JP4854192B2 - Transmission device, communication system, and computer program - Google Patents

Description

The present invention relates to a communication system with using a transmission device which is connected via one or more communication networks and receiving apparatus, transmission that sends communication information to the receiving apparatus from the transmitting apparatus communication apparatus, the transmission apparatus, and a computer program for realizing the transmission device, in particular transmit apparatus for transmitting image information to a receiving device used as an image forming apparatus, a communication system and a computer program.

  When making a print request for transmitting image information from a transmission apparatus using a personal computer to an image forming apparatus using a network printer, an operator operating the transmission apparatus performs an operation of selecting an image forming apparatus as a transmission destination. Do. However, when the operator selects an image forming apparatus by mistake when selecting an image forming apparatus connected to a distant communication network, unnecessary traffic is generated on the communication network connecting the transmitting apparatus and the image forming apparatus. There is a problem that occurs. Further, there is a problem that the risk of illegally intercepting transmitted image information increases by passing through a plurality of communication networks.

  As a method for solving these problems, devices connected to a communication network are grouped in advance, and a TTL (Time To Live) included in an IP header of a packet to be transmitted / received is set for each group. If the TTL value of the packet received by the connection device is within a predetermined range, it is determined that the packet is a normal packet, and if it is out of the range, the packet is determined to be an illegal packet and discarded. (See Patent Document 1).

JP-A-10-271154

  However, in the method disclosed in Patent Document 1, it is necessary to set an initial value of TTL for each group and further set a TTL range for each connected device. There's a problem. In addition, there is a problem that the setting must be changed every time the configuration of the communication network changes, and if a connection device that needs to be restarted is used for the changed setting to take effect, restart the connection device. Therefore, there is a problem that the stability of the communication network is impaired.

The present invention has been made in view of such circumstances, and determines the communication level to be transmitted or the security level (class of secrecy) set for the transmission apparatus, and the TTL is determined according to the determined level. by setting the initial value, communication to prevent an increase in the work of the system administrator, to resolve the problems relating to workability, also feed capable of maintaining the stability communication apparatus of a communication network, comprising the transmitting device An object of the present invention is to provide a system and a computer program for realizing the transmission apparatus.

In the transmission device according to the present invention, the number of passing devices indicating the number of connection devices that can pass is set to a receiving device connected via a single communication network or a plurality of communication networks connected by a connection device. in the transmission apparatus for transmitting communication information in packets, means for determining the rank of confidentiality that is set, the presence or absence of encryption of the communication information to be transmitted,及beauty, other devices through which to the receiving device and means for determining at least one of the safety based rather communication path to the type of permission or the connected network access from the communication network, it determines the secrecy of the class, as well as the presence or absence of encryption及beauty characterized in that it comprises a setting means for setting the number of passing device according to at least one of the determination results for the safety of the communication path.

In the transmission device of the present invention, the initial value of the number of passing devices at the time of transmission is set according to the security class in the communication network based on the confidentiality class , the presence / absence of encryption of information to be transmitted, the type of communication network, etc. By doing so, it is possible to limit the range in which the communication information to be transmitted reaches, and it is possible to prevent the transmission information from leaking to the outside due to an erroneous operation. In addition, since the initial value of the number of passing devices is set by the transmitting device, it is not necessary to change the setting for each group and each connected device, so it is possible to prevent an increase in the work amount of the system administrator. It is. Moreover, it does not affect the stability of the communication network. Furthermore, even if an erroneous operation of transmitting communication information to a device connected to a distant communication network is performed, communication information is not transmitted to a distant location more than necessary, so it is possible to prevent an increase in unnecessary traffic. is there.

  In the transmission device of the present invention, for example, communication information that is highly likely to be leaked during communication can be set with a low initial value of the number of passing devices. It is possible to reduce the risk of leakage. Conversely, the communication information that is being processed such as encryption is determined to have higher confidentiality and the initial value of the number of passing devices is set higher, and the communication information is transmitted to a device connected to a distant communication network. It is possible.

  The transmission device according to the present invention is the above-described invention, wherein in the above-mentioned invention, the means for reading the communication information recorded in the recording device connected to the communication network, and the connection that passes to the recording device in which the read communication information is recorded And a means for setting a confidentiality class in accordance with the number of devices.

  In the transmission device of the present invention, it is possible to set the limit for reaching the communication information to be transmitted to an appropriate range by setting the secrecy class according to the number of connection devices that pass through the recording device. . In addition, since it is automatically set according to the number of connection devices that pass through the recording device, it is possible to prevent an increase in the amount of work.

  The transmitting apparatus according to the present invention includes a table for recording information indicating confidentiality in association with information indicating a communication network, a means for detecting a connected communication network, and a detected communication network. Means for reading information indicating the confidentiality class associated with the information to be displayed from the table, and means for setting the confidentiality class of the communication information based on the read information indicating the confidentiality class. It is characterized by that.

  In the transmission device of the present invention, by changing the setting of the confidentiality class according to the connected communication network, even if the communication network to be connected is changed, the setting according to the newly connected communication network is automatically performed. Since it is changed, it does not cause an unexpected situation such as leakage of communication information due to forgetting to change the setting, so that it is safe and excellent in convenience.

  The transmitting apparatus according to the present invention is the information indicating the disconnected communication network, the means for detecting disconnection from the communication network and the information indicating the confidentiality class set when the disconnection is detected in the above-described invention. And a means for recording in a table in association with each other.

  In the transmission device of the present invention, for example, even when a confidentiality class is set manually, it is possible to record the optimum initial value in the table by recording the setting in the table when disconnected from the communication network. It is.

  The transmission device according to the present invention is characterized in that, in the above-mentioned invention, the information recorded in the table has an expiration date set.

  In the transmission device of the present invention, the information recorded in the table is deleted after a predetermined period of time, so that information about the old system is not retained indefinitely. Therefore, even when the system configuration is changed, the old configuration It is possible to avoid a situation where an incorrect setting is made based on information corresponding to.

  The transmission apparatus according to the present invention is characterized in that, in the above-mentioned invention, the communication information is image information for forming an image.

  The transmission apparatus of the present invention can be applied to a mode for transmitting image information to a network printer.

  A communication system according to the present invention includes the transmission device according to the above-described invention and a reception device connected to the transmission device via one or more communication networks.

  In the communication system of the present invention, by setting the initial value of the number of passing devices in the transmission device according to the class of confidentiality, it is possible to limit the range in which the communication information to be transmitted reaches, and the transmission device is transmitted by an erroneous operation. It is possible to prevent information from leaking outside. Further, since the number of passing devices is set by the transmitting device, it is not necessary to change the setting for each group and each connected device, so that it is possible to prevent an increase in the work amount of the system administrator. Moreover, it does not affect the stability of the communication network.

  The communication system according to the present invention is characterized in that, in the above-mentioned invention, the receiving device is a device that forms an image based on image information.

  The communication system of the present invention can be applied to a form in which a network printer is used as a receiving device.

  The communication system according to the present invention is characterized in that, in the above-described invention, the receiving device is a device that transmits the received image information to an image forming device that forms an image based on the image information.

  The communication system of the present invention can be applied to a printer server that transmits image information to an image forming apparatus using a network printer.

In the computer program according to the present invention, the number of passing devices indicating the number of connection devices that can pass is set in a computer connected to another device via a plurality of communication networks connected by one communication network or connection device. a computer program to transmit communication information to other devices on a packet basis, which is, in the computer, the procedure for determining the rank of confidentiality to be set, the computer, the presence or absence of encryption of the communication information to be transmitted,及beauty, a procedure for determining the at least one of the safety of whether or connected of types of communication networks have to based rather communication path access from other network devices through which to the receiving device, the computer, determine the confidentiality of classes, and passing device according to at least one of the determination results for the safety of the presence及beauty communications path encryption Characterized in that to execute a procedure for setting the.

In the computer program of the present invention, when the computer program such as a personal computer connected to a communication network such as a LAN is executed as a program such as a printer driver, the computer operates as a transmission device, and the confidentiality class and information to be transmitted are transmitted. By setting the initial value of the number of passing devices at the time of transmission according to the security in the communication network based on the presence / absence of encryption, the type of communication network, etc., it is possible to limit the reach of communication information to be transmitted Thus, it is possible to prevent transmission information from leaking to the outside due to an erroneous operation. Further, since the number of passing devices is set by the transmitting device, it is not necessary to change the setting for each group and each connected device, so that it is possible to prevent an increase in the work amount of the system administrator. Moreover, it does not affect the stability of the communication network. Furthermore, even if an erroneous operation of transmitting communication information to a device connected to a distant communication network is performed, communication information is not transmitted to a distant location more than necessary, so it is possible to prevent an increase in unnecessary traffic. is there.

Send apparatus of the present invention, communication system and computer program connects a transmitting apparatus such as a personal computer at one or more communication networks such as a LAN, and a receiving apparatus such as an image forming apparatus, the receiving apparatus from the transmitting device When transmitting communication information such as image information to form an image to the IP header of a packet that encapsulates communication information according to a confidentiality class preset for the transmission source device or communication information Set the initial value of the number of passing devices described in.

  With this configuration, it is possible to limit the range in which the communication information to be transmitted reaches, so that it is possible to prevent the transmission information from leaking to the outside due to an erroneous operation. In addition, since the number of passing devices is set by the transmitting device, there is no need to change the setting for the connected device, and it is possible to prevent an increase in the work amount of the system administrator. Play. In addition, when setting the number of passing devices, there is no need for processing such as restarting of the connection device, so that excellent effects can be obtained, for example, the stability of the communication network is not impaired. Moreover, even if an erroneous operation for transmitting communication information to a device connected to a distant communication network is performed, communication information is not transmitted to a distant location more than necessary, so it is possible to prevent an increase in unnecessary traffic. is there.

  Furthermore, in the present invention, when transmitting communication information read from a recording device such as a file server computer connected via a communication network, an initial value of the number of passing devices is set as the number of connecting devices that pass to the recording device. By setting the secrecy class as described above, it is possible to set the limit of reaching the communication information to be transmitted within an appropriate range and automatically depending on the number of connected devices that pass by the number of recording devices. Since the initial value of the number of passing devices is set, the setting of the initial value of the number of passing devices is not necessary, and an excellent effect can be obtained, for example, an increase in work amount can be prevented.

  Further, according to the present invention, in the transmission device, a table for recording information indicating the class of confidentiality is provided in association with the information indicating the communication network, and when the transmission device is connected to the communication network, When applied to a mode in which a portable transmission device such as a notebook personal computer is freely connected to a communication network by setting an initial value of the number of passing devices based on the associated confidentiality class However, since the class of confidentiality is automatically changed according to the connected communication network, it does not cause unexpected situations such as leakage of communication information due to forgetting to change the setting, so it is safe and convenient. Excellent effects such as high.

  Hereinafter, the present invention will be described in detail with reference to the drawings showing embodiments for carrying out the invention.

Embodiment 1 FIG.
FIG. 1 is a block diagram conceptually showing the configuration of the communication system according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a transmission apparatus according to the present invention using a personal computer. The transmission apparatus 1 is connected to a first communication network 101 using a LAN (Local Area Network), and is connected to the first communication network 101. Are connected to various devices such as a first receiving device 201 using an image forming apparatus such as a printer. Further, a first connection device 301 such as a gateway device or a router device is connected to the first communication network 101, and the first connection device 301 is connected to the second communication network 102. Furthermore, various devices such as a second receiving device 202 using an image forming apparatus are connected to the second communication network 102. The second communication network 102 is connected to the third communication network 103 by the second connection device 302. Connected. Further, various devices such as a third receiving device 203 using an image forming apparatus are connected to the third communication network 103. A third connection device 303 is connected to the third communication network 103, and the third connection device 303 is connected to another communication network. Further, the Nth connection device 300N connects to the Mth communication network 100M, and various devices such as the Mth reception device 200M are connected to the Mth communication network 100M. Thus, in the communication system of the present invention, the transmission device 1 and various receiving devices are connected via a plurality of communication networks connected by a single communication network or connection device. The system configuration shown in FIG. 1 is an example of the communication system of the present invention that can be developed in various forms. The present invention is not limited to the system configuration shown in FIG. 1 and can be expanded in various ways. It is.

  FIG. 2 is a block diagram showing configurations of transmitting apparatus 1, first receiving apparatus 201, and first connecting apparatus 301 included in the communication system according to Embodiment 1 of the present invention. The transmission apparatus 1 includes a control means 11 such as a CPU for controlling the entire apparatus, a CD-ROM drive for reading information from a recording medium REC such as a CD-ROM on which various information such as a computer program PG and data of the present invention is recorded. Connected to auxiliary storage means 12, recording means 13 such as a hard disk for recording various information read by auxiliary storage means 12, storage means 14 such as RAM for temporarily storing information, and various communication networks such as first communication network 101 A communication means 15 such as a LAN port, an input means 16 such as a mouse and a keyboard, and an output means 17 such as a monitor. Then, by reading various information such as the computer program PG and data of the present invention from the recording means 13, storing the information in the storage means 14, and executing various procedures included in the computer program PG, the computer performs the transmission apparatus 1 of the present invention. Works as. Note that a part of the recording area of the recording unit 13 included in the transmission device 1 is a confidentiality table (confidentiality TBL) that records information indicating a communication network, information indicating a confidentiality class, and information indicating an expiration date in association with each other. It is used as 13a.

  The first receiving device 201 includes a control unit 21, a recording unit 22 such as a ROM and a hard disk, a storage unit 23 such as a RAM, an image forming unit 24 that forms an image based on image information transmitted from the transmitting device 1, and a communication Means 25 are provided. When the first receiving device 201 is a device using a printer, the image forming unit 24 indicates a mechanism for forming and printing an image based on image information on a sheet. The other receiving devices such as the second receiving device 202, the third receiving device 203,... Have substantially the same configuration as the first receiving device 201.

  The first connection device 301 includes a control unit 31, a ROM 32, a RAM 33, a first communication unit 34 connected to the first communication network 101, and a second communication unit 35 connected to the second communication network 102. Other connection devices such as the second connection device 302, the third connection device 303,... Have substantially the same configuration as the first connection device 301. The ROM 32 and / or the RAM 33 is provided with a routing table for recording entries of devices connected to the communication network. The routing table is constructed by dynamic or static settings, and sends out the communication network to which the device to which the packet is to be connected is connected, the IP address of the connected device to be passed next to reach the communication network, and the packet. Information such as the interface to be recorded is recorded. In addition, an interface here shows the communication means with which a connection apparatus is provided.

  Next, a communication protocol used for communication of the communication system of the present invention will be described. In the communication system of the present invention, communication conforming to a communication protocol such as TCP / IP is performed. TCP / IP includes IPv4, which is the current standard, and IPv6, which is the next generation standard, and different packet formats are defined for each.

  FIG. 3 is a configuration diagram showing a format of an IP header of a communication protocol used in the communication system according to Embodiment 1 of the present invention. FIG. 3A shows an IP header format conforming to a standard defined by IPv4, and various fields are defined in an area of 20 octets. The field shown as version indicates the version of the IP header, and IPv4 is version 4. The field indicated as the header length indicates the octet length of the IP header. A field indicated as ToS (Type Of Service) indicates a service type, and indicates service quality such as a priority, a low delay request, and a high throughput request. The field indicated as the packet length indicates the octet length of the entire packet, which is the sum of the IP header and the IP data. A field indicated by ID indicates an identifier, which is necessary when reconstructing the divided data. A field indicated by a flag indicates a control code related to packet division. A field indicated as a fragment offset indicates a sequence number that is an order of packets obtained by dividing the original data. A field indicated as TTL (Time To Live) is the number of passing devices (the number of hops) that is the time that can exist on the communication network or the number of connection devices that can pass. In the present invention, TTL indicates the number of passing devices, and the value of the number of passing devices is decremented by 1 every time it passes through the connection device. If the connection device receives a packet with a TTL of 0, the packet is discarded. Is done. A field indicated as a protocol number indicates an upper layer protocol such as ICMP (Internet Control Message Protocol), TCP (Transmission Control Protocol), or UDP (User Datagram Protocol). A field indicated as a header checksum indicates a checksum of the IP header. A field indicated as a transmission source IP address indicates an IP address of a transmission source device. The field indicated as the destination IP address indicates the IP address of the device that is the transmission destination. The numerical value shown in parentheses that is written along with the field name indicates the number of bits of the field.

  FIG. 3B shows an IP header format conforming to a standard defined by IPv6, and various fields are defined in a 40-octet area. The field shown as version indicates the version of the IP header, and IPv6 becomes version 6. The field indicated as traffic class indicates a class related to communication such as priority, low delay request, and high throughput request, and corresponds to ToS of IPv4. A field labeled “flow label” indicates a label when a series of packets such as VoIP (Voice over IP) is designated as a flow. The field indicated as the payload length indicates the octet length of the IP data. The field indicated as “next header” indicates the header type of the subsequent IPv6 header, and corresponds to the IPv4 protocol number. The field indicated as hop limit indicates the number of passing devices, and corresponds to IPv4 TTL. A field indicated as a transmission source IP address indicates an IP address of a transmission source device. The field indicated as the destination IP address indicates the IP address of the device that is the transmission destination. The numerical value shown in parentheses that is written along with the field name indicates the number of bits of the field.

  Next, processing of the transmission device used in the communication system of the present invention will be described. FIG. 4 is a flowchart showing communication information transmission processing of transmission apparatus 1 used in the communication system according to Embodiment 1 of the present invention. The operator operates the transmission apparatus 1 to specify transmission information such as image information recorded in the recording unit 13, for example, and performs an operation of specifying a reception apparatus as a transmission destination. The transmission device 1 determines the specified transmission information or the confidentiality class set for the own device under the control of the control unit 11 that executes the computer program PG stored in the storage unit 14 (S101). The presence or absence of encryption of the communication information and the safety of the communication path to the designated receiving device are detected (S102), the confidentiality class determined in step S101, the presence or absence of encryption detected in step S102, and In accordance with the safety of the communication path, an initial value of the number of passing devices of packets encapsulating transmission information is set (S103), and the transmission information in units of packets in which the number of passing devices is set is sent from the communication means 15 to the first communication network. The data is transmitted to the specified receiving device via 101 (S104). The communication information transmitted from the transmission device 1 to the reception device is image information transmitted as a print request. The reception device that has received the image information forms an image on a sheet based on the received image information and outputs the image. Perform the printing process. The set secrecy class may be a numerical value indicating the number of passing devices, and the number of passing devices determined according to the secrecy class is based on the presence of encryption and the safety of the communication path. Corrections are made as necessary. For example, when encryption is not performed and the safety of the communication path is low, the initial value of the number of passing devices is subtracted and corrected so as to increase safety. The safety of the communication path is determined by conditions such as whether or not the communication route passes through a device that can be accessed from the outside, and whether or not the communication network is highly secure such as VPN.

  Next, the relationship between the number of passing devices and safety will be described. FIG. 5 is an explanatory diagram for explaining the safety of the communication system according to Embodiment 1 of the present invention. FIG. 5 shows a situation in which the highest security is achieved. The initial value of the number of passing devices for packets transmitted from the transmitting device 1 is set to “0”. By setting the initial value of the number of passing devices of packets transmitted from the transmitting device 1 to “0”, it is possible to transmit communication information to the first receiving device 201 connected to the first communication network 101. . However, the communication information is transmitted to a receiving device connected to a communication network other than the first communication network 101 such as the second receiving device 202 connected to the second communication network 102 and the third receiving device 203 connected to the third communication network 103. In this case, the first connection device 301 is routed. In the first connection device 301, when the number of passing devices set in the received communication information packet is “0”, the received packet is discarded. For this reason, when the initial value of the number of passing devices of the packet transmitted from the transmission device 1 is set to “0”, the packet transmitted from the transmission device 1 is the first communication network to which the transmission device 1 is connected. Therefore, even if an operator selects a receiving device connected to a communication network other than the first communication network 101 as a destination device by an erroneous operation, the transmission is not performed. When the device is a device other than the device connected to the first communication network 101, communication information is not transmitted to the device, so that a high degree of safety can be ensured.

  FIG. 6 is an explanatory diagram for explaining the safety of the communication system according to Embodiment 1 of the present invention. FIG. 6 illustrates a situation where the operator who operates the transmission apparatus 1 is permitted to transmit communication information to the third reception apparatus 203 when the standard safety is set. Since the third receiving device 203 is connected to the third communication network 103 and needs to pass through two connecting devices, the initial value of the number of passing devices is set to “2”. When communication information is transmitted from the transmission apparatus 1 to the third reception apparatus 203, a communication information packet is first received by the first connection apparatus 301 via the first communication network 101. The first connection device 301 confirms that the number of passing devices of the received packet is not “0”, and an entry for the destination IP address indicated in the packet is stored in the routing table recorded in the ROM 32 and / or the RAM 33. Check if it exists. If the corresponding entry does not exist, the first connection device 301 discards the received packet. If the corresponding entry exists, the number of passing devices of the packet is reduced by 1, and here the number of passing devices is “2”. Is rewritten to “1” and sent to the second communication network 102. In the case of IPv6, it is only necessary to reduce the value of the hop limit that is the number of passing devices, but in the case of IPv4, the checksum is recalculated after reducing the value of TTL that is the number of passing devices. Similar processing is performed in the second connection device 302. Accordingly, transmission information can be transmitted to the first reception device 201, the second reception device 202, and the third reception device 203, but the transmission information is transmitted to the Mth reception device 200M that needs to pass through three or more connection devices. It cannot be sent. As described above, the number of connection devices that pass through to the receiving device connected to the farthest communication network among the receiving devices such as printers that are permitted to transmit communication information such as image information is the initial value of the number of passing devices. By doing so, it is possible to avoid a risk that communication information transmitted from the transmission device 1 is transmitted to an external device that is not permitted to transmit, and to suppress an increase in unnecessary traffic.

Embodiment 2. FIG.
In the second embodiment, communication information such as image information recorded in a recording device such as a file server computer is read by the transmission device 1, and the read communication information is transmitted from the transmission device 1 to a reception device such as a printer. It is. FIG. 7 is a block diagram conceptually showing the structure of the communication system in the second embodiment of the present invention. As shown in FIG. 7, in the communication system according to the second embodiment, a first recording device 401 using a file server computer is connected to the first communication network 101 of the communication system according to the first embodiment. A second recording device 402 is connected to the second communication network 102, and a third recording device 403 is connected to the third communication network 103.

  FIG. 8 is a block diagram showing configurations of the first recording device 401, the second recording device 402, and the third recording device 403 included in the communication system according to Embodiment 2 of the present invention. The first recording device 401 includes a control unit 41a, a recording unit 42a, a storage unit 43a, and a communication unit 44a, and various information such as communication information that is image information is recorded in the recording unit 42a. The second recording device 402 includes a control unit 41b, a recording unit 42b, a storage unit 43b, and a communication unit 44b, and various information such as communication information that is image information is recorded in the recording unit 42b. The third recording device 403 includes a control unit 41c, a recording unit 42c, a storage unit 43c, and a communication unit 44c, and various information such as communication information that is image information is recorded in the recording unit 42c. Since the configuration of other devices is the same as that of the first embodiment, the first embodiment will be referred to and the description thereof will be omitted.

  Next, processing of the transmission device 1 used in the communication system of the present invention will be described. FIG. 9 is a flowchart showing communication information reading and transmission processing of the transmission apparatus 1 used in the communication system according to Embodiment 2 of the present invention. The operator operates the transmission apparatus 1 to specify transmission information recorded in a recording apparatus connected to the communication network, for example, the third recording apparatus 403 connected to the third communication network 103, and receive as a transmission destination. Perform an operation to specify a device. The transmission device 1 accesses the designated recording device under the control of the control unit 11 that executes the computer program PG stored in the storage unit 14, reads the designated transmission information (S201), and reads the transmission information that has been read. It is determined whether or not the recording device that records the message is connected to the same communication network as the own device, here the first communication network 101 (S202).

  In step S202, when it is determined that the recording device that records the read transmission information is connected to the same communication network as the own device (S202: YES), the transmission device 1 is controlled by the control unit 11. A secrecy class is set according to “0”, which is the number of connection devices that pass through the recording device (S203).

  Then, the transmission device 1 discriminates the set secrecy class under the control of the control means 11 (S204), and the initial value of the number of passing devices of packets encapsulating transmission information according to the discriminated secrecy class (S205), and transmission information in units of packets in which the number of passing devices is set is transmitted from the communication means 15 to the designated receiving device (S206). Here, the set secrecy class is the number of connected devices, and the initial value of the number of passing devices is also set to the number of connected devices indicated by the secrecy class. That is, the initial value of the number of passing devices is set to “0”.

  In step S202, when it is determined that the recording device that records the read transmission information is not connected to the same communication network as the own device (S202: NO), the number of connection devices that pass through the recording device is detected. (S207). The number of connection devices that pass to the recording device is determined by a command such as a tracert (trace route) command that detects a route to the designated device. Since the tracert command can detect a passing device as a route to a device specified by an IP address or a host name, the number of detected devices is set as the number of connected devices that pass.

  Under the control of the control unit 11, the transmission device 1 sets a confidentiality class according to the number of detected connection devices (S208), proceeds to step S204, and executes the subsequent processing. In this case, the initial value of the number of passing devices is set to the number of detected connected devices. The number of passing devices detected without using the concept of confidentiality class may be set as the initial value of the number of passing devices as it is.

  As described above, when the transmission information is read from the first recording device 401 by setting the initial value of the number of passing devices according to the number of connection devices that pass to the recording device from which the transmission information is read, The transmission information can be transmitted only to the device connected to the first communication network 101. When the transmission device is read from the third recording device 403, the device connected to the first communication network 101, the second communication Transmission information can be transmitted to a device connected to the network 102 and a device connected to the third communication network 103.

Embodiment 3 FIG.
In the third embodiment, a portable transmission device 1 such as a notebook personal computer can be used to connect to an arbitrary communication network. FIG. 10 is a block diagram conceptually showing the structure of the communication system in the third embodiment of the present invention. As shown in FIG. 10, in the communication system according to the third embodiment, the transmission apparatus 1 connected to the first communication network 101 is connected to other communication such as the third communication network 103 and the Mth communication network 100M as necessary. It can be moved to connect to the network.

  FIG. 11 is an explanatory diagram conceptually showing the recorded contents of the confidentiality table 13a secured in the recording means 13 of the communication device 1 included in the communication system according to Embodiment 3 of the present invention. The confidentiality table 13a is a table used when the operation as the third embodiment is performed, and is “192.168.1.0/24” and “192.168.2.0” which are information indicating the communication network. Subnet address such as “/ 24”, numerical values such as “2” and “1” indicating the confidentiality class, and “2004/10/15 — 12:25” and “2004/10/09 — 15:32” which are expiration dates. The information indicating the date and time is recorded in association with each other. The information indicating the confidentiality may be information indicating the number of passing devices.

  Next, processing of the transmission device 1 used in the communication system of the present invention will be described. FIG. 12 is a flowchart showing processing at the time of communication network connection of transmitting apparatus 1 used in the communication system according to Embodiment 3 of the present invention. The operator connects the portable transmission device 1 to an arbitrary communication network necessary for business in a communication network permitted to be connected. The transmission device 1 detects a connected communication network under the control of the control unit 11 that executes the computer program PG stored in the storage unit 14 (S301). By connecting the transmission device 1 to a communication network, for example, an IP address is assigned by a DHCP (Dynamic Host Configuration Protocol) function provided in the connection device. The transmission device 1 can detect the communication network by determining the address of the subnetwork indicating the connected communication network from the assigned IP address.

  The transmission device 1 determines whether or not the information indicating the confidentiality class associated with the information indicating the detected communication network is recorded in the confidentiality table 13a under the control of the control unit 11 (S302). ), When it is determined that the information is recorded in the confidentiality table 13a (S302: YES), the information indicating the confidentiality class associated with the information indicating the detected communication network is read from the confidentiality table 13a (S303). ), The standard value (default value) of the confidentiality class of the communication information is set based on the read information indicating the confidentiality class (S304), and the communication network connection process is terminated.

  In step S302, when it is determined that the information indicating the confidentiality class associated with the information indicating the detected communication network is not recorded in the confidentiality table 13a (S302: NO), the confidentiality of the communication information. Is set to a reference value in consideration of a preset safety, here “0” (S305), and the communication network connection process is terminated. The fact that the information indicating the communication network is not recorded in the confidentiality table 13a means that the transmission device 1 is connected to the communication network for the first time, and is away from the first communication network 1 to which the transmission device 1 is originally connected. It is determined that there is a high possibility that the communication network is far away. Therefore, the receiving device that can be selected as the transmission destination of the communication information from the transmitting device 1 at that time is likely to be far from the communication network to which the transmitting device 1 is connected. When communication information is transmitted to a receiving device connected to a network, unnecessary traffic is generated, and the risk of leakage of communication information increases. In order to prevent this, when the transmitting apparatus 1 is connected to a communication network that has not been connected, the standard value of the confidentiality class is set to a reference value “0” in consideration of safety. Note that after the standard value of the confidentiality class is automatically set, the standard value can be changed manually.

  When transmission information is transmitted from the transmission device 1, the standard value set in step S304 or S305 is used as the initial value for the initial value of the number of passing devices.

  FIG. 13 is a flowchart showing processing at the time of leaving the communication network of the transmission apparatus 1 used in the communication system according to Embodiment 3 of the present invention. The operator can disconnect the transmission device 1 connected to the communication network from the communication network as necessary. The transmission device 1 detects disconnection from the communication network under the control of the control unit 11 that executes the computer program PG stored in the storage unit 14 (S401), and the confidentiality class set when the disconnection is detected. Is recorded in the confidentiality table 13a in association with the information indicating the disconnected communication network and the information indicating the expiration date (S402). In addition, when the information which shows the class of secrecy about the said communication network is already recorded on the secrecy table 13a, information will be overwritten. The expiration date is set to 3 months from the time of recording or overwriting in the confidentiality table 13a. When the expiration date has passed, the information indicating the confidentiality class is changed to “0” or confidentiality. Deletion from the table 13a is performed.

Embodiment 4 FIG.
In the fourth embodiment, an image forming apparatus such as a printer is not used as a receiving apparatus, but a print server computer that distributes image information to the image forming apparatus is used as a receiving apparatus. FIG. 14 is a block diagram conceptually showing the structure of the communication system in the fourth embodiment of the present invention. As shown in FIG. 14, in the fourth embodiment, a print server computer connected to the first communication network 101 is used as the first receiving device 201, and the first image using a printer is used for the first communication network 101. The forming apparatus 501a, the second image forming apparatus 502a, and the third image forming apparatus 503a are connected. In the communication system having the configuration shown in FIG. 14, communication information that is image information is transmitted from the transmission apparatus 1 to the first reception apparatus 201, and an image forming apparatus designated by the first reception apparatus 201, for example, the first image formation apparatus 501 a. The communication information is transmitted to the first communication network 101. The first image forming apparatus 501a performs a printing process for forming and outputting an image on a sheet based on the received communication information.

  FIG. 15 is a block diagram conceptually showing the structure of the communication system in the fourth embodiment of the present invention. FIG. 15 shows another connection form in the fourth embodiment. In the form shown in FIG. 14, the first image forming apparatus 501a, the second image forming apparatus 502a, and the third image forming apparatus 503a perform the first communication. In contrast to the connection to the network 101, in the connection form shown in FIG. 15, the first image forming apparatus 501b, the second image forming apparatus 502b, and the third image forming apparatus 503b are connected to the first receiving apparatus 201. . That is, in the form shown in FIG. 14, the apparatus such as the first image forming apparatus 501a is connected to the first communication network 101 via a communication line defined by a standard such as 100BASE-T. Then, a device such as the first image forming device 501b is connected to the first receiving device 201 via a communication line defined by a standard such as a Centronics interface. Then, the communication apparatus as image information is transmitted from the transmission apparatus 1 to the first reception apparatus 201, and the communication information is transmitted from the first reception apparatus 201 to the designated image forming apparatus, for example, the first image formation apparatus 501a. The first image forming apparatus 501a performs print processing for forming and outputting an image on a sheet based on the received communication information.

  In the first to fourth embodiments, the receiving apparatus or the apparatus connected to the receiving apparatus is an image forming apparatus, and the communication information is image information. However, the present invention is not limited to this, and the image forming apparatus is not limited thereto. Other devices may be used as a receiving device or a device connected to the receiving device, and information other than image information may be used as communication information.

It is a block diagram which shows notionally the structure of the communication system in Embodiment 1 of this invention. It is a block diagram which shows the structure of the transmitter with which the communication system in Embodiment 1 of this invention is provided, a 1st receiver, and a 1st connection apparatus. It is a block diagram which shows the format of the IP header of the communication protocol used with the communication system in Embodiment 1 of this invention. It is a flowchart which shows the communication information transmission process of the transmitter used in the communication system in Embodiment 1 of this invention. It is explanatory drawing for demonstrating the safety | security of the communication system in Embodiment 1 of this invention. It is explanatory drawing for demonstrating the safety | security of the communication system in Embodiment 1 of this invention. It is a block diagram which shows notionally the structure of the communication system in Embodiment 2 of this invention. It is a block diagram which shows the structure of the 1st recording device with which the communication system in Embodiment 2 of this invention is equipped, the 2nd recording device, and the 3rd recording device. It is a flowchart which shows the communication information reading and transmission process of the transmitter used in the communication system in Embodiment 2 of this invention. It is a block diagram which shows notionally the structure of the communication system in Embodiment 3 of this invention. It is explanatory drawing which shows notionally the recording content of the confidentiality table ensured to the recording means of the communication apparatus with which the communication system in Embodiment 3 of this invention is provided. It is a flowchart which shows the process at the time of the communication network connection of the transmitter used in the communication system in Embodiment 3 of this invention. It is a flowchart which shows the process at the time of the communication network detachment | leave of the transmitter used in the communication system in Embodiment 3 of this invention. It is a block diagram which shows notionally the structure of the communication system in Embodiment 4 of this invention. It is a block diagram which shows notionally the structure of the communication system in Embodiment 4 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmission apparatus 101 1st communication network 102 2nd communication network 103 3rd communication network 100M M communication network 201 1st receiving apparatus 202 2nd receiving apparatus 203 3rd receiving apparatus 200M M receiving apparatus 301 1st connecting apparatus 302 1st 2nd connection device 303 3rd connection device 300N Nth connection device 401 1st recording device 402 2nd recording device 403 3rd recording device 501a, 501b 1st image forming device 502a, 502b 2nd image forming device 503a, 503b 3rd image Forming device PG computer program REC recording medium

Claims (10)

Communication information is transmitted in units of packets in which the number of passing devices indicating the number of connecting devices that can pass is set to receiving devices connected via a single communication network or a plurality of communication networks connected by a connecting device. In the transmission device,
Means for discriminating the set secrecy class;
At least of the security of the communication path based on the presence / absence of encryption of the communication information to be transmitted and the availability of access from the other communication network of the device passing to the receiving device or the type of the connected communication network Means for discriminating one,
A transmission device comprising: a setting unit configured to set the number of passing devices according to at least one of the determined confidentiality class and the determination result regarding the presence / absence of encryption and the security of the communication path. Means for reading communication information recorded in a recording device connected to the communication network;
The transmission device according to claim 1, further comprising: means for setting a confidentiality class according to the number of connection devices that pass through the recording device in which the read communication information is recorded. A table for recording information indicating confidentiality in association with information indicating a communication network;
Means for detecting a connected communication network;
Means for reading from the table information indicating the confidentiality class associated with the information indicating the detected communication network;
The transmission apparatus according to claim 1, further comprising: means for setting a confidentiality class of communication information based on the read information indicating the confidentiality class. Means for detecting disconnection from the communication network;
4. The information processing apparatus according to claim 3 , further comprising: a unit configured to record information indicating the confidentiality class set when disconnection is detected in a table in association with information indicating the disconnected communication network. Transmitter device. Information recorded in the table, transmitting apparatus according to claim 3 or claim 4, characterized in that the expiration date is set. It said communication information transmitting apparatus according to any one of claims 5 to be the image information for forming an image from claim 1, wherein. A transmission device according to any one of claims 1 to 6 ,
A communication system comprising: the transmission device; and a reception device connected via one or a plurality of communication networks. The communication system according to claim 7 , wherein the receiving device is a device that forms an image based on image information. The communication system according to claim 7 , wherein the receiving device is a device that transmits the received image information to an image forming device that forms an image based on the image information. Communication information in units of packets in which the number of connection devices indicating the number of connection devices that can pass is set in a computer connected to another device via a plurality of communication networks connected by one communication network or connection device. In a computer program to be transmitted to another device,
A procedure for allowing the computer to determine the confidentiality class to be set;
Whether the communication information to be transmitted to the computer is encrypted, and whether the communication route is safe based on whether or not the device that passes through the receiving device is accessible from other communication networks or the type of the connected communication network. A procedure for determining at least one of
And a step of causing the computer to set the number of passing devices according to at least one of the determined confidentiality class and the determination result regarding the presence or absence of encryption and the security of the communication path. Computer program.

Images