Sensitive information leakage prevention system, sensitive information leakage prevention method, and computer-readable recording medium

A method for preventing leakage of sensitive information between a client device that executes an application program and a server device that holds data to be used by the application program, the method comprising:

• a step (a) of the client device determining whether or not access by the application program is allowed, based on a security level that is set for the application program and a security level that is provided to the data held in the server device;
• a step (b) of the client device transmitting, if it is determined that access is allowed, a challenge code that is generated using packet data from the application program to the server device and requesting authentication;
• a step (c) of the server device transmitting, when the challenge code is transmitted thereto, a preset response code to the client device, and determining that authentication is successful if a set response to the response code is received from the client device;
• and
• a step (d) of the server device permitting access by the client device if it is determined that authentication is successful,
• wherein a processor of the client device performs steps (a) and (b), and a processor of the server device perform steps (c) and (d),
• wherein the client device assigns a label that indicates a preset security level to each of a plurality of application programs including the application program,
• wherein the client device monitors network access by the application programs, and upon network access by an application program having begun, determines s allowed in accordance the label assigned to the application program and a label of an access destination folder,
• wherein the server devices performs authentication processing with the client device in which access control is performed in accordance with the labels,
• and wherein the server device performs no authentication processing with the client device in which access control cannot be performed in accordance with the client device, such that all network communication is prohibited.

A non-transitory computer-readable recording medium storing a program for determining, by a computer, whether or not a client device is allowed to access data to be used by an application program that is executed by the client device, the program containing a command for causing the computer to execute:

• a step (a) of transmitting a preset response code to the client device if a challenge code that is generated using packet data from the application program is transmitted for requesting authentication from the client device;
• a step (b) of determining that authentication is successful if a set response to the response code is received from the client device after the step (a) is executed;
• and
• a step (c) of permitting access by the client device if it is determined in the step (b) that authentication is successful,
• wherein the client device assigns a label that indicates a preset security level to each of a plurality of application programs including the application pro rg am,
• wherein the client device monitors network access by the application programs, and upon network access by an application program having begun, determines s allowed in accordance the label assigned to the application program and a label of an access destination folder,
• wherein the server devices performs authentication processing with the client device in which access control is performed in accordance with the labels,
• and wherein the server device performs no authentication processing with the client device in which access control cannot be performed in accordance with the client device, such that all network communication is prohibited.