JPH1185624A - Data protector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data protector appropriate for protecting the profit of a composer by effectively preventing data from being temporally infinitely utilized even when the time of a clock timer unit is changed. SOLUTION: At a transmission side computer 1, utilization permitted time data setting time to start and stop the permission of utilization are related to protection object data and transmitted to a reception side computer 2 and at the reception side computer 2, when the time outputted from the clock timer unit is not within the utilization permitted time zone, based on the related utilization permitted time data, the protection object data are erased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data protection device for erasing data whose use time has been exceeded,
In particular, the present invention relates to a data protection device that suitably prevents data from being used indefinitely in time.

[0002]

2. Description of the Related Art Conventionally, there are the following data protection devices for limiting the use of data in terms of time.

[0003] First, in the transmission side computer, when a sender (for example, a data creator) designates a use permission time for which the use of protected data to be transmitted is permitted, the data use permission is terminated. The end time data for which the time has been set is added to the data to be protected,
This is sent to the receiving computer.

In the receiving computer, when a recipient (for example, a licensor who has been granted permission to use the data to be protected by the creator) activates an application program in order to use the received data to be protected, the receiving computer has a built-in computer. It is determined whether or not the time output from the clock timer device exceeds the end time set in the end time data, and when it is determined that the time is exceeded, the data to be protected is deleted.

[0005]

However, in the conventional data protection device, it is determined whether or not the time output from the clock timer device exceeds the end time set in the end time data. Therefore, if the time of the timer device is set before the current time by the receiver, the use time of the data to be protected is substantially extended. In other words, even if the use of data is temporally limited as described above, if the time of the clock timer device is set to a time far before the end time, after all, the data to be protected is unlimited. It will be used.

In this case, since data to be encrypted is generally extremely confidential, if the data is used for more than the set permitted time, the creator of the data suffers significant damage. Risk of suffering.

Accordingly, an object of the present invention is to solve such a conventional problem, and effectively prevents data from being used indefinitely even if the time of a clock timer device is changed. It is another object of the present invention to provide a data protection device suitable for protecting the interests of the creator.

[0008]

In order to achieve the above object, a data protection device according to the present invention is applied to a computer, and is provided with a predetermined time based on a time output from a clock timer device. In a data protection device adapted to erase data to be protected that exceeds the limit, a use permission time for specifying a use permission start time for starting data use permission and a use permission end time for ending the data use permission Use permission time data associating means for associating data with the data to be protected, and when the time output from the clock timer device is earlier than the use permission start time based on the use permission time data associated therewith. Or, when it is later than the use permission end time, the protection target data for erasing the protection target data. And means to, a.

With such a configuration, in order to temporally limit the use of the data to be protected, the permitted time data association means associates the permitted time data with the data to be protected. Here, the use permission time data is data in which the use permission start time and the use permission end time can be specified by the protected data erasing means, and for example, the use permission start time and the use permission end time are set. Data, and data in which a usage permission start time and a usage permission time width are set.

[0010] In the protected data erasing means, the time output from the clock timer device is based on the associated use permission time data before the use permission start time specified by the use permission time data. Or when the time is after the use permission end time, the data to be protected is deleted.

That is, the data to be protected is determined, for example, as to whether the time of the clock timer device is within the permitted use time width in response to activation of the application program, and is determined not to be within the permitted use time width. For example, it is always possible to execute an interrupt process for determining whether or not the time of the clock timer device is within the permitted use time width, and is erased when it is determined that the time is not within the permitted use time width. Or be done.

At this time, the state that the time of the clock timer device is earlier than the use permission start time is considered that the time of the clock timer device is changed after the use permission time data is associated. It is determined that the use permission time is to be illegally extended, and is to be deleted.

According to the first aspect of the present invention, associating the permitted use time data with the data to be protected includes adding the permitted use time data to the beginning or end of the protected data or using the permitted use time data in the auxiliary storage device. May be added to the beginning or end of the data to be protected as a link destination, or the data to be protected may be associated with the use permission time data in a correspondence table.

According to a second aspect of the present invention, there is provided a data protection apparatus as set forth in the first aspect.
The use permission time data associating means associates the plurality of use permission time data with the protection target data, and the protection target data erasing means outputs the use permission time data of the plurality of use permission time data. The erasure of the data to be protected is determined based on the use permission time data having the shortest width.

With this configuration, in order to temporally limit the use of the data to be protected, a plurality of permitted time data are associated with the data to be protected by the permitted time data associating means.

In the protected data erasing means, the use permission time width becomes the shortest among the plurality of use permission time data associated with each other, that is, the interval between the use permission start time and the use permission end time becomes the shortest. The use permission time data is selected, and the data to be protected is erased based on the data.

The data to be protected associated with the permitted use time data is deleted after the preset permitted use time is exceeded. However, it is also possible to extend the use permission time by falsifying the use permission time data. In this case, in particular, when only one permitted use time data is associated, the possibility that the permitted use time data is falsified is extremely high.

Therefore, in the second aspect of the present invention, in order to prevent unauthorized use of the permitted time, a plurality of dummy permitted time data are associated with the data to be protected. When deciding whether or not to delete the data to be protected, a data item having the shortest permitted time width among a plurality of permitted time data items is selected, and based on this, a plurality of permitted time data items are used. Even if any of the permitted time data is altered to extend the permitted time,
Unless all the permitted use time data is falsified, the data to be protected will not be used beyond the preset use permitted time.

In this case, when it is detected that the permitted time data has been falsified, for example, all the permitted time data is rewritten to the permitted time data having the shortest permitted time width. It is preferable to erase the data to be protected.

Further, according to a third aspect of the present invention, in the data protection apparatus according to the first or second aspect, the use permission time data associating means is provided in the transmission side computer, and The data erasing means is provided in a receiving computer connected to the transmitting computer via a network.

With such a configuration, when the transmission-side computer attempts to transmit the data to be protected to the reception-side computer, the use-permitted time data is associated with the data to be protected by the use-permitted-time data associating means. Sent to the receiving computer.

When the receiving computer receives the data to be protected associated with the permitted use time data, the protected data erasing means outputs the data from the clock timer device based on the permitted use time data. When the time is earlier than the use permission start time specified by the use permission time data or later than the use permission end time, the data to be protected is deleted.

Furthermore, a data protection device according to a fourth aspect of the present invention is a data protection device, comprising: a network in which a transmitting computer for transmitting data and a receiving computer for receiving data transmitted from the transmitting computer are connected. In the data protection device that is applied to the data protection device and erases the data to be protected after the predetermined time, specifies the use permission start time to start the data use permission and the use permission end time to end the data use permission Means for associating use-permitted time data with the data to be protected for providing the data to be protected, provided in the transmission-side computer, and when the data to be protected is received, at least one of the use permission is added to the data to be protected. Second use permission time data associating means for associating time data; When the time output from the clock timer device is earlier than the use permission start time or based on the use permission end based on the use permission time data having the shortest use permission time width among the use permission time data, When the time is later than the time, protection target data erasing means for erasing the protection target data is provided in the receiving computer.

With such a configuration, when the transmission-side computer attempts to transmit the data to be protected to the reception-side computer, the use-permitted time data is associated with the data to be protected by the use-permitted time data associating means. Sent to the receiving computer.

Then, when the receiving computer receives the data to be protected associated with the permitted time data in this manner, the second permitted time data associating means associates the received protected data with at least one useable data. Permitted time data is associated.

Next, in the protected data erasing means, the use permitted time data having the shortest use permitted time width is selected from the plurality of related use permitted time data, and based on this, the output from the clock timer device is selected. When the performed time is earlier than the use permission start time specified by the use permission time data or later than the use permission end time, the protection target data is deleted.

According to a fifth aspect of the present invention, there is provided the data protection apparatus according to the first, second, third or fourth aspect, wherein the use permission time data associating means is configured to store the data to be protected. At least one of the use permission start time and the use permission end time is variably set according to the intention of the creator or the owner.

With such a configuration, the use permission time data associating means converts the use permission time data based on the use permission start time or use permission end time specified by the creator or owner of the data to be protected. Generated and associated with protected data.

Further, the data protection device according to claim 6 according to the present invention is the data protection device according to claim 1, 2, 3, 4 or 5, wherein the use is performed in a direction in which the use permission time width is shortened. The use permission start time specified by the permission time data is reset to a time output from the clock timer device or a time before that.

With such a configuration, after the use permission time data is associated with the data to be protected, the use permission start time specified by the use permission time data becomes:
The time is reset to the time output from the clock timer device in the direction of shortening the use permission time width. In this case, the usage permission start time may be reset before the time output from the clock timer device if the usage permission time width is to be shortened.

When the time of the clock timer device is changed, if the time after the change is earlier than the use permission start time, the protection target data associated with the use permission time data is deleted. However, when the time of the clock timer device is changed within a range before the use permission end time and after the use permission start time, the time is not erased. Therefore, when the time is changed before the current time (current time output from the clock timer device) and after the use permission start time, the use permission time is substantially extended.

Therefore, in the invention according to claim 6, the time outputted from the clock timer device is referred to, and when the time is between the use permission start time and the use permission end time, the use permission start time is set to the present time. , And preferably reset to the current time. Then,
As a result of subtracting the elapsed usage time that has already been used from the preset usage permission time, it will be reset as a new usage permission time, and based on this new usage permission time, the data to be protected will be erased. Then, it is possible to reliably prevent the use permission time from being illegally extended by changing the time of the clock timer device.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the data protection device according to the present invention.

In the first embodiment, as shown in FIG. 1, the data protection device according to the present invention is configured such that the data to be protected transmitted from the transmitting computer 1 is unlimited in time by the receiving computer 2. It is applied to prevent it from being used for.

In the figure, a transmitting computer 1 for transmitting data to be protected and a receiving computer 2 for receiving data to be protected are connected by a data transmission line 3 for transmitting data.

As shown in FIG. 2, the transmission side computer 1 and the reception side computer 2 perform arithmetic processing based on a control program and an arithmetic processing unit 4 for controlling the entire system.
A main storage device 5 capable of electrically reading and writing data, a clock timer device 6 for counting elapsed time based on a set time, and an external device connected to the outside and the main storage device 5. An input / output control device 7 for inputting / outputting data; an arithmetic processing unit 4;
The main storage device 5, the clock timer device 6, and the input / output control device 7 are mutually connected by a bus which is a signal line for transmitting data. The input / output control device 7 includes, as external devices, an auxiliary storage device 8 that can magnetically read and write data, and a keyboard 9 as a human interface that can input data.
And the data transmission path 3 are connected to each other.

The main storage device 5 has a ROM in which a control program for the arithmetic processing device 4 is stored in a predetermined area in advance.
And a RAM for storing data read from the ROM or the auxiliary storage device 8 and a calculation result required in a calculation process of the calculation processing device 4.

Processing unit 4 of transmitting computer 1
Comprises a microprocessing unit MPU and the like, and when transmitting data to be protected stored in the auxiliary storage device 8, starts a predetermined program stored in a predetermined area of the ROM of the main storage device 5,
It is configured to execute the processing shown in the flowchart of FIG.

Here, the processing executed by the arithmetic processing unit 4 of the transmission side computer 1 when transmitting the data to be protected is configured as follows. First, in step S1, in FIG. 1, designation of data to be transmitted to be protected is input from the keyboard 9, and step S1 is executed.
2, the use permission start time for starting the use permission of the designated data to be protected is input from the keyboard 9, and the process proceeds to step S3 to terminate the use permission of the designated data to be protected. The end time is input from the keyboard 9, and the process proceeds to step S4.

In step S4, use permission time data in which the input use permission start time and use permission end time are set is generated, and the process proceeds to step S5 where the generated use permission time data is added to the head of the data to be protected. Then, the process proceeds to step S6.

In step S6, an encryption key for encrypting the data to be protected is input from the keyboard 9, and the flow shifts to step S7 to encrypt the data to be protected with the input encryption key, and then shifts to step S8. Then, the encrypted data to be protected is transmitted to the receiving computer 2, and a series of processing is terminated.

The arithmetic processing unit 4 of the receiving computer 2
Is composed of a micro-processing unit MPU, etc., and starts a predetermined program stored in a predetermined area of the ROM of the main storage device 5 when the input / output control device 7 receives the encrypted data to be protected. 4
The processing shown in the flowchart of FIG. 4A is executed, and the processing shown in the flowchart of FIG. 4B is executed in response to the activation of an application program that uses the data to be protected.

Here, the processing executed when the input / output control device 7 receives the encrypted data to be protected in the arithmetic processing unit 4 of the receiving computer 2 is configured as follows.

First, in the figure, in step S11, a decryption key for decrypting the received data to be protected is input from the keyboard 9, and the flow advances to step S12 to decrypt the data to be protected with the input decryption key. , Step S1
Then, the process proceeds to step S3, where it is determined whether or not the permitted use time data is added to the head of the decrypted data to be protected. If it is determined that the data is added, the process proceeds to step S14. .

In step S14, a plurality of usage permission time data identical to the added usage permission time data are generated, and the process proceeds to step S15, where the generated usage permission time data is respectively stored as individual files in the auxiliary storage device 8.
Then, the process proceeds to step S16, where the decrypted data to be protected is stored in the auxiliary storage device 8, and a series of processing ends.

On the other hand, if it is determined in step S13 that the use permission time data has not been added to the head of the decrypted data to be protected, the process proceeds to step S16.

The processing executed by the arithmetic processing unit 4 of the receiving computer 2 in response to the activation of an application program that uses the data to be protected is configured as follows.

First, in the figure, in step S21, the data to be protected to be used is read into the RAM of the main storage device 4, and the process proceeds to step S22, where the permitted data is added to the head of the data to be protected. It is determined whether or not the data has been added. If it is determined that the data is added, the process proceeds to step S23, in which all the use permitted time data is read into the RAM of the main storage device 4, and the process proceeds to step S24, where a plurality of usage permitted Among the permitted time data, the use permitted time data whose use permitted time width is set to the shortest is selected, and the process proceeds to step S25.

In step S25, the time output from the clock timer device 6 is obtained, and the process proceeds to step S26, where the obtained time is earlier than the use permission start time set in the selected use permission time data. It is determined whether or not there is, and if it is determined that it is not before, step S
27, it is determined whether or not the obtained time is later than the use permission end time set in the selected use permission time data, and if it is determined that it is later,
The process proceeds to step S28.

In step S28, the data to be protected is erased, and the process proceeds to step S29, where the application program is executed, and a series of processing ends.

On the other hand, if it is determined in step S27 that the obtained time is not later than the use permission end time set in the selected use permission time data, the process proceeds to step S29.

On the other hand, if it is determined in step S26 that the acquired time is earlier than the use permission end time set in the selected use permission time data, the process proceeds to step S28. .

On the other hand, if it is determined in step S22 that the use permission time data has not been added to the head of the data to be protected, the process proceeds to step S29.

Next, the operation of the first embodiment will be described. First, a case where a creator of data transmits data to be protected to the receiving computer 2 in the transmitting computer 1 will be described.

First, when the creator wants to transmit the data to be protected, he inputs the designation of the data to be protected, and when the specified data to be protected is transmitted to the receiving computer 2, A use permission start time for starting use permission of the target data and a use permission end time for ending use permission are input. At this time, the creator inputs the data A to be protected as the designation of the data to be protected, and sets the current time T as the use permission start time.
₁ Type of, when used to input time T ₁ + t after the use permission start time T ₁ t time as use permission end time, use permission start time T ₁ and authority end time T ₁
+ T is set as the permitted use time data, and the generated use permitted time data specifies the protection target data A.
Is added to the beginning of

Next, the creator inputs an encryption key for encrypting the data A to be protected. At this time, for example, assuming that the public key of the creator is input, the data A to be protected is encrypted by the input public key by the RSA encryption method or the like and transmitted to the receiving computer 2.

On the other hand, upon receiving the encrypted data A to be protected, the receiving computer 2 gives the user of the receiving computer 2 an encryption key designated by the creator (public key of the creator). Is required to input a decryption key corresponding to. At this time, assuming that the licensor who has been granted permission to use the data to be protected by the creator inputs the creator's private key provided with the license, the entered private key is used in the same manner as described above in the RSA encryption method or the like. The data A to be protected is decrypted.

Then, since the use permission time data is added to the head of the decrypted data A to be protected, a plurality of the same use permission time data are generated.
These and the decrypted data A to be protected are stored in the auxiliary storage device 8 as individual files.

Next, the case where the licenser uses the data A to be protected stored in the auxiliary storage device 8 in the receiving computer 2 in the receiving computer 2 will be described.

First, when the licensor tries to start the application program in order to use the data A to be protected, for example, by displaying or editing the contents of the data A to be protected, , The usage permission time data is added to the usage permission time data, and among the plurality of usage permission time data stored in the auxiliary storage device 8, the usage permission time width is set to the shortest. Allowed time data is selected,
The time output from the clock timer device 6 is obtained.

In this case, since the usage permission start time T ₁ and the usage permission end time T ₁ + t are set in the usage permission time data, the time output from the clock timer device 6 is used as the usage permission time data. Is later than the use permission start time T ₁ and the use permission end time T ₁
If it is earlier than + t, it is regarded that the time is within the use permission time width, and the application program is started without erasing the data to be protected.

However, when the time output from the clock timer device 6 is later than the use permission end time T ₁ + t set in the use permission time data, that is, when the time exceeds the use permission time, the protection is performed. After the target data is deleted, the application program is started.

In this case, the licensor tries to illegally extend the use permission time set by the creator and sets the time of the clock timer device 6 to the use permission end time T ₁ + t.
If it is set far before (before the use permission start time T ₁ ), the time output from the clock timer device 6 will be later than the use permission start time T ₁ in response to the activation of the application program. Is also determined to be before, the data to be protected is deleted.

In addition, the licensor tries to illegally extend the use permission time set by the creator, and starts the use permission start time T ₁ or use permission end of all the use permission time data stored in the auxiliary storage device 8. It is assumed that the time T ₁ + t has been falsified. However, since at least the use permission start time and the use permission end time of the use permission time data added to the head of the protection target data remain at T ₁ and T ₁ + t, it is determined whether or not to delete the protection target data. When the determination is made, the added usage permission time data is
The usage permission time width is selected as being set to the shortest, and the time output from the clock timer device 6 is earlier than the usage permission start time T ₁ as initially set, or When it is later than the use permission end time T ₁ + t, the data to be protected is erased.

If the receiving computer 2 does not add the permitted use time data to the head of the decrypted data to be protected, that is, if normal data is decrypted, the permitted use time data is generated. However, only the decrypted data to be protected is stored in the auxiliary storage device 8 as it is.
Is stored in

Further, when the application program is started in the receiving computer 2 and the usage-permitted time data is not added to the head of the data to be protected, that is, when normal data is to be used, No processing is performed on the data, and the application program is started.

As described above, in the transmission-side computer 1, the use permission time data in which the use permission start time and the use permission end time are set are associated with the data to be protected, and the data is transmitted to the reception computer 2. 2, when the time output from the clock timer device 6 is not within the usage permission time range based on the associated usage permission time data, the data to be protected is erased. Even if it is changed, it is possible to reduce the possibility that the data to be protected is used indefinitely in time, thereby effectively protecting the interests of the creator.

In particular, in response to the reception of the data to be protected, the receiving computer 2 generates a plurality of permitted use time data identical to the added permitted use time data, and determines whether to delete the protected data. Is determined based on the permitted time data for which the permitted time width is set to the shortest. If the permitted time data is falsified, the permitted time can be extended illegally. Performance can be reduced.

In the transmitting computer 1, the use permission start time and the use permission end time are variably set according to the intention of the creator of the data to be protected. The permitted time can be freely restricted, and the creator can easily use the data to be protected by the licensor.

Further, a plurality of dummy permitted time data is generated not in the transmitting computer 1 but in the receiving computer 2.
The data size transmitted from the transmitting computer 1 can be reduced.

Next, a second embodiment of the present invention will be described. According to the second embodiment, the data protection device according to the present invention can be used in the receiving computer 2 to erase protected data whose use permitted time has passed without using the time output from the clock timer device 6. It is applied to

This is based on the first embodiment.
The processing shown in the flowchart of FIG. 4A executed by the arithmetic processing unit 4 of the receiving computer 2 when the encrypted data to be protected is received by the input / output control unit 7,
Instead of the processing shown in the flowchart of FIG. 4B which is executed in response to the activation of the application program that uses the data to be protected, when the input / output control device 7 receives the encrypted data to be protected, FIG.
The processing shown in the flowchart of FIG.
After the processing shown in the flowchart of FIG. 5A is executed, the interrupt processing shown in the flowchart of FIG. 5B is executed at a predetermined interrupt cycle.

Here, in the processing unit 4 of the receiving computer 2, the processing executed when the input / output control unit 7 receives the encrypted data to be protected is configured as follows.

First, in the figure, in step S31, a decryption key is input from the keyboard 9, and the flow advances to step S32 to decrypt the data to be protected with the input decryption key. The flow then advances to step S33 to decrypt the data. It is determined whether or not use permission time data is added to the head of the protection target data, and when it is determined that the data is added, the process proceeds to step S34.

In step S34, the use permission time is acquired from the use permission time data, and the acquired permission time is registered in the interrupt processing of the flowchart of FIG.
35, the count data to be counted in the interrupt process of the flowchart of FIG. 5B is initialized, and the process proceeds to step S36, where the decrypted data to be protected is stored in the auxiliary storage device 8, and a series of processes is performed. To end.

On the other hand, when it is determined in step S33 that the use permission time data has not been added to the head of the decrypted data to be protected, the process proceeds to step S36.

The interrupt process executed at a predetermined interrupt cycle after the execution of such a process is configured as follows. First, in the figure, in step S41, the count data is added, and the process proceeds to step S42, where the count data is multiplied by an interrupt cycle, and the usage time elapsed from the reception of the protection target data to the present time is calculated. , The process proceeds to step S43.

In step S43, it is determined whether or not the calculated usage time has exceeded the usage permission time. If it is determined that the usage time has exceeded, the process proceeds to step S44 to erase the data to be protected. A series of processes is terminated. However, when it is determined in step S43 that the calculated use time does not exceed the use permission time, a series of processing is ended.

Next, the operation of the second embodiment will be described. First, when the receiving computer 2 receives the data A to be protected transmitted from the transmitting computer 1 in the same manner as described above, the user of the receiving computer 2 is required to input a decryption key. At this time, assuming that the licensor inputs the secret key of the creator, the data A to be protected is decrypted by the input secret key.

Then, since the use permitted time data is added to the head of the decrypted protected data A, the use permitted time is obtained from the use permitted time data,
This is registered in the interrupt processing of FIG. 5B, and “0” is set as an initial value in the count data counted in the interrupt processing of FIG. 5B. Then, the decrypted data A to be protected is stored in the auxiliary storage device 8.

Thereafter, at a predetermined interrupt cycle T _i , FIG.
Interrupt process (b) is performed for each interrupt period, the count data is added, the use time is calculated by multiplying the interrupt period T _i to count data. When it is determined that the use time exceeds the registered use permission time, the protection target data A is deleted.

In this case, it is assumed that the licensor falsifies the added use permission time data in order to illegally extend the use permission time set by the creator. However, at the same time as the reception, the use permission time set in the use permission time data is registered in the interrupt processing shown in FIG. 5B. In this interrupt processing, the data to be protected is registered based on the registered use permission time. Since it will be deleted, according to the initial usage permission time,
The data to be protected is erased.

As described above, in the interrupt processing at the predetermined interrupt cycle, whether or not the use permission time has been exceeded is constantly monitored. Therefore, regardless of the time output from the clock timer device 6, the use permission time is determined. Data that exceeds the limit can be immediately erased, and the possibility that the protected data is used indefinitely in time can be further reduced, thereby effectively protecting the interests of the creator. .

In particular, at the same time that the data to be protected is received, the use permission time is obtained from the added use permission time data, and the obtained use permission time is registered in the interrupt processing. Since the data to be protected is erased based on the time, the possibility that the use permission time is extended can be reduced.

In the above embodiment, the permitted time data is added to the head of the data to be protected. However, the present invention is not limited to this, and the permitted time data is added to the inside or at the end of the protected data. Or to configure
Alternatively, the use permission time data may be generated as data different from the protection target data, and the link target of the use permission time data may be held in the protection target data.

In the above-described embodiment, the use permission start time and the use permission end time are set directly in the use permission time data. However, the present invention is not limited to this. In this case, use permission time is divided into several stages and managed in advance, such as 1 hour for B, 3 hours for B, 10 hours for C, and so on. The data (in this case, any data of A to C) that specifies the permitted use time may be set as the permitted use time data. With such a configuration, since the use permission time is not directly set in the use permission time data, the possibility of the contents of the use permission time data being decrypted and falsified can be reduced.

Further, in the above embodiment, the use permission start time for starting the use permission and the use permission end time for ending the use permission are set in the use permission time data, and the use permission start time and the use permission end time are set as the use permission time data. Although it is configured to determine whether to erase the data to be protected on the basis of this, the present invention is not limited to this, and the transmission-side computer 1 sets the permitted use time width (for example, t time) to the permitted use time data. When the data to be protected is received by the receiving computer 2, the time at which the data was received is set as the use permission start time in the use permission time data, and the data is used based on the use permission start time and the use permission time width. The permission end time is calculated, and it is determined whether to delete the protection target data based on the calculated use permission end time and use permission start time. It may form.

Further, in the above-described embodiment, the receiving computer 2 is configured to execute processing for generating a plurality of dummy permitted use time data. However, the present invention is not limited to this. , When adding permitted time data to protected data,
The processing as the use permission time data associating means according to claim 2 for generating a plurality of dummy use permission time data may be executed, and these may be collectively transmitted to the reception side computer 2.

Furthermore, in the above embodiment, a plurality of dummy permitted use time data is generated. However, the present invention is not limited to this. In particular, a plurality of dummy permitted use time data is not generated. May be configured.

Further, in the above-described embodiment, the processing is not performed particularly when the use permission time data is tampered with illegally. However, the present invention is not limited to this, and the use permission time data may be tampered with illegally. When it is determined, for example, it is configured to execute a process of rewriting all the use permission time data to the use permission time data whose use permission time width is set to the shortest or deleting the protection target data. Is also good. With such a configuration, the possibility that the use permission time data is tampered with illegally can be further reduced.

Further, in the above-described embodiment, the transmission-side computer 1 is configured to encrypt and transmit the data to be protected. However, the present invention is not limited to this, and the data to be protected is transmitted without any particular encryption. May be configured.

Further, in the above embodiment, when the transmission-side computer 1 adds the permitted use time data to the data to be protected and transmits the data, and the reception-side computer 2 attempts to use the data to be protected, Although the protection target data is erased based on the added usage permission time data, the present invention is not limited to this, and a series of processes may be executed in one computer. .

Further, in the above embodiment, the use permission start time set in the use permission time data is not reset, but the present invention is not limited to this. The use permission start time may be reset to the current time obtained from the clock timer device 6. With such a configuration, a value obtained by subtracting the elapsed use time already used from the preset use permission time is reset as a new use permission time, and based on the new use permission time, If the data to be protected is erased, the possibility that the use permission time is illegally extended by changing the time of the clock timer device can be reduced.

Further, in the above embodiment, FIG.
In executing the processing shown in the flowcharts of FIGS. 4 and 5, the case where a program stored in advance in the ROM of the main storage device 5 is executed has been described. However, the present invention is not limited to this. The program may be read from a recording medium on which the program is recorded and loaded into the RAM of the main storage device 5 and executed.

Here, the recording medium is RAM, ROM,
Any recording medium such as an FD, a compact disk, a hard disk, a magneto-optical disk, or paper, which can be read by a computer regardless of an electronic, magnetic, optical, or other reading method. It includes a recording medium.

Further, in the above embodiment, FIG.
Although the processing shown in the flowcharts of FIGS. 4 and 5 has been described in the case of being configured by software,
Instead, electronic circuits such as a comparison circuit, an arithmetic circuit, and a logic circuit may be combined.

In the above embodiment, steps S4 and S5 correspond to the use permission time data associating means according to claim 1, 3 or 4, and steps S2 to S5 correspond to the use permission time according to claim 5. Steps S25 to S28 correspond to data protection means according to claim 1 or 3, and steps S24 to S28 correspond to data protection means according to claim 2 or 4. Corresponding to step S14 and S
Reference numeral 15 corresponds to the second use permission time data associating means.

[0098]

As described above, according to the data protection device of the present invention, even if the time of the clock timer device is changed, the possibility that the data to be protected is used indefinitely is reduced. Therefore, the effect that the profit of the creator can be effectively protected can be obtained.

According to the data protection device of the second or fourth aspect of the present invention, it is possible to reduce the possibility that the use permission time is illegally extended by falsifying the use permission time data. The effect that can be obtained is also obtained.

Further, according to the data protection device of the fifth aspect of the present invention, the creator or the owner can freely limit the permitted time for using the data to be protected. An effect is also obtained that the data to be protected is easily used by the licensor.

Furthermore, according to the data protection device of the sixth aspect of the present invention, the possibility that the use permission time is illegally extended can be reduced by changing the time of the clock timer device. The effect is also obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment.

FIG. 2 is a block diagram showing a configuration of a transmitting computer and a receiving computer in FIG.

FIG. 3 is a flowchart illustrating a process executed by a transmission-side computer.

FIG. 4 is a flowchart illustrating a first process executed by the receiving computer.

FIG. 5 is a flowchart illustrating a second process executed by the receiving computer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sending computer 2 Receiving computer 3 Data transmission line 4 Arithmetic processing unit 5 Main storage device 6 Clock timer device 7 Input / output control device 8 Auxiliary storage device 9 Keyboard

Claims (6)

[Claims] 1. A data protection device applied to a computer and erasing data to be protected exceeding a predetermined time on the basis of a time output from a clock timer device, to start data use permission. A use permission time data associating unit that associates use permission time data for specifying the use permission start time and the use permission end time for terminating the use permission of the data with the protection target data; When the time output from the clock timer device is before the use permission start time or after the use permission end time, the protection target data erasing means for erasing the protection target data. A data protection device comprising: 2. The use permission time data associating means,
A plurality of the use permission time data are associated with the data to be protected, and the protection target data erasing means includes the use permission time data having the shortest use permission time width among the plurality of use permission time data. 2. The data protection device according to claim 1, wherein the data to be protected is determined to be erased based on the following. 3. The method according to claim 2, wherein
3. The data protection device according to claim 1, wherein the data protection device is provided in a transmission side computer, and the protection target data erasing means is provided in a reception side computer connected to the transmission side computer via a network. 4. A method according to claim 1, wherein the transmitting computer that transmits the data and the receiving computer that receives the data transmitted from the transmitting computer are applied to a network connected thereto, and erase data to be protected that exceeds a predetermined time. In the data protection device, the use permission time data for specifying the use permission start time for starting the data use permission and the use permission end time for ending the data use permission are associated with the data to be protected. Second use permission time data associating means for associating at least one of the use permission time data with the protection target data when receiving the protection target data; And the use permission time width is the shortest among the plurality of use permission time data. When the time output from the clock timer device is before the use permission start time or after the use permission end time, the protection target data is erased based on the use permission time data. A data protection device for erasing data to be protected, which is provided in the receiving computer. 5. The use permission time data associating means,
2. The system according to claim 1, wherein at least one of the use permission start time and the use permission end time is variably set according to a creator or an owner of the data to be protected. 5. The data protection device according to 2, 3, or 4. 6. In the direction of shortening the use permission time width,
3. The system according to claim 1, wherein the use permission start time specified by the use permission time data is reset to a time output from the clock timer device or a time before the time. The data protection device according to 3, 4, or 5.