JPH11150554A - Data communication device, data communication method, and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an unnecessary operation and to maintain security by storing whether or not ciphering is executed for respective transmitted data, controlling the ciphering of data based on the stored propriety of ciphering and transmitting data which is ciphered or not ciphered. SOLUTION: A data storage part 17 is provided with a storage medium recording the transmission destination of an electronic mail and the telephone number and the address of a transmission source and storing them with information indicating whether security maintaining is required or not in data communication between the respective destinations and the transmission source. The storage area of the electronic mail, which is provided in the storage medium, is divided into a secret box and a regular mail box. In the transmission/ reception processing of the electronic mail to an opposite party whose security is to be maintained, the destination and the presence or absence of the necessity of security are previously mentioned in address data and they are security- registered. Thus, the electronic mail is automatically ciphered in transmitting it and it is accumulated in the secret box upon reception.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a data communication device, a data communication method, and a storage medium for performing data communication such as electronic mail.

[0002]

2. Description of the Related Art In recent years, with the spread of computer networks, data communication such as e-mail has been widely performed.

In general, data communication is often performed via a public line or wireless communication means, and is not necessarily a secure environment in terms of confidentiality. For this reason, various means have been developed for confidentiality.

[0004] For example, conventionally used e-mail transmission / reception software includes software for encrypting and transmitting an e-mail to be transmitted. A user who receives the e-mail transmitted by the software decrypts the e-mail and then browses the e-mail. Also, decide on a common password with the sending user beforehand,
Software has been used in which an e-mail can be decrypted by inputting this password, and software in which an e-mail cannot be viewed without inputting a password.

[0005]

However, if confidentiality is maintained by the above-described method, it is impossible to distinguish between an e-mail that does not need to be encrypted and an e-mail to be encrypted. There is a problem that a password must be entered when sending or reading an e-mail that does not need to be converted. For this reason, there has been a problem that the operation becomes very complicated.

The present invention has been made to solve the above problems,
In data communication, usually without performing encryption, by performing data encryption only when confidentiality is required, unnecessary operations can be reduced, and a data communication device capable of maintaining confidentiality; A data communication method and a storage medium are provided.

[0007]

According to a first aspect of the present invention, there is provided a data communication apparatus connected via communication means for transmitting data to another communication device. Encryption instruction data storage means for storing whether or not to encrypt the data; encryption means for controlling the encryption of the data based on the validity of the encryption stored in the encryption instruction data storage means; Transmitting means for transmitting encrypted or non-encrypted data under the control of the encrypting means.

According to the data communication apparatus of the present invention, the data is transmitted by the encryption instruction data storage means in the data communication apparatus which is connected via the communication means and transmits data to another communication device. Whether or not to encrypt for each data is stored, the encryption means controls the data encryption based on whether the encryption stored in the encryption instruction data storage means is correct, and the transmission means controls the encryption of the encryption means. Transmits encrypted or non-encrypted data under control.

Thus, by designating data to be encrypted by the encryption instruction data storage means in advance, it is not necessary to instruct data encryption every time data is transmitted, thereby reducing the number of operations by the operator. Is possible, and the secret can be securely maintained.

Here, the communication means may be, for example, a communication line such as a public line network, an independent dedicated line, or mediating data communication regardless of wired or wireless. Whatever is possible is possible.

According to a second aspect of the present invention, in the data communication apparatus according to the first aspect, the encryption instruction data storage means determines whether or not to encrypt the data to be transmitted for each destination of the data to be transmitted. Is stored.

According to the data communication device of the present invention, in the data communication device of the first aspect, the encryption instruction data storage means encrypts the data to be transmitted for each destination of the data to be transmitted. The encrypted data indicating whether or not to perform the encryption is stored.

Therefore, for example, by setting beforehand whether to transmit encrypted data or normal data to each destination described in a database having an address book function, Is transmitted as usual, the data is automatically encrypted when the data is transmitted to the other party who needs to keep the information confidential.

According to a third aspect of the present invention, in the data communication device according to the first aspect, the encryption instruction data storage unit stores a keyword for encrypting the data, and the encryption unit stores the keyword. When the data includes the keyword stored in the encryption instruction data storage means, the data is encrypted.

According to the data communication apparatus of the present invention, in the data communication apparatus of the first aspect, the encryption instruction data storage means stores a keyword for encrypting data, and the encryption means If the data includes the keyword stored in the encryption instruction data storage means, the data is encrypted.

[0016] Thus, data including a preset keyword is encrypted. Therefore, when it is desired to encrypt all data related to a specific theme, it is not necessary to set encryption for each data. Also, encryption can be performed by setting the theme as a keyword. Then, mistakes such as omission of setting can be reduced as compared with a case where setting is individually performed for each data.

According to a fourth aspect of the present invention, in the data communication device of the third aspect, the transmitting means transmits a keyword together with the encrypted or non-encrypted data.

According to the data communication apparatus of the present invention, the transmitting means transmits the keyword together with the encrypted or non-encrypted data.

Thus, when data is transmitted in the data communication apparatus according to the third aspect, for example, a keyword is attached to the data body in a format such as an e-mail title, and the data body is referred to. It is possible to easily recognize the keyword without performing, and the convenience can be further improved.

According to a fifth aspect of the present invention, in the data communication apparatus according to the second, third or fourth aspect, the encryption instruction data storage means includes a different encryption instruction data for each of the stored encryption instruction data or each keyword. Encryption key or a different encryption method, wherein the encryption means performs encryption based on the encryption key or the encryption method stored in the encryption instruction data storage means. .

According to the data communication device of the present invention, in the data communication device of the second, third or fourth aspect, the encryption instruction data storage means stores the encrypted instruction data for each of the stored encryption instruction data or A different encryption key or a different encryption method is stored for each keyword, and the encryption means performs encryption based on the encryption key or the encryption method stored in the encryption instruction data storage means.

Therefore, since the encryption key or the encryption method is different for the encryption instruction data or the data having different keywords, the encryption key or the encryption method applied to other data should be easily diverted. This makes it more difficult to keep secrets.

According to a sixth aspect of the present invention, there is provided a data communication apparatus which is connected via communication means and receives data from another communication device, wherein said encrypted data is stored for each of said received data. Data storage means; decryption instruction data storage means for storing decryption instruction data for instructing decryption of the data based on whether the encryption stored in the encrypted data storage means is correct; and storage of the decryption instruction data A decoding means for controlling decoding based on the means, and a display means for displaying data decoded or non-decoded under the control of the decoding means.

According to the data communication device of the present invention, in the data communication device connected via the communication means and receiving data from another communication device, the data communication device uses the encrypted data storage means for each data to be received. Whether the data is encrypted data, the decryption instruction data storage means stores decryption instruction data for instructing the decryption of the data based on whether the encryption stored in the encrypted data storage means is correct,
The decoding means controls the decoding based on the decoding instruction data stored in the decoding instruction data storage means, and the display means displays the data decoded or non-decoded by the control of the decoding means. .

Thus, it is possible to set in advance whether or not the data received by the data communication device is encrypted, so that the encrypted data can be received and the data can be decrypted. . Therefore,
It is not necessary to set the decryption every time the data is received and browsed, and the number of operations by the operator can be reduced.

According to a seventh aspect of the present invention, in the data communication apparatus according to the sixth aspect, the decoding instruction data means includes:
Decoding instruction data for instructing whether or not to decode data is stored for each transmission source of received data.

According to the data communication device of the present invention, in the data communication device of the present invention, the decoding instruction data storage means decodes the data for each transmission source of the data to be received. The decoding instruction data indicating whether or not the data is stored.

[0028] Thus, by registering in advance the destination of data to be kept secret, the data can be easily decrypted, and the secret can be kept with a small amount of labor.

According to an eighth aspect of the present invention, in the data communication apparatus according to the sixth aspect, the decoding instruction data storing means stores a keyword for decoding the data, and the decoding means stores the keyword for decoding the data. The data is decrypted based on the keyword stored in the decryption instruction data storage means.

According to the data communication apparatus of the present invention, in the data communication apparatus of the sixth aspect, the decoding instruction data storage means stores a keyword for decoding data, and the decoding means Decrypts the data based on the keyword stored in the decryption instruction data storage means.

According to a ninth aspect of the present invention, in the data communication apparatus according to the eighth aspect, the decoding means decodes the data when a keyword is stored in the decoding instruction data storage means. The configuration is characterized as follows.

According to the data communication device of the ninth aspect, the decoding means decodes the data when the keyword is stored in the decoding instruction data storage means.

Therefore, according to the data communication apparatus of the present invention, it is possible to set whether or not the received data is the encrypted data by using a keyword, for example, to specify data relating to a specific theme. It is possible to perform setting without mistake such as omission of setting by a simple operation as compared with the case of setting for each data. Further, the invention according to claim 8 is configured to perform decoding by detecting that a keyword is stored in the decoding instruction data storage means, as in the data communication device according to claim 9. Thereby, it can be realized more easily.

According to a tenth aspect of the present invention, in the data communication apparatus according to the eighth aspect, a keyword is received together with the encrypted or non-encrypted data, and the decrypting means determines that the received keyword is the decrypted keyword. When the instruction data is stored in the instruction data storage means, the data is decrypted.

According to the data communication apparatus of the present invention, in the data communication apparatus of the present invention,
The keyword is received together with the encrypted or non-encrypted data, and the decryption unit decrypts the data when the received keyword is stored in the decryption instruction data storage unit.

Therefore, by referring to the keyword transmitted together with the data body, the effect obtained by the invention according to claim 8 can be more easily obtained.

[0037] The invention according to claim 11 is the invention according to claims 6, 7,
11. The data communication device according to 8, 9, or 10, wherein the decryption instruction data storage unit stores a different decryption key or a different decryption method for each of the stored decryption instruction data or each keyword, and The decrypting means performs decryption based on a decryption key or a decryption method stored in the decryption instruction data storage means.

According to the data communication apparatus of the present invention, in the data communication apparatus of the sixth, seventh, eighth, ninth or tenth aspect, the decoding instruction data storage means stores the stored decoding instruction data. Stores a different decryption key or a different decryption method for each data or keyword,
The decryption unit performs decryption based on the decryption key or the decryption method stored in the decryption instruction data storage unit.

Therefore, since the decryption key or the decryption method is different for the decryption instruction data or the data having different keywords, it is difficult to use the decryption key or the decryption method applied to other data. And
The confidentiality can be maintained more reliably.

According to a twelfth aspect of the present invention, in a data communication method using a data communication device for performing data communication with an external communication device connected via communication means, data can be transmitted and received. An external communication device is stored as a transmission / reception destination, and each of these transmission / reception destinations stores secret designation data for designating whether or not the data communication with the transmission / reception destination is a secret communication destination to be kept secret. When transmitting data to the transmission / reception destination designated as the secret communication destination by the designated data, the data is encrypted and transmitted, and transmitted from the transmission / reception destination designated as the secret communication destination by the secret designation data. When the received data is received, the data is stored as secret data, and transmitted from the transmission / reception destination that is not designated as a secret communication destination by the secret designation data. Upon receiving the over data it is characterized in that, for storing the data as normal data.

According to the data communication method of the twelfth aspect of the present invention, in the data communication method using a data communication device for performing data communication with an external communication device connected via communication means, An external communication device capable of transmitting / receiving data is stored as a transmission / reception destination, and each of these transmission / reception destinations is a secret specification for specifying whether or not a data communication with the transmission / reception destination should be a secret communication destination to be kept secret. When the data is stored and the data is transmitted to the transmission / reception destination designated as the secret communication destination by the secret designation data, the data is encrypted and transmitted, and the data is designated as the secret communication destination by the secret designation data. When receiving data transmitted from a transmission / reception destination, the data is stored as secret data, and transmitted from a transmission / reception destination not specified as a secret communication destination by the secret designation data. Data upon receiving the stores the data as normal data.

Therefore, for example, by setting in advance whether to transmit the encrypted data or the normal data to each destination stored in the database having the address book function, the transmission is performed. Even if data is created and transmitted as usual, the data is automatically encrypted for the data that needs to be kept secret. Accordingly, it is not necessary to set data encryption or the like every time data communication is performed each time, so that it is possible to reduce the number of operations performed by an operator and further securely maintain secret.

When data transmitted from a transmission source designated in advance is received, it is automatically determined that the data is data to be kept secret and stored in a dedicated storage means. Thus, after receiving the data that needs to be kept secret, it is possible to prevent the data from being erroneously stored in the storage device that can be freely viewed, so that the secret can be reliably held.
Further, since a storage unit for storing ordinary data is provided, the trouble of browsing data that does not need to be kept confidential is not increased.

According to a thirteenth aspect of the present invention, there is provided a data communication method using a data communication device for performing data communication with an external communication device connected via communication means. When detecting whether or not the content of data transmitted and received by the data communication device includes the key information stored in the key information storage means, and transmitting the data by the data communication device. In the case where the key information is detected in the content of the data, the data is encrypted and transmitted, and when the data communication device receives the data, the key information is detected in the content of the data. If the key information is not detected in the content of the data when the data communication device receives the data, the data is stored as secret data. Storing the data as normal data, it is characterized in.

According to the data communication method of the thirteenth aspect of the present invention, in the data communication method using a data communication device for performing data communication with an external communication device connected via communication means, And detects whether the content of data transmitted and received by the data communication device includes the key information stored in the key information storage means, and transmits the data by the data communication device. When the key information is detected in the content of the data, the data is encrypted and transmitted, and when the data communication device receives the data, the key information is detected in the content of the data. In this case, the data is stored as confidential data, and when the data communication device receives the data, if the key information is not detected in the content of the data, the data is regarded as normal data. To 憶.

Therefore, since the data containing the key information set in advance is transmitted after being encrypted at the time of transmission, it is possible to encrypt only the data relating to a specific theme and keep the secret. it can. For example, data relating to "interest" usually includes many words "interest".
Therefore, if "interest rate" is set as key information, "interest rate"
All data is encrypted and confidential, and the number of operations reduces the work efficiency compared to encrypting each piece of data. Mistakes such as mistakes can be reduced.

When data containing key information set in advance is received, the data is stored in a dedicated storage device different from ordinary data. It cannot be viewed with other data, and can be kept secret. As a result, the data to be kept confidential can be surely kept without being made erroneously accessible by anyone. Further, since a storage unit for storing ordinary data is separately provided, the number of operations for browsing data that does not need to be kept secret does not increase.

According to a fourteenth aspect of the present invention, there is provided a storage medium storing a computer-readable program for performing data communication with an external communication device connected via communication means, wherein the data is stored in a storage medium. A program code for transmission, a destination for another data communication device capable of transmitting data, and a secret for designating whether or not a secret communication destination for which data communication with the destination should be kept secret. A program code for storing designated data, and a program code for encrypting and transmitting the data when transmitting data to the destination designated as a secret communication destination by the secret designated data. , Are stored.

According to the storage medium of the present invention, a storage medium storing a computer readable program for performing data communication with an external communication device connected via communication means. And a program code for transmitting data, another data communication device that is a destination capable of transmitting data, and a secret communication destination for confidentializing data communication between these destinations. And a program code for storing secret designation data for designating whether or not the data is to be transmitted, and when transmitting the data to a destination designated as a secret communication destination by the secret designation data, the data is encrypted and transmitted. And a program code for performing the program.

Therefore, by setting in advance whether each of the encrypted data or the normal data is transmitted to each destination stored in a database having an address book function, for example, Even if the data to be transmitted is created and transmitted as usual, the data is automatically encrypted for the data that needs to be kept secret. Accordingly, it is not necessary to set data encryption or the like every time data communication is performed each time, so that it is possible to reduce the number of operations performed by an operator and further securely maintain secret.

According to a fifteenth aspect of the present invention, there is provided a storage medium storing a computer-readable program for performing data communication with an external communication device connected via communication means, wherein the data is stored in a storage medium. A program code for transmitting and receiving, a program code for storing arbitrarily set key information, and whether or not the content of data to be transmitted and received includes the key information stored in the key information storage unit. Program code for detecting
When the key information is detected in the title of the data when the data is transmitted or received by the transmitting / receiving means, the data is encrypted and transmitted or the data is encrypted and stored. And a program code of

According to the storage medium of the present invention, a computer-readable program for performing data communication with an external communication device connected via communication means is stored. A medium,
A program code for transmitting and receiving data, a program code for storing arbitrarily set key information, and whether or not the content of the data to be transmitted and received includes the key information stored in the key information storage means. If key information is detected in the contents of the data when the data is transmitted or received by the transmission / reception means, and the program code for detecting the And a program code for encrypting and storing data.

Therefore, since the data containing the key information set in advance is transmitted after being encrypted, it is possible to encrypt only the data relating to the specific theme and keep the secret. In addition, work efficiency can be improved by reducing the number of operations, and errors such as erroneous transmission without encryption can be reduced. Further, since the data can be encrypted and stored, the data to be kept confidential can be kept confidential without being accidentally made available to anyone.

According to a sixteenth aspect of the present invention, in the storage medium of the fifteenth aspect, when the encrypted data is received, it is stored as secret data, and when the unencrypted data is received, it is stored as normal data. The program code is further stored.

According to the storage medium of the present invention, when the encrypted data is received, it is stored as confidential data, and when the unencrypted data is received, it is normally stored. Stores a program code to be stored as data.

Therefore, when data that needs to be kept confidential is received, the data is stored in a dedicated storage device different from ordinary data, so that it can be browsed together with other data. Can be kept secret. As a result, the data to be kept confidential can be surely kept without being made erroneously accessible by anyone. Further, since a storage unit for storing ordinary data is separately provided, the number of operations for browsing data that does not need to be kept secret does not increase.

[0057]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to FIGS.

(First Embodiment) First, the first embodiment of the present invention will be described.
The configuration of the data communication system 1 as the embodiment will be described.

FIG. 1 is a diagram schematically showing the configuration of the data communication system 1. FIG. 2 shows the data communication device 10 of FIG.
FIG. 2 is a block diagram showing an internal configuration of the device. FIG. 3 is a schematic diagram showing a configuration of address data stored in the data storage unit 17 of FIG. FIG. 4 is a flowchart showing an e-mail transmission process by the data communication device 10 of FIG.
FIG. 5 is a flowchart showing an e-mail receiving process by the data communication device 10 of FIG. FIG. 6 is a flowchart showing an e-mail decryption process by the data communication device 10 of the data communication system 1 of FIG.

As shown in these figures, a data communication system 1 includes a communication network 2, a mail server 3, an indoor converter 4, a base station 5, a mobile phone 6, and data communication devices 7, 1.
0, etc., and can perform data communication between each of the data communication devices 7, 10 and the mail server 3. In addition to the data communication devices 7 and 10, a large number of other communication terminal devices can be connected to the communication network 2, but they are not shown here.

The communication network 2 is an integrated service digital network (ISDN) capable of transmitting digitalized data.
vices Digital Network) line, PSTN (Public Swi)
It may be a public line such as a Tched Telephone Network) line or an independently constructed dedicated line network. A base station 5 and an indoor converter 4 are connected to this communication line network 2.

The base station 5 can transmit and receive data to and from a plurality of portable telephones 6 by wireless communication, and the data communication device 7 includes the portable telephone 6 and the base station 5.
Is connected to the communication line network 2 via the.

On the other hand, the data communication device 10 is connected to the communication network 2 via the indoor exchange 4 and exchanges data with the mail server 3 and the data communication device 7 which are also connected to the communication network 2. Communication is possible.

The mail server 3 has therein a storage area called a mailbox corresponding to each of the data communication devices 7 and 10, and data contained in each mailbox is transmitted by the corresponding data communication device 7 and 10. Can be viewed when connected.

All the e-mails transmitted from the data communication devices 7 and 10 are received by the mail server 3 and stored in a mailbox corresponding to the destination of the e-mail. Further, an e-mail reception signal indicating that the e-mail has arrived is transmitted to the data communication devices 7 and 10, which are the destinations of the e-mail. Therefore, the e-mail transmitted from the data communication devices 7 and 10 is transmitted to the desired destination via the mail server 3 and received.

Here, of the e-mails transmitted by the data communication devices 7 and 10, all the e-mails to be kept confidential are transmitted after being subjected to an encryption process. It is necessary to check a password determined between the data communication devices 7 and 10 in advance.

Next, the configuration of the data communication devices 7 and 10 will be described using the data communication device 10 as an example.

As shown in FIG. 2, the data communication device 10 includes a CPU 11, a display unit 12, an input unit 13, and a voice input / output unit 1.
4, a program storage unit 15, a RAM 16, a data storage unit 17, an RTC 18, a communication unit 19, and a bus 20. Each unit is connected to the bus 20.

CPU (Central Processing Unit) 11
Reads the program stored in the program storage unit 15, expands and executes the program in a memory area provided in the RAM 16, reads various data from the data storage unit 17, and executes the mail server 3 via the communication unit 19. And an e-mail transmission process for the e-mail transmitted from the mail server 3 is executed. Further, according to a program read from the program storage unit 15 and an instruction input from the input unit 13 or the voice input / output unit 14, data encryption and data decryption processing are executed.

Further, in the e-mail transmission / reception processing executed with the mail server 3, the CPU 11 generates display information for displaying the contents of the e-mail, outputs the display information to the display unit 12, and outputs the display information from the RTC 18. An e-mail transmission / reception time is displayed on the display unit 12 based on a signal indicating the input time. Further, according to the user's request input in advance, the contents to be output to the display unit 12 are simultaneously output to the audio input / output unit 14 as audio.

When an e-mail reception signal from the mail server 3 is received by the communication unit 19, the communication unit 19 connects to the mail server 3, reads an e-mail stored in a mailbox in the mail server 3, and reads the e-mail. Execute mail reception processing.

In the transmission / reception processing of the electronic mail, the destination or the source of the electronic mail is stored in the data
7, described in address data stored later,
Further, it is determined whether or not the secret is registered. If the secret is registered, a program for encrypting and decrypting the e-mail and verifying the password at the time of browsing is stored in the program storage unit 15. Read from and execute.

The display section 12 is a CRT (Cathode Ray Tub).
e), an LCD (Liquid Crystal Display), etc., and displays the destination of the e-mail input by the input unit 12 and the contents of the e-mail transmitted from the CPU 11 to the mail server 3 from the CPU 11. Display on the display screen based on the information.

The input unit 13 is composed of a keyboard having cursor keys, numeric input keys, and various function keys, and is used to press a key pressed to input data such as a destination telephone number or an e-mail address. Signal to CPU
11 is output. Further, a pointing device such as a mouse may be provided as necessary.

The voice input / output unit 14 includes a voice input device such as a microphone and a speaker, and a voice output device, and is set by the user as desired, so that the display unit 12 The displayed destination address and the content of the received e-mail are output by voice. In addition, it is possible to output data or the like input by voice to the CPU 11 and insert a voice message into e-mail, for example.

The program storage section 15 has a storage medium in which various programs are stored.
It is composed of an optical recording medium or a semiconductor memory. This storage medium is fixedly provided in the program storage device 15 or is detachably mounted.
The storage medium stores a program for causing the CPU 11 to execute processing such as e-mail reception processing, management of stored e-mails, and e-mail encryption and decryption processing.

The program stored in the storage medium of the program storage unit 15 may be received and stored from another device connected via a communication line or the like. It is also possible to provide a storage device provided with the above storage medium on another device side connected via the like, and to use a program stored in this storage medium via a communication line.

The RAM (Random Access Memory) 16
A memory area for temporarily storing various programs processed by the CPU and data related to the processing is formed.

The data storage unit 17 stores the data communication device 10
The destination to which the e-mail is transmitted and the telephone number and address of the source from which the e-mail is transmitted to the data communication device 10 are recorded as address data. A storage medium is provided for storing together with information indicating whether it is necessary or not. The storage medium is provided with a storage area for storing received e-mails and e-mails created by the user. The data storage unit 17 outputs each data to the CPU 11 in accordance with a read signal input from the CPU 11.

The storage area of the electronic mail provided in the storage medium of the data storage section 17 is divided into a secret box and a normal mailbox.

Here, the secret box is a storage area for storing secret registration data to which means for confidentiality described later is applied. In order to browse the stored data contents, processing such as input of a password is performed. is necessary. On the other hand, the normal mailbox is a storage area for storing a normal electronic mail, and the stored data can be easily browsed.

An RTC (Real Time Clock) 18 measures time with reference to a crystal oscillator or the like provided therein.
The information indicating the date and time is output to the CPU 11.

The communication section 19 is connected to the communication line network 2,
It is composed of a modulation circuit, a demodulation circuit, a transmission / reception mixer, etc., executes transmission / reception of e-mail via the communication network 2 in accordance with an instruction input from the CPU 11, and transmits from the mail server 3 via the communication network 2. When an e-mail reception signal transmitted by the e-mail is received, the e-mail reception signal is output to the CPU 11, and when reading of the e-mail is instructed from the CPU 11, the e-mail is connected to the mail server 3 and the e-mail is received. The contents of the mail are output to the CPU 11.

FIG. 3 shows the structure of the address data stored in the data storage unit 17 of FIG. In this address data, an e-mail address corresponding to each destination and the name of the destination are described. For example, the address described in the column D1 in FIG. 3 is a mail address of a person “Hiroshi Sato”.

Further, the status of the flag is described for each mail address. This flag specifies the presence or absence of secret registration that specifies the confidentiality of the communication contents when performing data communication with each destination. When this flag is set to “ON” In, the destination is secretly registered, data exchanged with this destination is treated as secret registration data, and a process for maintaining confidentiality such as an email encryption process described later is applied. On the other hand, the flag is “OFF”
In this case, it indicates that the destination is not registered as a secret, and normal e-mail transmission / reception is performed with the destination.

For example, the address described in D1 of FIG. 3 is a personal address "Hiroshi Sato". The data sent to this address is private,
In order to prevent data from leaking to others, the flag is set to "ON" and this address is registered as a secret. On the other hand, the address described in D3 of FIG. 3 is a mail address of “Edo University”. Many of the data exchanged with universities are of a public nature, and are not secretly registered because it is not necessary to keep all data secret.

Next, the operation of the data communication device 10 will be described.

FIG. 4 is a flowchart showing an encryption process at the time of transmitting an electronic mail. When transmitting data, first, in step S1, it is checked whether or not the destination of the e-mail to be transmitted is secretly registered by referring to the address data shown in FIG.
Move to

In step S2, the flag is set to "ON"
If it is determined that the e-mail is secret registration data, the process proceeds to step S3, where the content of the e-mail is encrypted, and the process proceeds to step S4.
If it is determined in step S2 that the data is not secret registration data, the process proceeds to step S4.

In step S4, the electronic mail is transmitted to the communication unit 1
9 to the mail server 3 and the e-mail transmission processing ends.

Next, according to FIG.
A series of processes related to the reception of an e-mail will be described.

At step S11, the electronic mail receiving signal transmitted from the mail server 3 is received, and the electronic mail is read from the mailbox in the mail server 3 and received. Subsequently, in step S12, the transmission source that transmitted the received e-mail is confirmed, and the data storage unit 17
Then, the process proceeds to step S13.

In step S13, it is determined whether the sender of the received electronic mail is registered as a secret or not. If it is determined in step S13 that the data is secret registration data, the process proceeds to step S14, where the received e-mail is stored in the secret box, and the process ends.

If it is determined in step S13 that the sender of the e-mail has not been described in the address data of the data storage unit 17 or has not been registered as a secret, the process proceeds to step S15. Then, the received e-mail is stored in the normal mailbox. When the accumulation of the received e-mail is completed, the e-mail reception processing is ended.

The e-mail received as described above and usually stored in the mailbox can be easily viewed.
In order to view the e-mail stored in the secret box, the processing shown in FIG. 6 is necessary.

In step S21, an e-mail to be viewed is specified from among the e-mails stored in the secret box, and the flow advances to step S22. In step S22, a password is input, and in step S23, a password inquiry is performed.

The electronic mail stored in the secret box is an electronic mail that needs to be kept confidential, and its contents are encrypted. For this reason, the content cannot be understood even if the user browses the content as it is. Thus, decryption is attempted, but at the time of decryption, it is necessary to input a password determined in advance with the transmission source.

In step S23, it is determined whether or not the password input in step S22 matches the password set in advance with the transmission partner. Display an error message and end the process.

If the passwords match in step S23, the process proceeds to step S24. In step S24, the designated e-mail is decrypted, and the process proceeds to step S25, where the e-mail is displayed on the display unit 12, and the process ends.

As described above, according to the first embodiment, in the transmission / reception processing of an e-mail with respect to a party who needs to keep secret, the destination and the necessity of keeping secret are described in the address data in advance. By registering the secret, the e-mail is automatically encrypted when the e-mail is transmitted, and is stored in the secret box when the e-mail is received. The e-mail stored in the secret box is encrypted and can be viewed by inputting a correct password. Therefore, the e-mail stored in the secret box is used when another person uses the data communication apparatus 10. However, it is possible to easily keep secrets. In addition, transmission and reception of an e-mail with a destination that is not registered as a secret are performed as usual, so that confidentiality protection processing is not performed more than necessary, and no complicated processing is forced.

Note that, in the first embodiment,
Although the e-mail transmitted from the secret registered destination is assumed to be encrypted, it is of course possible to store the unencrypted e-mail in the secret box. In this case, a password for browsing the secret box may be set in order to keep the secret, and the e-mail in the secret box may be browsed by checking the password. Further, the password for decrypting the e-mail in the secret box has been determined in advance with the sender, but may be determined between the mail server 3 and the data communication device 10.

(Second Embodiment) Next, a second embodiment of the present invention will be described.
A data communication system as an embodiment will be described. Since the configuration of the data communication system according to the second embodiment is common to the data communication system 1 according to the first embodiment, a flowchart showing the operation is shown in FIG. And description is omitted.

The data communication device 10 in the data communication system 1 stores a password for decrypting an e-mail, which is determined between each destination, in the address data stored in the data storage unit 17. By reading this password, the CPU 11 inputs the password and decrypts the encrypted e-mail.

FIG. 7 is a flowchart showing a series of processes relating to the reception of an electronic mail.

At step S31, the communication section 19 receives the e-mail reception signal transmitted from the mail server 3, connects to the mail server 3, reads the e-mail, and receives it.

Subsequently, in step S32, the sender of the e-mail is confirmed, the address is compared with the address data in the data storage unit 17, and the process proceeds to step S33. In step S33, it is determined whether the sender of the received e-mail is registered as a secret or not.

If it is determined in step S33 that the sender of the electronic mail has not been described in the address data of the data storage unit 17 or has not been registered as a secret, the process proceeds to step S38. The received e-mail is stored in the normal mailbox, and the process ends.

If it is determined in step S33 that the source of the received e-mail has been registered as a secret, the process proceeds to step S34.

In step S34, the password corresponding to the transmission source of the electronic mail is read from the address data in the data storage unit 17, and the password is verified. That is, if the password described in the address data is incorrect, the decryption processing is rejected even if the decryption processing is performed, and the decryption fails.

If the passwords do not match and the decryption fails in step S35, the flow shifts to step S37 to store the e-mail in the secret box without performing the decryption and terminate the processing.

If the passwords match in step S35, the flow shifts to step S36 to execute decryption of the e-mail, and stores the decrypted data in the secret box in step S37, thus ending the processing.

As described above, according to the second embodiment, the password set in advance with each destination is described in the address data corresponding to each destination, and when the e-mail is received. By reading this password into
The decryption can be performed simultaneously with the reception of the electronic mail, and even the data stored in the secret box can be browsed quickly. If the password does not match, decryption is not possible, but the encrypted e-mail is stored in the secret box, so after confirming the password again, the e-mail can be decrypted and viewed. can do.

(Third Embodiment) FIGS. 8 and 9 are flowcharts showing the operation of a data communication system according to a third embodiment of the present invention. The configuration of the data communication system according to the third embodiment is common to the data communication system 1 according to the first embodiment.
8 and 9 show flowcharts showing the operation, and the illustration and description of the configuration are omitted.

In the data communication device 10 in the data communication system 1 according to the third embodiment, a keyword is input and stored in the data storage unit 17 in advance. This keyword is intended to maintain the secrecy of the e-mail concerning a certain theme, and a keyword indicating the theme of the e-mail to be kept secret is set.

FIG. 8 is a flowchart showing a series of processes relating to transmission of an electronic mail.

In step S 40, when sending an e-mail to the mail server 3, the contents of the e-mail are compared with the keywords stored in the data storage unit 17. If the content includes a keyword, it is determined that the content is an e-mail in which the content according to the theme to be kept secret is described.

In step S41, a keyword of the content of the e-mail to be transmitted is detected. If a keyword is detected in step S41, it is determined that a process for maintaining confidentiality should be applied to this e-mail, and the process proceeds to step S42.

At step S42, while performing an encryption process, a keyword is added to the header information, and at step S43
Then, the mail is transmitted to the mail server 3 together with the header information.

If no keyword is detected in the contents of the e-mail in step S41, the process proceeds to step S43, the e-mail is transmitted, and the process is terminated.

FIG. 9 is a flowchart showing a series of processes relating to reception of an encrypted e-mail upon reception of the e-mail. Note that, among the received e-mails, a normal process is performed on an unencrypted e-mail, and a description thereof will be omitted.

In step S45, an e-mail is received from the mail server 3, and if the received e-mail is encrypted, the process proceeds to step S46.

In step S46, the content of the header information of the received e-mail is collated with the keyword stored in data storage unit 17.

At step S47, if a keyword is detected in the contents of the header information of the e-mail, the process proceeds to step S47.
The process proceeds to S48, where the e-mail is decrypted by decryption processing corresponding to the keyword. If no keyword is detected in the content of the received e-mail, the process proceeds to step S49.

In step S48, the encrypted e-mail is decrypted, and the flow advances to step S49.

In step S49, the e-mail is stored in the mailbox, and the process ends.

In the third embodiment, a plurality of encryption schemes are prepared for encryption, and a plurality of decryption schemes are prepared in advance for decryption. Is applied, more secure confidentiality can be maintained.

Specifically, the encryption method and the decryption method to be applied to each keyword are specified in advance in the data storage unit 17 together with the keyword. The program storage unit 15 stores a plurality of encryption programs and decryption programs for performing encryption and decryption by different methods, respectively, and the CPU 11 stores the encryption program designated by the data in the data storage unit 17. And read and execute the decryption program.

In step S40 of FIG. 8, a keyword is detected in the content of the e-mail to be transmitted. If a keyword is detected in step S41, the process proceeds to step S42, where the encryption program corresponding to the keyword is used. Perform encryption.

If the encrypted e-mail is received in step S45 of FIG. 9, step S4
6, the header part of the e-mail and the data storage part 1
A plurality of keywords stored in 7 are collated.

If a keyword is detected in step S47, in step S48, a plurality of decryption programs stored in the program storage unit 15 are selected.
Decryption is performed by a program set to correspond to the keyword. After that, in step S49, the decrypted e-mail is stored in the mailbox, and the process ends.

At the time of encryption and decryption, a password called an encryption key and a decryption key may be set. The encryption key and the decryption key may be stored in the data storage unit 17 in association with a plurality of keywords.

That is, when a keyword is detected in step S41 of FIG. 8, the encryption key corresponding to the keyword is read from the data storage unit 17, and the process proceeds to step S42.
Then, encryption is performed using this encryption key.

If a keyword is detected in step S47 of FIG. 9, a decryption key corresponding to the keyword is read from the data storage unit 17, and decryption is performed in step S48.

As described above, according to the third embodiment, confidentiality is required when a keyword is included in the content attached to an e-mail regardless of the destination and the source of the e-mail. to decide. Therefore, as long as the e-mail is for an e-mail about a theme for which secrecy is desired, there is no omission in exchanging e-mails with any destination and source, and the secrecy can be reliably maintained. Further, since setting for each destination is unnecessary, confidentiality of a specific theme can be easily maintained.

Although a keyword is added to the header information for the encrypted e-mail, the present invention is not limited to this. The e-mail can be transmitted and received without adding a keyword to the header information. The decryption may be performed on the side based on a preset password regardless of the keyword.

Although the data communication devices 7 and 10 are connected to the communication line network 2 in the above embodiment, a configuration in which a LAN (Local Area Network) is constructed to connect each data communication device is provided. Alternatively, a configuration may be employed in which electronic mail is transmitted and received between the data communication devices connected to different networks via the Internet (The Internet) or the like. Further, in the above embodiment, the configuration is such that the electronic mail is transmitted and received via the mail server 3. However, the configuration may be such that the electronic mail is transmitted and received directly between the data communication devices.
The configuration of the details can be arbitrarily changed without departing from the spirit of the present invention.

[0137]

According to the first aspect of the present invention, it is necessary to instruct data encryption every time data is transmitted by designating data to be encrypted in advance by the encryption instruction data storage means. Therefore, it is possible to reduce the number of operations by the operator, and it is possible to securely maintain the secret.

According to the second aspect of the present invention, it is determined in advance whether to transmit encrypted data or normal data to each destination described in a database having an address book function. By setting, even if the data is transmitted as usual, the data is automatically encrypted when the data is transmitted to the other party who needs to keep the information confidential.

According to the third aspect of the present invention, data including a preset keyword is encrypted. Therefore, when it is desired to encrypt all data related to a specific theme, for example, Even without setting encryption,
Encryption can be performed by setting the theme as a keyword. Then, mistakes such as omission of setting can be reduced as compared with a case where setting is individually performed for each data.

According to the fourth aspect of the present invention, when transmitting data in the third aspect of the present invention, for example, a keyword is attached to the data body in a format such as the title of an electronic mail and transmitted. In addition, the keyword can be easily recognized without referring to the data body, and the convenience can be further improved.

According to the fifth aspect of the present invention, encryption instruction data or data having different keywords is
Since the encryption key or the encryption method is different, it is difficult to easily use the encryption key or the encryption method applied to other data, so that the confidentiality can be maintained more reliably.

According to the sixth aspect of the present invention, it is possible to set in advance whether or not the data received by the data communication device is encrypted. Can be decoded. Therefore, it is not necessary to set the decryption every time the data is received and browsed, and it is possible to reduce the operation of the operator.

According to the seventh aspect of the present invention, it is possible to easily decrypt the data by registering in advance the destination of the data to be transmitted and received, so that the secret can be maintained with a small amount of labor. Can be.

According to the eighth aspect of the present invention, whether or not received data is encrypted data can be set by a keyword. For example, it is possible to specify data on a specific theme. It is possible, and it is possible to perform setting without mistakes such as omission of setting by a simple operation as compared with the case of setting for each data.

According to the ninth aspect of the present invention, in the invention of the eighth aspect, decoding is performed by detecting that a keyword is stored in the decoding instruction data storage means. It can be more easily realized.

According to the tenth aspect, the effect obtained by the eighth aspect can be more easily obtained by referring to the keyword transmitted together with the data body.

According to the eleventh aspect of the invention, since the encryption key or the decryption method is different for the decryption instruction data or the data having different keywords, the decryption key or the decryption applied to the other data is different. Since it is difficult to divert the conversion scheme, the secrecy can be maintained more reliably.

According to the data communication method of the twelfth aspect, for example, whether to transmit encrypted data or normal data to each destination stored in a database having an address book function Is set in advance, even if the data to be transmitted is created and transmitted as usual, the data is automatically encrypted for the data that needs to be kept secret. Accordingly, it is not necessary to set data encryption or the like every time data communication is performed each time, so that it is possible to reduce the number of operations performed by an operator and further securely maintain secret.

When data transmitted from a transmission source designated in advance is received, it is automatically determined that the data is data to be kept secret, and is stored in a dedicated storage means. Thus, after receiving the data that needs to be kept secret, it is possible to prevent the data from being erroneously stored in the storage device that can be freely viewed, so that the secret can be reliably held.
Further, since a storage unit for storing ordinary data is provided, the trouble of browsing data that does not need to be kept confidential is not increased.

According to the data communication method of the thirteenth aspect, the data containing the key information set in advance is:
Since the data is transmitted after being encrypted at the time of transmission, it is possible to encrypt only the data relating to a specific theme and keep the secret. Further, as compared with the case where each data is encrypted, the work efficiency is improved due to the reduced number of operations, and errors such as erroneous transmission without encryption can be reduced.

When the data containing the key information set in advance is received, the data is stored in a dedicated storage device different from the normal data. It cannot be viewed with other data, and can be kept secret. As a result, the data to be kept confidential can be surely kept without being made erroneously accessible by anyone. Further, since a storage unit for storing ordinary data is separately provided, the number of operations for browsing data that does not need to be kept secret does not increase.

According to the storage medium of the present invention, encrypted data or ordinary data is transmitted to each destination stored in advance in a database having an address book function, for example. With this setting, even if the data to be transmitted is created and transmitted as usual, the data is automatically encrypted with respect to the data that needs to be kept secret. Accordingly, it is not necessary to set data encryption or the like every time data communication is performed each time, so that it is possible to reduce the number of operations performed by an operator and further securely maintain secret.

According to the storage medium of the fifteenth aspect, since the data including the key information set in advance is transmitted after being encrypted, only the data relating to the specific theme is encrypted. You can keep it secret. In addition, work efficiency can be improved by reducing the number of operations, and errors such as erroneous transmission without encryption can be reduced. Further, since the data can be encrypted and stored, the data to be kept confidential can be kept confidential without being accidentally made available to anyone.

According to the storage medium of the sixteenth aspect, when data that needs to be kept confidential is received, the data is stored in dedicated storage means different from normal data, You will not be able to view it with the data, and you can keep it secret. As a result, the data to be kept confidential can be surely kept without being made erroneously accessible by anyone. Further, since a storage unit for storing ordinary data is separately provided, the number of operations for browsing data that does not need to be kept secret does not increase.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a data communication system according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an internal configuration of the data communication device of FIG.

FIG. 3 is a diagram illustrating a configuration of address data stored in a data storage unit of FIG. 2;

FIG. 4 is a flowchart showing an electronic mail transmission process by the data communication system of FIG. 1;

FIG. 5 is a flowchart showing an e-mail receiving process by the data communication system of FIG. 1;

FIG. 6 is a flowchart showing an email decryption process by the data communication system of FIG. 1;

FIG. 7 is a flowchart illustrating an electronic mail receiving process performed by the data communication system according to the second embodiment of the present invention.

FIG. 8 is a flowchart illustrating an electronic mail transmission process performed by the data communication system according to the third embodiment of the present invention.

FIG. 9 is a flowchart showing an e-mail receiving process by the data communication system of FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 data communication system 2 communication line network 3 mail server 4 indoor converter 5 base station 6 mobile phone 7, 10 data communication device 11 CPU 12 display unit 13 input unit 14 voice input / output unit 15 program storage unit 16 RAM 17 data storage unit 18 RTC 19 Communication unit 20 Bus

Claims (16)

[Claims] 1. A data communication device connected via communication means for transmitting data to another communication device, comprising: encryption instruction data storage means for storing whether or not to encrypt each data to be transmitted; Encryption means for controlling the encryption of the data based on the validity of the encryption stored in the encryption instruction data storage means, and transmission means for transmitting data encrypted or non-encrypted under the control of the encryption means A data communication device comprising: 2. The encryption instruction data storage means stores, for each destination of data to be transmitted, encrypted data for instructing whether or not to encrypt the data to be transmitted. Data communication equipment. 3. The encryption instruction data storage means stores a keyword for encrypting the data, and the encryption means includes the keyword in which the data is stored in the encryption instruction data storage means. 2. The data communication apparatus according to claim 1, wherein the data is encrypted when the data communication is performed. 4. The data communication apparatus according to claim 3, wherein said transmitting means transmits a keyword together with said encrypted or non-encrypted data. 5. The encryption instruction data storage means stores a different encryption key or a different encryption method for each of the stored encryption instruction data or each keyword. 5. The data communication device according to claim 2, wherein encryption is performed based on an encryption key or an encryption method stored in the instruction data storage unit. 6. A data communication device connected via communication means for receiving data from another communication device, comprising: an encrypted data storage means for storing, for each of the received data, whether the data is encrypted data; Decryption instruction data storage means for storing decryption instruction data for instructing decryption of the data based on whether the encryption stored in the encrypted data storage means is correct, and decryption based on the decryption instruction data storage means A data communication device, comprising: decoding means for controlling data decoding; and display means for displaying data decoded or non-decoded under the control of the decoding means. 7. The decoding instruction data storage means according to claim 6, wherein said decoding instruction data storage means stores decoding instruction data for instructing whether or not to decode data for each transmission destination of received data. Data communication device. 8. The decoding instruction data storage means stores a keyword for decoding the data, and the decoding means stores the keyword based on the keyword stored in the decoding instruction data storage means. The data communication device according to claim 6, wherein the data is decoded. 9. The data communication apparatus according to claim 8, wherein said decoding means decodes said data when a keyword is stored in said decoding instruction data storage means. 10. A receiving unit receives a keyword together with the encrypted or non-encrypted data, and the decryption unit decrypts the data if the received keyword is stored in the decryption instruction data storage unit. The data communication device according to claim 8, wherein: 11. The decryption instruction data storage means stores a different decryption key or a different decryption method for each of the stored decryption instruction data or each keyword. 11. The data communication device according to claim 6, wherein decoding is performed based on a decryption key or a decryption method stored in the instruction data storage unit. 12. A data communication method using a data communication device for performing data communication with an external communication device connected via a communication means, wherein the external communication device capable of transmitting and receiving data is transmitted and received. And stores secret specification data for specifying whether each of these transmission / reception destinations is a secret communication destination for which data communication with the transmission / reception destination is to be kept secret. When transmitting data to the transmission / reception destination designated as, the data is encrypted and transmitted, and the data transmitted from the transmission / reception destination designated as the secret communication destination by the secret designation data is received. In this case, the data is stored as secret data, and when data transmitted from the transmission / reception destination not specified as the secret communication destination by the secret designation data is received, Is
A data communication method comprising storing the data as normal data. 13. A data communication method using a data communication device for performing data communication with an external communication device connected via a communication means, wherein key information set arbitrarily in advance is stored, Detecting whether the key information stored in the key information storage means is included in the content of the data transmitted and received by the communication device, and transmitting the data by the data communication device; When the key information is detected, the data is encrypted and transmitted.When the data communication device receives the data, when the key information is detected in the content of the data, The data is stored as secret data, and when the key information is not detected in the content of the data when the data communication device receives the data, the data is regarded as normal data. And storing the data. 14. A storage medium storing a computer readable program for performing data communication with an external communication device connected via a communication means, wherein the program code is for transmitting data. And storing secret designation data for designating another data communication device capable of transmitting data with a transmission / reception destination and a secret communication destination to which data communication with the transmission destination should be kept secret. And a program code for encrypting and transmitting the data when transmitting data to the destination designated as a secret communication destination by the secret designation data. Storage medium. 15. A storage medium storing a computer-readable program for performing data communication with an external communication device connected via communication means, comprising: a program code for transmitting and receiving data. A program code for storing arbitrarily set key information; and a program for detecting whether or not the content of data to be transmitted and received includes the key information stored in the key information storage means. A code, when transmitting or receiving data by the transmission / reception means, when the key information is detected in the content of the data, encrypts the data and transmits or encrypts the data. A storage medium characterized by storing: a program code for storing; 16. A program code for storing the encrypted data as secret data when receiving the encrypted data, and storing the program data as normal data when receiving the unencrypted data. 16. The storage medium according to 15.