JPH07212353A - Data communication system and data communication method - Google Patents

Abstract

PURPOSE:To prevent an illicit access by making it possible to judge that an object to be accessed is a permitted opposite party and further changing information specifying the permitted opposite party every time an access is performed. CONSTITUTION:When a host computer 10 responds when an access is performed from a terminal 30 to the host computer 10, the user name and the password for an illicit access prevention which are preliminarily assigned to a terminal are transmitted to the host side. The host 10 investigates whether these match with the matters registered in a storage device 11. When they match, a connection program is started, and the terminal identifier and the access sequence check data(ASC) from the terminal are received. These and the matters registered in the device 11 are compared. If they match, it is judged that the access is not illicit access, new ASC data is generated in the host 10 and the data is transmitted to the terminal 30. A ciphering processing is performed for the data, it is transmitted to the host 10, it is restored, and it is compared with the new generated ASC data. When they match, a desired program is started and a desired processing is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data communication system and a data communication method, and more particularly to a data communication system and a data communication method capable of effectively preventing unauthorized access when data communication is performed via a network.

[0002]

2. Description of the Related Art In recent years, computer-related technology has developed,
It has become possible to perform data communication, distributed processing, etc. between a large number of information processing devices. Along with this, data communication between information processing devices connected to a public network that is widely available to anyone has become popular, and general users can access large-capacity files. There is. Also,
It has become possible to easily access a host computer capable of processing a large amount of data at high speed.

In a system in which the system is open to the public network as described above, basically anyone can access the system, which is very dangerous in view of system security.

[0004]

However, in the conventional system of this type, in many cases, only the authentication system using the user name and password provided by the system as a standard is relied upon. With this authentication system, anyone who knows only those two passwords can invade the system, and it is difficult to prevent the leakage of those keywords, so high security cannot be ensured. Further, in the above authentication system, even if the user name and password are leaked and the system is illegally invaded, it is difficult to recognize this unauthorized access.

[0005]

SUMMARY OF THE INVENTION The present invention has been made for the purpose of solving the above-mentioned problems, and it enables a high system security and easily realizes this fact even in the case of unauthorized access. For the purpose of being recognizable, the following configuration is provided as one means for achieving the purpose.

That is, in a data communication system in which a plurality of communication devices can be connected to each other via a communication medium, at least an activated communication device connected to the system is allowed to perform data communication with another communication device. Permitting device holding means for holding the specific permitting information for each of the other communication devices, specific permitting information receiving means for receiving the communicating device specific permitting information from the starting side device, and specific permitting information received by the specific permitting information receiving means Is included in the specific permission information for each of the other communication devices held in the permission device holding means, and the specific permission information received by the first determination means is the permission. When it is determined that it is included in the specific permission information for each of the other communication devices held in the device holding means, new specific permission information unique to the invoking device that permits communication at the next communication is generated, and Update information transmitting means for transmitting to the communication device on the moving side, and encrypted specific permission information encrypted by a predetermined encryption method with respect to the new specific permission information specific to the starting device transmitted by the updating means. An encrypted specific permission information receiving means for receiving, and a communication permission means for permitting communication with the activation side device when the encrypted specific permission information is the encrypted information of the newly generated specific permission information. It is characterized by being provided.

[0007] For example, the starting device holds its own device permission information holding means for holding specific permission information peculiar to the own device for permitting data communication with the activated communication device, and the own device at the start of communication. Specific information transmitting means for transmitting the specific permission information specific to the own device held in the permission information holding means to the activatable side device, and the specific permission information specific to the own device in the specific information transmitting means Update information receiving means for receiving update specific permission information permitting communication with the own device by the activatable side device unique to the new own device, and the update specific permission information received by the update information receiving means Encrypted specific information transmitting means for encrypting the data according to a predetermined encryption method and transmitting the encrypted specific information to the activatable side device, and the update specific permission information received by the update information receiving means by the own device permission information holder. Characterized in that it comprises a self apparatus permission information updating means for updating registered as new specific permission information.

Further, for example, the following configuration is provided. That is,
The communication permitting unit further requests the process requesting user name and password from the invoking side device, and makes a request of the invoking side device when the process requesting user name and password are the previously permitted process requesting user name and password. It is characterized by permitting execution of processing.

[0009]

In the above configuration, it is possible to judge that the person who is surely trying to access the system is the person who is permitted to access, and by changing the judging element each time of accessing, it is possible to prevent unauthorized access from others. It can be prevented and easily recognized even if there is an unauthorized access.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a communication system of an embodiment according to the present invention. In the figure, 10 is a host computer, 11 is a storage device provided in the host computer 10, and this storage device 11 is a host. The internal memory of the computer 10 and an external storage device are included. A modem 20 connects the host computer 10 to the public network 70. In FIG. 1, the public network 70 is shown to be connected via one modem 20, but the number of the modem 20 is not limited to one, and a plurality of modems may be used depending on the access frequency and the processing amount. It goes without saying that a modem may be provided which is connected to a public network via a line and is capable of data communication corresponding to the number of lines. In the following, for simplification of description, the case where the host computer 10 also has one connection line will be described as an example.

Reference numeral 30 denotes another communication device via the public network 70.
For example, a terminal which is an information processing device capable of data communication with the host computer 10, the other terminal 50, and the like, 31 is the terminal 30
The storage device 40 is a modem for connecting the terminal 30 to the public network 70. Further, 50 is a terminal which is another communication device, 60 is a modem which connects the terminal 50 to a public network 70, and 70 is a public network, which can be easily used by anyone such as a public telephone line network or a general-purpose line network such as an ISDN line network. It is composed of a network accessible to. Also in each terminal, the number of connected lines is arbitrary and is not limited to one line.

FIG. 2 shows an example of a partial configuration of an apparatus for performing data communication connected to the system of this embodiment having the above configuration. The configuration shown in FIG. 2 is an example of the configuration in which parts and the like necessary for data communication in the present embodiment described below are selected and shown, and it is needless to say that various configurations necessary for other processing are provided. . In FIG. 2, 101 is a CPU that controls the entire apparatus of this embodiment shown in FIG. 2, and 102 is a CPU 101.
R that stores the basic program and various basic parameters of
OM, 103 is a RAM for temporarily storing a part of a program being executed by the CPU 101 or the like, processing progress, etc., 104 is an operation unit for an operator to input an operation instruction or the like to the communication device, and 105 is an operation instruction or processing progress, A display unit for displaying, an output unit for outputting a processing result and the like, a line interface 107 for controlling the interface with the public network 70, and a modem 120 for controlling the public network 70 and having a network control function. When this communication device can simultaneously connect to a plurality of lines, the line interface 107 and the modem 120 can handle the number of lines that can be simultaneously connected.

Next, FIG. 3 shows an example of the stored contents of various kinds of information used when the host access is permitted for the storage device 11 included in the host computer 10 of the present embodiment having the above configuration. In FIG. 3, 12 is an operating system including a control program and a utility program for controlling execution of various programs of the host computer 10, 13 is an application program which is a program for various purposes used by a user, and 14 is a host described later. A terminal management data unit that manages terminal information accessible to the computer 10, and is updated each time the terminal identifier 15 assigned to each terminal and the terminal registered in association with the terminal identifier 15 are accessed. ASC data (access sequence check data), which is terminal specific data (specific permission information), is stored as a pair for each of the terminals to which access is permitted.

Reference numeral 17 denotes a user management data section, which includes a user name 18 previously assigned to each user and a password 19 assigned in association with the user name 18 for a user who is permitted to access as a pair. Only stored. It should be noted that this ASC data is check data of the number of digits determined by the system, and in this embodiment, it is 2
It consists of 4-digit numerical data.

Next, FIG. 4 shows an example of the stored contents of various information used at the time of host access to the storage device 31 provided in the terminal (for example, the terminal 30) of this embodiment. In FIG. 4, 32 is an operating system including a control program and a utility program for controlling execution of various programs of the terminal 30, 33 is communication software (emulator), which is connected to the terminal in addition to the terminal emulation function. It includes a modem control function for forming a communication path with another communication device using a modem.

Reference numeral 34 is an application program, which is a program for various purposes used by the terminal user, and reference numeral 35 is a terminal management data section for managing terminal information for the own apparatus when accessing the host computer 10 described later. The terminal identifier 36 assigned to the ASC data and the ASC data (access sequence check data) which is the specific data when the device accesses the host computer 10 next time are stored as a pair.

AS paired with this terminal identifier 36
The C data has the same contents as the ASC data paired with the same terminal identifier 15 as the terminal identifier 36 stored in the terminal management data unit 14 of the host computer 10 shown in FIG. If they are different, it means that some other device illegally interrupted the system in the meantime. Therefore, it is possible to easily recognize the unauthorized access.

In FIG. 4, this terminal management data section 35
Although only one pair of data is stored in, the terminal identifier and the ASC data of the accessible communication device are stored if the terminal can connect to a plurality of different communication devices. is there. Then, the terminal identifier and ASC data corresponding to the partner device to be accessed are used.

In the communication system of the present embodiment having the above-mentioned configuration, one communication device (for example, the terminal 30) connected to the public network 70 accesses another communication device (for example, the host computer 10) to access the data. A communication control procedure in the case of activating to start communication will be described below with reference to FIG. In the following description, the case where the public network 70 is a public telephone line network will be described as an example.

For example, from the terminal 30 to the host computer 1
A user who wants to access 0 inputs an instruction to start the network from the operation unit of the terminal 30 and an instruction to access the host computer 10. Upon receiving this instruction input, the CPU of the terminal 30 uses the above-mentioned communication software 33 or the like to connect the modem 4 through the line interface.
Start 0. The modem 40 forms a DC loop in the line to activate the public network 70, and at the same time, sends out a telephone number signal corresponding to a telephone number assigned to the host computer 10 to the line to call the host computer 10. .

Thereafter, the public network 70 calls the call destination (called side) specified by the transmitted telephone number signal. When the called side responds, a communication path is formed with the calling side. Therefore, at the calling terminal, the called host computer 1
When 0 is responded, the user name previously assigned to the terminal and the password registered in association with the user name are sent in order to start the access start program with the host computer 10.

This user name and password is an authentication system using a user name and password provided as a standard by a system similar to the authentication system generally used in the conventional communication system. The user name and password may be controlled so that the user inputs them from the operation unit here, but the user name and password registered beforehand in the storage device of the terminal are automatically read and sent to the host side. It may be one that does. In the device of the present embodiment, the transmission of the user name and password for the above connection constitutes, so to speak, only a part of the security measures against the unauthorized access of the system for logging in to the host computer, so that the user is not always required. This is because there is less need to rely on more instructions input.

The host computer 10 receiving this user name and password checks whether or not the user name and password registered in the storage device 11 match. Then, if the user name and password registered in the storage device 11 match, the connection program with the terminal peculiar to this embodiment is started subsequently. Then, subsequently, the terminal identifier and ASC data unique to the terminal device transmitted from the terminal are received.

The terminal management data section 1 of the storage device 11
4 is accessed to read the ASC data registered in association with the terminal identifier sent earlier, and the read ASC data is compared with the received ASC data from the terminal sent subsequently. Here, in the case of the first data communication between the host computer 10 and the terminal, the ASC data is set as the initial data determined by the system so that the two communication devices can be synchronized. . However, it may be controlled so that the ASC data designated in advance is input from the operation unit of the terminal at first.

Registration ASC in the terminal management data section 14
If the data and the ASC data received from the terminal match, it is determined that the access is not unauthorized and new ASC data is generated on the host computer 10 side and the updated ASC data is generated.
Send the SC data to the terminal side. Then, the new ASC data is assigned to the A corresponding to the terminal identifier of the terminal management data unit 14.
The ASC data is stored in the SC data storage area and used for the next access.

New ASC data (AS to be used next time)
The terminal which has received the C data) performs the encryption processing agreed with the predetermined host computer 10 on the received ASC data, and transmits the encrypted ASC data to the host computer 10. It should be noted that the terminal side also transmits new ASC data by encrypting it and registers the ASC data before the encryption as new ASC data in the terminal management data section of the storage device 31.

The host computer 10 receiving the encrypted new ASC data restores the encrypted ASC data to the original ASC data and compares the restored ASC data with the new ASC data sent earlier. . If the two ASC data are the same, then the user is prompted to enter the user name from the display unit or the like, the user name is input from the operation unit or the like, and the entered password is sent to the host computer 10 and the user is continuously input. Prompt for password. When a correct password is input by the user, the user is properly authorized to access the host computer 10, and the desired program is started by activating a program desired by the user. When the desired processing is completed, the line is opened and the series of access processing is completed.

In the above communication control procedure, if the input of the user name and password is different from the one registered in the user management data section 17, the fact is notified.
It is controlled so as to allow a predetermined number of retries, for example, three retries. The details of the security program control peculiar to the present embodiment until the program for each user is activated after the connection between the terminal and the host computer in the communication control procedure shown in FIG. 5 are described in the flowcharts of FIGS. 6 and 7. It will be described below with reference.

A user name and password for connection (for login to the host computer) are sent from the terminal to the host computer, and when the user name and password are correct, the processing of FIG. 6 is performed. The host computer 10, which is the called device, first sends a terminal ID request for sending the terminal ID (terminal identifier) to the access requesting terminal device, which is the calling device, in step S1. Then, in step S2, the terminal I from the terminal
Monitor the reception of D. If the terminal ID is not received even after the lapse of a predetermined time, the process returns to step S1.

On the side of the terminal which has been monitoring the reception of this terminal ID request in step S51, the host side sends a step S1.
When the terminal ID transmitted in step S52 is received, the process proceeds to step S52, the terminal management data unit 35 of the storage device 31 is searched, and a predetermined terminal identifier (3
6) is called and the host computer 1 is used as the terminal ID.
Send to 0. Then, in step S53, the reception of the ASC data request is monitored. If the ASC data request is not received within the predetermined time, step S5
I will return to 1.

When the terminal ID sent in step S52 is sent from the terminal in step S2, the terminal ID is received and the process proceeds to step S3, where the terminal management data section 1 of the storage device 11 is received.
4 is searched for a terminal identifier that matches the sent terminal ID, and if there is a corresponding terminal identifier, the terminal side
Send a request to send C data. Then, in step S4, reception of ASC data from the other party is monitored. If ASC data is not received even after the lapse of a predetermined time, the process returns to step S1. Note that if there is no corresponding terminal identifier, it is highly likely that the access is from a terminal that is not permitted to access, so although not shown in FIG. 6, the subsequent processing is not performed and the process returns to step S1. It should be noted that instead of step S1, control may be performed so as to shift to unauthorized access countermeasure processing.

When the terminal 30 receives the ASC data request sent from the host side in step S53, step S53
In step 54, the ASC data registered in association with the previously transmitted terminal identifier 36 of the terminal management data section 35 of the storage device 31 is read and transmitted to the host computer 10. Then, in step S55, the reception of new ASC data is monitored. If new ASC data is not received even after the lapse of a predetermined time, the process returns to step S51.

The host computer 10 receiving the ASC data from the terminal 30 in step S4, the terminal identifier specified by the previously received terminal ID stored in the terminal management data section 14 of the storage device 11 in the following step S5. It is checked whether the ASC data registered in association with the ASC data and the ASC data received here match (whether the terminal ID and the ASC data sent are correct data). If the ASC data registered in association with the terminal identifier specified by the previously received terminal ID does not match the ASC data received here, it is possible that the access is from a terminal that is not permitted to access. Since the property is strong, the process returns to step S1 without further processing. It should be noted that control may be performed such that the process proceeds to the unauthorized access handling process instead of step S1.

Further, in this case, there may be a case where the system has been illegally accessed during this period.
Furthermore, by checking the ASC data of both parties, it is possible to easily and easily know whether or not there has been an unauthorized access, and it is possible to take prompt measures. This is also an excellent function and effect peculiar to this embodiment. On the other hand, if the ASC data registered in association with the terminal identifier specified by the terminal ID previously received in step S5 matches the ASC data received here, the process proceeds to step S6, and the next Create ASC data to be used when accessing. The new updated ASC data may be a randomly determined number or a value obtained based on a predetermined arithmetic expression or the like.
In this case, a plurality of arithmetic expressions are prepared, and one arithmetic expression of the plurality of arithmetic expressions is randomly selected to create a new AS.
It is desirable that the data be such that other unauthorized access persons cannot easily be identified by obtaining C data. In addition,
Here, the constant in the predetermined arithmetic expression may be randomly changed.

Subsequently, the AS newly created in step S7
At the same time as transmitting the C data to the terminal side, it is encrypted in step S8 according to an algorithm predetermined with the terminal and temporarily stored in, for example, a RAM or the like. Then, in step S9, it is monitored whether the encrypted ASC data is sent from the terminal 30. Encryption AS
If the C data is not received, the process returns to step S1.

On the other hand, in step S55, the terminal side receiving the new ASC data (ASC data to be used next time) transmitted from the host side in step S7 stores the new ASC data received in the following step S56 in the storage device 31.
It is registered as new ASC data in the terminal management data section of. At the same time, the received new ASC data is encrypted according to an algorithm negotiated with a predetermined host computer 10, and the encrypted ASC data is transmitted to the host computer 10 in step S57. Then, after that, the ASC (access sequence check) normal termination signal sent from the host computer is received to execute the ASC termination processing, and subsequently, in step S59, the emulator mode is entered.

On the other hand, in the host computer 10 which received the encrypted ASC data transmitted from the terminal side in step S55 in step S9, the encrypted ASC data received in subsequent step S10 and the AS encrypted in step S8 are received.
It is checked whether the C data matches. If both ASC data match, an ASC normal termination signal is transmitted to notify access permission, and ASC termination processing is executed. Then, the process proceeds to step S12 to request the terminal to input the user name. On the side of the terminal 30 which has received the request for the user name, the user name input request screen is displayed on the display unit in step S60. The user who confirms the display on the display unit inputs a predetermined user name from the operation unit or the like in step S61. When the user name is input, the terminal 30 transmits the input user name to the host computer 10.

The host computer 10, which has received the user name from this terminal in step S13, searches the user management data section 17 of the storage device 11 and confirms that the received user name is registered, and then the step S14. Request the password from the terminal as shown in. On the side of the terminal which has received this password request, a password input request screen is displayed on the display unit in step S62.

The user who confirms the display on the display unit inputs a predetermined password from the operation unit or the like in step S63. When the password is entered, the terminal 30 sends the entered password to the host computer 10 and ends the series of login processing to the host computer. After that, the user performs desired program processing and host computer access processing.

On the other hand, the host computer 10 which has received the password from the terminal in step S15 judges whether or not it matches the user name and password in the user management data section 17 in the following step S16, and receives the received user name. If the password and the password match the user name and password in the user management data section 17, it is determined that the access request is from an authorized user and the desired processing is performed below. . If the received user name and password do not match the user name and password in the user management data section 17, step S1
Returning to step 2, the above user name and password request processing is repeated a predetermined number of times, for example, three times. If the received user name and password do not match the user name and password in the user management data unit 17 even after repeating this predetermined number of times, control is performed so that the process proceeds to step S1 as unauthorized access or to unauthorized access handling processing. You may.

As described above, according to this embodiment, it is possible to judge that the person who is surely trying to access the system is the partner who is permitted to access, and the ASC data is changed each time the access is made. It is possible to prevent unauthorized access from others and to easily recognize even if there is an unauthorized access.

[0042]

As described above, according to the present invention, it is possible to judge that the person who is surely trying to access the system is the partner to whom the access is permitted, and is the partner who is permitted to access each time. By changing the information for specifying that, it is possible to prevent unauthorized access from others and to easily recognize it even if there is an unauthorized access.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration example of a communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of a partial configuration of a device for performing data communication connected to the system of the present embodiment.

FIG. 3 is a diagram showing an example of stored contents of various kinds of information used at the time of host access permission in a storage device included in the host computer of the present embodiment.

FIG. 4 is a diagram showing an example of stored contents of various types of information used when host access is permitted in a storage device included in the terminal of the present embodiment.

FIG. 5 is a diagram showing a communication control procedure in the case of activating data communication according to the present embodiment.

FIG. 6 is a flow chart showing control at the start of access in the present embodiment.

FIG. 7 is a flow chart showing control at the start of access in the present embodiment.

[Explanation of symbols]

 10 host computer 11,31 storage device 20,40,60,120 modem 30,50 terminal 70 public network 101 CPU 102 ROM 103 RAM 104 operation unit 105 display unit 106 output unit 107 line interface

Claims (4)

[Claims] 1. A data communication system in which a plurality of communication devices can be connected to each other via a communication medium, and at least an activatable communication device connected to the system is allowed to perform data communication with another communication device. The permission device holding unit that holds the specific permission information of each of the other communication devices, the specific information receiving unit that receives the specific permission information from the starting side device, and the specific permission information received by the specific information receiving unit is the permission. Determination means for determining whether or not the specific permission information for each of the other communication devices held in the device holding means is included, and the specific permission information received by the determination means for other communication devices held in the permitted device holding means If it is determined that the specific permission information is included in the specific permission information for each communication device, new specific permission information unique to the activation side device that permits communication at the next communication is generated and transmitted to the activation side communication device. Information transmitting means, and encrypted specific information receiving means for receiving encrypted specific information encrypted by a predetermined encryption method with respect to the new specific permission information unique to the starting side device transmitted by the updating means. A data communication system, comprising: communication permission means for permitting communication with the activation side device when the encrypted specific information is the encrypted information of the newly generated specific permission information. 2. A self-device permission information holding unit that holds specific permission information specific to the start-side device that permits data communication with a boot-side communication device, and the self-device when starting communication. Specific information transmitting means for transmitting the specific permission information specific to the own device held in the permission information holding means to the activatable side device, and the specific permission information specific for the own device transmitted by the specific information transmitting means. An update information receiving unit that receives update specifying permission information that permits communication with the own device by the activatable device that is unique to the new own device, and the update specifying permission information received by the update information receiving unit Encrypted specific information transmitting means for transmitting the encrypted data according to a predetermined encryption method to the activatable side device, and the update specific permission information received by the update information receiving means to the own device permission information holding means. The data communication system according to claim 1, characterized in that it comprises a self apparatus permission information updating means for updating registered as a specific permission information. 3. The communication permission unit is activated when the processing request user name and password are further transmitted from the activation side device and the processing request user name and password are the previously permitted processing request user name and password. The data communication system according to claim 1, wherein execution of processing requested by the side device is permitted. 4. A data communication method in a data communication system in which a plurality of communication devices can be connected to each other via a communication medium, wherein a communication path is formed between communication devices connected to the system, A specific information transmitting step for transmitting specific permission information for permitting communication with the activated communication device registered in advance in the activation communication device, and the transmission specific permission information in the specific information transmission step is the activation target. Update specific permission information that permits communication with the new activation side device in the activatable side device when included in the specific permission information for each of the other communication devices that should permit communication held in the side device An update information transmission step of generating and transmitting to the activation side communication device, and new specific permission information specific to the activation side device transmitted in the update information transmission step by the activation side device, next specific permission information And an encrypted specific information transmitting step of transmitting encrypted specific permission information encrypted by a predetermined encryption method to the updated new specific permission information. Is provided with communication permission means for permitting communication with the activation side device when the encrypted permission information is the encrypted information of the specific permission information transmitted in the update information transmission step. And data communication method.