society H,
It is currently maintained by the manual labor of Center 7. Therefore, from time to time, the own member's RAM in the center file 706
The contents of the file area that should have the same contents as the contents of area file 4 of card 3 are stored in RAM card 3.
If you move it to area file 4, RAM card 3
area file 4 is currently maintained. This transfer is
This is called c update.

Next, RC updating will be explained with reference to FIG.

(3) RC update After completing the qualification confirmation described above, when attempting to update the RC (RC update in step S15 in FIG.
Enter #°. When the CPU 612 detects this,
"1#" is encrypted as described above and sent to the center 7 (step 517). Center 717) CPU 7
04 C. Decrypt this ciphertext received via the line control detection sending unit 701 as described above, read the file area corresponding to the member number 421 from the center file 706, and sequentially read "99" from the area number "00°". ”, the CPU 612 encrypts the file contents in the center file 706 and sends it to the secure connection device 6 (step 518).
The telephone number 4 of the member corresponding to the area number 410 of the area file 4 of the RAM card 3 set in the RAM card reader/writer 605 is received and decrypted.
, 12, member number 411, and member name etc. 414, write from "00" to "99°" (step 519). When this writing is completed, the CPU 612
“End” is displayed on the display 607 (Step 5)
20). The user sees this and presses the mode switch 601.
(step 521), and take out the RAM card 3 from the RAM card reader/writer 605 (step 522).

As mentioned above, the magnetic card 2 contains the telephone number 212.
is recorded, so when a user calls the phone number written on the magnetic card 2, he or she can receive the phone number by passing the magnetic card 2 through the slot of the magnetic card reader 604 without dialing the phone number written on the magnetic card 2. 212 will be automatically dialed. This is the MC dial mentioned above.

Next, the MC dial will be explained with reference to FIG.

(4) MC dial In step S2 of FIG. 7, after passing the magnetic card 2 through the slot of the magnetic card reader 604, the user presses the connection button 609 (step 823),
2 reads the telephone number 212 of the magnetic card 2 from the magnetic card reader 604, and the line control detection sending unit 602 reads “
After "Call Connection", call PB according to the read phone number 212.
The oscillator 603 is caused to oscillate, and an automatic dial is sent to the public network exchange 5 in the form of a PB dial via the line control detection and sending section 602 (step 524). Upon detecting the "reply from the other party" (Y in step S25), the CPU 612 outputs a "connection complete" display to the display 607 (step 526). Users who saw this can use the mode switch 60
1 to the (T) side and use telephone 1 (step 527).

As mentioned above, the area file 4 shown in FIG. 4 is stored in the RAM card 3. By using this area file 4 and inputting only the area number 410, automatic dialing is possible. This automatic dialing is the RC dial described above.

Next, the RC dial will be explained with reference to FIG.

(5) RC Dial In step S3 of FIG. 7, without pressing the confidential button 613, the user presses the area number of the person he/she wishes to call from the PB dial 608 (step 528). Here, the area number is
area file 4 in the center file 706 in advance.
Have it sent to the fax machine from the file area corresponding to it, and look for it. Telephone number 412 of the member in area file 4 corresponding to this manually entered area number
is stored (Y in step S29), CP
U612 looks at area file 4 of RAM card 3 and finds the phone number 412 and member number 4 of the member with the corresponding area number.
11 and the member's name etc. 414 are output to the display 607 (step 530). The user confirms this and presses the connection button 609 (step 531). C.P.
After "calling connection" is made by the line control detection and sending unit 602, the U 612 causes the PB oscillator 603 to oscillate with the member's telephone number 412 to automatically dial the member's telephone number 412 (step 532).

When the "other party response" is detected via the line control detection and sending unit 602 (Y in step 833), the CPU 612 outputs a "connection complete" display to the display 607 (step 534). Users who saw this can use the mode switch 60
1 to the (T) side to use telephone 1 (step 535).

In the personal information system, when each member receives a magnetic card 2 from another member, each member registers the contents of the received magnetic card 2 in the file area corresponding to his or her area file 4 in the center file 706 of the center 7. There is a need. This is called MC center registration and is performed after the qualification confirmation mode described in (1).

Next, MC center registration will be explained with reference to FIG.

(8) After MC center registration "qualification confirmation", when the user passes the magnetic card 2 through the slit of the magnetic card reader 604 (step 536),
The CPU 612 uses the magnetic card reader 604 to read the membership number 211, telephone number 212, and expiration date 213 in the magnetic card 2 (step 537). Here, the read expiration date 213 is not after the current month (step 338
(N), the CPU 612 outputs "unavailable" to the display 607 and disconnects (step 5 in FIG. 7).
10). On the other hand, when the read expiration date 213 is after the current month (Y in step 838), the CPU 612 encrypts the data of the membership number 211 and telephone number 212 and sends it to the center 7. The CPU 704 of the center 7 receives this and decodes it (step 539). CPU70
4 is the member number 42 received in advance in the qualification confirmation mode.
The file area in the center file 706 that corresponds to number 1 is searched, and it is checked whether there is an empty area in that file area (step 540). When there is an empty area (N in step S41), the CPU 704 writes the member number 211 and telephone number 212 in the empty area, encrypts the area number, and sends it to the secure connection device 6 (step 5).
42). The CPU 612 of the secure connection device 6 receives and decrypts this, and stores the decrypted area number and membership number 211.
and display the telephone number 212 on the display 607 (
Step 843) and the RAM card reader/writer 6
Area file 4 of RAM card 3 set in 05
Member number 2 is added to the area corresponding to the decrypted area number.
11 and telephone number 212 are stored, and "End" is displayed on the display 607 (step 544). After confirming this, the user turns the mode switch 601 to the (T) side to disconnect (step 545), and ends the process. On the other hand, in step S40, when there is no empty area (step S40),
41, the CPU 704 encrypts "no area" and sends it to the secure connection device 6 (step 546).

The CPU 612 of the secure connection device 6 receives and decodes this, and displays the decrypted "no area" on the display 607.
(Step 547).

In this way, in this embodiment, data is encrypted and sent using time information as an encryption key, so a third party can monitor and record the signal on the line and check whether the signal is being used from a legitimate terminal. It becomes impossible to connect to the center.

That is, in this embodiment, since the encryption ta (decryption ta>) is constantly changing and the encryption (decryption) operation is unknown, even if the signal on the line is monitored, it cannot be decoded. Almost impossible.

Although time information is used as the encryption key (decryption m) in this embodiment, for example, random numbers, pseudorandom numbers, etc.
Information whose contents change from time to time may be used as the encryption a (decryption key). Furthermore, although this embodiment has been described with reference to the case where it is used in a personal information system, it goes without saying that it can also be used in other information transmission systems.

〔Effect of the invention〕

As explained above, according to the present invention, since information whose content changes from moment to moment, such as time information, is used as an encryption key, it is possible to prevent information leakage during the line and maintain confidentiality. This has the effect of providing a high quality information transmission system.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of a personal information system to which an information transmission system according to an embodiment of the present invention is applied, Fig. 2 is a diagram showing an example of a magnetic card used in this embodiment, and Fig. 3 4 is a diagram showing an example of the RAM card used in this embodiment, FIG. 4 is a diagram showing the configuration of the area file in the RAM card of FIG. 3, and FIG. 5 is an external view of the secure connection device of FIG. 1. 6 is a rear perspective view showing the external appearance of the secure connection device shown in FIG. 1, FIG. 7 is a flowchart for explaining the operation of the qualification confirmation mode of this embodiment, and FIG. FIG. 9 is a flowchart for explaining the operation of the RC update mode of the example, FIG. 9 is a flowchart for explaining the operation of the MC dial mode of this embodiment, and FIG. 10 is a flowchart for explaining the operation of the RC dial mode of this embodiment. FIG. 11 is a flowchart for explaining the operation of the MC center registration mode of this embodiment. 1...Telephone (or facsimile), 2...Magnetic card, 21...Magnetic recording band, 211...Register's member number, 212...Register's telephone number, 213...Expiration date, 3...RAM card, 311...Membership number, 313...Expiration date, 318...IC section terminal, 319...IC section, 4...Area file, 42
1...Representative member number, 423...Expiry date, 42
4...PIN number, 410...Area number, 412...
...Telephone number of the member belonging to the area, 413...Membership number of the member belonging to the area, 414...Name etc. of the member belonging to the area, 5...Public network exchange, 6...Secret connection device, 601...Mode switch, 602...
Line $IJ detection sending unit, 603...PB oscillator, 6
04... Magnetic card reader, 605... RAM card reader writer, 606... Clock circuit, 607...
Display, 608...PB dial, 609...
・Connection button, 610... Center telephone number memory, 6
11...Memory bus, 612...Central processing unit (C
PU), 613...Secret button, 614...Back cover, 615...Battery, 616...Power cord, 7.
...Center, 701...Line control detection sending unit, 702
...PB oscillator, 703... Clock circuit, 704...
・Central processing unit (CPU), 705... memory bus,
706... Center file, 20... Modular plug, 30... Modular jack, 40... PB
Format % Formula % 5 tails, 6 cranes, and 1800 cranes (MC Takun Yu)

Claims (1)

[Claims] 1. In an information transmission system in which a terminal and a center exchange data via a communication line, each of the terminal and the center transmits information whose contents change from moment to moment using an encryption key. An information transmission system characterized in that the data is encrypted and transmitted. 2. The information transmission system according to claim 1, wherein the information whose content changes from moment to moment is time information.