JP4997920B2 - Management system - Google Patents

Description

  The present invention relates to a technique for managing document security in a mobile terminal device.

  Today, small information display devices (mobile terminal devices) such as so-called electronic book readers are beginning to become popular. These information display devices are advantageous in that they can carry and browse a large amount of information while being small. However, on the other hand, there is a problem that the risk of confidential information being taken out increases. Here, as a technique for managing the security of a document, for example, there is a technique described in Patent Document 1. Patent Document 1 discloses a technique for managing document duplication and distribution destination by embedding a wireless tag in paper on which information is described.

JP 2005-035095 A

  According to Patent Document 1, it is possible to know where a document has been distributed. However, there is a problem that it is not possible to limit the taking out of documents, that is, the information described therein. On the other hand, the present invention provides a technique capable of limiting document take-out.

  In order to solve the above-described problems, the present invention provides a data storage unit that stores document data encrypted with an encryption key, a first wireless writing device that stores a decryption key, and a second wireless that stores erasure information. Non-contact communication means for performing non-contact communication with a writing device, terminal key storage means for storing the decryption key received from the first wireless writing device via the non-contact communication means, and the non-contact communication means A storage control means for erasing the decryption key stored in the terminal key storage means on the basis of the erasure information received from the second wireless writing device, and a decryption key is stored in the terminal key storage means The decryption unit decrypts the document data stored in the document data storage unit using the decryption key, and displays the image according to the document data decrypted by the decryption unit. To provide a mobile terminal having an image display means for. When this mobile terminal device communicates with the second wireless writing device first and later with the first wireless writing device, the terminal key storage means stores the decryption key. In this case, the decoding unit can correctly decode the document data. On the other hand, when the mobile terminal device communicates with the first wireless writing device first and later with the second wireless writing device, the terminal key storage means stores no decryption key. In this case, the decoding unit cannot correctly decode the document data. As described above, according to the mobile terminal device, it is possible to limit document take-out.

  In a preferred aspect, in the mobile terminal device, the contactless communication means receives information indicating a security level from the first wireless writing device or the second wireless writing device, and is received by the contactless communication means. Security level storage means for storing the information indicating the security level, processing control means for performing one process among a plurality of processes related to the operation of the mobile terminal device, and an identifier of the process for each of the plurality of processes Stored in the storage means, a table storage means for storing a table including a security level required for the process, a selection means for selecting one process from the plurality of processes in response to a user operation. The security level corresponding to the security level included in the table stored in the table storage means. Determination means for determining whether or not the security level corresponding to the process selected by the selection means is met, and the security level stored in the storage means is stored in the table storage means by the determination means. If it is determined that the security level corresponding to the process selected by the selection means among the security levels included in the table is satisfied, the process control means performs one process selected by the selection means. Also good. According to this mobile terminal device, processing performed by the mobile terminal device can be managed according to the security level, in addition to management by the decryption key.

  In another preferred embodiment, in the mobile terminal device, the contactless communication means receives information indicating a security level from the first wireless writing device or the second wireless writing device, and the contactless communication means. Security level storage means for storing information indicating the security level received by the mobile terminal apparatus, processing control means for performing one process among a plurality of processes related to the operation of the mobile terminal apparatus, and each of the plurality of processes. A table storing means for storing a table including the identifier of the information and a security level required for the process, a selecting means for selecting one process from the plurality of processes according to a user operation, and a storage means The security level stored in the table stored in the table storage means Of these, the determination means for determining whether or not the security level corresponding to the process selected by the selection means is matched, and the security level stored in the storage means is included in the table stored in the table storage means by the determination means. Number of times storage means for storing the number of times determined not to match the security level corresponding to the process selected by the selection means among the security levels to be selected, and the number of times stored in the number of times storage means exceeded a threshold In this case, the mobile terminal device may include a lock unit that locks the mobile terminal device. According to this mobile terminal device, the mobile terminal device can be locked in a fixed case.

  In yet another preferred aspect, in the mobile terminal device, the non-contact communication means receives an instruction for requesting erasure of data stored in the data storage means from the second wireless writing device, and the storage The control means may erase the data stored in the data storage means in accordance with the command received by the non-contact communication means. According to this mobile terminal device, the document data can be deleted after communicating with the second wireless writing device.

  The present invention is also a management system including a first wireless writing device that stores a decryption key, a second wireless writing device that stores erasure information, and a mobile terminal device, wherein the mobile terminal device includes: Data storage means for storing document data encrypted with an encryption key, non-contact communication means for making contactless communication with a first wireless writing device storing a decryption key and a second wireless writing device storing erasure information Terminal key storage means for storing the decryption key received from the first wireless writing device via the non-contact communication means, and received from the second wireless writing device via the non-contact communication means Based on the erasure information, a storage control means for erasing the decryption key stored in the terminal key storage means, and if the decryption key is stored in the terminal key storage means, use the decryption key A management system comprising: decoding means for decoding the document data stored in the document data storage means; and image display means for displaying an image according to the document data decoded by the decoding means. provide. According to this management system, when the mobile terminal device communicates with the second wireless writing device first and later with the first wireless writing device, the terminal key storage means stores the decryption key. In this case, the decoding unit can correctly decode the document data. On the other hand, when the mobile terminal device communicates with the first wireless writing device first and later with the second wireless writing device, the terminal key storage means stores no decryption key. In this case, the decoding unit cannot correctly decode the document data. As described above, according to this management system, it is possible to limit document take-out.

  Furthermore, the present invention provides a data storage means for storing document data encrypted with an encryption key, a first wireless writing device storing a decryption key, and a second wireless writing device storing erasure information, and contactless communication. A non-contact communication means for performing information and a key storage means for storing information received from the first wireless writer or the second wireless writer, the computer via the non-contact communication means Based on the key storage processing for storing the decryption key received from one wireless writing device in the key storage means and the erasure information received from the second wireless writing device via the non-contact communication means, A storage control process for erasing the decryption key stored in the key storage means, and when the decryption key is stored in the terminal key storage means, the decryption key is used to store the document data. A decoding process for decoding the stored document data in the storage means, to provide a program for executing the image display processing for displaying an image in accordance with the document data decoded by the decoding process. According to this program, when the mobile terminal device communicates with the second wireless writing device first and later with the first wireless writing device, the terminal key storage means stores the decryption key. In this case, the decoding unit can correctly decode the document data. On the other hand, when the mobile terminal device communicates with the first wireless writing device first and later with the second wireless writing device, the terminal key storage means stores no decryption key. In this case, the decoding unit cannot correctly decode the document data. As described above, according to this program, it is possible to limit document take-out.

1. Configuration FIG. 1 is a block diagram showing a functional configuration of a document management system 1 according to an embodiment of the present invention. The document management system 1 includes a document display device 100, a gate device 200, and a gate device 300. The document display device 100 is a portable image display device such as an electronic paper or an electronic book reader, that is, a mobile terminal device. The document storage unit 101 stores document data D. Document data D is encrypted by the encryption key K _E. The wireless communication unit 102 performs wireless communication with the gate device 200 or the gate device 300. The document display device 100 acquires key information from the gate device 200 or the gate device 300 via the wireless communication unit 102. The key storage unit 103 stores the acquired key. The decryption unit 104 decrypts the document data D using the key stored in the key storage unit 103. The display unit 105 displays an image according to the decrypted document data D.

  The gate device 200 and the gate device 300 are devices installed between two regions having different required sensitivity. The gate device 200 and the gate device 300 have functions as a wireless reading device and a wireless writing device (so-called wireless reader / writer), respectively. For example, the gate device 200 and the gate device 300 are installed at the entrance of a laboratory in a laboratory. Now, a case will be described as an example where the inside of the laboratory has a high density and the outside of the laboratory has a low density. In other words, the document stored in the document display device 100 can be freely browsed inside the laboratory, but the browsing of the document is limited outside the laboratory.

In the gate apparatus 200, the storage unit 201 stores a key _{K D} for decrypting the document data D. Key _the K _D, is a legitimate key to the key K _E is an encryption key of the document data D. The wireless communication unit 202 transmits a decryption key _{K D} by wireless communication in the text display device 100. In the gate apparatus 300, the storage unit 301 stores a key _{K N} is a different key and the decryption key _{K D.} The key K _N is not a valid key to the key K _E is an encryption key of the document data D. The wireless communication unit 302 transmits the key _KN to the document display device 100 by wireless communication.

  FIG. 2 is a block diagram illustrating a hardware configuration of the document display device 100. A CPU (Central Processing Unit) 110 is a control device that controls elements of the document display device 100. A ROM (Read Only Memory) 120 is a storage device that stores programs and data necessary for the operation of the document display device 100. The RAM 130 is a storage device that functions as a work area when the CPU 110 executes a program. A video random access memory (VRAM) 131 is a storage device that stores an image to be displayed on the display device 151. An I / O (Input / Output) 140 is an input / output interface. The key button 141 outputs a signal corresponding to a user operation to the I / O 140. The wireless module 400 provides the document display apparatus 100 with a wireless communication function. Details of the wireless module 400 will be described later. In the following description, for the sake of convenience, a portion of the document display device 100 other than the wireless module 400 is referred to as “document display device 100 main body”.

  The display control unit 150 drives the display device 151 according to the image data stored in the VRAM 131. The display device 151 is a display device having a memory liquid crystal layer such as a cholesteric liquid crystal. The power control unit 160 is a control device that controls the supply of power from the battery 161. The battery 161 is a secondary battery such as a Ni—Cd battery or a Li ion battery. The communication control unit 170 is a control device that controls communication with other devices via a communication IF (Interface) 171. The communication IF 171 is an interface that performs communication conforming to standards such as USB (Universal Serial Bus), Blue Tooth (registered trademark), and wireless LAN (Local Area Network). The storage device control unit 180 is a control device that controls the internal storage device 181 and the removable medium 183. The built-in storage device 181 is a rewritable nonvolatile storage device such as a flash memory. The removable medium 183 is a detachable storage device connected to the document display device 100 via the memory IF 182. The removable medium 183 is, for example, an SD (registered trademark) memory card or a memory stick (registered trademark). The above elements are connected via a bus 190.

  FIG. 3 is a block diagram illustrating a hardware configuration of the wireless module 400. The CPU 410 is a control device that controls elements of the wireless module 400. The ROM 420 is a storage device that stores programs and data necessary for the operation of the wireless module 400. The RAM 430 is a storage device that functions as a work area when the CPU 410 executes a program. An EEPROM (Electronically Erasable and Programmable Read Only Memory) 431 is a storage device that stores data such as acquired encryption keys and security levels. The cryptographic engine 440 is a processor that performs encryption or decryption according to a known algorithm such as a Triple DES method or an RSA (Rivest Shamir Adleman) method. The transmission unit 450 is a transmitter that wirelessly transmits data via the antenna 452. The receiving unit 451 is a receiver that receives data via the antenna 452. The I / O 480 is an input / output interface. The wireless module 400 inputs / outputs data and signals to / from other elements of the document display device 100 via the I / O 480 and the I / O 140. The above elements are connected to each other via a bus 490. The wireless module 400 may be detachable from the document display device 100.

  Note that the wireless module 400 may have its own power source separately from the main body of the document display device 100. In the document display device 100, the power supply control unit 160 finely controls the supply or stop of power for power saving, but it is preferable that power is always supplied to the wireless module 400. From the viewpoint of the communicable distance between the document display device 100 and the gate device, the wireless module 400 is preferably an active device having a unique power source. For example, the wireless module 400 may use a UHF (Ultra High Frequency) band RFID (Radio Frequency Identification).

FIG. 4 is a block diagram illustrating a hardware configuration of the gate device 200. The CPU 210 is a control device that controls elements of the gate device 200. The ROM 220 is a storage device that stores programs necessary for the operation of the gate device 200. The RAM 230 is a program that functions as a work area when the CPU 210 executes the program. The transmission unit 240 is a transmitter that wirelessly transmits data via the antenna 260. The receiving unit 250 is a receiver that receives data via the antenna 260. EEPROM270 is a storage device for storing a decryption key _{K D} and security level _{L H.} The above elements are connected to each other via a bus 290.

FIG. 5 is a block diagram illustrating a hardware configuration of the gate device 300. The gate device 300 includes a CPU 310, a ROM 320, a RAM 330, a transmission unit 340, a reception unit 350, an antenna 360, an EEPROM 370, and a bus 390. The EEPROM 370 stores an unauthorized key K _N and a security level L _L. The functions of other elements are the same as those of the gate device 200. As the document display device 100, the gate device 200, and the gate device 300 each execute a control program, the document management system 1 has the functions shown in FIG.

2. Operation FIG. 6 is an image diagram for explaining the outline of the document management system 1. The gate device 200 and the gate device 300 are installed at the entrance and exit of a room with high security. In FIG. 6, the right hand is a high security room and the left hand is a low security room. The gate device 200 and the gate device 300 are arranged at different positions in the movement route (dotted arrow in the drawing) between the low security room and the high security room. Specifically, the gate device 200 is disposed near the higher security room, and the gate device 300 is disposed near the lower security room. The user can go in and out of the high security room while holding the document display device 100, but cannot enter the high security room unless passing through the place where the gate device 200 and the gate device 300 are arranged. When the user (that is, the document display device 100) enters the communicable area of the gate device 300, the document display device 100 communicates with the gate device 300. When the user enters the communicable area of the gate device 200, the document display device 100 communicates with the gate device 200.

  FIG. 7 is a diagram illustrating the operation of the document management system 1. The document management system 1 basically operates according to the flow of FIG. 7 both when entering the high security room and when leaving the high security room. Hereinafter, the operation of the document management system 1 will be described separately when entering the high security room and when leaving the high security room.

2-1. Operation when entering the high security room When the user enters the high security room with the document display device 100, the wireless module 400 of the document display device 100 first communicates with the gate device 300 and then with the gate device 200. connect. First, communication between the document display device 100 and the gate device 300 will be described.

In step S100, the CPU 310 of the gate device 300 authenticates the document display device 100. The authentication process is performed using a known technique. The gate device 300 outputs a request signal for requesting transmission of an ID to the mobile terminal device (here, the document display device 100) via the transmission unit 340 and the antenna 360. When receiving the request signal, the wireless module 400 transmits information necessary for authentication processing such as its own ID. The CPU 310 of the gate device 300 performs an authentication process for the document display device 100 based on the received information. When the document display device 100 is not authenticated as a valid terminal, the CPU 310 of the gate device 300 does not perform the following processing. When the document display device 100 is authenticated as a valid terminal, the CPU 310 of the gate device 300 reads key information and a security level from the EEPROM 370. The EEPROM 370 stores K _N as key information and L _L as a security level. CPU 310 transmits a signal including information indicating a key and a security level to document display device 100.

  The gate device 300 (the same applies to the gate device 200) may output the request signal at regular time intervals. Alternatively, the document display device 100 may output a signal requesting the start of the authentication process. In this way, any process that triggers the authentication process may be used.

In step S <b> 110, the CPU 410 of the wireless module 400 stores the key K _N and the security level L _L received from the gate device 300 in the EEPROM 431. If the key and security level are already stored in the EEPROM 431, the CPU 410 overwrites the already stored key and security level with the received key K _N and security level L _L. That is, previously stored keys and security levels are erased. Thus, when the communication with the gate device 300 is completed, the key K _N and the security level L _L are stored in the EEPROM 431 of the wireless module 400. For example, L _L = 0. In the following, an example will be described in which the security level is represented by an integer of 0 to 10, and the higher the number, the higher the security.

As the user walks toward the high-security room, the document display device 100 reaches an area where it can communicate with the gate device 200. In this way, the document display device 100 communicates with the gate device 200. Communication between the document display device 100 and the gate device 200 is performed in the same manner as communication between the document display device 100 and the gate device 300. However, the key and the security level is transmitted from the gate apparatus 200, the point is the key K _D and security level L _H are different. Here, for example, L _H = 10. CPU410 wireless module 400 stores the key _{K D} and security level _{L H} received from the gate device 200 to EEPROM431. Here, although already _{K N} and security level _{L L} in EEPROM431 is stored, CPU 410 makes these data are overwritten with the received key _{K D} and security level _{L H.} That is, upon entering the room of a high security, the EEPROM431 radio module 400, the key _{K D} and security level _{L H} is stored.

Thus, upon entering the region of the low security room high security, the EEPROM431 radio module 400, the key _{K D} and security level _{L H} is stored. In this state, when a triggering process is performed, such as the user operating the key button 141 to input a command to display the document data D, the document display apparatus 100 performs the processes of steps S120 to S140.

  In step S120, the CPU 110 performs a level check. “Level check” refers to a process of checking whether the security level of the requested process is compatible with the security level of the document display apparatus 100. The level check is performed as follows, for example. The CPU 110 outputs a command requesting the wireless module 400 to return the current security level. When this command is input, the CPU 410 of the wireless module 400 reads the security level stored in the EEPROM 431. The CPU 410 outputs the read security level to the main body of the document display device 100 via the I / O 480. The CPU 110 of the document display device 100 performs a level check based on the security level output from the wireless module 400 and the processing level table stored in the internal storage device 181.

FIG. 8 is a diagram illustrating a processing level table. The internal storage device 181 (which may be another storage device such as the ROM 120 and the removable medium 183) stores in advance a processing level table as shown in FIG. The processing level table has a plurality of data sets including a processing and a security level L _REQ necessary for executing the processing. For example, the security level L _REQ required for the “navigation operation” is “1”. The security level of the document display device 100 at this time is L _H. That is, if L _H is 1 or more, CPU 110 includes a requested operation being security level and security level of the document display apparatus 100 is judged to be compatible. In another example, the security level L _REQ required for “setting change” is “7”. That is, if L _H 7 or more, CPU 110 includes a requested operation being security level and security level of the document display apparatus 100 is judged to be compatible. If L _H is less than 7, CPU 110 includes a requested operation being security level and security level of the document display device 100 is determined not to be relevant.

A description will be given with reference to FIG. 7 again. If it is determined that the security level of the requested process does not match the security level of the document display device 100 (S120: NG), the CPU 110 shifts the process to step S150. If it is determined that the security level of the requested process and the security level of the document display device 100 are compatible (S120: OK), the CPU 110 shifts the process to step S130. Now, since L _H = 10, it is determined that the security level of the requested processing and the security level of the document display device 100 are compatible.

In step S <b> 130, the CPU 110 performs a requested process, here, a process of decoding the document data D as a previous stage of displaying the document data D. This process is performed as follows, for example. The CPU 110 outputs the document data D and a decryption instruction for the document data D to the wireless module 400 via the I / O 140. When a decryption command is input via the I / O 480, the CPU 410 of the wireless module 400 performs processing according to the input command. Since the input command is a decryption command, the CPU 410 first stores the input document data D in the RAM 430. Next, the CPU 410 controls the encryption engine 440 so as to decrypt the document data D using the key (here, the key K _D ) stored in the EEPROM 431. Cipher engine 440 decrypts the document data D by using the key _{K D.} Since key _the K _D is a legitimate decryption key for the key K _E used when encrypting the document data D, the document data D is successfully decoded. The CPU 410 stores the decrypted document data D in the RAM 430. The CPU 410 outputs the decrypted document data D to the main body of the document display device 100 via the I / O 480. The CPU 110 of the document display device 100 stores the input document data D in the RAM 130.

  In step S140, CPU 110 displays the document. The CPU 110 stores the document data D related to the screen to be displayed in the VRAM 131. The display control unit 150 controls the display device 151 according to the data stored in the VRAM 131. Here, since the document data D is normally decrypted, a normal document (a part thereof) is displayed on the display device 151.

2-2. Operation when exiting the high security room When the user exits the high security room with the document display device 100, the wireless module 400 of the document display device 100 first communicates with the gate device 200. Next, it communicates with the gate device 300. That is, when leaving the room with high security, the EEPROM 431 of the wireless module 400 stores the key K _N and the security level L _L.

Since L _L = 0 and L _REQ = 5 now, in the level check in step S120, it is determined that the security level of the requested process does not match the security level of the document display device 100. Accordingly, in step S150, CPU 110 causes display device 151 to display a message indicating that effect.

For example, if L _L = 5, it is determined that the security level of the requested process and the security level of the document display device 100 match in the level check in step S120. However, key stored in EEPROM431 are incorrect key _{K N,} i.e., key stored in EEPROM431 is not a valid key to the key _{K E} is an encryption key of the document data D. Therefore, the encryption engine 440 cannot normally decrypt the document data D. Therefore, the image displayed on the display device 151 in step S140 is unclear.

  As described above, according to the present embodiment, the key stored in the document display device 100 is rewritten to a valid one when entering the high security area, and is illegal when entering the low security area. To be rewritten. Accordingly, it is possible to limit the document data D from being taken out.

3. Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made.
In the above-described embodiment, the gate device 200 and the gate device 300 transmit two pieces of information of the key and the security level to the document display device 100. However, the gate device 200 and the gate device 300 may not transmit the security level. That is, the document display device 100 may not have a processing restriction function based on the security level. In this case, the process of step S120 in FIG. 7 is not performed. That is, in the document display device 100, the document is normally displayed if a valid decryption key is stored, and an unknown image is displayed if an invalid key is stored.

In the above-described embodiment, an example in which the gate device 200 located on the high security side writes a valid decryption key to the wireless module 400 and the gate device 300 located on the low security side writes an unauthorized key to the wireless module 400 has been described. . However, the division of roles between the gate device 200 and the gate device 300 is not limited to that described in the above embodiment. For example, the direction of entry / exit may be determined based on the communication time, and data transmitted from the gate device to the document display device 100 may be determined according to the determination result. Details are as follows. A server device is connected to the gate device 200 and the gate device 300. The server device has a function of measuring time using a timer or the like. The server device stores a valid decryption key K _D and unauthorized key K _N. Gate device 200 and gate device 300 output a signal indicating that communication with document display device 100 has been made to the server device. The server device stores a data set including an identifier of the gate device and a time when the gate device communicates with the gate device. The server device determines the direction of entry / exit based on this data. That is, when communicating with the gate device 200 first and the gate device 300 later, the server device determines that it has left the high security room. When first communicating with the gate device 300 and later with the gate device 200, the server device determines that it has entered a high security room. If it is determined that entered the room of high security, the server device to transmit the key K _D in the text display device 100, controls the gate unit 200. When it is determined that the user has left the high security room, the server device controls the gate device 300 to transmit the key K _N to the document display device 100.

  Instead of determining the entrance / exit direction based on the time, the moving direction may be determined based on the electric field strengths of the two gate devices.

In the embodiment described above, the gate device 300 transmits the unauthorized key K _N to the document display device 100. However, the information transmitted by the gate device 300 is not limited to the encryption key. If data other than legitimate decryption key K _D, any data may be transmitted. For example, a meaningless bit string may be transmitted. Alternatively, the instruction to erase the stored key or authorized decryption key _{K D} in EEPROM431 may be transmitted. When receiving this command, the CPU 410 deletes the key stored in the EEPROM 431. In short, any information may be used as long as the key data stored in the EEPROM 431 of the document display device 100 can be deleted.

In the embodiment described above, the gate device 300 transmits the unauthorized key K _N to the document display device 100. However, the gate device 300 may transmit to the document display device 100 a command for requesting deletion of the document data D (this command may include an identifier of the document data D) instead of the unauthorized key K _N. Good. The document display device 100 that has received this command may erase the document data D from the internal storage device 181. That is, the wireless module 400 may perform an interrupt process for erasing the document data D on the document display device 100 main body.

  In the above-described embodiment, when the security level of the requested process does not match the security level of the document display apparatus 100, the requested process is not performed. However, even in this case, the requested processing may be performed. At this time, the CPU 110 may generate log data indicating that processing not conforming to the security level has been performed, and store the log data in the internal storage device 181. Or CPU110 may memorize | store in RAM130 the frequency | count that the process which a security level does not adapt was performed. Furthermore, if processing that does not match the security level is performed a certain number of times or more, the CPU 110 may lock the document display device 100. In other words, any operation from the user may not be accepted.

  In the above-described embodiment, the example in which the gate device 200 and the gate device 300 are separate devices has been described. However, a single device may have the functions of the gate device 200 and the gate device 300. In this case, this apparatus only needs to have two antennas, two transmission units, and one reception unit, and only one CPU, RAM, and the like. Further, the memory and its control device may be provided individually for each data to be stored.

  In the above-described embodiment, the example in which the encryption key and the decryption key are different has been described. However, a so-called common key encryption system in which the encryption key and the decryption key are the same may be used.

  In the above-described embodiment, the update timing of the encryption key and the decryption key is not particularly mentioned, but the encryption key and the decryption are performed at a predetermined timing (for example, after a certain period of time or every time communication is performed). The key may be updated to a new one. Alternatively, the gate device may transmit a plurality of decryption keys to the mobile terminal device in one communication. At this time, the gate device may transmit information indicating the correspondence between the decryption key and the document data to the mobile terminal device. The mobile terminal device can decrypt the document data using a decryption key corresponding to the document data to be processed from among a plurality of decryption keys.

It is a block diagram which shows the function structure of the document management system 1 which concerns on one Embodiment. 2 is a block diagram illustrating a hardware configuration of a document display device 100. FIG. 2 is a block diagram showing a hardware configuration of a wireless module 400. FIG. 2 is a block diagram showing a hardware configuration of a gate device 200. FIG. 3 is a block diagram showing a hardware configuration of a gate device 300. FIG. It is an image figure explaining the outline | summary of the document management system 1. FIG. It is a figure which shows operation | movement of the document management system. It is a figure which illustrates a processing level table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Document management system 100 ... Document display apparatus 101 ... Document storage part 102 ... Wireless communication part 103 ... Key storage part 104 ... Decryption part 105 ... Display part 110 ... CPU, 120 ... ROM, 130 ... RAM, 131 ... VRAM, 140 ... I / O, 141 ... key button, 150 ... display control unit, 151 ... display device, 160 ... power supply control unit, 161 ... battery, 170 ... communication control unit, 171 ... IF for communication , 180 ... Storage device control unit, 181 ... Built-in storage device, 182 ... Memory IF, 183 ... Removable media, 190 ... Bus, 200 ... Gate device, 201 ... Storage unit, 202 ... Wireless communication unit, 210 ... CPU, 220 ... ROM, 230 ... RAM, 240 ... transmitter, 250 ... receiver, 260 ... antenna, 270 ... EEPROM, 290 ... bus, 300 ... gate 301, storage unit, 302 ... wireless communication unit, 310 ... CPU, 320 ... ROM, 330 ... RAM, 340 ... transmission unit, 350 ... reception unit, 360 ... antenna, 370 ... EEPROM, 390 ... bus, 400 ... Wireless module, 410 ... CPU, 420 ... ROM, 430 ... RAM, 431 ... EEPROM, 440 ... cryptographic engine, 450 ... transmitting unit, 451 ... receiving unit, 452 ... antenna, 460 ... battery, 480 ... I / O, 490 ... bus

Claims (4)

A first radio frequency write device, a second wireless write device disposed in high-security side than the first radio writing apparatus, and a mobile terminal device possess,
The first wireless writing device is
First storage means for storing a decryption key;
First transmission means for transmitting the decryption key stored in the first storage means to the mobile terminal device that has entered the predetermined area with the first wireless writing device as a reference by non-contact communication When
Have
The second wireless writing device comprises:
Second storage means for storing erasure information;
Second transmission means for transmitting the erasure information stored in the second storage means to the mobile terminal device that has entered the predetermined area with the second wireless writing device as a reference by non-contact communication When
Have
The mobile terminal device
Data storage means for storing document data encrypted with an encryption key;
A non-contact communication means for performing first wireless writing device or the second radio writing apparatus and the non-contact communication,
Stores either the decryption key received from the first wireless writing device via the non-contact communication means or the erasure information received from the second wireless writing device via the non-contact communication means Terminal key storage means;
When the decryption key or the erasure information is received from the first wireless writing device or the second wireless writing device via the non-contact communication means , the terminal key is used with the received decryption key or the erasure information. Storage control means for overwriting information stored in the storage means;
A decryption means for decrypting the document data stored in the document data storage means using the decryption key when a decryption key is stored in the terminal key storage means;
An image display means for displaying an image according to the document data decoded by the decoding means. The contactless communication means receives information indicating a security level from the first wireless writing device or the second wireless writing device;
The mobile communication terminal is
Security level storage means for storing information indicating the security level received by the non-contact communication means;
A process control means for performing one of a plurality of processes related to the operation of the mobile terminal device;
For each of the plurality of processes, table storage means for storing a table including an identifier of the process and a security level required for the process;
Selecting means for selecting one process from the plurality of processes in accordance with a user operation;
Determination means for determining whether the security level stored in the storage means is compatible with the security level corresponding to the process selected by the selection means among the security levels included in the table stored in the table storage means; Have
The security level stored in the storage unit by the determination unit is adapted to the security level corresponding to the process selected by the selection unit among the security levels included in the table stored in the table storage unit. 2. The management system according to claim 1, wherein when the determination is made, the process control unit performs the one process selected by the selection unit. The contactless communication means receives information indicating a security level from the first wireless writing device or the second wireless writing device;
The mobile communication terminal is
Security level storage means for storing information indicating the security level received by the non-contact communication means;
A process control means for performing one of a plurality of processes related to the operation of the mobile terminal device;
For each of the plurality of processes, table storage means for storing a table including an identifier of the process and a security level required for the process;
Selecting means for selecting one process from the plurality of processes in accordance with a user operation;
Determination means for determining whether the security level stored in the storage means is compatible with the security level corresponding to the process selected by the selection means among the security levels included in the table stored in the table storage means; The determination means determines that the security level stored in the storage means does not conform to the security level corresponding to the process selected by the selection means among the security levels included in the table stored in the table storage means. A number storage means for storing the number of times
The management system according to claim 1, further comprising: a lock unit that locks the mobile terminal device when the number of times stored in the number storage unit exceeds a threshold value. The non-contact communication means receives a command for requesting erasure of data stored in the data storage means from the second wireless writing device;
The management system according to claim 1, wherein the storage control unit erases data stored in the data storage unit in accordance with a command received by the non-contact communication unit.

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