JP2002268549A - Method for controlling access to information, device for controlling access to information, network system for controlling access to information and program for controlling access to information - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control access to information by deciphering ciphered information with a decipher key generated from information regarding the geographical position of a deciphering terminal and deciphering time. SOLUTION: In an information transmission/reception terminal 101, from geographical present position information generated by a position information generation means 105, a key generation means 106 generates the decipher key for trial. An information deciphering means 108 tries the deciphering of the ciphered information with the decipher key for the trial. Only when the geographic present position information generated by the position information generation means 105 and the geographic position information which is the base of generating the decipher key match, the ciphered information is deciphered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling access to information using information on a geographical position and time,
The present invention relates to an information access control device, an information access control network system, and a program for causing a computer to execute an information access control method.

[0002]

2. Description of the Related Art Computers, portable information terminals, and other devices access information recorded on recording media such as floppy (registered trademark) disks, hard disks, and CD-ROMs, as well as general telephone lines, dedicated lines, and wireless lines. Can access information stored in another device via a network.

[0003] Among the information that can be accessed in this way, access may be restricted due to secret information or the like. As a conventional method of restricting access to information, a password input is required when attempting to access information recorded on a recording medium or when connecting to a network, and the input password is set in advance. A method of permitting access only when the password matches the password, or encrypting the information to be accessed in advance using a specific encryption key, and decrypting it correctly when accessing the encrypted information. There is a method of decrypting using a decryption key that can be used. Each of these methods controls access to information by authenticating the user.

On the other hand, as a method of controlling access to information that does not authenticate a user, an access to stored information and an actual geographical position determined based on a signal received by a receiver supplying position information are permitted. The actual geographic location is within the permitted geographic area or the actual geographic location determined based on the signal received by the receiver providing the time information. If the time belongs to a predetermined period during which access to the stored information is permitted, the user is permitted to access the stored information, and the information is accessed using geographical location information and time information. Japanese Patent Laid-Open No.
No. 00-163379.

[0005]

In recent years, with the development of portable devices such as portable telephones and portable information terminals, it has become possible to access information anytime and anywhere. However, depending on the information, it may not be desirable to be accessed anytime and anywhere, for example, information that is desired to be disclosed only to a person who has visited a specific place or information that can be browsed only at a specific time. In the method of authenticating the user, such as the method of requesting the input of the password or the method of decrypting with the decryption key that can correctly decrypt the information, if the user is authenticated, the information can be accessed anytime and anywhere. However, it has not been possible to restrict access to information that is desired to be disclosed only at a specific place or time as described above.

The method described in Japanese Patent Application Laid-Open No. 2000-163379 solves this problem, but compares the actual geographical location where information is accessed with the geographical area where information access is allowed. Therefore, it is necessary to store the geographical area to which the access is permitted in association with the information to be accessed in the information storage means provided in the device that accesses the information. However, there has been a problem that the information accessing device becomes accessible by falsification such as deletion or alteration of the information on the geographical area to which the access is permitted. This is an inevitable problem in that information for permitting access is stored in the information storage means.

Japanese Patent Application Laid-Open No. 2000-163379 describes a step of encrypting stored information using an encryption key, and a method of determining the actual geographical position of accessing information by the geographical location to which information access is permitted. When located within the area,
A method for controlling access to information by providing a decryption key that allows decryption of the stored information is also described. According to this method, even if the encrypted stored information is directly accessed, the content cannot be referred to. However, as described above, tampering such as deleting or altering the information on the geographical position and time to which access is permitted as described above. Had a problem of being weak.

[0008] If the information relating to the geographical position to which access to the information is permitted is further encrypted, the information will be more resistant to tampering as described above. However, if an unspecified device intends to permit access to the same information only at a specific location, any device must be able to decrypt the information related to the geographical position that permits access to the encrypted information. Therefore, there is not much significance in performing the encryption, and there is a problem that the process of encrypting or decrypting the information relating to the geographical position where the access to the information is permitted is rather troublesome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to generate encrypted information from information relating to a geographical position of a terminal to be decrypted and time to be decrypted. Controlling access to information by decrypting with a decryption key, an information access control method, an information access control device, an information access control network system, and a method for causing a computer to execute an information access control method To provide a program.

[0010]

The method for controlling access to information according to the present invention is intended to solve the above-mentioned problems.
A method for controlling access to information encrypted so that it can be decrypted with a decryption key generated from geographical location information, comprising: a first step of generating geographical current location information;
A second step of generating a trial decryption key from the geographical current position information generated in the first step;
And a third step of attempting to decrypt the encrypted information with the trial decryption key generated in the step of generating the geographical current position information obtained in the first step and the decryption key. Only when the geographical position information matches, the encrypted information is decrypted.

Here, the geographical current position information is the geographical position at which access is attempted when the access control method for information according to the present invention is executed and access to the encrypted information is attempted. Is information that indicates

In order to generate geographical current position information in the first step, for example, a GPS (Global Positioning S
ystem) The current position may be generated using a receiver, or the current position of the receiver may be generated by signals received from multiple base stations, such as a method for obtaining position information in a PHS (Personal Handyphone System). May be calculated and generated.

With the above arrangement, a trial decryption key is generated in the second step from the geographical current position information generated in the first step, and the trial decryption key is generated in the third step using the trial decryption key. Attempt to decrypt the encrypted information. Since the encrypted information is decrypted only when the geographical current position information generated in the first step matches the geographical position information for generating the decryption key, the device accessing the information is actually The access control to the information according to the place can be performed such that whether the access to the information is permitted or not is determined according to the place located at the location.

That is, in the access control method of the present invention, the permission information for permitting the access is not stored in the information storage means. Therefore, there is no possibility that the access control is broken by the falsification of the permission information. It is also difficult to refer to the content of the information by falsifying the encrypted information itself, so that the security of the information can be enhanced.

[0015] The encryption key and the decryption key may be the same or different from each other depending on the encryption method. For example, in the case of an encryption system such as a single alphabet system, the same encryption key and the same decryption key are used. In the case of an encryption method such as a public key method, the encryption key and the decryption key are different keys forming a pair.

If the former method is used, the encryption key for encrypting so that it can be correctly decrypted with a decryption key generated from certain geographical location information is the same as the geographical location information for generating the decryption key. Therefore, the processing can be simplified.

[0017] The accuracy of the geographical current position information obtained in the first step affects the range of the information that can be accessed. What is the accuracy of your geographic location?
For example, when the geographical current position information is expressed by latitude and longitude, whether the accuracy is expressed in degrees, minutes, or seconds,
That's what it means. If the accuracy of the geographical current location information obtained in the first step is high, the actual geographical area where the same geographical current location information is obtained becomes smaller, and the area where the information can be accessed becomes smaller. .

Conversely, if the accuracy of the geographical position information obtained in the first step is low, the actual geographical area in which the same geographical current position information can be obtained becomes large, so that the information is accessed. The area that can be made is also wider. The degree of accuracy of the geographical current position information obtained in the first step is determined by the size of an area for which access to information is to be restricted and the geographical current position information that can be generated in the first step. What is necessary is just to determine in advance according to the highest precision.

In order to solve the above-mentioned problems, the method for controlling access to information according to the present invention, in addition to the above-mentioned configuration, further comprises one or more geographically neighboring areas based on the geographical current position information. A fourth step of generating geographical neighboring position information that becomes the following. When the trial decryption key cannot be correctly decrypted in the third step, the fourth step
Generating a new trial decryption key from the geographical proximity position information generated in the step, and attempting to decrypt the encrypted information with the new trial decryption key. It is characterized by:

According to the above configuration, when the encrypted information is not decrypted by the trial decryption key in the third step, the fifth step is generated in the fourth step. A new trial decryption key is generated from the geographical proximity position information, and an attempt is made to decrypt the encrypted information with the new trial decryption key. As a result, when the geographical proximity position information matches the geographical position information for generating the decryption key, it is possible to successfully decrypt the encrypted information.

Therefore, the actual geographical location of the device attempting to access the information by implementing the information access control method according to the present invention is used to generate a decryption key capable of correctly decrypting the encrypted information. Even if the information does not completely match the geographical position of the information, the information can be correctly decoded by trying to decode the information at least once or more if it is in the vicinity.

According to a method for controlling access to information according to the present invention, in order to solve the above-mentioned problems, in addition to the above-mentioned configuration, one or more geographical positions can be determined from the geographical current position information. A sixth step of generating different-accuracy geographical position information having changed accuracy; and a step of generating the different-accuracy geographical information generated in the sixth step when the trial decryption key cannot be correctly decrypted in the third step. And generating a new trial decryption key from the target position information, and attempting to decrypt the encrypted information with the new trial decryption key.

According to the above configuration, when the encrypted information is not decrypted with the trial decryption key in the third step, the seventh step is generated in the sixth step. A new trial decryption key is generated from the different precision geographical position information, and an attempt is made to decrypt the encrypted information with the new trial decryption key. Therefore, even if the accuracy of the geographical location information that generated the decryption key is not known,
By generating a new trial decryption key from the different-accuracy geographical location information, if the different-accuracy geographical location information matches the geographical location information that generates the decryption key, the encrypted information is decrypted. Can succeed.

Therefore, for the side controlling the access to the information, the information for which the geographical position that can be decrypted is to be widened is encrypted so that it can be decrypted with a decryption key generated from the coarse geographical position information, Conversely, for information that requires a narrower geographical location that can be decrypted, control the geographical area that can access the information by encrypting it so that it can be decrypted with a decryption key generated from highly accurate geographical location information. You can do it.

According to the method for controlling access to information according to the present invention, a method for controlling access to information encrypted so as to be decrypted with a decryption key generated from time information for solving the above-mentioned problem. Wherein a first step of generating current time information, a second step of generating a trial decryption key from the current time information generated in the first step, and a second step of generating a trial decryption key are performed in the second step. And a third step of attempting to decrypt the encrypted information with the trial decryption key, when the current time information obtained in the first step matches the time information for generating the decryption key. Only the encrypted information is correctly decrypted.

Here, the current time information is information indicating the time when the access control method for the information according to the present invention is executed and the access to the encrypted information is attempted. However, as will be described later, the unit of time of the current time information changes depending on the accuracy of expressing the current time.

In order to generate the current time information in the first step, for example, a clock function usually built in a computer may be used, or the current time information may be received from another device via a network. Time information may be used.

According to the above configuration, a trial decryption key is generated in the second step from the current time information generated in the first step, and the trial decryption key is generated in the third step using the trial decryption key. Attempt to decrypt the encrypted information. Since the encrypted information is decrypted only when the current time information generated in the first step and the current time information for generating the decryption key match, according to the time when the information is to be accessed. It is possible to control access to information according to time so that whether access to information is permitted or not is determined.

In this access control method, since information for permitting access is not stored in the information storage means, there is no possibility that the access control may be broken by falsification of the information. It is also difficult to refer to the contents of the information by falsifying itself, so that the security of the information can be enhanced.

The accuracy of the current time information obtained in the first step affects a period during which the information can be accessed. The accuracy of the current time information is, for example, year, month, week,
Whether to represent the current time with day, hour, minute, or second precision,
That's what it means. When the accuracy of the current time information obtained in the first step is high, the width of the actual period during which the same current time information is obtained becomes narrower, and the period during which the information can be accessed becomes shorter. Conversely, if the accuracy of the current time information obtained in the first step is low, the width of the actual period in which the same current time information is obtained becomes wider,
The width of the period during which the information can be accessed is widened. The accuracy of the current time information obtained in the first step is determined by the width of the period in which access to the information is to be restricted and the maximum accuracy of the current time information that can be generated in the first step. Accordingly, it may be determined in advance.

According to the method for controlling access to information according to the present invention, in order to solve the above-described problem, in addition to the above-described configuration, one or more temporally neighboring information is obtained from the current time information. A fourth step of generating near-time information; and a new trial decryption key based on the near-time information generated in the fourth step, when the trial decryption key cannot be correctly decrypted in the third step. And attempting to decrypt the encrypted information with the new trial decryption key.

According to the above configuration, when the encrypted information is not decrypted by the trial decryption key in the third step, the fifth step is generated in the fourth step. A new trial decryption key is generated from the neighboring time information, and an attempt is made to decrypt the encrypted information with the new trial decryption key. As a result, when the nearby time information matches the time information for generating the decryption key, the encrypted information can be successfully decrypted.

Therefore, the actual time for accessing the information by implementing the method for controlling access to information according to the present invention is completely equal to the time for generating a decryption key that can correctly decrypt the encrypted information. Does not match
If it is temporally close, the information can be correctly decoded by trying decoding the information at least once.

According to the method of controlling access to information according to the present invention, in order to solve the above-described problem, in addition to the above-described configuration, one or a plurality of time precisions are changed from the current time information. A sixth step of generating different precision time information, and when the third step fails to correctly decrypt with the trial decryption key, a new trial time is obtained from the different precision time information generated in the sixth step. Generating a decryption key and attempting to decrypt the encrypted information with the new trial decryption key.

According to the above configuration, when the encrypted information is not decrypted by the trial decryption key in the third step, the seventh step is generated in the sixth step. A new trial decryption key is generated from the different precision time information, and an attempt is made to decrypt the encrypted information with the new trial decryption key. Therefore, even if the accuracy of the time information at which the decryption key was generated is not known, by generating a new trial decryption key from the different accuracy time information, the different precision time information matched the time information at which the decryption key was generated. In this case, the encrypted information can be successfully decrypted.

Therefore, for the side controlling the access to the information, the information for which the range of the decryptable time is desired to be widened is encrypted so that it can be decrypted with the decryption key generated from the coarse time information, and conversely. For information for which the range of time that can be decrypted is desired to be narrowed, by encrypting the information so that it can be decrypted with a decryption key generated from highly accurate time information, the range of time during which information can be accessed can be controlled. .

In the method for controlling access to information according to the present invention, the encrypted information is information relating to an advertisement.

[0038] According to the above configuration, the encrypted advertisement information can be decrypted and referred to only at a specific place and time, and the encrypted advertisement information can be tampered with to obtain the content. Is difficult to refer to, so it is possible to increase the effect of attracting customers by permitting information access from a specific geographical location, for example, that only people who visit the advertiser's store can see the contents. It is possible to realize an advertisement in which the content can be referred to only by time and the time is limited like a time service.

In the method of controlling access to information according to the present invention, the encrypted information is message data for performing communication between users.

According to the above configuration, the encrypted message data can be correctly decrypted and referred to only at a specific place and time, and the content of the encrypted message data is falsified by alteration. Since it is difficult to refer to the message, communication using a message such as a bulletin board that can be referred to only in a specific place can be performed.

In the method for controlling access to information according to the present invention, the encrypted information is a game (or a game)
It is characterized in that it is information used for.

With the above arrangement, the encrypted game information can be correctly decrypted and referred to only at a specific place or time, and the information used for the encrypted game can be obtained. Since it is difficult to falsify and refer to the contents, it is possible to realize a game using positions and times in the real world, such as treasure hunting and orienteering.

It goes without saying that an access control method for controlling access to information based on geographical location information and an access control method for controlling access based on time information can be combined. For example, a trial generated by encrypting information encrypted so that it can be decrypted with a decryption key generated from time information and decrypting it with a decryption key generated from geographical location information, and generating the information from geographical current location information When the decryption key for use matches the decryption key generated from the geographical location information, a part of the information is decrypted to clarify the target location, and the trial decryption key generated from the current time information is Access to the information can be controlled such that if the decryption key matches the decryption key generated from the time information, all of the information is decrypted and the target time is also revealed.

The information access control device according to the present invention controls access to information encrypted so that it can be decrypted with a decryption key generated from geographical position information in order to solve the above-mentioned problem. An access control device,
Position information generating means for generating geographical current position information, trial decryption key generating means for generating a trial decryption key from the geographical current position information generated by the position information generating means, and trial trial key generation Information decryption means for attempting to decrypt the encrypted information with the trial decryption key generated by the means, and the geographical current position information generated by the position information generation means and the geographical information generating the decryption key. Only when the position information matches, the encrypted information is decrypted.

With the above arrangement, the trial decryption key generation means generates a trial decryption key from the geographical current position information generated by the location information generating means, and the information decryption means uses the trial decryption key. Attempt to decrypt the encrypted information. Since the encrypted information is decrypted only when the geographical current position information generated by the position information generating means matches the geographical position information for generating the decryption key, the information related to the present invention The access control to the information according to the place can be performed such that whether the access to the information is permitted or not is determined according to the place where the access control device is actually located.

That is, in the access control device of the present invention, since the permission information for permitting the access is not stored in the information storage means, there is no possibility that the access control is broken by the falsification of the permission information. Since it is difficult to refer to the contents of the information by falsifying the encrypted information itself, the security of the information can be enhanced.

In order to solve the above-mentioned problems, the information access control device according to the present invention, in addition to the above-described configuration, generates an encryption key from the geographical position information generated by the position information generating means. A first encryption key generation unit for generating, a first information encryption unit for encrypting the information decrypted by the information decryption unit with the encryption key, and a first information transmission / reception via a network. Communication means.

With the above arrangement, the first information encrypting means further encrypts the information decrypted by the information decrypting means with the encryption key generated by the first encryption key generating means, The encrypted information is transmitted by the first communication means. Another device for controlling access to information according to the present invention that has received the encrypted information decrypts the encrypted information as described above.

Therefore, by encrypting the information received and decrypted by the access control device for information relating to the present invention again and transmitting it to another access control device, it is possible to refer to the content only at a specific place. Using information that can be
Communication between access control devices can be achieved. In addition, a certain access control device can function as a server device serving as a distribution source of encrypted information.

The information access control device according to the present invention is an access control device for controlling access to information encrypted so as to be decrypted with a decryption key generated from time information in order to solve the above-mentioned problem. A control device, comprising: time information generation means for generating current time information; trial decryption key generation means for generating a trial decryption key from the current time information generated by the time information generation means; Information decryption means for attempting to decrypt the encrypted information with the trial decryption key generated by the key generation means, and current time information generated by the time information generation means and time information for generating the decryption key Is characterized in that the encrypted information is decrypted only when 一致 matches.

With the above arrangement, the trial decryption key generation unit generates a trial decryption key from the current time information generated by the time information generation unit, and the information decryption unit uses the trial decryption key to generate the encryption key. Attempt to decrypt the coded information. Since the encrypted information is decrypted only when the current time information generated by the time information generating means and the current time information for generating the decryption key match, according to the time to access the information, It is possible to control access to information according to time so that whether access to information is permitted or not is determined.

That is, in the access control apparatus of the present invention, since information for permitting access is not stored in the information storage means, there is no possibility that access control may be broken by falsification of information. Since it is difficult to falsify the encrypted information itself and refer to the contents of the information, security of the information can be improved.

In order to solve the above-mentioned problem, the information access control device according to the present invention, in addition to the above configuration, generates an encryption key from the time information generated by the time information generating means. First encryption key generation means, first information encryption means for encrypting information decrypted by the information decryption means with the encryption key, first communication for transmitting and receiving information via a network Means.

According to the above configuration, further, the first information encryption means encrypts the information decrypted by the information decryption means with the encryption key generated by the first encryption key generation means, The encrypted information is transmitted by the first communication means. Another device for controlling access to information according to the present invention that has received the encrypted information decrypts the encrypted information as described above.

Therefore, by encrypting the information received and decrypted by the access control device for information related to the present invention again and transmitting it to another access control device, the content can be referred to only at a specific time. Using information that can be
Communication between access control devices can be achieved. In addition, a certain access control device can function as a server device serving as a distribution source of encrypted information.

The network system for controlling access to information according to the present invention is designed to solve the above-mentioned problems.
Second encryption key generation means for generating a key for encrypting information from the above access control device and geographical location information of an arbitrary place, and encrypting information with an encryption key generated by the encryption key generation means And a server device provided with a second information encrypting means to be encrypted and a second communication means for transmitting and receiving information via a network.

As a method of acquiring the geographical position information of an arbitrary place, a method of reading out map information stored in advance, a method of receiving and acquiring information from an external device for providing geographical position information, a method of obtaining a keyboard, and the like are provided. It may take various forms, such as a method of acquiring geographical position information input by a user using an input device.

According to the above configuration, the access control device receives the information transmitted from the server device and encrypted with the encryption key generated by the second encryption key generation means, and In this way. Therefore, for a wide range of access control devices, it is possible to perform access control to information according to a place, and it is difficult to falsify the encrypted information and refer to the contents of the information.
Security for information can be increased.

A network system for controlling access to information according to the present invention is provided to solve the above-mentioned problems.
A second encryption key generating means for generating a key for encrypting information from the above access control device and arbitrary time information, and a second encryption key generating means for encrypting information with an encryption key generated by the encryption key generating means. And a server device having a second communication unit for transmitting and receiving information is connected via a network.

As a method of obtaining arbitrary time information,
A method for reading information stored in a preset manner such as a timetable, a method for receiving and acquiring information from an external device that provides preset time information, and a method in which a user inputs information using an input device such as a keyboard. It can take various forms, such as a method of acquiring time information.

According to the above configuration, the access control device receives the information transmitted from the server device and encrypted with the encryption key generated by the second encryption key generation means, and In this way. Therefore, for a wide range of access control devices, it is possible to control access to information according to time, and it is difficult to falsify the encrypted information and refer to the contents of the information.
Security for information can be increased.

The information access control program according to the present invention is a program for causing a computer to execute the above information access control method in order to solve the above-mentioned problems.

With the above configuration, it is possible to realize that a general computer executes the above-described information access control method.

It is needless to say that a computer-readable recording medium on which an information access control program for causing a computer to execute the information access control method described above is also included in the scope of the present invention.

Further, the terminal device that implements the method for controlling access to information according to the present invention stores an identifier such as a number unique to each terminal device, and the encrypted information is a reference to the information. Is further encrypted so that it can be decrypted with a decryption key generated from the identifier of the terminal device that permits the terminal device, before the terminal device attempts to decrypt the encrypted information by the information decryption means, A decryption key may be generated from an identifier possessed by the device, and the encrypted information may be decrypted with the generated decryption key.

In this way, since the encrypted information can be correctly decrypted only by the specific terminal device which has been previously permitted to refer to the information as described above, the information is copied to another terminal device. Decryption can be suppressed.

Further, the identifier has a hierarchical structure such as a tree structure, and the encrypted information indicates up to a hierarchy including a terminal device permitted to refer to the information.
The terminal device is further encrypted so that it can be decrypted with a decryption key generated from a part of the identifier, and the terminal device represents up to a certain layer before attempting to decrypt the encrypted information by the information decryption means. A decryption key may be generated from a part of the identifier possessed by, and the encrypted information may be decrypted with the generated decryption key.

For example, it is assumed that the format is such that the identifier is “abcd” and the upper group name to the lower group name are connected by “.”. This is similar to describing a large group to a small group, such as "Nara prefecture. Tenri city. Ishimoto town". At this time, the encrypted information is further encrypted so that it can be decrypted with a decryption key generated from “ab” in order to allow the terminal devices included in the group of “ab” to correctly decrypt.

On the other hand, for example, a terminal device having an identifier “abef” is a part of the identifier “a”, “a.
b) "abe""abef" Each to generate a decryption key, and try to decrypt the information with each decryption key,
The information is decrypted with the decryption key generated from "ab". On the other hand, for example, the terminal device having the identifier “aghi” cannot decode the information.

As described above, if the decryption key generated from a part of the identifier indicating the higher hierarchy of the identifier can be correctly decrypted, the number of terminal devices that can correctly decrypt can be increased. A terminal capable of correctly decrypting the encrypted information, such that the terminal device capable of correctly decrypting can be limited to a small number if the decryption key is generated from a part of the identifier representing the hierarchy. The range of the device can be controlled.

[0071]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) The first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a block diagram showing the configuration of a system for transmitting and receiving information using an information access control device according to the first embodiment of the present invention.

In FIG. 1, reference numeral 101 denotes an information transmission / reception terminal for transmitting / receiving information, which is an information access control apparatus according to the present invention, and reference numeral 102 denotes a network for connecting a plurality of information transmission / reception terminals 101.

The information transmitting / receiving terminal 101 may be a device such as a general computer, a portable information terminal, a portable telephone, or the like, which can execute the method for controlling access to information according to the present invention. The network 102 is configured using a public telephone line, a wireless line, a dedicated line, the Internet, or the like. Here, only four information transmitting / receiving terminals 101 are shown, but the number is not limited to this.

The information transmitting / receiving terminal 101 has a GPS receiver 104 for receiving a signal as position information from one or a plurality of GPS satellites 103, and a signal represented by latitude and longitude from a signal received by the GPS receiver 104. Position information generating means 105 for generating geographical current position information,
Key generation means 106 (trial decryption key generation means and first encryption key generation means) for generating a trial decryption key or an encryption key from the geographical current position information generated in Information receiving means 107 for receiving the encrypted information from the information transmitting / receiving terminal 101, and the information receiving means 107 using the trial decryption key generated by the key generating means 106.
(A first communication unit) an information decryption unit 108 for attempting to decrypt the encrypted information received by the (first communication unit); a storage unit 109 for storing the information decrypted by the information decryption unit 108;
An information encryption means 110 (first information encryption means) for encrypting information stored in the storage means 109 with the encryption key generated in 106, and the information encrypted by the information encryption means 110 is transmitted to the network 102. Information transmitting means 111 (first communication means) for transmitting to another information transmitting / receiving terminal 101 connected to
Are respectively constituted.

Here, as a method for generating the actual geographical position information (geographical current position information) by the position information receiving means 105, the GPS satellite 10 received by the GPS receiver 104 is used.
Although the example using the signal from 3 has been shown, PH
As in the position information acquisition method by S 1, it may be configured to obtain actual geographical position information by processing signals received from a plurality of base stations.

The storage means 109 may store the information received from the information transmitting / receiving terminal 101 connected to the network 102 as it is, in addition to the information decoded by the information decoding means 108. If the received information is not encrypted, the information can be used as it is. Further, if the received information is encrypted, the information can be temporarily stored in the storage means 109 without being decrypted at the time of reception, and can be decrypted later by the information decrypting means 108. Further, the storage unit 109 may store information input by a separately connected input device or information transferred from a separately connected external storage device.

It is not necessary that all information transmitting / receiving terminals 101 have a configuration for transmitting / receiving information. For example, if the terminal only receives information and does not need to transmit, the information encryption unit 110 and the information transmission unit 111 may be omitted from the configuration.

Further, a server device for transmitting the encrypted information may be connected to the network 102. Such a server device only transmits information and does not need to receive it. FIG. 2 shows an example of the configuration of the server device.

The server device 120 shown in FIG. 2 includes a storage unit 109 ′, an information encryption unit 110 ′ (second information encryption unit), An information transmission unit 111 '(second communication unit) is provided. Further, a map information storage unit 121 stores map information in accordance with geographical position information represented by latitude and longitude.
A position information specifying device 122 that generates geographical position information by specifying a location such as a point or an area on a map stored in the map information storage device 121,
It is possible to generate geographical location information of an arbitrary place.

Further, an encryption key generation means 123 (second encryption key generation means) for generating an encryption key from the geographical position information generated by the position information specifying device 122 is provided. The map information storage device 121 may be configured as a part of the storage means 109 '.

With the configuration shown in FIG. 2, the encryption key generation means 123 generates an encryption key from the geographical position information of an arbitrary place designated by the position information designation means 122. The information encrypting means 110 'is stored in the storage means 109' using the encryption key.
Encrypts the information stored in. The information transmitting means 111 '
Transmits the encrypted information to another information transmitting / receiving terminal 101 connected to the network 102. The geographical location information for generating an encryption key for encryption is transmitted to the information transmitting / receiving terminal.
Regardless of the actual position of 101, the position information specifying device 122
Since the position can be set to the position specified by the above, the configuration is effective as a server device that only transmits the encrypted information.

An example in which an encryption key or a decryption key is generated from geographical position information will be described below. For example, the latitude and longitude of a point in Tokyo is 35 degrees 41 minutes 15.2 seconds north latitude and 139 degrees east longitude
46 minutes and 24.1 seconds. By arranging the numbers that appear in these values in order, a value of “354115213946241” can be obtained. In this example, units representing degrees, minutes, seconds, etc. and decimal points are ignored, and numbers expressing latitude and longitude are simply arranged.

The value obtained in this way is, for example, DES
(Data Encryption Standard) and other common key cryptosystems. In the common key encryption method, the encryption key and the decryption key use the same key,
Information encrypted with a certain encryption key can be decrypted by using the same key as the encryption key as a decryption key.

Alternatively, when using an encryption method such as a public key encryption method using different keys for the encryption key and the decryption key, the value obtained from the geographical position information as described above is used. As a source, an encryption key and a decryption key that obey the rules determined for each encryption method are obtained, and an encryption key can be used when encrypting information, and a decryption key can be used when decrypting information. .

When the latitude and longitude are used as the geographical position information as described above, in order to cover the world, the latitude of the north pole is 0 degrees and the latitude of the equator is 0 degrees in order to correspond to south latitude and west longitude. You can convert it to 90 degrees and 180 degrees in the South Pole. This transformation calculates the latitude of north latitude or south latitude θ degrees,
It can be obtained by setting 90-θ degrees for north latitude and 90 + θ degrees for south latitude. Similarly, if the longitude is 0 degrees to 360 degrees
As represented by degrees, the longitude of 変 換 longitude or east longitude may be converted to 経 度 degrees for east longitude and 360-φ degrees for west longitude.

Also, for example, 35 degrees 41 minutes 5 seconds north latitude and 35 degrees north latitude
In the case of 4 minutes and 15 seconds, simply arranging the numbers that appear as described above would result in both being “35415” and the same value. Therefore, when the number of digits of each of the degrees, minutes, and seconds is less than the maximum number of digits, 0 may be inserted so that, for example, “05” is set for 5 minutes. In the above example, "354105" and "35
0415 ”, and a different value can be obtained.

Further, the values of latitude and longitude may be converted into values that are evenly distributed. For example, the range of the latitude targeted by the information access control method of the present invention is at least 24 degrees north latitude,
Assuming that it is limited to less than 45 degrees, north latitude a degree b minutes c seconds is calculated as INT ((a + b / 60 + c / 3600-24) x 10000 / (45-24)), so that it is in the range of 0 to 9999 Values that are evenly distributed can be obtained. Where INT is a function that returns an integer that does not exceed the given value.

With this conversion, the same value (geographical position information) can be obtained in the range of 21/10000 degrees. By using such a transformation and changing the range in which the values are distributed (for example, changing 10000 to another number in the above equation), it is possible to adjust the range (accuracy) of the geographical location that generates the same decryption key. it can.

When receiving and decrypting the encrypted information, the position information generating means 105 obtains the geographical neighboring position information which is the neighborhood of the geographical position generated from the signal received by the GPS receiver 104. They may be generated together. When the encrypted information cannot be correctly decrypted with the trial decryption key generated from the geographical current position information, the key generation means 106
Generates a new trial decryption key from the geographical proximity position information, and the information decryption means 108 attempts to decrypt the information with the trial decryption key. At least one such decryption attempt
The number of times, a geographical position for generating a decryption key capable of correctly decrypting the encrypted information, and an information transmitting / receiving terminal 101 for decrypting the encrypted information.
Even if the current geographical position does not completely match, it can be correctly decoded if it is in the vicinity.

For example, latitude 35 degrees 41 minutes 15.2 seconds north longitude 139 degrees east longitude
35 ° 41′1N for a geographical position of 46 minutes 24.1 seconds
Geographical location at 5.1 seconds, 139 degrees 46 minutes, 24.1 seconds east, 35 degrees 41 minutes 15.2 seconds north, 139 degrees 46 minutes, 24.0 seconds east latitude, 35 degrees 41 minutes 15.1 seconds north, 139 degrees east longitude A geographical position of 46 minutes and 24.0 seconds is a geographically close position.

Geographic neighboring position information such as a certain range with respect to the actual geographical position, for example, a range of latitude and longitude of ± 1 second, is sequentially generated, and from the geographical neighboring position information. Attempting to decrypt the encrypted information by generating a trial decryption key, determining whether or not the decryption was successful, and if the decryption was unsuccessful, the same processing is performed with another geographical neighboring position information. Good. The information decoding means 108
In order to determine whether or not the encrypted information has been correctly decrypted, for example, a specific data pattern is included in the information before encryption, and it is determined whether or not the decrypted information includes the same data pattern. What is necessary is just to judge.

Alternatively, an attempt is made to decrypt the encrypted information, and the improperly decrypted information obtained when the decryption is not performed correctly does not make sense. Is displayed, the user can judge whether or not decoding has been correctly performed by looking at the display. Therefore, instead of including the specific data pattern as described above, the information obtained by attempting to decrypt is displayed, and the user looks at the displayed information and determines that the information is not correctly decrypted. Then, the user may input an instruction to try to decrypt the encrypted information with a trial decryption key generated from another geographical proximity position information.

When the information is information such as characters or figures, the information obtained by attempting decoding may be displayed. However, when the information is information such as voice, decoding is attempted. The obtained information may be reproduced as audio.

[0095] The range of the generated geographical vicinity position may be set in advance, or information indicating the range may be transmitted and received separately along with the encrypted information.

Furthermore, by encrypting information so that it can be correctly decrypted with a decryption key generated from geographical position information represented with a given precision, the geographical area over which the information can be decrypted is controlled. be able to.

For example, latitude 35 degrees 41 minutes 15.2 seconds north longitude 139 degrees east longitude
For the geographical location information of 46 minutes and 24.1 seconds, if the accuracy is expressed in minutes, different precision geographical location information of 35 degrees 41 minutes north latitude and 139 degrees 46 minutes east longitude can be obtained. The decryption key “354113946” is obtained by sequentially arranging the numbers expressing the different precision geographical position information. Similarly, if the accuracy is in units of 10 seconds, the latitude is 35 degrees 41 minutes 20 seconds and 139 degrees 46 minutes 20 seconds east.
39462 ”, if the precision is in seconds,
Degrees 41:15, east longitude 139: 46: 24 from `` 3541151394624
Are obtained respectively.

Here, values less than the precision are rounded off, but may be processed by rounding down or rounding up.
In addition, as in the example in which the precision is in units of 10 seconds, the figure of a digit rounded off (in the above example, 1 second digit “0”) is not used when generating an encryption key.

If the encrypted information has been encrypted so that it can be correctly decrypted with a decryption key generated from geographical position information with minute accuracy, the information is within a range of about 2 km, and accuracy in seconds. If the information is encrypted so that it can be correctly decrypted with a decryption key generated from the geographical location information of
In the range of m, decoding can be performed.

When receiving and decrypting the encrypted information, the position information generating device 105 sequentially changes the accuracy from the signal received by the GPS receiver 104 to generate different-accuracy geographical position information, The generating means 106 generates a trial decryption key from each of the different precision geographical location information generated by the location information generating apparatus 105, and the information decrypting means 108 decrypts the encrypted information with the trial decryption key. Attempts may be made to determine whether or not decoding was successful. Alternatively, as described above, information obtained by attempting decoding may be displayed or reproduced as audio to determine whether the user has correctly decoded.

Further, if accuracy information indicating the accuracy of the geographical position information is set for the encrypted information, the position information generating means 105 outputs a different-accuracy geographical position of the accuracy indicated by the accuracy information. Information may be generated. In this way, there is no need to generate different-accuracy geographical position information in which a plurality of precisions are changed.

FIG. 3 is a flowchart showing a process for decrypting the encrypted information received by the information transmitting / receiving terminal 101.

First, the GPS receiver 104 receives a signal from the GPS satellite 103 (Step 201; hereinafter abbreviated as S201).

Next, the position information generating means 105 generates information on the latitude and longitude, which is the geographical current position information, from the signal received in S201 (S202).

The processing of S201 and S202 is the same as the processing of receiving a signal from a GPS satellite and converting it into information relating to latitude and longitude, which is generally used in car navigation systems and the like.

Next, the key generation means 106 generates a trial decryption key from the geographical current position information generated in S202, and the encrypted information received by the information reception means 107 is decrypted by the information decryption means 108. Decryption is performed with the trial decryption key (S203). An example of the method of generating the trial decryption key from the geographical current position information is as described above.

Next, it is determined whether or not the encrypted information has been correctly decrypted in S203 (S204). An example of a method for determining whether or not decoding has been correctly performed is as described above.
In the above-described embodiment in which the user determines whether or not decoding has been correctly performed, the process of S204 may be replaced with a process of determining whether or not an instruction to retry decoding has been input. If decoding is successful, the process ends. If decoding has failed, the process proceeds to S205.

Next, the position information generating means 105 generates geographical neighboring position information that is in the vicinity of the geographical current position information generated in S202 (S205). An example of the geographic proximity position information is as described above.

Next, the key generation means 106 generates a trial decryption key from the geographical neighboring position information generated in S205, and the encrypted information received by the information receiving means 107 is decrypted by the information decrypting means 108. Decryption is performed with the trial decryption key (S206). An example of a method for generating the trial decryption key from the geographic proximity position information is as described above.

Next, it is determined whether or not the encrypted information has been correctly decrypted in S206 (S207). An example of a method for determining whether or not decoding has been correctly performed is as described above.
Note that the above-described modified example of the processing of S204 is also applicable to the processing of S207. If decoding is successful, the process ends. If decoding was not successful, the process proceeds to S208.

Next, for all of the geographical neighboring position information that is in the vicinity of the geographical position information generated in S202, S205 to S2
It is determined whether the process of 07 has been performed (S208). If the process has been performed for all the neighborhoods, the process proceeds to S209. If the process has not been performed for all the neighbors, the process returns to S205, and S205 to S2 for another geographical neighbor position information.
Perform the process of 07.

Details of the processing from S205 to S208 will be described later.

Next, the position information generating means 105 generates different-accuracy geographical position information in which the accuracy of the geographical position information generated in S202 is reduced (S209). An example of a method for changing the accuracy of the geographical position information is as described above.

Next, the key generating means 106 generates a trial decryption key from the different-accuracy geographical position information generated in S209, and the encrypted information received by the information receiving apparatus 107 is decrypted by the information decrypting means 108. Decrypts with the trial decryption key (S210).

Next, it is determined whether or not the encrypted information has been correctly decrypted in S210 (S211). An example of a method for determining whether or not decoding has been correctly performed is as described above.
Note that the above-described modified example of the process of S204 is also applicable to the process of S211. If decoding is successful, the process ends. If decoding was not successful, the process proceeds to S212.

Next, it is determined whether or not the accuracy lowered in S209 has reached a predetermined minimum accuracy (S211). If the minimum precision has been reached, the process ends. If the minimum accuracy has not been reached, the process returns to S209.

The minimum accuracy is determined in advance between apparatuses that execute the method for controlling access to information according to the present invention, and is stored in the position information generating means 105. Or,
Information indicating the minimum precision may be added to the encrypted information, and the position information generating means 105 may refer to the information indicating the minimum precision. In this way, different minimum precisions can be set for each piece of encrypted information, so that one piece of information can be correctly decrypted in a wide geographical area and another piece of information can be decoded in a narrow geographical area. In order to be able to decode correctly, it is possible to control the geographical range in which decoding can be performed correctly.

The details of the processing from S209 to S212 will be described later.

FIG. 4 is a flowchart for explaining the details of the processing from S205 to S208 in FIG.

First, the position information generating means 105 attempts to acquire information on the range of the nearby geographical neighboring position received by the information receiving means 107 (S301). The information relating to the range of the geographical proximity position may be received in advance by the information receiving means 107 and stored in the storage means 109 separately from the encrypted information, or may be added to the encrypted information. May be received simultaneously by the information receiving means 107.

Next, it is determined whether or not information on the range of the geographical neighboring position has been obtained in S301 (S302). If the information on the range of the geographical proximity position has been obtained, the process proceeds to S304. If not, the process proceeds to S303.

If the information on the range of the geographical neighboring position cannot be obtained in S302, the position information generating means 105 is set in advance.
The information about the range of the default geographical proximity position, which is set and stored, is acquired (S303). The storage means 109 stores information on the range of the default geographical proximity position.
May be stored and referred to.

Next, the longitude X near the actual longitude X0
The value of the minimum longitude range is substituted for the variable x for calculating the value (S304). For example, if the range of the nearby geographical position acquired in S301 or S303 is within ± 1 second of the actual longitude, the minimum value of −1 second is substituted for x.

Next, the latitude Y at a position near the actual latitude Y0
Is substituted for the value of the minimum latitude range into a variable y for calculating (S305).

Next, the value obtained by adding x to the actual longitude X0 is substituted for the value of longitude X at the nearby position, and the value obtained by adding y to actual latitude Y0 is substituted for the value of latitude Y at the nearby position. Yes (S30
6).

Next, the key generation means 106 generates a trial decryption key from the geographical position information whose longitude is X and latitude is Y, and decrypts the encrypted information received by the information receiving device 107. The means 108 performs a decryption process for decrypting with the trial decryption key (S307). This process is the same as the process of S206 in FIG.

Next, it is determined whether or not the encrypted information has been correctly decrypted in S307 (S308). This process is the same as the process of S207 in FIG. If decoding is successful, the process ends. If decryption has failed, the process proceeds to S309.

If decoding was not successful in S308, Δx which is a unit amount of longitude for calculating the neighborhood of longitude is added to the value of x (S309). The unit quantity Δx of longitude may be a minimum value in the accuracy of longitude generated by the position information generating means 105. For example, if the position information generating means 105 generates longitude with an accuracy of 0.1 second, Δx is 0.1 second.

Next, it is determined whether or not the value of x is larger than the value of the maximum longitude range (S310). For example, if the range of the nearby geographical position is ± 1 second of the actual longitude, it is determined whether x> 1 second. If the value of x is larger than the value in the maximum longitude range, the process proceeds to S311. If the value of x is smaller than or equal to the value of the maximum longitude range, the process returns to S306 and continues.

If the value of x is larger than the value of the maximum longitude range in S310, the value of the minimum longitude range is substituted for the value of x (S311). This processing is the same as in S304.

Next, Δy, which is a unit amount of latitude for calculating the vicinity of latitude, is added to the value of y (S312). S309
As described above, the latitude unit amount Δy may be set to the minimum value of the accuracy of the latitude generated by the position information generating unit 105.

Next, it is determined whether or not the value of y is larger than the value in the range of the maximum latitude (S313). Similarly to S310, for example, if the range of the nearby geographical position is ± 1 second of the actual latitude, it is determined whether y> 1 second. If the value of y is larger than the value in the maximum latitude range, the process ends. S3 if the value of y is less than or equal to the value in the maximum latitude range
Return to 06 and continue processing.

As described above, according to the processing described with reference to FIG. 4, a rectangular region centered on the actual geographical position can be set as the range of the geographical neighboring position. Other than this, for example, S3
Instead of the processing of 10 and S313, the distance between (0,0) and (x, y) is less than or equal to the distance to be in the range of the geographic proximity position,
If the process of determining whether or not the value of the square root of the sum of the square of the value of x and the square of the value of y is greater than the value of the distance within the range of the geographical neighboring position, A circular area centered on the position can be set as the range of the geographical proximity position.

Alternatively, the determination as to whether or not the position represented by the longitude X0 + x and the latitude Y0 + y satisfies the condition of being a geographically neighboring position is performed by referring to separately stored map information. In such a case, an area having a complicated shape such as an administrative district can be set as a geographically close range. Further, by referring to such map information, in addition to using the latitude and longitude as the geographical position information as described above, the place name of an adjacent area may be set as a geographical neighboring position using a place name. Can be.

FIG. 5 is a flowchart for explaining the details of the processing from S209 to S212 in FIG.

First, the position information generating means 105 attempts to obtain information on the accuracy of the different-accuracy geographical position information received by the information receiving means 107 (S401). Information on the accuracy of heterogeneous geographic location information is information such as the highest accuracy, the lowest accuracy, and the intermediate accuracy between the highest accuracy and the lowest accuracy expressed in stages. is there. The information on the accuracy of the different precision geographical position may be received in advance by the information receiving means 107 and stored in the storage means 109 separately from the encrypted information, or may be added to the encrypted information. And received by the information receiving means 107 at the same time.

Next, it is determined whether or not information on the accuracy of the different-accuracy geographical position has been obtained in S401 (S402). S4 when the information on the accuracy of the different precision geographical position can be obtained
Proceed to 04. If not, the process proceeds to S403.

If the information on the accuracy of the different-accuracy geographical position cannot be obtained in S402, the position information
Information about the accuracy of the default different-accuracy geographical position, which is set and stored as 5, is acquired (S403). Information relating to the accuracy of the default different-accuracy geographical position may be stored in the storage means 109 and referred to.

Next, a variable p for storing the precision during processing is:
The value of the smallest geographical position that can be expressed with the highest geographical position accuracy is substituted (S404). For example, if the highest geographic location accuracy can represent at least 0.1 seconds, p is 0.
Substitute 1 second.

Alternatively, the number of digits representing the geographical position may be substituted into the variable p as the precision during processing. For example, when representing latitude and longitude in degrees, if the precision is represented by the number of digits after the decimal point, the highest precision is 0.
Since 1 second can be expressed as 5 digits, substitute 5 for p. In this method, since the precision is expressed by the number of digits, the precision during the processing can be changed only by increasing or decreasing the value of the variable p, and the processing is simplified. On the other hand, since the value corresponding to the precision represented by the variable p changes exponentially, it is not suitable for complicatedly changing the precision.

Next, the value of the variable p is changed to a value representing a state where the precision is lowered by one step (S405). For example, if the value of p is 1
Assuming that the time is in seconds, and the accuracy of one step lower than this is in units of 2 seconds, change the value of p to 2 seconds.

The value representing the accuracy of each stage can be obtained by calculation when the accuracy of each stage is constant. Alternatively, when the information about the accuracy of the different-accuracy geographical position information includes a value representing the accuracy of each stage, the value representing the accuracy of each stage is stored in advance as a table, and the table is stored in the table. You may ask for it by referring. Alternatively, when the precision is expressed by the number of digits as described above, in the process of S405, for example, the value of p may be reduced by 1, and the precision can be exponentially reduced.

Next, different-accuracy geographical position information having an accuracy represented by p is generated from the actual geographical position information (S40).
6). For example, when the value of p is 1 second, 35 ° 41′15.15 ° N
35 degrees 41 minutes 15 minutes north latitude
Seconds are generated. When p is represented by the number of digits, for example, when the value of p is 3, the accuracy of the different-accuracy geographical position is 0.1 minute, so from 35 ° 41'15.15'N, 35 ° 41'20'N
Seconds are generated (where the first digit of the 20 seconds is 0 because it is less than the precision represented by p). In the above example, values less than the precision are rounded off. Such processing is performed for both latitude and longitude.

Next, the key generation means 106 generates a trial decryption key from the different-accuracy geographical position information generated in S406, and the encrypted information received by the information receiving apparatus 107 is decrypted by the information decrypting means 108. Performs a decryption process for decrypting with the trial decryption key (S407). This process is the same as the process of S206 in FIG.

Next, it is determined whether or not the encrypted information has been correctly decrypted in S407 (S408). This process is the same as step S211 in FIG. If decoding is successful, the process ends. S409 if decryption failed
Processing proceeds to

Next, it is determined whether or not p has reached a predetermined minimum precision (S409). If the minimum precision has been reached, the process ends. If the minimum precision has not been reached, the process returns to S405.

According to the above-described processing, information that has been encrypted so that it can be correctly decrypted at a certain geographical location can be converted to a different precision represented by any of the information relating to the precision of the different precision geographical location information. Decryption can be tried with a decryption key generated from the accurate geographical location information.

Hereinafter, with reference to FIGS. 6 to 10, a specific example of a game method using a system implementing a method of controlling access to information according to the present invention will be described.

FIG. 6 is a diagram for specifically explaining the flow of the game method. In FIG. 6, reference numeral 501 denotes a game information server that manages information used for a game (or game) and wirelessly transmits and receives the information; 502, an antenna connected to the game information server for performing wireless communication with a terminal device; One player, 504 is a terminal device for playing a game possessed by the first player, 505 is a second player, and 506 is a terminal device for playing a game possessed by the second player.

The game information server 501 and the terminal devices 504 and 506 are access control devices for implementing the information access control method according to the present invention, and the game information server 501 includes the server device 120 shown in FIG. apparatus
504 and 506 correspond to the information transmitting / receiving terminal 101 shown in FIG.
Each is equivalent.

FIG. 6A shows a state in which the first player is at the point A ′ which is a place near the point A. At this location, the first player encrypts the first information encrypted so that it can be correctly decrypted with the decryption key generated from the different precision geographical location information in which the precision of the geographical location information of the point A is reduced. It is assumed that the possessed terminal device 504 receives from the game information server 501 and attempts to decode the first information. In this case, the different-accuracy geographical position information obtained by lowering the accuracy of the geographical current position information representing the point A 'is equal to the different-accuracy geographical position information obtained by lowering the accuracy of the geographical position information of the point A. , The first information can be correctly decoded at point A '.

It is assumed that the first information is decoded at the point A ′, and information having contents as shown in FIG. 7 is displayed. This information has more detailed information that can be seen near the actual location of the first player 503, that is, it can be correctly decrypted with a decryption key generated from more accurate geographical location information Suggests location and encrypted information nearby. In this way, by using the decryption key generated from the reduced precision geographical location information, the information can be encrypted so that it can be decrypted in a wide range, and the accurate location of a game such as a treasure hunt can be obtained. Hints can be given to the player.

Next, it is assumed that the first player 503 looks at the screen of FIG. 7 and moves to the point A ((2) of FIG. 6). At the point A, the second information encrypted so as to be able to be correctly decrypted with the decryption key generated from the highly accurate geographical position information representing the point A is received from the game information server 501, and the decryption of the information is attempted. I do. At this time, the first player 503:
Since it is suggested that the accuracy of the geographical location information be increased at the point A ′, the second information is obtained at the point A by using the decryption key generated from the highly accurate geographical location information representing the point A. It can be decoded correctly. In addition,
Note that the second information cannot be correctly decoded at point A '.

When the second information is correctly decoded, FIG.
Is displayed ((3) in FIG. 6).
The decrypted information includes an instruction to the player, "Can you take me to point B?"

It is assumed that the first player 503 has moved to the point B in accordance with the contents of the instruction as shown in FIG. 8 (see FIG. 6).
(Four) ). The terminal device 504 stores the geographical position information of the point B and
Since the information on the destination included in the second information decrypted in (3) above was compared and matched, the content shown in FIG. 9 is displayed.

The content shown in FIG. 9 may be included in advance in the second information received at point A, or may be provided as game information at point B as third information according to the content of the second information. It may be received from the server 501. The third information may be encrypted so that it can be correctly decrypted with a decryption key generated based on the geographical location information of the point B.

[0157] In this way, it is possible to give information to the first player 503 as a reward according to the instruction included in the second information. Furthermore, if a score or a special item is given to the player in the third information, the motivation of the player to follow the instruction can be increased.

Next, the first player 503 encrypts the second information (see FIG. 8) so that it can be decrypted with the decryption key generated from the geographical position information of the point B, and the game information server
The message is transmitted to 501 ((5) in FIG. 6). The encrypted information will be referred to as fourth information. The generation of the encryption key from the geographical position information of the point B is performed by the key generation means 106 of the information transmitting / receiving terminal 101, and the generation of the encrypted fourth information is performed by the information encryption means 110. The transmission of the fourth information to the game information server 501 is performed by the information transmitting means 111.

Before encrypting the second information into the fourth information in (5) of FIG. 6, a new destination is added to the list of new destination candidates included in the second information in advance. May be selected and set. In this manner, a new instruction can be given to another player who subsequently receives and decodes the fourth information. Here, unless a new destination is specified, the instruction to the player based on the fourth information will be the same as the second information, "Can you take me to point B?" Please be careful. By setting a new destination as described above, the instruction to the player can be changed, for example, "Can you take me to point C?"

The second player 505 having received the fourth information encrypted in (5) of FIG. 6 from the game information server 501.
Moves from another location to point B,
When the fourth information is decrypted with the decryption key generated from the geographical position information of the point B, the contents shown in FIG. 10 can be seen.

As described above, the second information which can be correctly decrypted at the point A and whose contents can be referred to is carried by the first player 503 to the point B, encrypted again, and It becomes fourth information, and the fourth information is referred to by the second player 505. In this way, it is possible to realize a game such as a treasure hunt, in which information can be handled as if it exists at an actual place.

At this time, by encrypting the information so that it can be decrypted with the decryption key generated from the geographical position information as described above, it becomes difficult to falsify the information and refer to the contents. In addition, it is possible to prevent impropriety of the game. Also, only when the geographical current location information where the information transmitting / receiving terminal 101 is located matches the geographical location information used to generate the decryption key, access to the information is permitted. There is no possibility that the access control will be broken by falsification of the permission information as in the case where the permission information is stored in the information storage means. Therefore, it can be said that information security is double-protected in the access control method, the access control device for implementing the method, and the access control system of the present invention.

Also, if the game information server 501 appropriately changes the geographical position information for generating a decryption key necessary for correctly decrypting certain information, it can be determined whether the information is moving at an actual place. Can be treated as follows. In this way, a game in which a virtual animal that moves around is searched for can be realized.

Further, in (5) of FIG. 6, the first player 503 is
For example, as in the case of inputting a message, the content of the second information may be changed and then encrypted to obtain the fourth information. In this way, by additionally writing a message, communication using message data, such as a bulletin board, whose contents can be referred to only in a specific place, can be realized.

(Second Embodiment) A second embodiment of the present invention will be described with reference to FIGS. 11 and 12.
It is as follows. In the first embodiment, a specific example of the method and apparatus for controlling access to information using geographical position information has been described. In the second embodiment, an example using time information will be described. Further, by encrypting the information encrypted so as to be able to be decrypted with the decryption key generated from the time information so that it can be decrypted with the decryption key generated from the identifier of the terminal device, the information can be accessed. An example in which the range of the terminal device is narrowed will also be described.

FIG. 11 is a block diagram showing a configuration of a system for transmitting and receiving information using an information access control device according to the second embodiment of the present invention.

In FIG. 11, reference numeral 601 denotes an information server for encrypting stored information so that it can be decrypted with a decryption key generated from time information and transmitting the encrypted information to the information receiving terminal 602;
602 is an information receiving terminal that receives information, 603 is a time information server that distributes time information, 604 is one or more information servers 601, information transmitting / receiving terminals 602, and a time information server.
603 network. The numbers of the information server 601, the information receiving terminal 602, and the time information server 603 shown here are not limited to these.

The information receiving terminal 602 has a time information server 60
3, time information measuring means 605 for receiving time information, time information generating means 606 for generating current time information from a signal supplied from the time information measuring means 605, and for receiving encrypted information from the information server 601. Information receiving means 607
(First communication means), a terminal identifier storage means 608 for storing an identifier unique to each of the information receiving terminals 602, an identifier stored in the terminal identifier storage means 608 or a current time information generated by the time information generation means 605. Key generation means 609 (trial decryption key generation means and first encryption key generation means) for generating a trial decryption key, and the encrypted information received by information receiving means 607 An information decrypting means 610 for decrypting with the generated trial decryption key and a storage means 611 for storing the information decrypted by the information decrypting means 610 are provided.

Here, as means for obtaining the actual time, a combination of the time information server 603 and the time information measuring means 605 is shown. In addition, a signal received from a GPS satellite or the like is processed to obtain the actual time. Alternatively, the information receiving terminal 602 may have a built-in clock and the time information server 603 may not be used.

In the latter method of incorporating a clock, the network is designed to prevent the problem that the time measured by the clock is incorrect and the problem that the user intentionally sets a time different from the actual time by using a network. When the time is measured, the time measured by the clock may be adjusted to the time supplied from the time information server 603, or the setting from outside may not be changed.

The method in which the key generation means 609 generates the trial decryption key from the current time information is the same as the above-described method of generating the trial decryption key from the geographical current position information. For example, starting at 18:19:45 on July 11, 2000, the numbers used to represent this time are arranged in order and "2000071118
1945 ". Here, in July, "07" is included, including 0, to unify the number of digits. Further, a value representing the time elapsed from a specific time in a predetermined unit such as a second may be used as a decryption key.

The method of generating time information near a certain time and the method of generating time information by changing the accuracy of a certain time stepwise are the same as in the example shown in the above-mentioned geographical position information. is there. However, during the process of decrypting the encrypted information, it is not possible to try decryption with another trial decryption key. In the case of time information, a problem that the time at which decoding can be performed correctly passes during the time period can be considered. to solve this problem,
The maximum precision of the time information for generating the decryption key may be reduced to some extent so that the minimum time unit that can be represented by the precision is longer than the time required for the decryption processing.

Examples of the identifier stored in the terminal identifier storage means 608 include a telephone number and an IP (Internet Protocol).
There are numbers such as addresses. In the case of an identifier represented by a numerical value like these, the identifier may be used as it is as a decryption key. Also, since telephone numbers and IP addresses are composed of hierarchical information, for example, if only the area code of the telephone number is used as a decryption key, it can be correctly decrypted by a terminal device having the same area code. By performing encryption so as to be able to correctly decrypt with a decryption key generated from a part of the hierarchy, it is possible to perform encryption in which a range of terminal devices that can be decrypted is specified.

The encryption using such an identifier and specifying the range of terminals that can be decrypted is performed not only in the example using the time information as in the second embodiment, but also in the first embodiment. It is also applicable to the example using the geographical position information as described.

In the case of information that does not limit the range of terminal devices that can be decrypted, furthermore, the information can be decrypted with a decryption key generated from a part of the identifier, which represents the highest hierarchy including all terminal devices. Encryption may be performed, or further encryption that can be decrypted with a decryption key generated from the identifier may be omitted.

FIG. 12 shows that the information receiving terminal 602 is an information server.
6 is a flowchart showing a process for decrypting encrypted information received from the 601. Here, after the encrypted information is encrypted so that it can be correctly decrypted with a decryption key generated from certain time information, it is correctly decrypted with a decryption key generated from an identifier of one of the terminals receiving the information. It is assumed that the data is further encrypted so that it can be decrypted.

First, the key generation means 609 generates a trial decryption key from the identifier stored in the terminal identifier storage means 608,
The information decrypting means 610 uses the trial decryption key to
Attempts to decrypt the encrypted information received from the information server 601 (S701).

Next, it is determined whether or not the encrypted information has been correctly decrypted in S701 (S702). An example of a method for determining whether or not decoding has been correctly performed is as described above. If decoding is successful, the process proceeds to S703. If decoding was not successful, the process ends.

As described above, in the case where information that can be accessed by all terminal devices is omitted from further encryption so that the information can be correctly decrypted with the decryption key generated from the identifier, before the process of S701, The information receiving means 607 determines whether the encrypted information received from the information server 601 has omitted further encryption. If the encrypted information has been omitted, the processes of S701 and S702 can be omitted. Good. In order to determine whether or not further encryption has been omitted, for example, a specific data pattern is included in the information from which further encryption has been omitted, and the presence or absence of the specific data pattern is determined. What should I do?

Next, the time information measuring means 605 receives a signal from the time information server 603 (S703).

Next, the time information generating means 606 generates current time information from the signal received in S703 (S704).

Next, the key generation means 609 generates a trial decryption key from the current time information generated in S704,
610 attempts to decrypt the information decrypted in S701 using the trial decryption key (S705). An example of a method for generating the trial decryption key from the time information is as described above.

Next, it is determined in S705 whether the information has been correctly decoded (S706). An example of a method for determining whether or not decoding has been correctly performed is as described above. If decoding is successful, the process proceeds to S707. If decoding was not successful, the process returns to S703.

If the data has been correctly decoded in S706, the decoded information is stored in the storage means 611 (S707). After that, the process ends.

With the above processing, the information receiving terminal 602 once receives the encrypted information transmitted from the information server 601, and tries to decrypt it using the terminal identifier of the information receiving terminal 602. If the decryption is successful, the information is
Since it is known that the information is destined for No. 2, the processing of S703 to S706 is repeated until the information can be decrypted with the current time information. it can. The information receiving terminal 602
If the decoding is attempted with the terminal identifier held by the terminal and the decoding fails, the process can be terminated because the information is not the information addressed to the information receiving terminal 602.

Also, in the processing of S701 to S702, an example has been described in which the decryption key is generated using the terminal identifier as it is. However, a part of the terminal identifier higher than a certain layer is used to generate the decryption key. By doing so, it is possible to encrypt information so that the information receiving terminals 602 included in a certain layer or higher can correctly decrypt.

In the processing of S703 to S706, the example in which the time information generating means 606 generates the trial decryption key from the time information generated in accordance with the accuracy of the preset time information has been described. In the same manner as the above processing, if the decoding is attempted by generating the different precision time information with the changed precision, the length of the time (period) in which the decoding can be performed correctly can be set according to the information for which access is to be controlled. Can be.

Further, in the processing of S704 to S706, one or a plurality of temporally neighboring time information is generated from the current time information generated in S704 in the same manner as the processing described with reference to FIG. However, when the trial decryption key obtained from the current time information fails to decrypt correctly, a new trial decryption key is generated from the nearby time information, and the information encrypted with the new trial decryption key is generated. May be attempted.

In this way, even if the actual time to access the information does not completely coincide with the time to generate a decryption key that can correctly decrypt the encrypted information, the time is not , The decoding can be correctly performed by attempting decoding at least once.

When the second embodiment of the information access control method according to the present invention described above is used for advertisement, privilege information such as discount information is encrypted and the information
If transmitted to 602, information not to be disclosed until a specific time, such as the detailed contents of the time service, can be distributed to a specific user such as a customer, as described above. By encrypting the information so that it can be decrypted with the decryption key generated from the time information, it is possible to prevent the information from being tampered with and referencing the contents.

At this time, the information receiving terminal 602 operates until the time information generating means 60 until the encrypted information is correctly decrypted.
The decryption may be attempted each time the time information generated by step 6 changes, or unnecessary decryption processing can be reduced by transmitting the correct decryption time together with the encrypted information in advance. In this case, due to the security of the information, as described above, the information receiving terminal 602 cannot receive the input of the time information from outside.
May be set so that the user can be informed in advance of the correct decoding time. Even if the user is informed in advance of the correct decryption time, the information can be actually decrypted only when the current time information matches the decryption key generation time information.

The information access control device described above is realized by a program for causing the information access control process to function. This program is stored in a computer-readable recording medium. In the present invention, as this recording medium, since processing is performed by a general computer, a memory such as a ROM (Read Only Memory) built in or connected to the general computer may be a program medium, Further, a program reading device may be provided as an external storage device, and may be a program medium readable by inserting a recording medium therein.

In any case, the stored program may be configured to be accessed and executed by a microprocessor, or in any case, the program may be read, and the read program may be a general program. RAM (Random Access Memo)
ry), the program may be downloaded to a program storage area and the program may be executed.
It is assumed that this download program is stored in the main unit in advance.

Here, the program medium is a recording medium configured to be separable from the main body, such as a tape system such as a magnetic tape or a cassette tape, a magnetic disk such as a floppy disk or a hard disk, or a CD-ROM / MO / MD / Disc system for optical discs such as DVD, card system for IC card (including memory card) / optical card, or mask ROM, EP
It may be a medium that carries a fixed program including a semiconductor memory such as a ROM, an EEPROM, a flash ROM, or the like.

Further, since the present invention has a system configuration that can be connected to a communication network including the Internet, a medium that carries the program in a fluid manner may be used to download the program from the communication network. When the program is downloaded from the communication network as described above, the download program may be stored in the main device in advance, or may be installed from another recording medium.

The content stored in the recording medium is not limited to a program but may be data.

[0197]

According to the method for controlling access to information according to the present invention, as described above, a method for controlling access to information encrypted so as to be decrypted with a decryption key generated from geographical position information. A first step of generating geographical current position information; and a second step of generating a trial decryption key from the geographical current position information generated in the first step.
And a third step of attempting to decrypt the encrypted information with the trial decryption key generated in the second step, and the geographical current position information obtained in the first step The encrypted information is decrypted only when the information and the geographical position information for generating the decryption key match.

[0198] Therefore, it is possible to perform access control to information according to a place such that whether or not access to the information is determined according to the place where the device accessing the information is actually located. That is, in the access control method of the present invention, since the permission information for permitting the access is not stored in the information storage means, there is no possibility that the access control may be broken by falsification of the permission information, and the encryption Since it is also difficult to falsify the information itself and refer to the content of the information, it is possible to enhance the security of the information.

The method for controlling access to information according to the present invention is, as described above, in addition to the above-described configuration, one or more geographically neighboring geographical locations based on the geographical current position information. A fourth step of generating neighboring position information; and, if the trial decryption key cannot be correctly decrypted in the third step, a new trial position is obtained from the geographic neighboring position information generated in the fourth step. A fifth step of generating a decryption key and attempting to decrypt the encrypted information with the new trial decryption key.

Therefore, the actual geographical location of the device attempting to access the information by implementing the method for controlling access to the information according to the present invention is such that the encrypted information can be correctly decrypted. Even if it does not completely match the geographical position where the key is generated, if it is in the vicinity, it can be decrypted correctly by trying to decrypt the information at least once or more.

In the method of controlling access to information according to the present invention, as described above, in addition to the above configuration, the accuracy of one or more geographical positions is changed from the geographical current position information. A sixth step of generating different-accuracy geographical position information; and, if the trial-decryption key cannot be correctly decrypted in the third step, from the different-accuracy geographical position information generated in the sixth step. Generating a new trial decryption key and attempting to decrypt the encrypted information with the new trial decryption key.

Therefore, for the side controlling the access to the information, the information for which the geographical position that can be decrypted is to be widened is encrypted so that it can be decrypted with a decryption key generated from the coarse geographical position information. In contrast, for information that wants to narrow the geographical position that can be decrypted, the information can be accessed by encrypting it so that it can be decrypted with a decryption key generated from highly accurate geographical location information. Can be controlled.

The method for controlling access to information according to the present invention is a method for controlling access to information encrypted so that it can be decrypted with a decryption key generated from time information, as described above. A first step of generating current time information, a second step of generating a trial decryption key from the current time information generated in the first step, and a trial decryption generated in the second step A third step of attempting to decrypt the encrypted information with a key, wherein the encryption is performed only when the current time information obtained in the first step matches the time information for generating the decryption key. It is characterized in that decoded information is correctly decoded.

[0204] Therefore, it is possible to control access to information according to time so that whether or not access to information is determined according to the time at which the information is to be accessed. That is, in the access control method of the present invention, since the permission information for permitting the access is not stored in the information storage means, there is no possibility that the access control may be broken by falsification of the permission information, and the encryption Since it is also difficult to falsify the information itself and refer to the content of the information, it is possible to enhance the security of the information.

According to the method for controlling access to information according to the present invention, as described above, in addition to the above-described configuration, one or more neighboring time information that is temporally neighboring can be obtained from the current time information. Generating a fourth trial decryption key from the neighboring time information generated in the fourth step, when the trial decryption key cannot be correctly decrypted in the fourth step of generating, and in the third step, A fifth attempt to decrypt the encrypted information with the new trial decryption key.
Steps.

Therefore, the decryption key is generated so that the actual time for accessing the information by implementing the method for controlling access to the information according to the present invention can correctly decrypt the encrypted information. Even if the time does not completely coincide with the time, if the time is close to the time, decoding of the information is attempted at least once, thereby providing an effect that the information can be correctly decoded.

The method for controlling access to information according to the present invention is, as described above, in addition to the above configuration, one or more different-accuracy time information obtained by changing the accuracy of time from the current time information. And generating a new trial decryption key from the different precision time information generated in the sixth step when the trial decryption key cannot be correctly decrypted in the third step. And attempting to decrypt the encrypted information with the new trial decryption key.

Therefore, for the side controlling the access to the information, the information for which the range of the decodable time is desired to be widened is encrypted so as to be decodable with the decoding key generated from the coarse time information, Conversely, for information for which the range of time that can be decrypted is to be narrowed, the range of time during which information can be accessed can be controlled by encrypting the information so that it can be decrypted with a decryption key generated from highly accurate time information. This has the effect.

In the method of controlling access to information according to the present invention, the encrypted information is information relating to advertisement.

[0210] Therefore, for example, by allowing information access from a specific geographical location such that only people who have come to the advertiser's shop can refer to the contents, the effect of attracting customers can be improved, or at a specific time. You can only refer to the contents and limit the time like a time service,
It is possible to realize such an advertisement.

[0211] In the method for controlling access to information according to the present invention, the encrypted information is message data for performing communication between users.

[0212] Therefore, there is an effect that communication using a message such as a bulletin board which can be referred to only in a specific place can be performed.

In the method of controlling access to information according to the present invention, the encrypted information is information used for a game.

[0214] Therefore, there is an effect that a game such as a treasure hunt or orienteering using a position and time in the real world can be realized.

The access control device for information according to the present invention is, as described above, an access control device for controlling access to information encrypted so as to be decrypted with a decryption key generated from geographical position information. A position information generating means for generating geographical current position information; a trial decryption key generating means for generating a trial decryption key from the geographical current position information generated by the position information generating means; Information decryption means for attempting to decrypt the encrypted information with the trial decryption key generated by the decryption key generation means, and the geographical current position information generated by the position information generation means and the decryption key. The encrypted information is decrypted only when the generated geographical position information matches.

Therefore, the access control to the information according to the place is performed so that the access control apparatus for the information according to the present invention determines whether or not the access to the information is possible according to the place where the information is actually located. Can be. That is, in the access control device of the present invention, the permission information for permitting the access is not stored in the information storage means.
Since there is no possibility that access control is broken by falsification of the permission information, and it is difficult to falsify the encrypted information itself and refer to the contents of the information, it is possible to improve the security of the information. Play.

The information access control device according to the present invention, as described above, further comprises a first key for generating an encryption key from the geographical position information generated by the position information generating means, in addition to the above configuration. Encryption key generation means, information decrypted by the information decryption means, first information encryption means for encrypting with the encryption key, and first communication means for transmitting and receiving information via a network, It has.

[0218] Therefore, there is an effect that communication between access control devices can be performed using information which can be referred to only in a specific place. Further, there is an effect that a certain access control device can function as a server device serving as a distribution source of encrypted information.

The information access control device according to the present invention is an access control device for controlling access to information encrypted so as to be decrypted with a decryption key generated from time information as described above. A time information generating means for generating current time information, a trial decryption key generating means for generating a trial decryption key from the current time information generated by the time information generating means, and a trial decryption key generating means. Information decryption means for attempting to decrypt the encrypted information with the generated trial decryption key, and the current time information generated by the time information generation means matches the time information for generating the decryption key. It is characterized in that the encrypted information is decrypted only at times.

[0220] Therefore, it is possible to control access to information according to time, such that whether or not access to information is determined according to the time at which the information is to be accessed. That is, in the access control device of the present invention, since information for permitting access is not stored in the information storage means, there is no possibility that the access control may be broken by falsification of the information. Since it is difficult to falsify the information itself and refer to the contents of the information, it is possible to improve the security of the information.

The information access control device according to the present invention, in addition to the above-described configuration, further comprises a first cryptographic key for generating an encryption key from the time information generated by the time information generating means. Encryption key generation means, first information encryption means for encrypting the information decrypted by the information decryption means with the encryption key, and first communication means for transmitting and receiving information via a network. ing.

[0222] Therefore, there is another effect that communication between the access control devices can be performed using the information whose contents can be referred to only at a specific time. Further, there is an effect that a certain access control device can function as a server device serving as a distribution source of encrypted information.

The information access control network system according to the present invention, as described above, generates a key for encrypting information from the above-described access control device and the geographical position information of an arbitrary place. Server device equipped with an encryption key generation means, a second information encryption means for encrypting information with an encryption key generated by the encryption key generation means, and a second communication means for transmitting and receiving information, It is characterized by being connected via a network.

[0224] Therefore, it is possible to control access to information according to a place for a wide range of access control devices, and it is difficult to falsify the encrypted information and refer to the contents of the information. Therefore, there is an effect that security for information can be enhanced.

As described above, the network system for controlling access to information according to the present invention uses the above-described access control device and a second encryption key for generating a key for encrypting information from arbitrary time information. Generating means, a second information encrypting means for encrypting information with an encryption key generated by the encryption key generating means, and a server device including second communication means for transmitting and receiving information via a network. It is characterized by being connected.

Therefore, it is possible to control access to information according to time for a wide range of access control devices, and it is difficult to falsify the encrypted information and refer to the contents of the information. Therefore, there is an effect that security for information can be enhanced.

The information access control program according to the present invention is a program for causing a computer to execute the above information access control method as described above.

Therefore, there is an effect that a general computer can execute the above-described method for controlling access to information.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a system for transmitting and receiving information using an information access control device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a configuration of a server device that only transmits information.

FIG. 3 is a flowchart illustrating a process in which an information transmitting / receiving terminal receives information encrypted using geographical location information and decrypts the information using the geographical current location information.

FIG. 4 is a flowchart for explaining details of processing in S205 to S208 in FIG. 3;

FIG. 5 is a flowchart for explaining details of processing in S209 to S212 in FIG. 3;

FIG. 6 is a diagram for explaining a specific example of a game method using a control system to access information according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating an example of the content of information in a game method using a control system to access information according to the first embodiment of the present invention.

FIG. 8 is a diagram illustrating another example of the content of information in a game method using a control system to access information according to the first embodiment of the present invention.

FIG. 9 is a diagram for explaining still another example of the content of information in a gaming method using a control system to access information according to the first embodiment of the present invention.

FIG. 10 is a diagram illustrating still another example of the content of information in a game method using a control system to access information according to the first embodiment of the present invention.

FIG. 11 is a block diagram illustrating a configuration of a system that transmits and receives information using an information access control device according to a second embodiment of the present invention.

FIG. 12 is a flowchart showing a process in which an information transmitting / receiving terminal receives information encrypted using time information and decrypts the information using current time information.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Information transmission / reception terminal (access control apparatus) 102 Network 103 GPS satellite 104 GPS receiver 105 Position information generation means 106 Key generation means (trial decryption key generation means and first encryption key generation means) 107 Information reception means (No. One communication means) 108 information decryption means 109 storage means 110 information encryption means (first information encryption means) 110 'information encryption means (second information encryption means) 111 information transmission means (first communication Means) 111 'information transmitting means (second communication means) 120 server apparatus 121 map information storage means 122 location information designating means 123 encryption key generation means (second encryption key generation means) 601 information server 602 information receiving terminal (Access control device) 603 Time information server 604 Network 605 Time information measuring means 606 Time Information generation means 607 Information reception means (first communication means) 608 Terminal identifier storage means 609 Key generation means (trial decryption key generation means and first encryption key generation means) 610 Information decryption means 611 Storage means

Claims (16)

[Claims] 1. A method for controlling access to information encrypted so that it can be decrypted with a decryption key generated from geographical location information, comprising: a first step of generating geographical current location information; A second step of generating a trial decryption key from the geographical current position information generated in the first step, and decryption of the encrypted information with the trial decryption key generated in the second step And decrypting the encrypted information only when the geographical current location information obtained in the first step matches the geographical location information for generating the decryption key. A method for controlling access to information characterized by being performed. 2. A fourth step of generating one or a plurality of pieces of geographically neighboring locations that are geographically neighboring from the geographical current location information; When the decryption key fails to decrypt correctly, a new trial decryption key is generated from the geographical proximity position information generated in the fourth step, and the information encrypted with the new trial decryption key is generated. 5. A method for controlling access to information according to claim 1, further comprising a fifth step of attempting to decrypt the information. 3. A sixth step of generating one or a plurality of different-accuracy geographical location information in which the accuracy of the geographical location is changed from the geographical current location information; When the trial decryption key fails to decrypt correctly, a new trial decryption key is generated from the different precision geographical position information generated in the sixth step, and the encryption is performed with the new trial decryption key. 7. A method for controlling access to information according to claim 1, further comprising a seventh step of attempting to decode the converted information. 4. A method for controlling access to information encrypted so as to be decrypted with a decryption key generated from time information, comprising: a first step of generating current time information; A second step of generating a trial decryption key from the current time information generated in the step, and a third step of attempting to decrypt the encrypted information with the trial decryption key generated in the second step. The encrypted information is correctly decrypted only when the current time information obtained in the first step and the time information for generating the decryption key match. Access control method. 5. A fourth step of generating one or a plurality of temporally neighboring time information from the current time information, and in the third step, the trial decryption key correctly generates When the decryption failed, a new trial decryption key is generated from the near time information generated in the fourth step,
5. The method according to claim 4, further comprising a fifth step of attempting to decrypt the encrypted information with the new trial decryption key. 6. A sixth step of generating one or more different-accuracy time information having changed time accuracy from the current time information, and in the third step, When the decryption has failed, a new trial decryption key is generated from the different precision time information generated in the sixth step, and an attempt is made to decrypt the encrypted information with the new trial decryption key. The method for controlling access to information according to claim 4, comprising: a seventh step. 7. The method for controlling access to information according to claim 1, wherein the encrypted information is information relating to an advertisement. 8. The access control to information according to claim 1, wherein the encrypted information is message data for performing communication between users. Method. 9. The method according to claim 1, wherein the encrypted information is information used for a game. 10. An access control device for controlling access to information encrypted so as to be decrypted with a decryption key generated from geographical position information, wherein the position information generating means generates geographical current position information. Trial decryption key generation means for generating a trial decryption key from the geographical current position information generated by the location information generating means; and a trial decryption key generated by the trial decryption key generation means. Information decryption means for attempting to decrypt the encrypted information, and only when the geographical current position information generated by the position information generation means matches the geographical position information for generating the decryption key, the encryption is performed. An access control device for information, wherein the decoded information is decoded. 11. An encryption key generating means for generating an encryption key from geographical position information generated by said position information generating means; 11. The information access control device according to claim 10, further comprising: first information encryption means for encrypting the information with a first communication means; and first communication means for transmitting and receiving information via a network. 12. An access control device for controlling access to information encrypted so that it can be decrypted with a decryption key generated from time information, comprising: time information generating means for generating current time information; Trial decryption key generation means for generating a trial decryption key from the current time information generated by the information generation means, and decryption of the encrypted information with the trial decryption key generated by the trial decryption key generation means And decrypting the encrypted information only when the current time information generated by the time information generating means matches the time information for generating the decryption key. Access control device to the information to be. 13. An encryption key generation means for generating an encryption key from the time information generated by said time information generation means, and information decrypted by said information decryption means being encrypted with said encryption key. 13. The information access control device according to claim 12, further comprising: a first information encryption unit for encrypting information; and a first communication unit for transmitting and receiving information via a network. 14. An access control network system for controlling access to information encrypted so that it can be decrypted with a decryption key generated from geographical location information, wherein the access control network system is described in claim 10 or 11. A second encryption key generating means for generating a key for encrypting information from the geographical position information of an arbitrary location, and an encryption key generated by the encryption key generating means. An information access control network system, characterized in that a second information encrypting means for encrypting information and a server device having a second communication means for transmitting and receiving information are connected via a network. 15. An information access control network system for controlling access to information encrypted so that it can be decrypted with a decryption key generated from time information, wherein the information according to claim 12 or 13. A second encryption key generating means for generating a key for encrypting information from arbitrary time information, and a second encrypting information with an encryption key generated by the encryption key generating means. An information access control network system, wherein the information encryption means and a server device having a second communication means for transmitting and receiving information are connected via a network. 16. An information access control program for causing a computer to execute the information access control method according to any one of claims 1 to 9.