JP2001320362A - Communication terminal equipment and program recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically mange a ciphering system and a password key, in communication terminal equipment having data-ciphering function. SOLUTION: A reception log table 7a which is communication history including communication opposite side information and information on ciphering by each communication is stored in a RAM 7. A main control part 1 of a personal computer 20 decides the ciphering system and the password key, based on the communication history stored at the time of transmission (step S15 in a Figure 5) and ciphers data such as image data for an electronic mail and a facsimile (step S16). In the other embodiment, an address book table 7b storing information on ciphering for each communication opposite side is installed, and the main control part 1 updates the information on ciphering, which is stored based on the ciphering system used, whenever communication is terminated (step S6a in Figure 6).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal device such as a personal computer or a facsimile device having a data encryption function and a program recording medium for recording a program therefor.

[0002]

2. Description of the Related Art When e-mail or facsimile transmission is performed via the Internet, e-mail data and facsimile image data are often encrypted for security maintenance. When encrypting such data, it is necessary to use an encryption method and an encryption key corresponding to the other party so that the data can be decrypted by the communication terminal apparatus of the other party.

[0003]

However, in the prior art, since the user can arbitrarily select the encryption method and the encryption key, it is necessary to manage the encryption method and the encryption key for each destination. There was a problem that management became complicated.

An object of the present invention is to solve the above problems and provide a communication terminal device having a data encryption function capable of automatically managing an encryption method and an encryption key, and a program therefor. Another object of the present invention is to provide a recorded program recording medium.

[0005]

According to the present invention, there is provided a communication terminal device for storing a communication history including communication partner information and information relating to encryption for each communication, and storing the communication history stored at the time of transmission. And a control means for determining an encryption method and an encryption key based on the information.

[0006] Further, a communication terminal device according to the present invention comprises a storage means for storing information related to encryption for each communication partner,
Control means is provided for updating the stored information on encryption based on the encryption method used each time communication is completed.

Further, the program recording medium according to the present invention stores a communication history including communication partner information and information on encryption for each communication in a storage device, and based on the stored communication history at the time of transmission. And a step of determining an encryption method and an encryption key.

Still further, the program recording medium according to the present invention stores the information on encryption for each communication destination in a storage device, and stores the information based on the encryption method used each time communication ends. And updating the information related to encryption.

[0009]

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

<First Embodiment> FIG. 1 is a block diagram showing a configuration of a personal computer 20 having a data encryption function according to a first embodiment of the present invention. The personal computer 20 of this embodiment is a personal computer having a data encryption function. The RAM 7 stores a reception log table 7 as a communication history including communication partner information and information on encryption for each communication.
The main controller 1 determines an encryption method and an encryption key based on the communication history stored at the time of transmission (step S15 in FIG. 5), and transmits data such as e-mail and facsimile image data. (Step S1)
6) is characterized.

In FIG. 1, a personal computer 2
No. 0 has a function of transmitting and receiving a conventional e-mail, a function of facsimile communication such as the G3 system, and a function of encrypting data. The main control unit 1 is specifically composed of a CPU, is connected to the following hardware units via a bus 13, controls them, and executes various software functions to be described later. Image reading unit 2
Reads a document with a scanner using a CCD or the like, and outputs dot image data converted to black and white binary. The image recording unit 3 is a printer device of an electrophotographic system or the like, and receives character data (text data) of an e-mail received from a communication terminal device such as another personal computer, or receives the data by facsimile communication from another facsimile device or a personal computer. The printed image data is printed out as a hard copy and recorded. The display unit 4
A display device such as a liquid crystal display (LCD) or a CRT display, which displays the operation state of the personal computer 20, character data of an e-mail to be transmitted, image data of a document image, and characters of a received e-mail. Display data and received image data.

The operation unit 5 is composed of a keyboard including character keys, numeric keys, and various function keys necessary for operating the personal computer 20. The ROM 6 stores various software programs and data necessary for the operation of the personal computer 20 and executed by the main control unit 1 in advance.
The RAM 7 is composed of an SRAM, a flash memory, or the like, and is used as a working area of the main control unit 1 and stores temporary data generated when a program is executed. When a flash memory is used as the RAM 7, even if the power is cut off due to a power failure, a movement of the apparatus, or the like, the contents of the data are not lost.

The hard disk drive 8 is a storage device having a built-in recording medium, and stores in advance various software programs and data to be executed by the main control unit 1, and the programs include at least the reception processing shown in FIG.
5 includes the transmission processing program of FIG. These programs are stored in the CD-ROM 14a in advance,
The ROM 14a is inserted into the CD-ROM drive 14, the program stored therein is read, stored in the hard disk drive 8, and executed. The hard disk drive 8 stores e-mail data and image data to be transmitted and received, in addition to the above programs.

The fax modem 10 is connected to a public telephone line L
, And has a function of a normal fax modem for facsimile communication or a modem for data communication. The modem demodulates the data of the outgoing telephone number information received as the FSK signal and outputs it to the main control unit 1. An NCU (Network Control Unit) 11 is a hardware circuit that performs closing and opening operations such as a DC loop of an analog public telephone line L and has an automatic dial function. To the public telephone line L. Here, the NCU 11 detects the ID receiving terminal activation signal and the ordinary telephone call signal in the outgoing telephone number notification service and, if necessary, the primary response signal and the second response signal in the outgoing telephone number notification service.
A next response signal can be transmitted. Note that NCU11
May be connected to a baseband transmission type digital line (for example, an ISDN line) via a predetermined terminal adapter and a DSU (Digital Service Unit).

The LAN interface 12 connects the facsimile machine 20 to, for example, Ethernet (registered trademark).
And an interface circuit for performing signal conversion and protocol conversion of signals and data in order to connect to a local area network (hereinafter, referred to as LAN) 30 such as a LAN.
The LAN 30 has a mail server device 31 and a router device 32
Is connected. Further, the router device 32 is connected to a destination mail server device (not shown) via the Internet 40. When the facsimile device 20 transmits the image data by attaching the image data to the body of the mail, the image data is transmitted from the LAN interface 12 to the mail server device 31 via the LAN 30 once, and then the mail server device 31 transmits the e-mail on the Internet. LA
The packet is transmitted to the destination facsimile machine via the N30, the router device 32, the Internet 40, and the destination mail server device (not shown). On the other hand, when receiving an e-mail packet, the e-mail is received through the reverse route. The line connection to the Internet 40 is not limited to a dedicated line or the like, but may be a dial-up connection using the public telephone line L1.

The personal computer 20 of the present embodiment configured as described above has a data encryption function in addition to a normal electronic mail transmission / reception function and a facsimile communication function such as the G3 system. In the facsimile communication function, dot image data read by the image reading unit 2 is encoded by software in accordance with an encoding system such as MH, MR, MMR, etc. defined in the standard of the facsimile communication, and then the other personal computer is used. On the other hand, the coded data received from the other party's facsimile machine or personal computer is also decoded into image data by software and output from the image recording unit 3 as a hard copy. Further, when facsimile transmission is performed via the Internet 40, the image data after facsimile encoding is encrypted using a predetermined encryption method, the encrypted data is encoded in MIME format and inserted into the mail text. Send a packet.
On the other hand, when facsimile reception is performed via the Internet 40, processing reverse to these processings is executed.

FIG. 2 is a diagram showing an example of the reception log table 7a in the RAM 7 of FIG. As shown in FIG. 2, the reception log table 7a includes, for each reception communication, a reception start date and time, a communication time (for facsimile reception) or a data amount (for e-mail reception), A facsimile number or an e-mail address, the number of transmissions, an encryption method, and an encryption key are stored. In the example of the first line in FIG. 2, the encryption method is “none”, and the data is not encrypted.

FIG. 4 shows the personal computer 2 of FIG.
7 is a flowchart showing a reception process executed by a main control unit 1 of the first embodiment. In FIG. 4, first, in step S1
It is determined whether or not there is an incoming electronic mail or facsimile on the Internet. Here, when receiving an e-mail on the Internet or a facsimile via the Internet, for example, the mail server 31 connected to the LAN 30 is periodically accessed to check whether there is an incoming call. In step S1, if YES, the process proceeds to step S2, while if NO, the process returns to step S1. In step S2, the electronic mail data or the facsimile image data on the Internet is received and stored in the hard disk drive 8. In step S3, it is determined whether the received data is encrypted. If YES, the process proceeds to step S4, while if NO, the process proceeds to step S5. In step S4, the encrypted data is decrypted with a predetermined encryption method and an encryption key, and the decrypted data is stored in the hard disk drive 8. In step S5, after the Internet email arrival notification is output to the display unit 4 or the image of the facsimile image data is recorded using the image recording unit 3,
In step S6, a reception log is generated based on the reception content of the data and added to the reception log table 7a to update the reception log table 7a, and step S1 is executed.
Return to

FIG. 5 shows the personal computer 2 of FIG.
7 is a flowchart illustrating a transmission process executed by a main control unit 1 of the first embodiment. In FIG. 5, first, step S1
At 1, data of a transmission destination and Internet e-mail to be transmitted or facsimile image data (this image data is obtained by reading a document image in advance by using the image reading unit 2 and converting the image data into image data). It is specified by using the operation unit 5, and in step S12, the reception log table 7a is searched for the reception log of the other party, and it is determined in step S13 whether there is the reception log of the other party. Next, in step S14, whether to encrypt the data to be transmitted is determined based on the reception log table 7b. If YES, the process proceeds to step S15, while if NO, the process proceeds to step S17. Then, the encryption method and the encryption key are determined based on the latest reception log among the reception logs searched in step S15, and the data to be transmitted is encrypted using the encryption method and the encryption key determined in step S16. After the conversion, step S1
In step 7, the data to be transmitted is transmitted to the other party, and the transmission processing ends.

Although the encryption method and the encryption key are determined based on the latest reception log among the reception logs searched in step S15, the present invention is not limited to this. It may be configured to be displayed on the display unit 4 and made to be selected by the operator.

As described above, according to the present embodiment, the reception log table 7a which is the communication history including the communication partner information and the information on the encryption for each communication is stored in the RAM 7.
The main control unit 1 determines an encryption method and an encryption key based on the communication history stored at the time of transmission (step S15 in FIG. 5), and stores data such as e-mail and facsimile image data. Encrypt (step S16).
Therefore, the encryption method and the encryption key can be automatically managed and updated using the communication history of the reception log table 7a, and the encryption method and the encryption key are always determined based on the latest communication history. Therefore, it is possible to prevent the receiving side from being unable to decrypt the encryption due to an error in the encryption method or the encryption key.

<Second Embodiment> A personal computer 20 according to a second embodiment is a personal computer having a data encryption function, and has the same configuration as that of FIG. In RAM7, the first
Is provided with an address book table 7b for storing information relating to encryption for each communication partner in place of the reception log table 7a according to the embodiment, and the main control unit 1 is configured based on the encryption method used each time communication is completed. The stored encryption-related information is updated (step S6a in FIG. 6), and an encryption method and an encryption key are determined based on the stored address book table 7b at the time of transmission (step S15 in FIG. 7).
a) It is characterized by encrypting data such as e-mail and facsimile image data (step S16). Hereinafter, differences from the first embodiment will be described in detail.

FIG. 3 is a diagram showing an example of an address book table 7b in the RAM 7 provided in the personal computer 20 according to the second embodiment. As shown in FIG. 3, the address book table 7b includes, for each communication destination,
The name of the communication partner, the facsimile number or e-mail address of the partner, the encryption method, and the encryption key are stored. In the example of the second line in FIG. 3, the encryption method is “none”, and the data is not encrypted.

FIG. 6 is a flowchart showing a receiving process executed by the main controller 1 of the personal computer 20 according to the second embodiment. In FIG. 6, FIG.
The difference from the receiving process of the first embodiment is that the process of step S6a is executed instead of the process of step S6. Step S
At 6a, the data in the address book table 7b is updated based on the received content of the received data. In particular,
In the case of a new destination, the data of the destination is added, while in the case of a registered destination, the data of the destination information, the encryption method, and the encryption key are checked, and if there is a change,
Update to the latest data.

FIG. 7 is a flowchart showing a transmission process executed by the main controller 1 of the personal computer 20 according to the second embodiment. In FIG. 7, FIG.
Are different from the transmission processing of steps S12, S13, S13
Steps S12 and S15 instead of steps S12 and S15, respectively.
a, S13a, S14a and S15a are executed. In step S12a in FIG. 7, the reception log of the destination is searched with reference to the address book table 7b, and it is determined in step S13a whether there is data in the address book of the destination. Next, in step S14a, it is determined whether to encrypt the data to be transmitted based on the address book table 7b. If YES, the process proceeds to step S15a, whereas if NO, the process proceeds to step S17.
Proceed to. Then, the encryption method and the encryption key are determined based on the data of the address book searched in step S15a. Then, the processing of steps S16 and S17 is executed in the same manner as in the first embodiment.

The updating process of the address book table 7b in step S6a in FIG. 6 is not limited to the above-described process for each reception, and may be performed periodically at a predetermined cycle based on the reception log table 7a. Good.

As described above, according to the present embodiment, the RAM 7 is provided with the address book table 7b for storing information on encryption for each communication partner, and the main control unit 1
Updates the stored encryption-related information based on the encryption method used each time communication ends (step S6a in FIG. 6), and encrypts the information based on the stored address book table 7b at the time of transmission. A method and an encryption key are determined (step S15a in FIG. 7), and data such as e-mail and facsimile image data is encrypted (step S15).
16). Therefore, the encryption method and the encryption key can be automatically managed and updated using the address book table 7b, and the encryption method and the encryption key are always encrypted based on the address book table 7b including the latest information on the encryption of the other party. Since the method and the encryption key can be determined, it is possible to prevent the receiving side from being unable to decrypt the encryption due to an error in the encryption method or the encryption key.

<Modification> In the above embodiment, an example of the personal computer 20 has been described.
The present invention is not limited to this. For example, a facsimile device connected to a public network such as a public telephone network or a public digital line network, a facsimile server device connected to a LAN, a communication terminal device including a telephone, a data communication device, and the like. Can be applied.

In the above embodiment, FIGS.
Is stored in the CD-ROM 14a, but the present invention is not limited to this, and CD-R, CD-R
It may be stored on various types of recording media such as W, MO, and DVD.

[0030]

As described above in detail, according to the communication terminal apparatus of the present invention, a storage means for storing communication history including communication partner information and information on encryption for each communication, and the communication history stored at the time of transmission. Control means for determining an encryption method and an encryption key based on the communication history. Therefore, the encryption method and encryption key can be automatically managed and updated using the communication history, and the encryption method and encryption key can always be determined based on the latest communication history. It is possible to prevent the receiving side from being able to decrypt the encryption due to an error in the encryption method or encryption key.

Further, according to the communication terminal device of the present invention, the storage means for storing information related to encryption for each communication partner, and the storage means for storing the information based on the encryption method used each time the communication ends. Control means for updating information on encryption is provided. Therefore, the encryption method and the encryption key can be automatically managed and updated using the information on the encryption of the other party, and the encryption method and the encryption key can be always updated based on the latest information on the encryption of the other party. Since the key can be determined, it is possible to prevent the receiving side from being unable to decrypt the encryption due to an incorrect encryption method or encryption key.

Further, according to the program recording medium of the present invention, a step of storing a communication history including communication partner information and information on encryption for each communication in a storage device;
Determining an encryption method and an encryption key based on the stored communication history at the time of transmission. Therefore, the encryption method and encryption key can be automatically managed and updated using the communication history, and the encryption method and encryption key can always be determined based on the latest communication history. It is possible to prevent the receiving side from being able to decrypt the encryption due to an error in the encryption method or encryption key.

Further, according to the program recording medium of the present invention, the step of storing information related to encryption for each communication destination in the storage device, and the above-described method based on the encryption method used each time communication is completed. Updating the stored information related to encryption. Therefore, the encryption method and the encryption key can be automatically managed and updated using the information on the encryption of the other party, and the encryption method and the encryption key can be always updated based on the latest information on the encryption of the other party. Since the key can be determined,
It is possible to prevent the receiving side from decrypting the encryption due to an error in the encryption method or the encryption key.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a personal computer 20 having a data encryption function according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a reception log table 7a in a RAM 7 of FIG.

FIG. 3 is an address book table 7 in a RAM 7 provided in a personal computer 20 according to the second embodiment.
It is a figure showing an example of b.

FIG. 4 is a flowchart showing a receiving process executed by main controller 1 of personal computer 20 in FIG.

FIG. 5 is a flowchart showing a transmission process executed by main controller 1 of personal computer 20 in FIG.

FIG. 6 is a flowchart illustrating a reception process executed by a main control unit 1 of the personal computer 20 according to the second embodiment.

FIG. 7 is a flowchart illustrating a transmission process executed by a main control unit 1 of the personal computer 20 according to the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main control part, 6 ... ROM, 7 ... RAM, 7a ... Reception log table, 7b ... Address book table, 8 ... Hard disk drive, 10 ... Fax modem, 11 ... NCU, 12 ... LAN interface, 13 ... Bus, 14 ... CD-ROM drive device, 14a ... CD-ROM, 20 ... personal computer, 30 ... LAN, 31 ... mail server device, 32 ... router device, 40 ... internet, L ... public telephone line.

Claims (4)

[Claims] 1. A storage unit for storing communication history including communication partner information and information on encryption for each communication, and control for determining an encryption method and an encryption key at the time of transmission based on the stored communication history. A communication terminal device comprising means. 2. A storage means for storing information on encryption for each communication partner, and a control means for updating the stored information on encryption based on the encryption method used each time communication is completed. A communication terminal device. 3. A step of storing a communication history including communication partner information and information on encryption for each communication in a storage device, and determining an encryption method and an encryption key at the time of transmission based on the stored communication history. And a program recording medium having recorded thereon a program including the steps of: 4. A step of storing information related to encryption for each communication partner in a storage device, and a step of updating the stored information related to encryption based on an encryption method used each time communication is completed. A program recording medium characterized by recording a program including: