JP2010034651A - Information terminal, computer virus countermeasure program thereof, and navigation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance security to computer virus. <P>SOLUTION: A navigation device 100 includes: a virus countermeasure data database 121 for storing virus countermeasure data received from a virus countermeasure data providing device 200; a virus countermeasure part 112 for facilitating countermeasures to virus by using the virus countermeasure data; a data management part 113 for determining whether or not the virus countermeasure data stored in the database 121 satisfy countermeasure sufficient conditions; and a virus countermeasure input/output control part 114 for, when the countermeasure sufficient conditions are not satisfied, executing communication with an information providing device 400 through a repeater system 300 whose virus countermeasure are sufficient. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a computer virus countermeasure technique for an information terminal.

  There is a car navigation device as an in-vehicle information terminal. This car navigation apparatus initially displays its own vehicle position and provides route guidance to a destination using map data in the apparatus and position information from an artificial satellite.

  However, in recent years, car navigation apparatuses are connected to the outside via a communication means such as a mobile phone and can acquire information from the outside. In addition, information can be acquired from portable storage media such as CDs, DVDs, and memories.

  When the information terminal acquires data from the outside, the data held in the information terminal may be damaged by unauthorized data that adversely affects the information terminal, so-called computer virus. As a countermeasure against this computer virus, it is a mainstream to store in advance in the information terminal a feature pattern that exists for each computer virus, and to monitor whether the information terminal itself has data having such a feature pattern. .

  When taking measures against computer viruses as described above, it is essential to update feature pattern data and computer virus measures programs. As this update technique, for example, there is a technique described in Patent Document 1 below. This technology is a technology for receiving a computer virus countermeasure program circulated by digital terrestrial broadcasting and using this new program for computer virus countermeasures.

JP 2005-151193 A

  However, in the technique described in Patent Document 1, when the vehicle is in an area where digital terrestrial broadcasting cannot be received, a computer virus countermeasure program or the like cannot be received, and information is not received from the outside with insufficient computer virus countermeasures. There is a problem that there is a risk of being contaminated by a computer virus.

  The present invention pays attention to such problems of the prior art, and an object of the present invention is to provide a technique that can further enhance security against computer viruses.

  In order to achieve the object, the present invention executes the following processing.

  Computer virus countermeasure data is received by the data reception means of the computer, the received computer virus countermeasure data is stored in the storage device of the computer, and the computer virus countermeasure data stored in the storage device is used from the outside. The computer virus countermeasure process is executed on the received data.

  Further, it is determined whether or not the computer virus countermeasure data stored in the storage device satisfies a predetermined countermeasure sufficient condition, and if it is determined that the countermeasure sufficient condition is not satisfied, the storage device stores the computer virus countermeasure data in advance. Using the stored communication address of the information providing apparatus and the communication address of the relay apparatus that executes computer virus countermeasure processing, the communication means of the computer is communicated with the information providing apparatus via the relay apparatus. Let it run.

  In the above invention, when the computer virus countermeasure data stored in the storage device does not satisfy the predetermined countermeasure sufficient condition, the computer virus countermeasure data is transmitted to the information providing device via the relay device that executes the computer virus countermeasure processing. Therefore, even when computer virus countermeasures are insufficient, the possibility of being contaminated by computer viruses can be minimized, and security against computer viruses can be further increased.

In addition, the invention relating to the car navigation device for achieving the above object is as follows:
In a car navigation device that acquires information from an information providing device connected to a communication network,
Wireless communication means for performing wireless communication with a wireless communication access point device that performs relay processing for the communication network;
Ad hoc wireless communication means for wireless communication with other car navigation devices;
Countermeasure data receiving means for receiving computer virus countermeasure data and a generation time stamp of the computer virus countermeasure data;
Countermeasure data storage means for storing the computer virus countermeasure data and the generation time stamp received by the countermeasure data receiving means;
Virus countermeasure processing means for executing computer virus countermeasure processing on data received from the outside using the computer virus countermeasure data stored in the countermeasure data storage means;
When the ad hoc wireless communication means receives the generated time stamp from the other car navigation device, the ad hoc wireless communication means compares it with the latest time stamp among the time stamps stored in the handling data storage means, and the other car navigation device. If the generated time stamp from is older than the latest time stamp stored in the countermeasure data storage means, among the countermeasure data stored in the countermeasure data storage means, the other car navigation device Response data of a time stamp that is newer than the generated time stamp is transmitted to the other car navigation device by the ad hoc wireless communication means, and the generated time stamp from the other car navigation device is stored in the response data storage means. If it is newer than the latest time stamp And data management means for transmitting to said other car navigation device by the ad-hoc radio communication means the latest timestamp,
It is characterized by having.

  In the invention related to the car navigation device described above, even when the latest anti-virus data cannot be obtained from the anti-virus data providing device, the anti-virus data possessed by the own navigation device is transmitted to other car navigation devices by ad hoc communication. By transmitting the time stamp, it is possible to make a request for acquiring the latest virus countermeasure data. Here, the invention relates to a car navigation device, but may be another navigation device, for example, a navigation device for guiding a pedestrian.

  According to the present invention, security against computer viruses can be further increased.

  Hereinafter, embodiments of an information terminal according to the present invention will be described with reference to the drawings.

  The information terminal of this embodiment is a car navigation device 100 mounted on a vehicle C as shown in FIG.

  The car navigation apparatus 100 includes a CPU 110 that executes various arithmetic processes, a storage device 120 such as a hard disk drive that stores various programs and various data, a memory 101 that serves as a work area for the CPU 110, and a DVD that can be used. A disk recording / reproducing apparatus 102 for recording / reproducing data to / from a portable disk storage medium, an input / output device 140 having a display and an input operation unit, an I / O interface 103 as an interface of the input / output apparatus 140, and wireless An infrastructure wireless device 131 that accesses the communication network 1 via the access point 2 via a LAN, an ad hoc communication device 132 that wirelessly communicates with other information terminals without going through the access point 2, a GPS receiver 133, and broadcast reception Device 134 and It is equipped with. As described above, the navigation device 100 is not much different from a normal computer except that the navigation device 100 includes the GPS receiver 133 and the like in order to realize the navigation function.

  The storage device 120 includes a virus countermeasure data database 121 that stores computer virus countermeasure data, an encryption processing key table 122 that stores keys for data encryption and decryption, and communication at a communication destination. A communication address table 123 in which addresses are stored, a map information database 124 in which map information is stored, and a checked file list 125 in which feature values relating to data after checking for computer viruses are stored are provided. Yes. Further, the storage device 120 stores various programs such as a computer virus countermeasure program 126, an infrastructure communication control program 127a, an ad hoc communication program 127b, an encryption processing program 126, and a navigation program 129.

  The CPU 110 functionally includes a navigation processing unit 111 that executes navigation processing, a computer virus handling unit 112 that deals with computer viruses, a data management unit 113 that manages input / output of data to / from the storage device 120, and an infrastructure wireless communication. An anti-virus input / output control unit 114 that performs anti-virus measures for input / output devices such as the device 131 and the disk recording / reproducing device 102, an infrastructure communication control unit 115, an ad hoc communication control unit 116, an encryption processing unit 117; have. Among these functional units, the navigation processing unit 111 functions when the CPU 110 executes the navigation program 129 stored in the storage device 120. Further, the computer virus countermeasure unit 112, the data management unit 113, and the virus countermeasure input / output control unit 114 function by the CPU 110 executing the virus countermeasure program 126 stored in the storage device 120. The infrastructure communication control unit 115, the ad hoc communication control unit 116, and the cryptographic processing unit 117 are executed by the CPU 110, respectively, with the infrastructure communication program 127a, the ad hoc communication program 127b, and the cryptographic processing program 128 stored in the storage device 120. It works with.

  In the communication network 1 described above, the virus countermeasure data providing device 200 that provides computer virus countermeasure data to the car navigation device 100 of each vehicle C and the car navigation device 100 etc., regional information, store information, traffic information, etc. Are connected to an information providing apparatus 400 that provides various types of information and a relay apparatus 300 that is provided with anti-virus measures.

  As shown in FIG. 2, the virus countermeasure data providing apparatus 200 is a computer, and executes a CPU 210 that performs various arithmetic processes, a storage device 220 such as a hard disk drive that stores various programs and various data, and the CPU 210. And a communication device 231 that communicates with the outside via the communication network 1.

  The storage device 220 includes a virus countermeasure data database 221 that stores the latest computer virus countermeasure data provided to the car navigation device 100 and the like, and an encryption process that stores a key for encrypting the virus countermeasure data. A key table 222 is provided. Further, although not shown, the storage device 220 stores a data input / output control program, a cryptographic processing program, a communication control program, and the like for the storage device 220.

  The CPU 210 functionally includes a data management unit 211 that manages input / output of data to / from the storage device 220, an encryption processing unit 212, and a communication control unit 213. The data management unit 211, the encryption processing unit 212, and the communication control unit 213 function by the CPU 210 executing a data input / output control program, an encryption processing program, and a communication control program stored in the storage device 220, respectively. .

  The relay device 300 is a computer, a CPU 310 that executes various arithmetic processes, a storage device 320 such as a hard disk drive that stores various programs, various data, and the like, a memory 301 that is a work area of the CPU 310, and communication And a communication device 331 that communicates with the outside via the network 1.

  The storage device 320 includes a virus countermeasure data database 321 in which the latest computer virus countermeasure data is stored, and a communication address necessary for relaying a message from the car navigation device 100 or the like to the information providing device 400 or the like. A relay table 322 to be stored is provided. Furthermore, the storage device 320 stores a computer virus countermeasure program 323, a communication program 324, a data input / output control program (not shown) for the storage device 320, and the like.

  The CPU 310 functionally includes a computer virus handling unit 311 that deals with computer viruses, a communication control unit 312, and a data management unit (not shown). The computer virus countermeasure unit 311, the communication control unit 312, and the data management unit respectively store a computer virus countermeasure program 323, a communication program 324, and a data input / output control program for the storage device 320 stored in the storage device 320. Works by running.

  The information providing apparatus 400 is a computer, a CPU 410 that executes various arithmetic processes, a storage device 420 such as a hard disk drive that stores various programs, various data, and the like, a memory 401 that is a work area of the CPU 410, And a communication device 431 that communicates with the outside via the communication network 1.

  The storage device 420 is provided with an information database 421 that stores regional information, store information, traffic information, and the like to be provided to the car navigation device 100 and the like. The storage device 420 further stores a communication program (not shown), a data input / output control program for the storage device 320, and the like.

  The CPU 410 functionally includes a data management unit 411 that manages data input / output with respect to the storage device 420, and a communication control unit 412. The data management unit 411 and the communication control unit 412 function when the CPU 410 executes a data input / output program and a communication program for the storage device 420, respectively.

  Next, the operation of each device of this embodiment will be described.

  First, the operation of the car navigation apparatus 100 when receiving an information request will be described with reference to the flowchart shown in FIG.

  When the data management unit 113 receives the information request (S111), the data management unit 113 determines whether the data stored in the virus countermeasure data database 121 satisfies a sufficient countermeasure condition for a computer virus (S112). This information request may be, for example, when the driver requests information about the store from the information providing device 400 by operating the input / output device 140, or when the data management unit 113 itself sets a predetermined update period ( For example, it occurs when it is determined that one week has passed and virus countermeasure data is requested from the virus countermeasure data providing apparatus 200. Further, the sufficient countermeasure condition here is that the update time stamp of the data stored in the virus countermeasure data database 121 is less than a predetermined period (for example, one week) from the present time.

  Here, the virus countermeasure data database 121 provided in the storage device 120 will be described with reference to FIG.

  As shown in FIG. 3, the virus countermeasure data database 121 stores a feature pattern data column 121d in which feature pattern data indicating a feature pattern for each type of computer virus is stored, and the date and time when the feature pattern data was updated. The update time stamp field 121a, the creation time stamp field 121b in which the creation date and time of the feature pattern data are stored, and the electronic signature field 121c in which the electronic signature from which the feature pattern data is created are stored.

  In the above-described step S112, the data management unit 113 refers to the update time stamp field 121a of the virus countermeasure database 121, compares the latest update date and time with the current date and time, and determines a time period in which the date and time difference between the two is predetermined (for example, It is determined whether it is less than 1 week), and if it is less than this period, it is assumed that a sufficient coping condition is satisfied.

  If the data management unit 113 determines that the sufficient handling condition is satisfied in step S112, the data communication unit 113 causes the infrastructure communication control unit 115 to create an information request packet to the request destination (S113). Subsequently, the infrastructure communication control unit 115 determines whether there is an access point 2 with which communication is possible (S115). In the wireless LAN, the access point 2 transmits a beacon. The infrastructure communication control unit 115 determines whether or not communication with the access point 2 is possible based on whether or not the beacon from the access point 2 received by the infrastructure wireless device 131 is equal to or higher than a predetermined radio wave intensity. .

  When the infrastructure communication control unit 115 determines that there is a communicable access point 2, the infrastructure communication control unit 115 causes the infrastructure radio apparatus 131 to transmit the packet created in step S 113 or the packet created in step S 114 described later (S 117). Then, a series of information request processing ends. On the other hand, when the infrastructure communication control unit 115 determines that there is no communicable access point 2, it determines whether or not it is within a predetermined time from the point when preparation for packet transmission is completed (packet creation is completed). Determination is made (S116), and if it is within a predetermined time, the process returns to step S115, and if the predetermined period is exceeded, a series of information request processing is terminated without packet transmission. That is, if the access point 2 does not exist at a communicable position with respect to the current location of the vehicle C on which the car navigation device 100 of this embodiment is mounted, the request is requested even if an information request is accepted. You may not be able to send first. When the information request cannot be transmitted to the request destination, it is preferable to display on the display of the input / output device 140 that the request packet has not been transmitted.

  In step S112, if the data management unit 113 determines that the sufficient countermeasure condition is not satisfied, the virus management input / output control unit 114 is notified of the fact. The virus countermeasure input / output control unit 114 refers to the communication address table 123, acquires the communication address of the relay device 300 as the destination address when the sufficient countermeasure condition is not satisfied, and sets the information request destination as the final transmission destination. The destination address and the final transmission destination address are passed to the infrastructure communication control unit 115. Further, the virus countermeasure input / output control unit 114 determines the message number of the information request and passes it to the infrastructure control unit 115 as well. Then, the infrastructure communication control unit 115 creates an information request packet to the request destination via the relay device 300 (S114).

  Here, an information request packet to a request destination via the relay apparatus 300 will be described with reference to FIG.

  This information request packet 10 has a header part 11 and a payload part 15. The header part 11 has a source address area 12 in which a source address is stored and a destination address area 13 in which a destination address is stored. In the transmission source address area 12, the communication address of the car navigation apparatus 100 itself is stored, and in the destination address area 13, the communication address of the relay apparatus 300 specified by the virus countermeasure input / output control unit 114 is stored. The payload section 15 has a message area 16 in which an information request message is stored, a message number area 17 in which the message number of this message is stored, and a transmission destination address area 18 in which a transmission destination address is stored. ing. In the message number area 17, the message number designated by the virus countermeasure input / output control unit 114 is stored. This message number is a number that uniquely identifies the information request message stored in the message area 16. The transmission destination address area 18 stores the final transmission destination designated by the virus countermeasure input / output control unit 114, that is, the communication address of the information request destination.

  When the infrastructure communication control unit 115 creates an information request packet to the request destination via the relay device 300 (S114), as described above, the infrastructure communication control unit 115 determines whether there is a communicable access point 2 (S115). If there is a communicable access point 2, the packet created in step S114 is transmitted to the infrastructure radio apparatus 131 (S117), and a series of information request processing ends.

  As described above, in the present embodiment, when an information request is made via the communication network 1, if the countermeasure against the computer virus is insufficient, the information request destination By communicating, the possibility that the car navigation apparatus 100 is attacked by a computer virus is kept small.

  Next, it is assumed that the information request packet created in step S113 described above is a virus countermeasure data request packet for the virus countermeasure data providing apparatus 200, and the operation of the virus countermeasure data providing apparatus 200 in that case will be described.

  The virus countermeasure data database 221 of the virus countermeasure data providing apparatus 200 stores feature pattern data indicating feature patterns for each type of computer virus, from the past to the latest. In the virus countermeasure data database 221, in addition to the feature pattern data, a creation time stamp in which the creation date and time of the corresponding feature pattern data is stored and an electronic signature from which the corresponding feature pattern data is created are stored in pairs. ing.

  When the communication control unit 213 of the virus countermeasure data providing apparatus 200 receives the virus countermeasure data request packet from the car navigation apparatus 100, the data management unit 211 sends the latest feature pattern data from the virus countermeasure data database 211 and the creation time. A stamp and a set of electronic signatures of the creation source (hereinafter, a set of feature pattern data, a creation time stamp, and a digital signature are referred to as a feature pattern data set) are extracted. The encryption processing unit 212 encrypts the feature pattern data set using the secret key stored in the encryption processing key table 222. The communication control unit 213 packetizes this and transmits it to the car navigation device 100 that is the transmission source of the virus countermeasure data request packet.

  Note that when the virus countermeasure data providing apparatus 200 receives a virus countermeasure data request packet from the car navigation apparatus 100 via the relay apparatus 300, the virus countermeasure data providing apparatus 200 does not encrypt the feature pattern data set that is the virus countermeasure data. Then, the data is transmitted to the car navigation device 100 via the relay device 300. This is because, as will be described later, since the relay device 300 performs computer virus check, if it is encrypted, virus check cannot be performed. As a method of not encrypting the feature pattern data set in communication via the relay device 300, it is determined in advance that the virus countermeasure data providing device 200 is not encrypted in communication via the relay device 300, There is a method of incorporating a message to the effect that data is not encrypted in the data request packet from the car navigation device 100 as a request source.

  Next, the operation of the relay apparatus 300 that has received the information request packet created in step S114 described above will be described.

  When the communication control unit 312 of the relay device 300 receives the information request packet from the car navigation device 100 that is the information request source, the virus handling unit 311 stores the data in the information request packet in the virus handling data database 321. It is checked whether there is any data corresponding to any of the feature pattern data being processed. If there is data corresponding to any of the feature pattern data, the information request packet is discarded. If none of the feature pattern data corresponds, the communication control unit 312 analyzes the information request packet and stores the data obtained by the analysis in the relay table 322.

  This relay table 322 is a table that stores data for sending a response to an information request from the information request destination to the car navigation device 100 that is the information request source. As shown in FIG. 4, the relay table 322 stores a transmission source address area 322a in which the transmission source address of the received information request packet is stored, and a final transmission destination address of the information request packet. Destination address area 322b and a message number area 322c in which the message number included in the information request packet is stored.

  The communication control unit 312 stores the source address stored in the source address area 12 of the received information request packet 10 (FIG. 12), the destination address stored in the destination address area 18, and the message number area 17. The stored message numbers are stored in the transmission source address area 322a, transmission destination address area 322b, and message number area 322c of the relay table 322, respectively.

  Next, as shown in FIG. 12, the communication control unit 312 stores the communication stored in the destination address area 13a of the information request transfer packet 10a and the transmission destination address area 18 of the information request packet 10 from the car navigation device 100. The address is stored, and the communication address stored in the destination address area 13 of the information request packet 10 from the car navigation apparatus 100, that is, the communication address of the relay apparatus 300 is stored in the source address area 12a of the information request transfer packet 10a. Store. Further, the information request stored in the information request message area 16 of the information request packet 10 from the car navigation device 100 in the information request message area 16 and the message number area 17 of the payload part 15a of the information request transfer packet 10a, respectively. The message number stored in the message and message number area 17 is stored. Then, this information request transfer packet 10 a is sent to the communication network 1. That is, the information request message included in the information request packet 10 is transferred to the request destination.

  Here, the communication address stored in the destination address area 13a of the information request transfer packet 10a, that is, the communication address stored in the transmission destination address area 18 of the information request packet 10 from the car navigation device 100 is provided as information provision. It is assumed that the communication address of the device 400 is used.

  In this case, the communication apparatus 431 of the information providing apparatus 400 receives the information request transfer packet 10a. The communication control unit 412 of the information providing apparatus 400 analyzes the information request transfer packet 10a and passes the information request message included in the packet 10a to the data management unit 411. The data management unit 411 extracts information requested by the information request message from various pieces of information stored in the information database 421 and passes it to the communication control unit 431.

  The communication control unit 431 stores the information from the data management unit 411 in the response message area 16b of the response packet 20 illustrated in FIG. Further, the communication address stored in the destination address area 13a of the information request transfer packet 10a from the relay device 300, respectively in the source address area 12b, the destination address area 13b, and the message number area 17 of the response packet 20, The communication address stored in the source address area 12a of the information request transfer packet 10a and the message number stored in the message number area 17 of the information request packet 10a are stored. The response packet 20 is sent to the communication network 1.

  When the communication control unit 312 of the relay device 300 receives the response packet 20 via the communication device 331, the virus handling unit 311 stores the data in the response packet in the virus handling data database 321. It is checked whether there is data corresponding to any of the feature pattern data. If there is data corresponding to any of the feature pattern data, the response packet is discarded. If there is no data corresponding to any feature pattern data, the communication control unit 312 creates a response transfer packet to be described later based on the response packet.

  When creating the response transfer packet, the communication control unit 312 first determines that the message number stored in the message number area 17 of the response packet 20 and the communication address stored in the source address area 12b of the response packet 20 are: It is determined whether there are records stored in the message number area 322c and the transmission destination address area 322b of the relay table 222, respectively. If the corresponding record exists, the communication address stored in the transmission source address area 322a of this record, that is, the communication address of the car navigation device 100 that is the information request source is acquired. Next, as shown in FIG. 12, the communication address of the information requesting car navigation device 100 acquired from the transmission source address area 322a of the relay table 222 is stored in the destination address area 13c of the response transfer packet 20a. The communication address of the relay device 300 stored in the destination address area 13b of the response packet 20 is stored in the source address area 12c of the transfer packet 20a. Further, the response message stored in the response message area 16b of the payload part 15b of the response packet 20 and the message number stored in the message number area 17 are respectively set to the response message area 16b of the payload part 15b of the response transfer packet 20a. Stored in the message number area 17. Then, the communication control unit 312 sends the response transfer packet 20a to the communication network 1.

  This response transfer packet 20a is obtained when the information requesting car navigation device 100 exists at a position where it can communicate with any one of the plurality of access points 2 connected to the communication network 1. It is received by the car navigation device 100.

  Next, the operation when the infrastructure radio apparatus 131 of the car navigation apparatus 100 receives a communication packet from the communication network 1 will be described with reference to the flowchart shown in FIG.

  The infrastructure communication control unit 115 constantly monitors whether the infrastructure wireless device 131 has received a communication packet from the communication network 1 (S121), and the infrastructure wireless device 131 has received data from the communication network 1. When this is detected, the data management unit 113 is notified of this.

  Upon receiving this notification, the data management unit 113 determines whether or not the data stored in the virus countermeasure data database 121 satisfies a sufficient condition for dealing with computer viruses (S122). The determination by the data management unit 113 is the same as the determination by the data management unit 113 in step S112 in FIG.

  If the data management unit 113 determines that the sufficient handling condition is not satisfied, the data management unit 113 checks where the transmission source is based on the information of the header portion of the received communication packet (S123). If the transmission source is the relay device 300, the process proceeds to step S127. If the transmission source is a device other than the relay device 300, the received communication packet is discarded (S159), and a series of processing is performed. finish.

  In addition, even when the data management unit 113 determines that the sufficient handling condition is satisfied in step S122, the data management unit 113 checks where the transmission source is from the information of the header portion of the received communication packet (S124). If the transmission source is the virus countermeasure data providing apparatus 200, the data management unit 113 causes the encryption processing unit 117 to decrypt the data in the communication packet (S125).

  As described above, the feature pattern data set from the virus countermeasure data providing apparatus 200 is encrypted with the secret key in the virus countermeasure data providing apparatus 200. Therefore, the encryption processing unit 117 of the car navigation device 100 extracts the public key for this secret key from the encryption processing key table 122 and decrypts the feature pattern data set with this public key.

  Next, the data management unit 113 determines whether or not the encryption processing unit 117 has successfully decrypted the data in the communication packet (S126). If the decoding has failed, the received communication packet is discarded (S159), and the series of processing ends.

  In addition to the case where it is determined in step S123 described above that the transmission source of the communication packet is the relay device 300, in the case where it is determined in step S124 that the transmission source of the communication packet is not the virus countermeasure data providing device 200, further If it is determined in step S126 that the decoding is successful, the process proceeds to step S127.

  In step S127, the virus handling unit 112 checks whether there is data corresponding to the feature pattern data in the virus handling data database 121 in the data in the communication packet. In the present embodiment, as described above, the virus check is also performed on the data in the communication packet transmitted from the relay apparatus 300 that performs the computer virus check with the latest feature pattern data. For the data in the communication packet transmitted from the relay device 300, this may not be performed and the process may immediately proceed to step S129 described later.

  As a result of the virus check by the virus handling unit 112, if there is a computer virus in the data in the communication packet, the data management unit 113 discards the communication packet (S159). If no computer virus is found, the data management unit 113 determines what processing should be performed on the data in the communication packet (S129).

  If it is determined that the registration process is necessary, the data management unit 113 executes a registration process to a predetermined area in the storage device 120 (S160), and ends the series of processes. If it is determined that another process such as a reply process is necessary, the other processes are executed by various functions of the CPU 110 (S158), and the series of processes ends.

  As described above, according to the present embodiment, when a communication packet is received from the communication network 1 and the countermeasure against the computer virus is insufficient, only the communication packet via the relay apparatus 300 that is sufficiently capable of dealing with the computer virus is used. This is received and other communication packets are discarded to prevent the car navigation apparatus 100 from being attacked by a computer virus.

  Next, operations when the ad hoc wireless device 132 of the car navigation device 100 receives a communication packet and transmits the communication packet will be described with reference to the flowchart shown in FIG.

  The ad hoc communication control unit 116 always monitors whether there is a partner capable of ad hoc communication (S131). When there is a partner capable of ad hoc communication, the ad hoc communication control unit 116 determines whether a communication packet has been received from the partner within a predetermined time (S132). If the ad hoc communication packet is not received within the predetermined time, the data management unit 113 obtains the latest time stamp from the time stamps stored in the creation time stamp area 121b (FIG. 3) of the virus countermeasure data database 121. It is acquired (S141), and this is transferred to the encryption processing unit 117 for encryption (S142). At this time, the cryptographic processing unit 117 obtains a symmetric key shared by the car navigation device group that receives the anti-virus data sharing service between the car navigation devices from the cryptographic processing key table 122, and uses the symmetric key as described above. Encrypt the latest timestamp for. When the latest creation time stamp is encrypted, the ad hoc communication control unit 116 packetizes it and transmits it to a partner capable of ad hoc communication (S143).

  In this way, by encrypting the creation time stamp, it is possible to conceal a clue that an external third party knows virus countermeasure data that is not handled by the car navigation device 100. Further, the time stamp may be encrypted using a symmetric key and random number data so that a certain time stamp does not become the same ciphertext every time it is encrypted.

  In this case, the latest time is used regardless of whether or not the transmission partner is one of the car navigation devices in the group of car navigation devices that have received the virus countermeasure data sharing service between the car navigation devices. Although the stamp is transmitted, since it is encrypted, there is basically no problem even if the transmission partner is not a car navigation device that receives the sharing service. However, preferably, when the existence of the communication partner is confirmed (S131), it is checked whether or not this communication partner is a car navigation device that receives the sharing service. It is preferable to send a time stamp.

  Also, here, if a communication packet is not received within a predetermined time from a partner capable of ad hoc communication (NO in step S132), the latest generated time stamp is sent to the partner through the processing of step S141 and step S142. Transmission (S143) is performed, but when a communication packet is not received within a predetermined time from a partner capable of ad hoc communication (NO in step S132), only when a predetermined condition is satisfied, steps S141 and S142 are performed. Through the above process, the latest time stamp may be transmitted to the other party (S143). In this case, the driver of the vehicle C equipped with the car navigation device 100 instructs the transmission of the latest time stamp from the input / output device 140, and a predetermined period has elapsed since the latest time stamp was transmitted previously. It is preferable that the predetermined condition is that the load on the CPU 110 is not more than a predetermined value.

  In addition, when there are a plurality of parties capable of ad hoc communication, a time stamp may be transmitted to these partners by broadcast, or only those who satisfy a predetermined standard among these partners by unicast. A time stamp may be transmitted.

  Also, in the above, a symmetric key is used to encrypt the time stamp, but the symmetric key and random number data are used so that the same ciphertext is not obtained each time the same time stamp is encrypted, The time stamp may be encrypted.

  In step S132, if the ad hoc communication control unit 116 determines that an ad hoc communication packet has been received from a partner capable of ad hoc communication within a predetermined time, the data management unit 113 is stored in the virus countermeasure data database 121. It is determined whether or not existing data satisfies a sufficient condition for dealing with computer viruses (S133). The determination by the data management unit 113 is the same as the determination by the data management unit 113 in step S112 in FIG.

  If the data management unit 113 determines that the sufficient handling condition is not satisfied, the data management unit 113 checks the transmission source from the information in the header part of the received ad hoc communication packet (S145). If the transmission source is not the car navigation device that receives the sharing service, the received communication packet is discarded (S149), and the series of processing ends. Whether or not the transmission source is a car navigation apparatus that receives the sharing service is checked by checking the transmission source address stored in the header part of the ad hoc communication packet, and the car that receives the sharing service is included in this transmission source address. Judgment is made based on whether there is a common part in the navigation device.

  Further, even when the data management unit 113 determines that the sufficient handling condition is satisfied in step S133, the data management unit 113 checks where the transmission source is based on the information of the header portion of the received communication packet (S134). If the transmission source is not the car navigation device that receives the sharing service, the process proceeds to step S137. In step S145 and step S134, if it is determined that the transmission source is a car navigation device that receives the sharing service, the data management unit 113 decrypts the data in the ad hoc communication packet to the encryption processing unit 117. Processing is performed (S135).

  In step S145 and step S134, it is determined whether or not the transmission source is a car navigation device, but this is not particularly performed. If it is determined in step S136 that the decoding is successful, this decoding is performed. Processing may be performed assuming that the transmission source of the communication packet that has been successfully converted is the car navigation device.

  Data in the ad hoc communication packet from the car navigation device that receives the sharing service is encrypted with a symmetric key shared by the car navigation device group that receives the sharing service. Therefore, when it is determined in step S145 and step S134 that the transmission source is a car navigation device that receives the sharing service, the encryption processing unit 117 is stored in the encryption processing table 122 in step S135. The data in the ad hoc communication packet is decrypted using the key.

  Next, the data management unit 113 determines whether or not the encryption processing unit 117 has successfully decrypted the data in the ad hoc communication packet (S136). If the decoding has failed, the received ad hoc communication packet is discarded (S149), and the series of processing ends. Possible causes of this decryption failure include data modification during transmission, attacks by viruses during transmission, and the like. If the decryption is successful, and if it is determined in step S134 that the source of the ad hoc communication packet is not a car navigation device that receives the shared service, the virus handling unit 112 includes the data in the ad hoc communication packet. Then, it is checked whether there is data corresponding to the feature pattern data in the virus countermeasure data database 121 (S137).

  As a result of the virus check by the virus handling unit 112, if a computer virus exists in the data in the ad hoc communication packet, the ad hoc communication packet is discarded by the data management unit 113 (S149). If no computer virus is found, the data management unit 113 determines what processing should be performed on the data in the ad hoc communication packet (S139).

  When the creation time stamp is stored in the data in the ad hoc communication packet, it is determined that the time stamp processing described later is necessary. In this case, the time stamp processing is executed (S150), and a series of time stamp processing is performed. The process ends. If it is determined that registration processing is necessary, the data management unit 113 executes registration processing in a predetermined area in the storage device 120 (S160), and the series of processing ends. In this registration process, when the registered countermeasure is virus countermeasure data, the virus countermeasure data is registered in the virus countermeasure data database 121. Further, when it is determined that another process such as a reply process is necessary, the other processes are executed by various functions of the CPU 110 (S148), and the series of processes is terminated.

  Next, details of the time stamp processing in step S150 will be described according to the flowchart shown in FIG.

  First, the data management unit 113 acquires the latest time stamp from the time stamps stored in the creation time stamp area 121b (FIG. 3) of the virus countermeasure data database 121 (S151). Next, the data management unit 113 compares the generation time stamp included in the ad hoc communication packet received by the ad hoc communication with the new and old times of the time stamp acquired in step S151 (S152). If the time stamp acquired in step S151 is older, the process proceeds to step S142 in FIG. 7, and this time stamp is encrypted and transmitted to the communication partner (S143).

  If the time stamp acquired in step S151 is the same as the generated time stamp included in the ad hoc communication packet, the time stamp processing (S150) is terminated. This is because the other party owns the same feature pattern data group that he owns.

  Further, if the time stamp acquired in step S151 is newer than the generated time stamp included in the ad hoc communication packet, all newer time stamps than the generated time stamp included in the ad hoc communication packet are obtained from the virus countermeasure data database 121. A feature pattern data group corresponding to the generation time stamp is extracted and transferred to the encryption processing unit 117 (S153). The encryption processing unit 117 encrypts the feature pattern data group with the symmetric key (S154) and passes it to the ad hoc communication control unit 116. The ad hoc communication control unit 116 packetizes the encrypted feature pattern data group, wirelessly transmits it from the ad hoc wireless device 132 (S155), and ends this time stamp processing (S150). That is, if its own generation time stamp is newer than the other party's generation time stamp, it means that it owns a new feature pattern data group, and this feature pattern data group is transmitted to the other party.

  The reason why the feature pattern data group is encrypted in step S154 is to conceal the feature pattern data held by the car navigation device 100 from an external third party.

  Next, details of the registration process in step S160 in FIGS. 6 and 7 will be described according to the flowchart shown in FIG.

  In the registration process, first, the data management unit 113 determines whether the data in the received packet is already registered in the storage device 120 (S161). If it is registered data, the data is discarded (S164), and the process is terminated. If the data is unregistered data, it is determined whether the data is virus countermeasure data (characteristic pattern data group) (S162). If this data is virus countermeasure data, it is verified whether or not the electronic signature included in this data is authentic (S163). In this case, the public key certificate of the virus countermeasure data creation source is registered in the storage device 120 in advance, and the data management unit 113 verifies using this certificate.

  If the electronic signature included in the virus countermeasure data is not authentic, this data is discarded (S164), and the process is terminated. Further, when it is determined that the electronic signature is genuine, and when it is determined in step S162 that this data is not virus countermeasure data, this data is registered in the storage device 120 for processing. finish. If the data in the received packet is virus countermeasure data, it is registered in the virus countermeasure data database 121 in the storage device 120. When registering the virus countermeasure data, the decrypted data (S135) may be registered as it is, or may be registered after rearranging it into a form used by the virus countermeasure unit 112.

  As described above, in the present embodiment, the generation time stamp of the feature pattern data is received by ad hoc communication with another car navigation device that receives the sharing service, and the self-generated time stamp is newer. The latest feature pattern data group is transmitted to the other car navigation device, and if the self-generated time stamp is older, the self-generated time stamp is transmitted to the other car navigation device. The latest feature pattern data group is received. In other words, in the present embodiment, the latest feature pattern data group is shared by ad hoc communication between car navigation devices that receive a sharing service.

  Next, write / read processing for the portable disk storage medium D loaded in the disk recording / reproducing apparatus 102 will be described with reference to the flowchart of FIG.

  The data management unit 113 constantly monitors whether or not a disc is loaded in the disc recording / reproducing apparatus 102 (S171). When a disk is mounted, the data management unit 113 determines whether to perform data writing processing or data reading processing on this disk in accordance with an instruction from the input / output device 140 (S172). When it is determined that the data writing process is to be performed, according to an instruction from the input / output device 140, a part of the data stored in the storage device 120, the data input from the input / output device 140, etc. The data is written on the disk by the device 102 (S181), and the process is terminated.

  When the data management unit 113 determines that the reading process is to be performed, the data management unit 112 causes the virus handling unit 112 to check whether or not a computer virus exists in the data on the disk. At this time, the virus handling unit 112 checks whether there is data in the disk corresponding to the feature pattern data in the virus handling data database 121 (S173).

  As a result of the virus check by the virus countermeasure unit 112, if a computer virus is present, the anti-virus input / output control unit 114 displays on the input / output device 140 that the computer virus is present in the data on this disk. (S183). The driver or the like of the vehicle C on which the car navigation device 100 is mounted looks at this display and performs processing such as taking out the disc from the disc recording / reproducing device 102. At this time, even if the driver operates the input / output device 140 and tries to register the data in the disk in the storage device 120, the registration is rejected by the virus countermeasure input / output control unit 114. That is, the use of this data is denied.

  When the virus handling unit 112 determines that the computer virus is not present in the data on the disk, the data management unit 113 determines whether the data stored in the virus handling data database 121 satisfies a sufficient condition for handling a computer virus. Is determined (S175). The determination by the data management unit 113 is the same as the determination by the data management unit 113 in step S112 in FIG.

  If the data management unit 113 determines that the sufficient handling condition is satisfied, it extracts a feature value from the data in the disk (S176), records this in the checked file list 125 of the storage device 120 (S177), and step The process proceeds to S179. Note that the feature value of the data may be a hash value of this data. If the data management unit 113 determines in step S175 that the sufficient handling condition is not satisfied, whether or not the data in the disc has the feature value recorded in the checked file list 125 is determined. (S178). If the feature value recorded in the checked file list 125 exists in the data in the disc, it is confirmed that the data corresponding to the data in the disc was not invalid data in the past. The inside data is also considered safe, and the process proceeds to step S179. Further, if the feature value recorded in the checked file list 125 does not exist in the data in the disc, the data in the disc may contain a computer virus. Thus, the fact that there is a possibility that a computer virus exists in the data of this disk is displayed on the input / output device 140 (S183). At this time, even if the driver operates the input / output device 140 to register the data on the disk in the storage device 120, the registration is rejected by the virus countermeasure input / output control unit 114.

  In step S179, the data management unit 113 determines what processing should be performed on the data in the disk (S179). If the creation time stamp is stored in the data on the disc, it is determined that the time stamp process is necessary. In this case, the time stamp process is executed (S190), and the series of processes is terminated. If it is determined that the registration process is necessary, the data management unit 113 executes a registration process to a predetermined area in the storage device 120 (S160 (FIG. 9)) and ends the series of processes. To do. In this registration process, when the registered countermeasure is virus countermeasure data, the virus countermeasure data is registered in the virus countermeasure data database 121. Furthermore, when it is determined that other processing such as display processing is necessary, the other processing is executed by various functions of the CPU 110 (S182), and the series of processing ends.

  Next, details of the time stamp processing in step S190 will be described with reference to the flowchart shown in FIG.

  First, the data management unit 113, among the time stamps stored in the creation time stamp area 121b (FIG. 3) of the virus countermeasure data database 121, similarly to the time stamp processing (S150) described with reference to FIG. The latest time stamp possessed by the terminal is acquired from the terminal (S191). Next, the data management unit 113 compares the generation time stamp included in the data on the disc with the new and old of the time stamp acquired in step S191 (S192). If the latest time stamp of the own terminal acquired in step S191 is older, the disc recording / reproducing apparatus 102 causes the latest time stamp of the own terminal acquired in step S191 to be written on the disc (S195). The stamp process (S190) ends. As described above, the time stamp acquired in step S191, that is, the own time stamp is written to the disk by informing the time stamp to the device that has written the time stamp on the disk earlier than the own time stamp. This is to convey the need for new feature pattern data.

  If the latest time stamp of the terminal acquired in step S191 is the same as the generated time stamp included in the disk data, the time stamp processing (S150) is terminated. This is because the other party owns the same feature pattern data group that he owns.

  If the latest time stamp of the terminal acquired in step S191 is newer than the generation time stamp included in the disk data, the generation time included in the disk data is read from the virus countermeasure data database 121. A feature pattern data group corresponding to all generation time stamps newer than the stamp is extracted (S193), and the disc recording / reproducing apparatus 102 writes the feature pattern data group on the disc (S194), and this time stamp processing (S150). ) Ends. In other words, if its own generation time stamp is newer than the other party's generation time stamp, it means that it owns a new feature pattern data group, so to the device that previously wrote the time stamp on this disc, This feature pattern data group is notified.

  As described above, in this embodiment, the generation time stamp of the feature pattern data is received by exchanging the storage medium with another car navigation device that receives the sharing service, and the self-generated time stamp is newer. For example, the latest feature pattern data group is transferred to another car navigation device via a storage medium, and if the self-generated time stamp is older, the self-generated time stamp is transferred to another car navigation device via the storage medium. The latest feature pattern data group is received from the other car navigation apparatus via the storage medium. That is, in this embodiment, the latest feature pattern data group is shared by exchanging storage media between car navigation apparatuses that receive a sharing service.

  In the above embodiment, the case where a disk-type storage medium is used is illustrated, but the present invention is not limited to this, and other portable storage media such as a memory device are used. Needless to say.

  As described above, according to the present embodiment, the latest virus countermeasure data (characteristic pattern data group) is periodically acquired from the virus countermeasure data providing apparatus 200. When communication using the communication network 1 is performed when virus countermeasure data cannot be acquired and the latest virus countermeasure data is not held, communication is performed via the relay device 300 with sufficient virus countermeasures. Therefore, the possibility that the car navigation apparatus 100 is attacked by a computer virus can be reduced. In this case, in the present embodiment, even when the latest virus countermeasure data is not held, communication via the relay device 300 is allowed, so that the connection with the communication network 1 is completely cut off. Thus, the inconvenience of the driver or the like can be reduced.

  Further, in this embodiment, when the latest virus countermeasure data cannot be acquired from the virus countermeasure data providing apparatus 200 and the latest virus countermeasure data is not held, the data import from the disk recording / reproducing apparatus 102 is also restricted. Therefore, also from this point, the possibility that the car navigation apparatus 100 is attacked by a computer virus can be reduced. In this case, since the data acquisition from the disk recording / reproducing apparatus 100 is not uniformly restricted but a part of the data acquisition is restricted based on the past results, the driver who cannot use the storage medium is used. Inconveniences such as these can be kept small.

  In the present embodiment, even when the latest virus countermeasure data cannot be acquired from the virus countermeasure data providing apparatus 200 via the access point 2, the ad hoc communication or the storage medium of the storage medium is transmitted from another car navigation apparatus that receives the sharing service. Since the latest virus countermeasure data can be acquired by the exchange, the period during which the latest virus countermeasure data is not held can be shortened. For this reason, it is possible to shorten the period for restricting the use of the communication network 1 and restricting data capture from the disc recording / reproducing apparatus 100.

  In the present embodiment, a wireless LAN is used for connection between the car navigation device 100 and a communication network, but instead of this, for example, data communication using a mobile phone may be used.

  In this embodiment, the car navigation device 100 determines whether the self-generated time stamp is new or old by exchanging the generated time stamp with another car navigation device. You may make it deliver the newest production | generation time stamp with a broadcast wave from the facility which manages the apparatus 200. FIG. In this case, if the own car navigation device 100 determines that the self-generated time stamp is older than the latest generated time stamp, the anti-virus data is requested from the anti-virus data 200 via the relay device 300, or Instead of exchanging the generated time stamp with another car navigation device, the virus handling data is requested from another car navigation device, and the latest virus handling data is obtained from these.

  In the present embodiment, the distribution of virus countermeasure data from the virus countermeasure data providing apparatus 200 is performed using the communication network 1 as a medium, but a broadcast wave may be used as a medium. In this case, it is preferable to create a distribution schedule so that virus countermeasure data is frequently distributed. When virus countermeasure data is distributed by broadcasting, it is not necessary for the car navigation device 100 to make a virus countermeasure data distribution request to the virus countermeasure data providing device 200.

  The broadcast wave may be obtained by superimposing data on an analog broadcast, or may be a digital broadcast that includes the above information or data in digital data to be transmitted. A data broadcast channel may be assigned to each model that is the target of feature pattern data. Data for a plurality of targets such as different models may be mixed in the same channel. In this case, an identifier for determining the target model or the like may be assigned for each data, and the information terminal may be selectable.

  Data may be divided into several blocks and transmitted. When a block that cannot be received due to the influence of a radio wave reception state or the like is generated, the block may be received at the time of re-broadcasting the corresponding block, and the reception of data may be completed by integrating the received block.

  Furthermore, the above description is directed to the car navigation device, but the present invention may be applied to a navigation device other than the car navigation device, for example, a navigation device for pedestrian route guidance.

It is a lineblock diagram of a car navigation device in one embodiment concerning the present invention. It is a block diagram of each apparatus which comprises the system in one Embodiment which concerns on this invention. It is explanatory drawing which shows the data structure of the virus countermeasure data database in one Embodiment which concerns on this invention. It is explanatory drawing which shows the data structure of the table for relay in one Embodiment which concerns on this invention. It is a flowchart which shows the process at the time of the information request | requirement with respect to the communication network in one Embodiment which concerns on this invention. It is a flowchart which shows the process at the time of the packet reception from the communication network in one Embodiment which concerns on this invention. It is a flowchart which shows the process at the time of ad hoc communication in one Embodiment which concerns on this invention. It is a flowchart which shows the detail of the time stamp process (S150) in the flowchart of FIG. It is a flowchart which shows the detail of the registration process (S160) in the flowchart of FIG. It is a flowchart which shows the process at the time of the writing and reading of the data with respect to the disk in one Embodiment which concerns on this invention. It is a flowchart which shows the detail of the time stamp process (S190) in the flowchart of FIG. It is explanatory drawing which shows the data structure of the various communication packets in one Embodiment which concerns on this invention.

Explanation of symbols

  1: communication network, 2: access point, 10: information request packet, 10a: information request transfer packet, 20: response packet, 20a: response transfer packet, 100: car navigation device, 101: memory, 102: disc recording / playback device 110, 210, 310, 410: CPU, 111: Navigation processing unit, 112, 311: Virus countermeasure unit, 113, 211, 411: Data management unit, 114: Anti-virus input / output control unit, 115: Infrastructure communication control , 116: ad hoc communication control unit, 117: Ando processing unit, 120, 220, 320, 420: storage device, 121, 221, 321: virus countermeasure data database, 122: key table for encryption processing, 123: communication address Table 124: Map information data 125, checked file list, 126, 323: anti-virus program, 127a: infrastructure communication program, 127b: ad hoc communication program, 128: cryptographic processing program, 129: navigation program, 131: infrastructure wireless device, 132: Ad hoc wireless device, 133: GPS receiver, 140: input / output device, 200: virus countermeasure data providing device, 300: relay device, 400: information providing device

Claims (10)

In the information terminal that receives information from the information providing device,
A communication address storage means for storing a communication address of the information providing apparatus and a communication address of a relay apparatus that executes computer virus countermeasure processing;
Communication means for receiving information from the information providing device;
Countermeasure data receiving means for receiving computer virus countermeasure data;
Countermeasure data storage means for storing the computer virus countermeasure data received by the countermeasure data receiving means;
Virus countermeasure processing means for executing computer virus countermeasure processing using the computer virus countermeasure data stored in the storage means;
Data management means for determining whether or not the computer virus countermeasure data stored in the storage means satisfies a predetermined countermeasure sufficient condition;
When the data management means determines that the sufficient handling condition is not satisfied, the communication means uses the communication address of the information providing apparatus and the communication address of the relay apparatus stored in the communication address storage means. Information input / output control means for executing communication with the information providing device via the relay device;
With
If the data management unit determines that the sufficient handling condition is not satisfied, the data management unit discards the data when the transmission source of the data received by the communication unit is not the relay device. The information terminal according to claim 1,
A recording / reproducing apparatus that is mounted with a storage medium and writes / reads data to / from the storage medium;
If the data management means determines that the sufficient handling condition is not satisfied, the data management means restricts reading of data from the storage medium attached to the recording / reproducing apparatus,
An information terminal characterized by that. The information terminal according to claim 2,
Feature value storage means for storing feature values of data in the storage medium;
When the data management means has a storage medium attached to the recording / reproducing device and reads the data from the storage medium and determines that the sufficient handling condition is satisfied, the data management means has characteristics of the data in the storage medium. Extracting a value, storing the feature value in the feature value storage means,
The data management means, when a recording medium is mounted on the recording / reproducing apparatus, and when reading the data from the storage medium, when determining that the sufficient handling condition is not satisfied, the data in the storage medium It is determined whether or not there is a feature value stored in the feature storage means. If there is data having the feature value, the data is read from the storage medium, If there is no data having the feature value, the subsequent processing for the data is restricted.
An information terminal characterized by that. In the information terminal according to any one of claims 1 to 3,
Data input / output means
The countermeasure data receiving means receives a generation time stamp indicating a generation time of the countermeasure data together with the computer virus countermeasure data, stores the generation time stamp together with the countermeasure data in the countermeasure data storage means,
When the data input / output unit receives the generated time stamp from another information terminal, the data management unit compares the time stamp stored in the handling data storage unit with the latest time stamp, If the generated time stamp from the information terminal is older than the latest time stamp stored in the countermeasure data storage means, the other information among the countermeasure data stored in the countermeasure data storage means Data corresponding to a time stamp that is newer than a generated time stamp of the terminal is output to the data input / output unit, and the generated time stamp from the other information terminal is stored in the processed data storage unit. If newer, the latest time stamp is output to the data input / output means.
An information terminal characterized by that. In the information terminal according to claim 4,
The data input / output means is an ad hoc communication means for performing ad hoc communication with the other information terminal.
An information terminal characterized by that. In the information terminal according to claim 4,
The data input / output means is a recording / reproducing means for a storage medium;
Information terminal characterized by that. The information terminal according to any one of claims 1 to 6,
The relay device;
A system characterized by comprising: In a navigation device that acquires information from an information providing device connected to a communication network,
Wireless communication means for performing wireless communication with a wireless communication access point device that performs relay processing for the communication network;
Ad hoc wireless communication means for wireless communication with other navigation devices;
Countermeasure data receiving means for receiving computer virus countermeasure data and a generation time stamp indicating a generation time of the computer virus countermeasure data;
Countermeasure data storage means for storing the computer virus countermeasure data and the generation time stamp received by the countermeasure data receiving means;
Virus countermeasure processing means for executing computer virus countermeasure processing on data received from the outside using the computer virus countermeasure data stored in the countermeasure data storage means;
When the ad hoc wireless communication means receives the generated time stamp from the other navigation device, it compares it with the latest time stamp among the time stamps stored in the handling data storage means, If the generated time stamp is older than the latest time stamp stored in the countermeasure data storage means, among the countermeasure data stored in the countermeasure data storage means, the generation time stamp of the other navigation device Response data of a newer time stamp is transmitted to the other navigation device by the ad hoc wireless communication means, and the generated time stamp from the other navigation device is stored in the response data storage means. If it is newer than the stamp, the latest time And data management means for transmitting to the another of the navigation device by the ad-hoc radio communication means flop,
A navigation device comprising: The navigation device according to claim 8, wherein
The countermeasure data receiving means is the wireless communication means capable of accessing a communication network to which a computer virus countermeasure data providing apparatus that distributes the computer virus countermeasure data and the generation time stamp is connected.
A navigation device characterized by that. In an anti-virus program for a computer that executes computer anti-virus processing on data received from outside by communication means,
A handling data receiving step for receiving computer virus handling data by the data receiving means of the computer;
A countermeasure data storage step of storing the computer virus countermeasure data received in the countermeasure data reception step in a storage device of the computer;
Using the computer virus countermeasure data stored in the storage device, a virus countermeasure step for executing computer virus countermeasure processing on data received from the outside;
A data management step for determining whether or not the computer virus countermeasure data stored in the storage device satisfies a predetermined sufficient countermeasure condition;
If it is determined in the data management step that the sufficient countermeasure condition is not satisfied, the communication address of the information providing apparatus stored in advance in the storage device of the computer and a relay apparatus that executes a computer virus countermeasure process An information input / output control step for causing the communication means to perform communication with the information providing device via the relay device using a communication address;
An anti-virus program that causes the computer to execute

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