JP2012114702A - Communication apparatus, communication method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce data volume of the data transmitted and received in accordance with transmission and reception of distribution information.SOLUTION: A communication apparatus 1 repeatedly transmits first authentication information used for verifying a second authentication information while repeatedly transmitting distribution information and a second authentication information used for verifying the distribution information. A distribution information processing part 3 specifies whether the first authentication information is transmitted or identification information on the first authentication information is transmitted instead of transmitting the first authentication information, in every transmission timing which comes repeatedly. A communication part 5 transmits at least the first authentication information to other communication device 2 in a transmission timing when the transmission of the first authentication information is specified by the distribution information processing part 3, and transmits the identification information of the first authentication information, the distribution information, and the second authentication information by associating one another to other communication device 2 in a transmission timing when the transmission of the identification information of the first authentication information is specified by the distribution information processing part 3.

Description

The present invention relates to a communication system that transmits and receives distribution information between communication devices and transmits and receives related information related to the distribution information.
For example, the present invention relates to a communication system that transmits and receives distribution information between vehicle-mounted devices mounted on a vehicle, between a vehicle-mounted device and a roadside device installed on a roadside, and transmits and receives authentication information for verifying the validity of the distribution information. .

  In recent years, through roadside-to-vehicle communication and vehicle-to-vehicle communication, information related to traffic congestion and signals, vehicle speed, Driving support to help you drive safely and efficiently by sending information on driving conditions such as location, emergency vehicle approach information such as ambulances, vehicle control information during platooning (hereinafter collectively referred to as distribution information) The system is being considered.

FIG. 25 shows a configuration diagram of a general driving support system.
The roadside device distributes distribution information to surrounding vehicle-mounted devices, and similarly, the vehicle-mounted device distributes distribution information to other vehicle-mounted devices.
In such a system, a malicious user can misuse an on-board device (C or D) to impersonate a roadside device or an emergency vehicle, distribute false information to other on-vehicle devices, and cause confusion. It may cause a traffic accident.
Therefore, it is necessary to provide a security means by which the receiving side that confirms the legitimacy of the transmitting side that distributes information, that is, the roadside device and the vehicle-mounted device that distributes information.
As an example of such countermeasures, Patent Document 1 describes a road-vehicle communication system using a digital signature of a public key encryption algorithm.
Hereinafter, the system described in Patent Document 1 will be described with reference to FIGS. 26 and 27.

In the system of Patent Document 1, a certificate authority issues a public key certificate A to a roadside device.
The roadside device distributes the public key certificate B of the certificate authority that issued the public key certificate A to the vehicle-mounted device.
Further, the roadside device generates a digital signature of the information to be distributed as shown in FIG. 27, and distributes the information to be distributed, the digital signature, and the public key certificate A that can verify the signature to the vehicle-mounted device.
The in-vehicle device verifies the received public key certificate A with the public key certificate B of the certificate authority and verifies the digital signature of the distributed information with the public key certificate A so that it is distributed from the legitimate roadside device. Confirm that the information is correct.
Patent Document 1 describes a road-to-vehicle communication system, but the same security measures can also be applied to vehicle-to-vehicle communication. By verifying information and certificates delivered from an onboard device pretending to be an emergency vehicle, It can be detected that a general on-vehicle device impersonates an emergency vehicle.

JP 2007-88737 A

However, in the conventional system as described above, the roadside machine that is the transmitting side needs to distribute authentication information that the receiving side confirms the validity of the transmitting side in addition to the information to be distributed.
The authentication information in the above system is the public key certificate B of the certificate authority, the signature of the distribution information, and the public key certificate A of the roadside device.
Since the number of certificate authority certificates B is small, it can be stored in advance in the on-board device on the receiving side, but the number of roadside devices is very large, It is not realistic to leave.
In addition, when vehicle-to-vehicle communication is included, it is not possible to store in advance the certificates of all roadside devices on the transmission side and onboard devices in the onboard device on the reception side.
Therefore, it is necessary to transmit the certificate on the transmission side together with the distribution information and the signature for each distribution.
Here, a digital signature using RSA (registered trademark) (Rivest Shamir Adleman) having a key length of 1024 bits is considered as a public key encryption algorithm.
Since the public key certificate includes the public key and the certificate authority's signature, the transmitter certificate includes at least the transmitter public key (1024 bits) and the certificate authority signature (1024 bits).
The signature of the distribution information is 1024 bits.
Thus, at least 3072 bits of authentication information is required in addition to the distribution information.
In addition, since the receiving side performs verification of the received public key certificate and signature verification of the distribution information, high processing capability is required.
Furthermore, since the distribution information is used after the distribution information signature verification, the signature verification of all received distribution information must be performed, which requires high processing capacity and is wasteful. Many.

  One of the main objects of the present invention is to solve the above problems, and it is a main object of the present invention to reduce the amount of data transmitted / received in association with transmission / reception of distribution information.

The communication device according to the present invention is
A communication device that repeatedly transmits distribution information and repeatedly transmits related information related to the distribution information,
For each transmission timing that repeatedly arrives, a transmission target designating unit that designates whether to transmit the related information or to transmit identification information of the related information instead of the related information;
At the transmission timing at which transmission of the related information is designated by the transmission target designating unit, at least the related information is transmitted, and at the transmission timing at which transmission of identification information of the related information is designated by the transmission target designating unit, It has a communication part which matches and transmits the identification information of related information, and the said delivery information.

  According to the present invention, instead of transmitting the related information, the identification information of the related information having a smaller data amount than the related information is transmitted, so that the amount of data to be transmitted can be reduced.

FIG. 3 shows a configuration example of a communication apparatus according to the first embodiment. FIG. 3 is a flowchart showing processing at the time of transmission of the communication apparatus according to the first embodiment. FIG. 3 is a diagram showing a configuration example of communication data according to the first embodiment. FIG. 3 is a flowchart showing processing at the time of reception of the communication apparatus according to the first embodiment. FIG. 4 is a diagram showing an example of a first authentication information storage method according to the first embodiment. FIG. 9 is a flowchart showing processing at the time of transmission of the communication apparatus according to the second embodiment. FIG. 6 shows a configuration example of communication data according to the second embodiment. FIG. 4 is a flowchart showing processing at the time of reception by a communication device according to Embodiment 2. FIG. 9 shows a configuration example of a communication apparatus according to Embodiment 3. FIG. 9 is a flowchart showing processing at the time of transmission of the communication apparatus according to the third embodiment. FIG. 10 shows a configuration example of communication data according to the third embodiment. FIG. 10 is a flowchart showing processing at the time of reception by the communication apparatus according to the third embodiment. FIG. 10 is a diagram illustrating a specific example of an ID recording process and an ID comparison process according to the third embodiment. FIG. 9 is a flowchart showing processing at the time of transmission by a communication apparatus according to Embodiment 4; FIG. 10 shows a configuration example of communication data according to the fourth embodiment. FIG. 9 is a flowchart showing processing at the time of reception by a communication device according to Embodiment 4; FIG. 9 shows a configuration example of a communication apparatus according to Embodiment 5. FIG. 6 is a flowchart showing processing at the time of transmission by a communication apparatus according to Embodiment 5; FIG. 9 is a flowchart showing processing at the time of reception by a communication apparatus according to Embodiment 5. FIG. 10 is a diagram illustrating a specific example of an ID recording process and an ID comparison process according to the fifth embodiment. FIG. 6 is a diagram illustrating an example of a method for determining the number of times N according to the first embodiment. FIG. 6 is a diagram illustrating an example of a method for determining the number of times N according to the first embodiment. FIG. 10 is a diagram illustrating an example of a method for determining the number of times N according to the second embodiment. FIG. 3 shows a configuration example of a communication apparatus according to the first embodiment. The figure explaining a prior art. The figure explaining a prior art. The figure explaining a prior art. The figure which shows the hardware structural example of the communication apparatus which concerns on Embodiment 1-5.

Embodiment 1 FIG.
In Embodiments 1 to 5, the distribution information is repeatedly transmitted and received, the second authentication information used for verifying the validity of the distribution information, and the first authentication for verifying the validity of the second authentication information A road-to-vehicle / vehicle-to-vehicle communication system that repeatedly transmits and receives authentication information (an example of related information) will be described.
Further, in the present embodiment, only the first authentication information is transmitted once (the distribution information is not transmitted) with respect to a predetermined communication count N (N is an arbitrary integer greater than or equal to 2), and the rest An example in which the distribution information and the second authentication information are transmitted N-1 times will be described.

FIG. 1 is a diagram illustrating a configuration example of a communication device 1 according to the present embodiment.
In the case of road-to-vehicle and vehicle-to-vehicle communication, the roadside device installed on the roadside communicates with the vehicle-mounted device mounted on the vehicle, and the vehicle-mounted device communicates with the roadside device and other vehicle-mounted devices.
In this embodiment, the roadside device and the vehicle-mounted device are described as the communication device 1.
The other communication device 2 for the communication device 1 is an example of a communication device.

The communication device 1 transmits the distribution information to the other communication device 2 and receives the distribution information transmitted by the other communication device 2.
The communication device 1 includes a distribution information processing unit 3 that generates distribution information to be transmitted to another communication device 2 and processes the distribution information received from the other communication device 2.
The communication apparatus 1 also includes an authentication information processing unit 4 that generates and verifies authentication information for the reception side to confirm the validity of the transmission side using distribution information and key information stored in advance.
The communication device 1 also includes a communication unit 5 that performs wireless communication with other communication devices 2 such as DSRC (Dedicated Short Range Communication) and wireless LAN (Local Area Network).

The distribution information processing unit 3 has a counter 6 that counts the number of times of data transmission, and refers to the counter value of the counter 6 for each transmission timing that repeatedly arrives. Specifies whether the identification information of the first authentication information is transmitted instead of the one authentication information.
The distribution information processing unit 3 is an example of a transmission target designating unit.
The authentication information processing unit 4 is provided with a storage unit 7 that is a readable / writable memory for the authentication information processing unit 4 and stores key information used for generating / verifying the authentication information.
The key information is, for example, when a digital signature by a public key algorithm is applied, a public key certificate issued by a certificate authority, a private key corresponding to a public key included in the public key certificate, a public key certificate of the certificate authority, etc. If a common key algorithm is applied, it is a common key used for communication.
Although not shown, the communication device 1 receives current position information and date / time information indicating a date and time from an installed roadside machine or vehicle.
These are generated by a GPS (Global Positioning System) receiver, a gyroscope, a clock, or the like installed in a roadside machine or a vehicle.

Moreover, in the communication apparatus 1 mounted in a vehicle, for example, as illustrated in FIG. 24, each component illustrated in FIG. 1 may be disposed separately in a navigation device 70 and an in-vehicle device 80.
FIG. 24A shows a configuration in which the authentication information processing unit 4 is arranged in the vehicle-mounted device 80, and FIG. 24B shows a configuration in which the authentication information processing unit 4 is arranged in the navigation device 70.
The navigation device 70 is provided with the vehicle-mounted device communication unit 71, and the vehicle-mounted device 80 is provided with the navigation communication unit 81, and communication between the navigation device 70 and the vehicle-mounted device 80 is possible.

Next, a processing flow at the time of data transmission of the communication apparatus 1 will be described with reference to FIGS. 2 and 3.
FIG. 2 is a processing flow diagram at the time of data transmission, and FIG. 3 is a configuration diagram of communication data.

When the communication device 1 is turned on or the transmission timing comes, the distribution information processing unit 3 checks the counter value of the counter 6 (S100).
In the present embodiment, the initial value of the counter immediately after the communication apparatus 1 is turned on is 1, and the counter is incremented every time transmission is performed thereafter.
When the counter value is 1, the distribution information processing unit 3 of the communication device 1 determines to transmit the first authentication information (transmission target specifying step), and acquires the first authentication information from the authentication information processing unit 4 ( S101).
At this time, the authentication information processing unit 4 does not need to generate the first authentication information if it is held in the storage unit 7, but if it does not hold it, it generates the first authentication information and distributes the distribution information. Output to the processing unit 3.
The first authentication information is, for example, a public key certificate of the communication device 1 in the case of a digital signature using a public key algorithm, and does not need to be generated in this case.
In the case of a common key algorithm, session key information obtained by encrypting a session key to be temporarily used with a common key, session key information obtained by encrypting a session key with a message authentication code added, etc. In this case, it is necessary to generate session key information.
Further, the first authentication information may include identification information of the first authentication information for uniquely identifying the first authentication information and an expiration date indicating a period during which the first authentication information is valid.
Then, “no distribution information” is set in the data identification information 21 which is information indicating whether or not the communication data includes distribution information (S102), and the communication data is set in the first configuration shown in FIG. It transmits from the communication part 5 (S103) (communication step).

On the other hand, when the counter value is other than 1 in the determination of S101, the distribution information processing unit 3 determines to transmit the identification information of the first authentication information instead of the first authentication information (transmission target). (Designation step), distribution information is generated (S104).
Then, the generated distribution information is input to the authentication information processing unit 4.
The authentication information processing unit 4 generates second authentication information using the key information and the first authentication information stored in the storage unit 7 (S105).
The second authentication information is, for example, a digital signature of distribution information generated by the secret key of the communication device 1 in the case of a public key algorithm, and a message authentication code generated by a session key in the case of a common key algorithm. There is.
Then, the authentication information processing unit 4 responds to the distribution information processing unit 3 with identification information of the first authentication information that uniquely identifies the first authentication information used for generating the second authentication information (S106).
The identification information of the first authentication information only needs to uniquely identify the first authentication information. The ID (Identification) included in the public key certificate and the hash value (digest) of the certificate calculated using the hash function Or a part thereof, an ID included in the session key information, a digest of the session key, or a part thereof.
If the identification information of the first authentication information is a certificate digest, the communication device 1 generates the public key certificate of the communication device 1 and stores it in the storage unit 7. Therefore, it is not necessary to generate at the time of communication, and the processing load at the time of communication can be reduced.
In this case, the distribution information processing unit 3 may obtain and hold the authentication information processing unit 4 from the authentication information processing unit 4 before storing the certificate or before communication after power-on, and configure the communication data using the information.
Then, the distribution information processing unit 3 sets “with distribution information” in the data identification information 21 (S107), and transmits communication data from the communication unit 5 with the second configuration shown in FIG. 3B (S103). .

After transmitting the communication data, the distribution information processing unit 3 checks whether or not the counter value has reached a predetermined communication count N (S108).
The number of times of communication N is determined from the communication frame interval of the communication device, the time interval of distribution information required by the communication device, the characteristics of the corresponding system, and the like.
Further, depending on the system to be applied, the communication count N may be infinite, that is, the first authentication information may be transmitted once and then always used.

As a method for determining the number of times of communication N, the methods shown in FIGS.
FIG. 21 shows an example of determining the number of times of communication N from the communication area radius L of the roadside machine, the vehicle speed V, the minimum distance R for receiving distribution information, and the transmission cycle F in the case of a roadside machine.
21 shows an example in which the communication count N is set to 25 times or 20 times or less, the communication count N may be, for example, about 3 to 10 times.
FIG. 22 shows an example in which the distribution information division count + 1 is the communication count N.
FIG. 22 shows a case in which one piece of distribution information is divided into M (M is an arbitrary integer equal to or larger than 2) and transmitted. In this case, since the distribution information is transmitted M times, Adding authentication information once, the opportunity for data transmission is (M + 1) times.
That is, in FIG. 22, the number of times of communication is N = (M + 1) times.
Note that the communication count N may be determined by a method other than that shown in FIGS. 21 and 22.

2, if the counter value has not reached the communication count N, the distribution information processing unit 3 counts up the counter value (S109). If the counter value has reached the communication count N, the counter value Is returned to the initial value (S110).
In this way, the communication data shown in FIG. 3 is transmitted.
Although not shown, communication data and distribution information may be encrypted and transmitted according to the system.

Next, the flow at the time of reception of the communication apparatus 1 will be described using FIG.
FIG. 4 is a processing flow chart at the time of reception.

The communication device 1 receives communication data through the communication unit 5 (S150).
And the communication part 5 sends communication data to the delivery information processing part 3, and the delivery information processing part 3 confirms the data identification information 21 in communication data (S151).
When the data identification information 21 is “no distribution information”, the first authentication information 20 included in the communication data is sent to the authentication information processing unit 4, and the authentication information processing unit 4 stores the first authentication information 20. It is confirmed that the data is stored in the unit 7 (S152).
If the first authentication information 20 is held in the storage unit 7, the receiving process is terminated without doing anything.
If not, the authentication information processing unit 4 verifies the first authentication information 20 using key information recorded in advance in the storage unit 7 (S153).
For example, in the case of a public key algorithm, the verification is performed by verifying the signature of a certificate received using a public key certificate of a pre-recorded certificate authority, searching for a pre-recorded CRL (certificate revocation list), etc. is there.
In the case of the common key algorithm, decryption using a pre-recorded common key, verification of a message authentication code, confirmation of a padding value in the decryption result, and the like.
In addition, if the first authentication information 20 has an expiration date, the expiration date is confirmed by comparing with the current date and time. If it has expired, the first authentication information is deleted.
Then, the verification result is judged (S154), and if the validity of the first authentication information 20 is confirmed, the first authentication information 20 is stored in the storage unit 7 (S155).
At this time, identification information of the first authentication information 20 is created and recorded together with the first authentication information 20 as necessary.
When the first authentication information 20 includes identification information of the first authentication information, the information is recorded together.
On the other hand, if the validity of the first authentication information 20 cannot be confirmed, the first authentication information is discarded (S156).

Here, FIG. 5 shows an example of a method for storing the first authentication information 20 in the storage unit 7.
In the configuration of FIG. 5, the first authentication information 20, the identification information 24, the date 25 using the first authentication information, and the number of times 26 using the first authentication information are recorded.
Although not shown, the date when the first authentication information 20 is received or the date when the first authentication information 20 is verified may be recorded.
The used date 25 is used to search for information on the oldest date and overwrite or delete it in order to record new first authentication information when the capacity of the storage unit 7 reaches the limit. Can do.
Thereby, the memory | storage part 7 can be used effectively.
Similarly to the above, when the capacity of the storage unit 7 reaches the limit, the number of times of use is overwritten or deleted in order to record new first authentication information, and the storage unit 7 Can free up storage space.
These items may be omitted depending on the system and the encryption algorithm used.

Next, when the data identification information 21 of the received communication data is “with distribution information”, the distribution information processing unit 3 confirms the unencrypted part of the distribution information 22, that is, all or part of the distribution information 22. The necessity of the information is determined (S157).
The determination is made based on the position and time included in the distribution information 22, the communication device ID that uniquely identifies the transmission destination and the transmission source communication device, and the like.
For example, the information on the traffic jam in the opposite lane is information on the lane opposite to the traveling direction of the vehicle, and can be determined as unnecessary.
When the received distribution information 22 is necessary, it is necessary to verify the distribution information 22, and when not necessary, verification is not necessary.
In this way, not all the received information is verified, but only the necessary information is verified, so that efficient verification can be performed and the specification of processing capability for the communication device can be lowered. Cost reduction is possible.
Further, the identification information 24 of the first authentication information may be used for determining the necessity.
For example, when the identification information 24 of the first authentication information designated by the driver is included via an input unit (not shown) that accepts the driver's operation provided in the vehicle, the distribution information 22 is required. You may make it judge.
Then, the distribution information processing unit 3 determines the necessity of verification from the necessity of the distribution information 22 (S158), and discards the distribution information 22 if unnecessary (S159).
If necessary, the identification information 24 of the first authentication information, the distribution information 22 and the second authentication information 23 are sent to the authentication information processing unit 4, and the authentication information processing unit 4 stores the first authentication information 20 in the storage unit. It is confirmed that it is held (S160).
When the first authentication information 20 is not held, the result is returned to the distribution information processing unit 3 and the distribution information 22 is discarded (S159).
In this case, since the distribution information processing unit 3 is assumed to be used as reference information without discarding the distribution information 22, whether or not to actually discard depends on the service or system.
In the following description, the example in which the distribution information 22 is discarded will be described.

On the other hand, when the first authentication information 20 is held, the authentication information processing unit 4 verifies the second authentication information 23 using the first authentication information 20 (S161).
For example, in the case of a public key algorithm, the verification includes signature verification of distribution information received using a transmission-side public key certificate that is first authentication information.
In the case of the common key, verification of the message authentication code of the distribution information using the session key included in the first authentication information 20 and confirmation of the padding value in the decrypted result are performed.
At this time, if the first authentication information 20 has an expiration date, it is confirmed that the expiration date has not expired by comparing it with the current date and time. If the time limit has expired, the first authentication information is deleted.
Then, the authentication information processing unit 4 determines the result of the verification (S162). If the validity of the second authentication information 23 cannot be confirmed, the result is transmitted to the distribution information processing unit 3, and the distribution information processing unit 3 Discards the distribution information 22 (S159).
In this case, as described above, the distribution information processing unit 3 may be used as reference information without discarding the distribution information 22, so whether or not to actually discard the distribution information 22 depends on the service or system. Dependent.
In the following description, the example in which the distribution information 22 is discarded will be described.

When the validity of the second authentication information 23 can be confirmed, the authentication information processing unit 4 sends the result to the distribution information processing unit 3, and the distribution information processing unit 3 processes the distribution information 22 (S163).
At this time, the distribution information 22 is also sent to the distribution information processing unit 3 as necessary.
The processing of the distribution information 22 is not shown, but is transmitted to a display device that can be confirmed by the driver, prompting the driver to pay attention and warning, or transmitted to the control unit of the vehicle for speed adjustment and steering adjustment. To go.
The above processing may be performed by comprehensively judging from a plurality of communication data.

Thus, in the communication count N, the first authentication information is transmitted once, and the remaining (N-1) times are transmitted the second authentication information, the identification information of the first authentication information, and the distribution information. With this configuration, the communication data length can be shortened.
Here, a case is considered where a digital signature using RSA (registered trademark) having a public key encryption algorithm key length of 1024 bits is used.
When the distribution information is not transmitted, the first authentication information is a public key (1024 bits) included in the certificate of the communication device and a signature (1024 bits) of the certificate authority.
When transmitting the distribution information, the second authentication information is a signature (1024 bits) of the distribution information, and the identification information of the first authentication information is the hash value of the public key certificate using the hash function SHA-1. Then, it is 160 bits, and the communication data length can be shortened by at least 1024 bits compared to the conventional case.
Thereby, communication of longer delivery information and communication quality can be improved.
In the case of the common key algorithm, since the common key used for verification can be changed every N times of communication, the security level is improved.
In addition, since the identification information of the first authentication information is transmitted together with the second authentication information, the first authentication information and the second authentication can be accurately and easily performed in the communication device even when communicating with a plurality of communication devices. Information can be associated.
Furthermore, the verification of both the first authentication information and the second authentication information has been performed at the time of conventional reception, but the first authentication information and the second authentication information are received separately. The verification can be performed separately, the processing load can be reduced, the apparatus can be realized with a low processing capability, and the cost can be reduced.
In addition, verification is not performed for all received distribution information, but only necessary distribution information is verified. Therefore, efficient verification can be performed, and processing capacity specifications for communication devices can be reduced. Cost reduction is possible.
In addition, the first authentication information verified and confirmed to be valid is recorded in the storage unit, and when the same first authentication information is received again, it is confirmed that the first authentication information is retained and the first authentication information is confirmed. If the information has an expiration date, the expiration date is confirmed. Therefore, useless verification can be omitted and the processing load can be reduced.
As a result, it is possible to efficiently increase the security strength even with a communication device having a low processing capability.

In the communication apparatus 1, the configuration at the time of transmission and at the time of reception may be changed.
For example, although the communication unit 5 is configured to be connected only to the distribution information processing unit 3, the transmission information processing unit 3 generates the communication unit 5 by connecting the communication unit 5 to the authentication information processing unit 4 at the time of transmission. The authentication information processing unit 4 may generate authentication information from the distributed information, and the distribution information and the authentication information may be transmitted from the communication unit 5 together.
The communication unit 5 may be configured to transmit the distribution information of the distribution information processing unit 3 and the authentication information of the authentication information processing unit 4 together.
At the time of reception, in the above-described embodiment, the verification of the second authentication information determined to be necessary by the distribution information processing unit 3 has been performed, but the validity is confirmed from the communication unit 5 via the authentication information processing unit 4. When only the confirmed distribution information is sent to the delivery information processing unit 3, it can be configured to verify all received communication data.
In addition, the communication device 1 determines the data identification information in the communication unit 5, and when there is no distribution information, transmits the first authentication information to the authentication information processing unit 4. The communication data may be transmitted to the distribution information processing unit 3.
Furthermore, a counter that is in the distribution information processing unit 3 may be provided in the authentication information processing unit 4.

Further, the present embodiment is applied only to the vehicle-mounted device in which low cost is more strictly required, and the roadside unit may be a road-to-vehicle / vehicle-to-vehicle communication system having the same configuration as the conventional one.
Further, in the case of a road-to-vehicle / vehicle-to-vehicle communication system having a plurality of channels, the first authentication information is transmitted to a certain channel, the distribution information on the other channel, the identification information of the first authentication information, the second The authentication information may be transmitted.
Further, in the case of communication data including distribution information, the entire communication data or only distribution information is encrypted, and when transmitting only the first authentication information not including distribution information, it is configured to transmit without encryption. Also good.
In the present embodiment, a configuration is shown in which the counter value is 1 and starts from transmission after the power is turned on.

Embodiment 2. FIG.
In the first embodiment described above, when only the first authentication information is transmitted for the predetermined number of communication times, the identification information of the first authentication information, the distribution information, and the second authentication information are transmitted. In this case, it is transmitted separately.
Next, the distribution information is transmitted every time, and the first authentication information, the distribution information, and the second authentication information are transmitted once for the predetermined communication number N, and the remaining (N-1) times. Indicates a form in which the identification information and distribution information of the first authentication information and the second authentication information are transmitted.
Although such a configuration increases the communication data length as compared with the first embodiment, it can transmit the distribution information every time and can cope with a decrease in the transmission frequency of the distribution information.
Note that the configuration of the communication apparatus according to the present embodiment is the same as that of FIG.

Next, processing during transmission will be described with reference to FIGS.
FIG. 6 is a processing flow diagram at the time of data transmission, and FIG. 7 is a configuration diagram of communication data.

When the communication device 1 is turned on or when the transmission timing comes, the distribution information processing unit 3 generates distribution information (S200) and outputs the distribution information to the authentication information processing unit 4.
And the authentication information processing part 4 produces | generates 2nd authentication information using the key information stored in the memory | storage part 7 (S201), and responds to the delivery information processing part 3. FIG.
The second authentication information is the same as in the first embodiment.
Then, the distribution information processing unit 3 confirms the counter value of the counter 6 (S202).
In the present embodiment, as in the first embodiment, the initial value of the counter immediately after the communication apparatus 1 is turned on is 1, and the counter is incremented each time transmission is performed thereafter.

When the counter value is 1, the distribution information processing unit 3 acquires the first authentication information from the authentication information processing unit 4 (S203).
The processing in the authentication information processing unit 4 and the first authentication information at this time are the same as those in the first embodiment.
Then, “first authentication information” is set in the data identification information 21 which is information indicating whether the communication data includes the first authentication information or the identification information of the first authentication information (S204). Communication data is transmitted from the communication unit 5 in the first configuration shown in FIG. 7A (S205).
When the counter value is other than 1, the distribution information processing unit 3 acquires the identification information of the first authentication information used for generating the second authentication information (S206).
The identification information of the first authentication information is the same as in the first embodiment.
Then, the distribution information processing unit 3 sets “identification information of first authentication information” in the data identification information 21 (S207), and communication data is transmitted from the communication unit 5 with the second configuration shown in FIG. Transmit (S205).
After transmission of the communication data, the distribution information processing unit 3 checks whether or not the counter value has reached a predetermined number of times of communication N (S208).
If the counter value has not reached the number of times of communication N, the counter value is counted up (S209), and if it has reached, the counter value is returned to the initial value (S210).
In this way, the communication data shown in FIG. 7 is transmitted.
Although not shown, communication data and distribution information may be encrypted and transmitted according to the system.

In the present embodiment, since the distribution information is transmitted every time, the communication count N is determined by the method shown in FIG. 23, for example.
FIG. 23 corresponds to FIG. 22 in the first embodiment.
FIG. 23 shows an example in which the distribution information division count = communication count N.
FIG. 23 shows a case in which one piece of distribution information is divided into M and transmitted. In this case, since the first authentication information is also transmitted together with the distribution information, there are M data transmission opportunities.
That is, in FIG. 23, the number of communication times N = M times.
Instead of the method of FIG. 23, the number of times of communication N may be determined by the method shown in FIG. 21, or may be determined by another method.

Next, the flow at the time of reception by the communication apparatus will be described with reference to FIG.
FIG. 8 is a processing flow chart at the time of reception.

The communication device 1 receives communication data through the communication unit 5 (S250).
Then, the communication unit 5 sends the communication data to the distribution information processing unit 3, and the distribution information processing unit 3 confirms the unencrypted part of the distribution information 22, that is, all or part of the distribution information 22, Is determined (S251).
The determination is the same as in the first embodiment.
Then, the distribution information processing unit 3 determines the necessity of verification from the necessity of the distribution information 22 (S252), and discards the distribution information 22 if unnecessary (S253).
If necessary, the distribution information processing unit 3 sends communication data to the authentication information processing unit 4, and the authentication information processing unit 4 confirms that the first authentication information 20 is held in the storage unit 7 (S254). .
At this time, if the first authentication information 20 includes an expiration date, it is confirmed that the expiration date has not expired compared to the current date and time.
In this way, not all the received information is verified, but only the necessary information is verified, so that efficient verification can be performed and the specification of processing capability for the communication device can be lowered. Cost reduction is possible.

If the first authentication information 20 is not held, the data identification information 21 is confirmed (S255).
When the data identification information 21 is “identification information of the first authentication information”, the distribution information processing unit 3 discards the distribution information 22 in response to the distribution information processing unit 3 as invalid communication data (S253).
When the data identification information 21 is “first authentication information”, the authentication information processing unit 4 verifies the first authentication information 20 using the key information recorded in advance in the storage unit 7 (S256).
The verification process is the same as in the first embodiment.
Then, the verification result is determined (S257), and when the validity of the first authentication information 20 cannot be confirmed, the first authentication information is discarded, and the distribution information processing unit 3 is notified of this, and the distribution information processing is performed. The unit 3 discards the distribution information 22 (S253).
When the validity of the first authentication information 20 is confirmed, the first authentication information 20 is stored in the storage unit 7 (S258).
At this time, identification information of the first authentication information is created as necessary and recorded together with the first authentication information 20.
When the first authentication information 20 includes identification information of the first authentication information, the information is recorded together.
Then, the authentication information processing unit 4 performs verification of the second authentication information 23 using the first authentication information (S259).
The verification process is the same as in the first embodiment.
Thereafter, the authentication information processing unit 4 determines the result of verification (S260), and if the validity of the second authentication information 23 cannot be confirmed, the result is transmitted to the distribution information processing unit 3, and the distribution information processing unit 3 discards the distribution information 22 (S253).
If the validity of the second authentication information 23 can be confirmed, the authentication information processing unit 4 sends the result to the distribution information processing unit 3, and the distribution information processing unit 3 processes the distribution information (S261).
At this time, the distribution information 22 is also sent to the distribution information processing unit 3 as necessary.
The processing of the distribution information 22 is the same as that in the first embodiment.
In S254, if the first authentication information is held, it is not necessary to verify the first authentication information, so verification of the second authentication information 23 is performed (S259).
The subsequent processing is the same as described above.

In this way, in the communication count N, the first authentication information, distribution information, and second authentication information are transmitted once, and the remaining (N-1) times are the second authentication information, first authentication. With the configuration for transmitting the identification information and the distribution information, the communication data length can be shortened comprehensively compared to the conventional case without reducing the transmission frequency of the distribution information.
Here, a case is considered where a digital signature using RSA (registered trademark) having a public key encryption algorithm key length of 1024 bits is used.
When transmitting the first authentication information, the first authentication information including the public key (1024 bits) and the certificate authority signature (1024 bits) included in the certificate of the communication device, and the distribution information as the second authentication information A signature (1024 bits), which is the same as the conventional one, but when transmitting identification information of the first authentication information, a hash value that is identification information of the first authentication information instead of the first authentication information (at least 2048 bits) It is 160 bits, and the communication data length can be shortened comprehensively compared to the conventional case.
As a result, communication quality can be improved without reducing the transmission frequency of distribution information.
In the case of the common key algorithm, since the common key used for verification can be changed every N times of communication, the security level is improved.
Further, when the first authentication information is not transmitted, the identification information of the first authentication information is transmitted together with the second authentication information. Therefore, even when communicating with a plurality of communication devices, the communication device is accurate and simple. The first authentication information and the second authentication information can be associated with each other.
Further, when the identification information of the first authentication information is received, only the second authentication information needs to be verified, so the processing load is reduced without reducing the transmission frequency of the distribution information. be able to.
In addition, verification is not performed for all received distribution information, but only necessary distribution information is verified. Therefore, efficient verification can be performed, and processing capacity specifications for communication devices can be reduced. Cost reduction is possible.
In addition, the first authentication information verified and confirmed to be valid is recorded in the storage unit, and when the same first authentication information is received again, it is confirmed that the first authentication information is retained and the first authentication information is confirmed. If the information has an expiration date, the expiration date is confirmed. Therefore, useless verification can be omitted and the processing load can be reduced.

In the communication device, the configuration at the time of transmission and at the time of reception may be changed.
For example, although the communication unit 5 is configured to be connected only to the distribution information processing unit 3, the transmission information processing unit 3 generates the communication unit 5 by connecting the communication unit 5 to the authentication information processing unit 4 at the time of transmission. The authentication information processing unit 4 may generate authentication information from the distributed information, and the distribution information and the authentication information may be transmitted from the communication unit 5 together.
The communication unit 5 may be configured to transmit the distribution information of the distribution information processing unit 3 and the authentication information of the authentication information processing unit 4 together.
At the time of reception, in the above-described embodiment, the verification of the second authentication information determined to be necessary by the distribution information processing unit 3 has been performed, but the validity is confirmed from the communication unit 5 via the authentication information processing unit 4. When only the confirmed distribution information is sent to the delivery information processing unit 3, it can be configured to verify all received communication data.
Further, the counter 6 provided in the distribution information processing unit 3 may be provided in the authentication information processing unit 4.
Further, the present embodiment is applied only to the vehicle-mounted device in which low cost is more strictly required, and the roadside unit may be a road-to-vehicle / vehicle-to-vehicle communication system having the same configuration as the conventional one.
Further, the entire communication data or only the distribution information may be encrypted and transmitted.
In the present embodiment, a configuration is shown in which the counter value is 1 and starts from transmission after the power is turned on.

Embodiment 3 FIG.
In the first and second embodiments, the first authentication information is transmitted and the identification information of the first authentication information is transmitted separately for a predetermined number of communications. It is a thing.
Next, select whether to send the first authentication information or the identification information of the first authentication information based on the information received from another communication device immediately after sending the first authentication information. The embodiment which determines and transmits automatically is shown.

FIG. 9 is a diagram illustrating a configuration of the communication device 1 according to the present embodiment.
The description of the same numbers as those in FIG. 1 of Embodiment 1 is omitted.

The reception ID storage unit 50 stores a communication device ID that can uniquely identify another communication device that is a transmission source of the received communication data, and is connected to the distribution information processing unit 3.
The reception ID storage unit 50 includes a readable / writable memory.
The communication device ID is for uniquely identifying the communication device, and may be an ID set in the communication device or identification information of the first authentication information.
In the present embodiment, the communication device ID will be described as identification information of the first authentication information.

In addition, the distribution information processing unit 3 is provided with a transmission flag 51 and a reception flag 52, which are constituted by a readable / writable memory.
The transmission flag 51 is a flag indicating whether or not the communication device 1 has transmitted the first authentication information. In the present embodiment, the transmission flag 51 is “H” when the first authentication information is transmitted, and the first authentication information. When the identification information is transmitted, it is indicated by “L”, and the initial value immediately after power-on is “L”.
The reception flag 52 is a flag indicating whether or not the first authentication information should be transmitted in the next transmission from the information received by the communication device 1, and it is not necessary to transmit the first authentication information in the present embodiment. That is, “H” is displayed when the identification information of the first authentication information is transmitted, “L” is displayed when the first authentication information needs to be transmitted, and the initial value immediately after power-on is “L”. Yes.

Further, the distribution information processing unit 3 is provided with a transmission processing unit 31 and a reception processing unit 32.
When the communication device 1 is a vehicle-mounted device mounted on a vehicle, the other communication device 2 is a vehicle-mounted device mounted on another vehicle or a roadside device installed on the road side. The other communication device 2 located in the communicable range (range where radio waves for wireless communication reach) of the communication device 1 with the movement of the vehicle on which the vehicle is mounted or the vehicle on which the other communication device 2 is mounted is It will change.
Similarly, when the communication device 1 is a roadside machine, the other communication device 2 is a vehicle-mounted device mounted on the vehicle, and the communication device is moved along with the movement of the vehicle on which the other communication device 2 is mounted. The other communication devices 2 located in the communication range 1 (range in which radio communication radio waves reach) change.
Moreover, in this Embodiment, while the communication apparatus 1 transmits communication data periodically, it receives the communication data from the other communication apparatus 2 in the period between transmission timings.

The reception processing unit 32 can receive the communication data from the communication device 1 using the communication device ID included in the communication data received by the communication unit 5 during the period between the transmission timings. (Another communication device 2 within the communicable range of the communication device 1) is detected.
The reception processing unit 32 has a condition that the transmission flag is “L” when the reception flag 52 is “H”, and a condition that the communication device 2 that has not been detected until then is newly detected. When one of the two conditions is satisfied, the reception flag 52 is set to “L” to notify the transmission processing unit 31 that the first authentication information needs to be transmitted because the new communication device 2 has been detected.
If the transmission flag 51 is “L” and the reception flag 52 is “L” when the transmission timing arrives, the transmission processing unit 31 uses the information transmitted at the previous transmission timing as the first authentication information. The transmission processing unit 31 designates the transmission of the first authentication information, and the communication processing unit 31 designates the transmission of the first authentication information. The unit 5 transmits communication data including the first authentication information.
On the other hand, if the transmission flag is “H” when the transmission timing arrives, that is, if the information transmitted at the previous transmission timing is the first authentication information, or the transmission flag is “L”. If the reception flag 52 is “H”, that is, the condition that the information transmitted at the previous transmission timing is the identification information of the first authentication information is satisfied, the reception processing unit 32 performs a new communication device. 2 is not detected, the transmission processing unit 31 designates transmission of the identification information of the first authentication information, and the communication unit 5 specifies the identification information of the first authentication information, the distribution information, and the second authentication. Communication data including information is transmitted.

As described above, when the transmission processing unit 31 transmits the identification information of the first authentication information at the previous transmission timing, and the reception processing unit 32 detects a new communication device 2. Only choose to send the first authentication information.
In other words, if the first authentication information is transmitted at the previous transmission timing, even if a new communication device 2 is detected by the reception processing unit 32 after the previous transmission timing, At the transmission timing, the identification information of the first authentication information is transmitted.
In the present embodiment, the transmission processing unit 31 is an example of a transmission target designating unit, and the reception processing unit 32 is an example of a device detection unit.

Although not shown in FIG. 9, the communication device 1 receives current position information and date / time information indicating date and time from a mounted roadside machine or vehicle.
These are generated by a GPS signal communication device or a clock installed in a roadside machine or vehicle.

Next, the flow at the time of transmission in the communication apparatus will be described using FIG. 10 and FIG.
FIG. 10 is a flowchart of transmission processing, and FIG. 11 is a diagram showing a configuration of communication data.

The transmission processing unit 31 first checks the transmission flag 51 (S300).
When the transmission flag 51 is “H”, the transmission processing unit 31 generates the distribution information 22 (S301) and outputs it to the authentication information processing unit 4.
The authentication information processing unit 4 generates the second authentication information 23 from the key information and distribution information recorded in the storage unit 7 (S302), and responds to the distribution information processing unit 3.
In the distribution information processing unit 3, the transmission processing unit 31 acquires the identification information of the first authentication information (S304).
Thereafter, the transmission processing unit 31 sets “with distribution information” in the data identification information 21 (S305), and sets the transmission flag to “L” (S306).
And the identification information of 1st authentication information, delivery information, and 2nd authentication information are transmitted to the other communication apparatus 2 via the communication part 5 as shown in FIG.11 (b) (S307).

On the other hand, when the transmission flag is “L” in S300, the transmission processing unit 31 checks the reception flag 52 (S308).
When the reception flag 52 is “H” in S308, it is not necessary to transmit the first authentication information. Therefore, by performing the same processing as when the transmission flag is “H”, the identification information and distribution of the first authentication information are performed. Send information and second authentication information.
When the reception flag is “L” in S308, the transmission processing unit 31 acquires the first authentication information (S309).
Thereafter, the transmission processing unit 31 sets “no distribution information” in the data identification information 21 (S310), sets the transmission flag to “H” (S311), and sets the reception flag to “H” (S312).
Then, the contents recorded in the reception ID storage unit 50 are deleted (S313), and the first authentication information is transmitted to the other communication device 2 via the communication unit 5 as shown in FIG. (S307).
In this way, the communication data shown in FIG. 11 is transmitted.
Although not shown, communication data and distribution information may be encrypted and transmitted according to the system.

  Next, the flow at the time of reception in the communication apparatus 1 will be described using FIG.

FIG. 12 is a flowchart of reception processing, and the processing of the first authentication information and the second authentication information is omitted because it is the same as that of FIG.
This figure focuses on processing related to a transmission flag, a reception flag, and a reception ID storage unit that are not included in FIG.

First, the communication unit 5 receives communication data from another communication device 2 (S150).
Then, the same processing as in FIG. 4 is performed, and finally the distribution information is discarded (S159), the distribution information is processed (S163), and the first authentication information is processed by the distribution information processing unit 3 and the authentication information processing unit 4. Is discarded (S156), and the first authentication information is stored (S155).
Thereafter, the reception processing unit 32 of the distribution information processing unit 3 checks the transmission flag 51 (S350).
When the transmission flag 51 is “H”, since the first authentication information is transmitted immediately before, the reception processing unit 32 stores the received communication device ID in the reception ID storage unit 50 (S351), and the process ends.
The communication device ID recorded in the reception ID storage unit 50 will be described with reference to FIG.
The communication device 1 transmits communication data at a certain fixed interval determined by the system (60), and similarly receives communication data transmitted by another communication device 2 (61).
As shown in FIG. 13, the reception ID storage unit 50 transmits communication data including the first authentication information (60a) and then transmits the communication data again after one transmission cycle (60b). The communication device ID included in the communication data of the other communication device 2 received during (T1) is recorded.

In S350 of FIG. 12, when the transmission flag 51 is “L”, the reception processing unit 32 checks the reception flag 52 (S352).
If the reception flag 52 is “L”, no processing is performed and the process ends.
When the reception flag 52 is “H”, the reception processing unit 32 compares the received communication device ID with the previously received communication device ID stored in the reception ID storage unit 50 (S353).
Comparison will be described with reference to FIG.
When the transmission flag 51 is “L”, these comparison results are classified into the following two types.
A) When the received communication device ID is included in the ID recorded in the reception ID storage unit 50 B) When the received communication device ID is not included in the ID recorded in the reception ID storage unit 50, or received When the communication device ID is not stored in the ID storage unit 50 (for example, immediately after turning on the power)
If the received communication device ID is included in the received ID storage unit 50 (in the case of A), the process ends without performing any processing.
When the received communication device ID is not included in the received ID storage unit 50 (in the case of B above), the communication device 2 identified by the communication device ID is a newly detected communication device, and the communication Since the first authentication information needs to be transmitted to the apparatus, the reception processing unit 32 sets the reception flag 52 to “L” (S354), and the process ends.

The transmission and reception processes will be described in time series with reference to FIG.
As described above, the communication device 1 transmits communication data at a certain fixed interval determined by the system (60), and similarly receives communication data transmitted by another communication device 2 (61).
In FIG. 13, after the communication device 1 transmits communication data including the first authentication information (60a), the transmission flag is “H”. Until (60b), the communication device ID included in the communication data of the other communication device 2 received during (T1) is recorded.
Since the communication data (60b) transmitted by the communication device 1 has the transmission flag “H”, the identification information of the first authentication information is included from the flowchart of FIG.
Thus, the next communication data transmitted with the first authentication information always includes the identification information of the first authentication information.
After the communication device 1 transmits the communication data (60b) including the identification information of the first authentication information, the transmission flag is “L” from FIG.
Since the reception flag remains “H”, the communication apparatus 1 determines the other communication apparatus 2 that has received (T2) until it again transmits communication data (60c) after one transmission period from FIG. The communication device ID included in the communication data is compared with the communication device ID recorded in the reception ID storage unit 50.
As a result of the comparison when the communication data (61a) of the other communication device 2 is received, if the communication device ID of the received other communication device 2 is included in the communication device ID in the reception ID storage unit 50, the communication The device 1 does nothing and ends the reception process.
Next, as a result of comparison when communication data (61b) of another communication device is received, the communication device ID of the other communication device 2 received is not included in the communication device ID in the reception ID storage unit 50 The communication apparatus 1 sets the reception flag to “L” and ends the reception process.
This means that a new communication device 2 is in the communication area in addition to the other communication device 2 received after transmitting the first authentication information, so it is necessary to transmit the first authentication information again. It means that there is.
Then, when the communication data (61c) of another communication device is received, the reception flag is “L”, so the reception process is terminated without comparison.
This is because it is not necessary to detect a plurality of new communication devices 2 because the first authentication information must be transmitted when at least one new communication device 2 is in the communication area. Is streamlining.
As described above, when at least one new communication device 2 is detected, the comparison after detection is not performed, so that the processing load can be reduced and the efficiency can be improved.
When the communication device transmits the communication data (60c), since the transmission flag is set to “L” and the reception flag is set to “L”, the communication data including the first authentication information from FIG. Can be sent.
In addition, when the communication data (61b) of another communication device is received, the comparison is performed when the communication data (61c) of the next other communication device is received when included in the reception ID storage unit 50. To do.
Then, when all the received communication device IDs are included in the received ID storage unit before the communication device transmits the communication data (60c), that is, when another new communication device 2 cannot be detected, FIG. Since the transmission flag is “L” and the reception flag is “H”, the communication data (60c) including the identification information of the first authentication information is transmitted from the transmission flow of FIG.
In this way, the first authentication information is transmitted when a new communication device is detected as compared with the information received immediately after the first authentication information is transmitted. Information identification information is transmitted.

In this way, in consideration of the state of communication devices existing in the surroundings, when there is a new communication device, it is transmitted using the first authentication information, and when there is no communication device, identification information of the first authentication information is transmitted. Since it is configured to transmit, necessary information can be transmitted efficiently and the communication data length can be shortened.
In addition, since the identification information of the first authentication information is transmitted together with the second authentication information, the first authentication information and the second authentication can be accurately and easily performed in the communication device even when communicating with a plurality of communication devices. Information can be associated.
Furthermore, the verification of both the first authentication information and the second authentication information has been performed at the time of conventional reception, but the first authentication information and the second authentication information are received separately. The verification can be performed separately, the processing load can be reduced, the apparatus can be realized with a low processing capability, and the cost can be reduced.
In addition, verification is not performed for all received distribution information, but only necessary distribution information is verified. Therefore, efficient verification can be performed, and processing capacity specifications for communication devices can be reduced. Cost reduction is possible.
In addition, the first authentication information verified and confirmed to be valid is recorded in the storage unit, and when the same first authentication information is received again, it is confirmed that the first authentication information is retained and the first authentication information is confirmed. If the information has an expiration date, the expiration date is confirmed. Therefore, useless verification can be omitted and the processing load can be reduced.
In addition, after the first authentication information is transmitted by the transmission flag, the identification information of the first authentication information is always transmitted, so that the distribution information can be reliably transmitted at least once every two times. it can.
Furthermore, since the received ID is recorded in the received ID storage unit regardless of whether the received distribution information is necessary or not, it is possible to grasp the state of the communication device existing more accurately and efficiently transmit the information. Can be sent.
In addition, when a new communication device is detected, the comparison after detection is not performed, so that the processing load can be reduced and the efficiency can be improved.

In the communication apparatus 1, the configuration at the time of transmission and at the time of reception may be changed.
For example, the communication unit 5 is configured to be connected only to the distribution information processing unit 3, but is generated by the distribution information processing unit 3 so that the communication unit is connected to the authentication information processing unit 4 during transmission. The authentication information processing unit 4 may generate authentication information from the distributed information, and the distribution information and the authentication information may be transmitted from the communication unit 5 together.
The communication unit 5 may be configured to transmit the distribution information of the distribution information processing unit 3 and the authentication information of the authentication information processing unit 4 together.
At the time of reception, in the above-described embodiment, the verification of the second authentication information determined to be necessary by the distribution information processing unit 3 has been performed, but the validity is confirmed from the communication unit 5 via the authentication information processing unit 4. When only the confirmed distribution information is sent to the delivery information processing unit 3, it can be configured to verify all received communication data.
In addition, the communication device 1 determines the data identification information in the communication unit 5, and when there is no distribution information, transmits the first authentication information to the authentication information processing unit 4. The communication data may be transmitted to the distribution information processing unit 4.
Furthermore, the transmission flag 51 and the reception flag 52 that existed in the distribution information processing unit 3 may be provided in the authentication information processing unit 4, and the reception ID storage unit 50 may be connected to the authentication information processing unit 4.
Further, the present embodiment is applied only to the vehicle-mounted device in which low cost is more strictly required, and the roadside unit may be a road-to-vehicle / vehicle-to-vehicle communication system having the same configuration as the conventional one.
Further, in the case of a road-to-vehicle / vehicle-to-vehicle communication system having a plurality of channels, the first authentication information is transmitted to a certain channel, the distribution information on the other channel, the identification information of the first authentication information, the second The authentication information may be transmitted.
Further, in the case of communication data including distribution information, the entire communication data or only distribution information is encrypted, and when transmitting only the first authentication information not including distribution information, it is configured to transmit without encryption. Also good.
In the present embodiment, after the power is turned on, the initial value of each flag is “L” and the transmission starts. However, it goes without saying that the present invention can also be applied to a case where a different flag or reception starts.

Embodiment 4 FIG.
In the third embodiment, the first authentication information is transmitted for the predetermined number of times of communication, and the distribution information and the second authentication information are transmitted separately. Next, a configuration in which distribution information is transmitted every time will be described.
That is, as in the third embodiment, when a new other communication device is detected, if the identification information of the first authentication information is transmitted at the previous transmission timing, the first authentication information At this time, the distribution information and the second authentication information are also transmitted.
Such a configuration is similar to the relationship between the first embodiment and the second embodiment, but the communication data length is longer than that of the third embodiment, but the distribution information can be transmitted every time. It is possible to cope with a decrease in information transmission frequency.

  Since the communication apparatus according to the present embodiment is the same as that in FIG. 9 of the third embodiment, description thereof is omitted.

Next, processing during transmission will be described with reference to FIGS. 14 and 15.
FIG. 14 is a processing flow diagram at the time of transmission, and FIG. 15 is a configuration diagram of communication data.

After starting transmission, the communication device 1 generates distribution information in the transmission processing unit 31 (S400), transmits the distribution information to the authentication information processing unit 4, and the authentication information processing unit 4 is stored in the storage unit 7. Second authentication information is generated using the existing key information (S401), and responds to the distribution information processing unit 3.
The second authentication information is the same as in the first embodiment.
Then, the transmission processing unit 31 checks the transmission flag 51 (S402).
When the transmission flag is “H”, the transmission processing unit 31 acquires the identification information of the first authentication information (S403).
Thereafter, “identification information of first authentication information” is set in the data identification information 21 (S404), and the transmission processing unit 31 sets the transmission flag 51 to “L” (S405).
Then, the identification information 24 of the first authentication information, the distribution information 22 and the second authentication information 23 are transmitted to the other communication device 2 via the communication unit 5 as shown in FIG. 15A (S406). .
When the transmission flag 51 is “L”, the transmission processing unit 31 checks the reception flag 52 (S407).
When the reception flag 52 is “H”, it is not necessary to transmit the first authentication information. Therefore, the transmission processing unit 31 performs the same processing as the processing when the transmission flag 51 is “H”, thereby performing the first authentication. Information identification information 24, distribution information 22 and second authentication information 23 are transmitted.
When the reception flag 52 is “L”, the distribution information processing unit 4 acquires first authentication information (S408).
Thereafter, the transmission processing unit 31 sets “first authentication information” in the data identification information 21 (S409), sets the transmission flag 51 to “H” (S410), and sets the reception flag 52 to “H” (S411). Set.
Then, the contents recorded in the received ID storage unit 50 are deleted (S412), and the first authentication information 20, as shown in FIG. The distribution information 22 and the second authentication information 23 are transmitted (S406).
In this way, the communication data shown in FIG. 15 is transmitted.
Although not shown, communication data and distribution information may be encrypted and transmitted according to the system.

Next, the flow at the time of reception in the communication apparatus 1 will be described using FIG.
FIG. 16 is a flowchart of reception processing, and the processing of the first authentication information and the second authentication information is omitted because it is the same as that of FIG.
This figure focuses on processing related to a transmission flag, a reception flag, and a reception ID storage unit that are not included in FIG. 8.

First, the communication unit 5 receives communication data from another communication device 2 (S250).
Then, the same processing as in FIG. 8 is performed, and finally the distribution information is discarded (S253) and the distribution information processing (S261) is performed by the processing of the distribution information processing unit 3 and the authentication information processing unit 4.
Thereafter, the reception processing unit 32 of the distribution information processing unit 3 checks the transmission flag 51 (S450).
When the transmission flag 51 is “H”, since the first authentication information is transmitted immediately before, the received communication device ID is stored in the reception ID storage unit 50 (S451), and the process ends.
The communication device ID recorded in the reception ID storage unit 50 is the same as that in FIG. 13 of the third embodiment.
When the transmission flag 51 is “L”, the reception processing unit 32 checks the reception flag 52 (S452).
If the reception flag 52 is “L”, no processing is performed and the process ends.
When the reception flag 52 is “H”, the communication device ID received by the reception processing unit 32 is compared with the communication device ID previously received stored in the reception ID storage unit 50 (S453).
The comparison process is the same as in the third embodiment.
If it is included in the reception ID storage unit 50, the process ends without performing any processing.
If it is not included in the reception ID storage unit 50, it is necessary to transmit the first authentication information, so the reception flag 52 is set to "L" (S454) and the process ends.

In this way, in consideration of the state of communication devices existing in the surroundings, when there is a new communication device, it is transmitted using the first authentication information, and when there is no communication device, identification information of the first authentication information is transmitted. Since it is configured to transmit, the communication data length can be shortened comprehensively compared to the conventional one without reducing the transmission frequency of the distribution information.
Further, when the first authentication information is not transmitted, the identification information of the first authentication information is transmitted together with the second authentication information. Therefore, even when communicating with a plurality of communication devices, the communication device is accurate and simple. The first authentication information and the second authentication information can be associated with each other.
Further, when the identification information of the first authentication information is received, only the second authentication information needs to be verified, so the processing load is reduced without reducing the transmission frequency of the distribution information. be able to.
In addition, verification is not performed for all received distribution information, but only necessary distribution information is verified, so that efficient verification can be performed and processing capacity specifications for communication devices can be reduced. Cost reduction is possible.
In addition, the first authentication information verified and confirmed to be valid is recorded in the storage unit, and when the same first authentication information is received again, it is confirmed that the first authentication information is retained and the first authentication information is confirmed. If the information has an expiration date, the expiration date is confirmed. Therefore, useless verification can be omitted and the processing load can be reduced.
In addition, after the first authentication information is transmitted by the transmission flag, the identification information of the first authentication information is always transmitted, so that communication data shorter than the conventional one is transmitted at least once every two times. Can do.
Furthermore, since the received ID is recorded in the received ID storage unit regardless of whether the received distribution information is necessary or not, it is possible to grasp the state of the communication device existing more accurately and efficiently transmit the information. Can be sent.
In addition, when a new communication device is detected, the comparison after detection is not performed, so that the processing load can be reduced and the efficiency can be improved.

In the communication apparatus 1, the configuration at the time of transmission and at the time of reception may be changed.
For example, the communication unit 5 is configured to be connected only to the distribution information processing unit 3, but is generated by the distribution information processing unit 3 so that the communication unit is connected to the authentication information processing unit 4 during transmission. The authentication information processing unit 4 may generate authentication information from the distributed information, and the distribution information and the authentication information may be transmitted from the communication unit 5 together.
The communication unit 5 may be configured to transmit the distribution information of the distribution information processing unit 3 and the authentication information of the authentication information processing unit 4 together.
At the time of reception, in the above-described embodiment, the verification of the second authentication information determined to be necessary by the distribution information processing unit 3 has been performed, but the validity is confirmed from the communication unit 5 via the authentication information processing unit 4. When only the confirmed distribution information is sent to the delivery information processing unit 3, it can be configured to verify all received communication data.
Further, the authentication information processing unit 4 may be provided with a transmission flag and a reception flag that exist in the distribution information processing unit 3, and the authentication information processing unit 4 may be connected to the reception ID storage unit 50.
Further, the present embodiment is applied only to the vehicle-mounted device in which low cost is more strictly required, and the roadside unit may be a road-to-vehicle / vehicle-to-vehicle communication system having the same configuration as the conventional one.
Further, the entire communication data or only the distribution information may be encrypted and transmitted.
In the present embodiment, after the power is turned on, the initial value of each flag is “L” and the transmission starts. However, it goes without saying that the present invention can also be applied to a case where a different flag or reception starts.

Embodiment 5 FIG.
In Embodiments 3 and 4 described above, the first authentication information is transmitted by comparing the other communication device ID received after transmitting the first authentication information with the other communication device ID received before the transmission. And the case of transmitting the identification information of the first authentication information are selectively determined and transmitted.
In the third and fourth embodiments, even when a new communication device is detected, the identification information of the first authentication information is transmitted at the next transmission timing after transmitting the first authentication information. Therefore, the first authentication information cannot be immediately transmitted to another communication device that has entered the communication area after transmitting the first authentication information.
In the present embodiment, a format in which the first authentication information is transmitted at the next transmission timing when a new other communication device is detected even though the first authentication information is transmitted will be described.
More specifically, in this embodiment, regardless of whether or not the first authentication information is transmitted, another communication device ID received from another communication device two times before the transmission cycle is received one time before. A method of selectively determining and transmitting the case of transmitting the first authentication information and the case of transmitting the identification information of the first authentication information by comparing other communication device IDs is shown.

FIG. 17 is a diagram illustrating a configuration of the communication device 1 according to the present embodiment.
Description of the same numbers as those in FIG. 1 of the first embodiment and FIG. 9 of the third embodiment is omitted.

The first reception ID storage unit 55 and the second reception ID storage unit 56 store the received IDs of other communication devices 2 and are connected to the distribution information processing unit 3. These consist of readable and writable memory. The communication device ID may be the same as that in the third embodiment.
The distribution information processing unit 3 is provided with a recording flag 57, which is composed of a readable / writable memory.
The recording flag 57 is a flag indicating the recording destination of the ID of the other communication device 2 received by the communication device 1, that is, the first reception ID storage unit 55 or the second reception ID storage unit 56. In this embodiment, “H” is indicated when recording is to be performed in the first reception ID storage section 55, and “L” is indicated when recording is performed in the second reception ID storage section 56. “L”.
The reception flag 52 provided in the distribution information processing unit 3 is the same as that in the third embodiment.
Although not shown, the communication device 1 receives current position information and date / time information indicating date and time from an installed roadside machine or vehicle.
These are generated by a GPS signal communication device or a clock installed in a roadside machine or vehicle.

Next, the flow at the time of transmission in the communication apparatus will be described with reference to FIGS.
FIG. 18 is a flowchart of the transmission process.

The transmission processing unit 31 of the distribution information processing unit 3 first generates distribution information (S500), transmits the distribution information to the authentication information processing unit 4, and the authentication information processing unit 4 is stored in the storage unit 7. Using the key information, second authentication information is generated (S501), and the response to the distribution information processing unit 3 is made.
The second authentication information is the same as in the first embodiment.
Then, the transmission processing unit 31 confirms the reception flag 52 (S502).
When the reception flag 52 is “H”, the transmission processing unit 31 acquires the identification information of the first authentication information (S503).
Thereafter, the transmission processing unit 31 sets “identification information of the first authentication information” in the data identification information 21 (S504), and transmits it to another communication apparatus via the communication unit 5 as shown in FIG. The identification information 24 of the first authentication information, the distribution information 22 and the second authentication information 23 are transmitted to (S505).
When the reception flag is “L” in S502, the transmission processing unit 31 acquires the first authentication information (S506).
Thereafter, the transmission processing unit 31 sets “first authentication information” in the data identification information 21 (S507), and sets the reception flag 52 to “H” (S508).
Then, the first authentication information 20, the distribution information 22, and the second authentication information 23 are transmitted to the other communication device 2 via the communication unit 5 as shown in FIG. 15B (S505).
After transmitting the communication data, the transmission processing unit 31 confirms the recording flag 57 (509).
When the recording flag 57 is “L”, the transmission processing unit 31 clears the first reception ID storage unit 55 (S510), sets the recording flag 57 to “H” (S511), and ends.
If the recording flag 57 is “H” in S509, the transmission processing unit 31 clears the second reception ID storage unit 56 (S512), sets the recording flag 57 to “L” (S513), and ends.
In this way, the communication data shown in FIG. 15 is transmitted.
Although not shown, communication data and distribution information may be encrypted and transmitted according to the system.

Next, the flow at the time of reception in the communication apparatus 1 will be described using FIG.
FIG. 19 is a reception processing flowchart, and the processing of the first authentication information and the second authentication information is the same as that in FIG.
This figure focuses on processing related to the recording flag, reception flag, first reception ID storage unit, and second reception ID storage unit not included in FIG.

First, the communication unit 5 receives communication data from another communication device 2 (S250).
Then, the same processing as in FIG. 8 is performed, and finally the distribution information is discarded (S253) and the distribution information processing (S261) is performed by the processing of the distribution information processing unit 3 and the authentication information processing unit 4.
Thereafter, the reception processing unit 32 checks the recording flag 57 (S550).
When the recording flag 57 is “H”, it is a case where recording is to be performed in the first reception ID storage unit 55, so the reception processing unit 32 stores the received communication device ID in the first reception ID storage unit 55. (S551).
Then, the reception processing unit 32 checks the reception flag 52 (S552).
If the reception flag 52 is “L”, no processing is performed and the process ends.
When the reception flag 52 is “H”, the reception processing unit 32 compares the received communication device ID with the previously received communication device ID stored in the second reception ID storage unit 56 (S553).
These comparison results are classified into the following two types.
A) When the received communication device ID is included in the ID recorded in the second reception ID storage unit 56 B) The received communication device ID is included in the ID recorded in the second reception ID storage unit 56 If the communication device ID is not stored in the second reception ID storage unit 56 (for example, immediately after turning on the power)
If it is included in the second reception ID storage unit 56 (in the case of A), the reception processing unit 32 ends without performing any processing.
If it is not included in the second reception ID storage unit 56 (in the case of B above), the first authentication information needs to be transmitted, so the reception processing unit 32 sets the reception flag 52 to “L”. Then (S554) ends.
When the recording flag 57 is “L” in S550, it is a case where recording is to be performed in the second reception ID storage unit 56, and thus the received communication device ID is stored in the second reception ID storage unit 56 (S555). .
Then, the reception processing unit 32 confirms the reception flag 52 (S556).
If the reception flag 52 is “L”, no processing is performed and the process ends.
When the reception flag 52 is “H”, the reception processing unit 32 compares the received communication device ID with the previously received communication device ID stored in the first reception ID storage unit 55 (S557).
If it is included in the first reception ID storage unit 55, the reception processing unit 32 ends without performing any processing.
If it is not included in the first reception ID storage unit 55, it is necessary to transmit the first authentication information, so the reception processing unit 32 sets the reception flag 52 to "L" (S558) and ends. .

The transmission and reception processes will be described in time series with reference to FIG.
FIG. 20 is a communication image diagram.

As described above, the communication device 1 transmits communication data at a certain fixed interval determined by the system (60), and similarly receives communication data transmitted by another communication device 2 (61).
In FIG. 20, the recording flag 57 before the communication device 1 transmits (60d) communication data is “L”.
After transmitting the communication data (60d), the first reception ID storage unit 55 is cleared from FIG. 18, and the recording flag 57 becomes “H”. In addition, the reception flag is always “H” after communication data is transmitted from FIG.
And communication data is received from another communication apparatus.
At this time, from FIG. 19, the communication device ID included in the communication data of the other communication device 2 received (T3) until the communication data is again transmitted (60e) after one transmission cycle is recorded in the recording flag 57. Since it is “H”, it is recorded in the first reception ID storage unit 55.
Thereafter, since the reception flag 52 is “H”, the received communication device ID is compared with another communication device ID recorded in the second reception ID storage unit 56.
As a result of the comparison, when the received communication device ID is included in another communication device ID recorded in the second reception ID storage unit 56, the reception flag 52 remains “H” as it is.
If not included, the reception flag 52 is set to “L”.
As in the third embodiment, since these operations are not included, there is no new other communication device, so it is not necessary to transmit the first authentication information. This means that the first authentication information needs to be transmitted because another communication device exists.
When the communication device 1 transmits the communication data (60e), the communication data including the first authentication information or the identification information of the first authentication information is transmitted by the reception flag 52 from FIG.
Since the recording flag 57 is “H” after the communication data (60e) is transmitted, the second received ID storage unit 56 is cleared and the recording flag 57 is set to “L” from FIG.
Similarly to the above, the reception flag 52 is “H”.
And the communication data of the other communication apparatus 2 are received.
At this time, from FIG. 19, the communication device ID included in the communication data of the other communication device 2 received (T4) until the communication data is again transmitted (60f) after one transmission cycle is recorded in the recording flag 57. Since it is “L”, it is recorded in the second reception ID storage unit 56.
Thereafter, the same processing is performed. When there is no new other communication device, the reception flag remains “H”, and when there is a new other communication device 2, the reception flag 52 is set to “L”. Become.
Then, after transmitting the communication data (60f), the other received communication device ID is recorded in the first reception ID storage unit 55 and compared with the ID recorded in the second reception ID storage unit 56. .
In this way, when the new communication device 2 is detected by comparing the information received immediately after transmitting the communication data twice before and the information received immediately before, the first authentication information is transmitted and detected. If not, the identification information of the first authentication information is transmitted.

In this way, in consideration of the state of communication devices existing in the surroundings, when there is a new communication device, it is transmitted using the first authentication information, and when there is no communication device, identification information of the first authentication information is transmitted. Since it is configured to transmit, necessary information can be transmitted efficiently and the communication data length can be shortened.
Also, comparing the information received immediately after transmitting the communication data twice before and the information received immediately before, if a new communication device is detected, the first authentication information is transmitted, if not detected, Since the identification information of the first authentication information is configured to be transmitted, information to be transmitted can be selected more finely, and communication efficiency can be improved.
Further, when the identification information of the first authentication information is received, only the second authentication information needs to be verified, so the processing load is reduced without reducing the transmission frequency of the distribution information. be able to.
Further, when the first authentication information is not transmitted, the identification information of the first authentication information is transmitted together with the second authentication information. Therefore, even when communicating with a plurality of communication devices, the communication device is accurate and simple. The first authentication information and the second authentication information can be associated with each other.
In addition, since not all received information is verified, only necessary information is verified, so that efficient verification can be performed, processing capacity specifications for communication devices can be reduced, and cost can be reduced. Reduction is possible.
In addition, the first authentication information verified and confirmed to be valid is recorded in the storage unit, and when the same first authentication information is received again, it is confirmed that the first authentication information is retained and the first authentication information is confirmed. If the information has an expiration date, the expiration date is confirmed. Therefore, useless verification can be omitted and the processing load can be reduced.
Furthermore, since the received IDs are recorded in the first and second received ID storage units regardless of whether or not the received distribution information is necessary, it is possible to grasp the state of the communication device existing in the vicinity more accurately. , Can transmit information efficiently.
In addition, when a new communication device is detected, the comparison after detection is not performed, so that the processing load can be reduced and the efficiency can be improved.

In the communication device, the configuration at the time of transmission and at the time of reception may be changed.
For example, the communication unit 5 is configured to be connected only to the distribution information processing unit 3, but is generated by the distribution information processing unit 3 so that the communication unit is connected to the authentication information processing unit 4 during transmission. The authentication information processing unit 4 may generate authentication information from the distributed information, and the distribution information and the authentication information may be transmitted from the communication unit 5 together.
The communication unit 5 may be configured to transmit the distribution information of the distribution information processing unit 3 and the authentication information of the authentication information processing unit 4 together.
At the time of reception, in the above-described embodiment, the verification of the second authentication information determined to be necessary by the distribution information processing unit 3 has been performed, but the validity is confirmed from the communication unit 5 via the authentication information processing unit 4. When only the confirmed distribution information is sent to the delivery information processing unit 3, it can be configured to verify all received communication data.
In addition, the communication device 1 determines the data identification information in the communication unit 5, and when there is no distribution information, transmits the first authentication information to the authentication information processing unit 4. The communication data may be transmitted to the distribution information processing unit 3.
Furthermore, the record flag 57 and the reception flag 52 that existed in the distribution information processing unit 3 are provided in the authentication information processing unit 4, and the first and second reception ID storage units 55 and 56 are connected to the authentication information processing unit 4. May be.
Further, the present embodiment is applied only to the vehicle-mounted device in which low cost is more strictly required, and the roadside unit may be a road-to-vehicle / vehicle-to-vehicle communication system having the same configuration as the conventional one.
Further, in the case of a road-to-vehicle / vehicle-to-vehicle communication system having a plurality of channels, the first authentication information is transmitted to a certain channel, the distribution information on the other channel, the identification information of the first authentication information, the second The authentication information may be transmitted.
Further, in the case of communication data including distribution information, the entire communication data or only distribution information is encrypted, and when transmitting only the first authentication information not including distribution information, it is configured to transmit without encryption. Also good.
In the present embodiment, after the power is turned on, the initial value of each flag is “L” and the transmission starts. However, it goes without saying that the present invention can also be applied to a case where a different flag or reception starts.

In the above-described first to fifth embodiments,
A communication device has been described that divides the case of transmitting the first authentication information from the case of transmitting the identification information of the first authentication information, the second authentication information, and the distribution information.

In the first to fifth embodiments described above,
A communication device has been described that divides the case of transmitting the first authentication information, the second authentication information, and the distribution information from the case of transmitting the identification information of the first authentication information, the second authentication information, and the distribution information.

In the first to fifth embodiments described above,
A communication apparatus has been described in which the first authentication information is transmitted once every N times and the identification information of the first authentication information is transmitted the remaining N-1 times.

In the first to fifth embodiments described above,
The communication apparatus has been described that selectively transmits the first authentication information and the identification information of the first authentication information as compared with the ID received after transmitting the first authentication information.

In the first to fifth embodiments described above,
The communication device that selectively transmits the first authentication information and the identification information of the first authentication information as compared with the ID received twice before has been described.

In the first to fifth embodiments described above,
In the comparison, when there is at least one new communication device, the communication device that does not perform the subsequent comparison process has been described.

In the first to fifth embodiments described above,
A communication apparatus that selectively verifies without verifying all communication data has been described.

In the first to fifth embodiments described above,
If you have already verified the first authentication information, check the expiration date, and if it is within the expiration date, use it for verification of the second authentication information. A communication device for deleting authentication information has been described.

Finally, a hardware configuration example of the communication device 1 shown in the first to fifth embodiments will be described.
FIG. 28 is a diagram illustrating an example of hardware resources of the communication device 1 described in the first to fifth embodiments.
Note that the configuration in FIG. 28 is merely an example of the hardware configuration of the communication device 1, and the hardware configuration of the communication device 1 is not limited to the configuration illustrated in FIG. .

In FIG. 28, the communication device 1 includes a CPU 911 (also referred to as a central processing unit, a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, and a processor) that executes a program.
The CPU 911 is connected to, for example, a ROM (Read Only Memory) 913, a RAM (Random Access Memory) 914, a communication board 915, a display device 901, and a magnetic disk device 920 via the bus 912, and controls these hardware devices. To do.
When the communication device 1 is mounted on a vehicle, for example, a console 902 on which buttons and keys for input are arranged may be connected to the CPU 911.
The console 902 may be a touch panel type.
In the case of the touch panel type, the display device 901 and the console 902 are integrated.
Further, an FDD 904 (Flexible Disk Drive), a compact disk device 905 (CDD), or the like may be connectable to the CPU 911.
Although not shown, a USB (Universal Serial Bus) memory or the like may be used.
Further, instead of the magnetic disk device 920, a storage device such as an SSD (Solid State Drive), an optical disk device, or a memory card (registered trademark) read / write device may be used.
The RAM 914 is an example of a volatile memory. The storage media of the ROM 913, the FDD 904, the CDD 905, and the magnetic disk device 920 are an example of a nonvolatile memory. These are examples of a storage device or a storage unit.
The “storage unit 7”, “reception ID storage unit 50”, “first reception ID storage unit 55”, and “second reception ID storage unit 56” described in the first to fifth embodiments are the RAM 914 and the magnetic disk. This is realized by the device 920 or the like.
The communication board 915, the console 902, the FDD 904, and the like are examples of input devices.
The communication board 915, the display device 901, and the like are examples of output devices.

  As described above, the communication board 915 has a DSRC communication function and a wireless LAN communication function.

The magnetic disk device 920 stores an operating system 921 (OS), a window system 922, a program group 923, and a file group 924.
The programs in the program group 923 are executed by the CPU 911 using the operating system 921 and the window system 922.

The RAM 914 temporarily stores at least part of the operating system 921 program and application programs to be executed by the CPU 911.
The RAM 914 stores various data necessary for processing by the CPU 911.

The ROM 913 stores a BIOS (Basic Input Output System) program, and the magnetic disk device 920 stores a boot program.
When the communication device 1 is activated, the BIOS program in the ROM 913 and the boot program in the magnetic disk device 920 are executed, and the operating system 921 is activated by the BIOS program and the boot program.

  The program group 923 includes “˜unit” (““ storage unit 7 ”,“ reception ID storage unit 50 ”,“ first reception ID storage unit 55 ”, and“ second ”in the description of the first to fifth embodiments. A program that executes the function described below as “other than the reception ID storage unit 56” is stored. The program is read and executed by the CPU 911.

In the file group 924, in the description of the first to fifth embodiments, “determination of”, “generation of”, “confirmation of”, “comparison of”, “acquisition of”, “update of” ”,“ Setting of ”,“ registration of ”,“ selection of ”,“ input of ”,“ output of ”, etc. Values and parameters are stored as items of “˜file” and “˜database”.
The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory.
Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit.
The read information, data, signal value, variable value, and parameter are used for CPU operations such as extraction, search, reference, comparison, calculation, calculation, processing, editing, output, printing, and display.
Information, data, signal values, variable values, and parameters are stored in the main memory, registers, cache memory, and buffers during the CPU operations of extraction, search, reference, comparison, calculation, processing, editing, output, printing, and display. It is temporarily stored in a memory or the like.
The arrows in the flowcharts described in the first to fifth embodiments mainly indicate input / output of data and signals.
Data and signal values are recorded on a recording medium such as a memory of the RAM 914, a flexible disk of the FDD 904, a compact disk of the CDD 905, a magnetic disk of the magnetic disk device 920, other optical disks, a mini disk, and a DVD.
Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

In addition, what is described as “˜unit” in the description of the first to fifth embodiments may be “˜circuit”, “˜device”, “˜device”, and “˜step”, It may be “˜procedure” or “˜processing”.
That is, the communication method according to the present invention can be realized by the steps, procedures, and processes shown in the flowcharts described in the first to fifth embodiments.
Further, what is described as “˜unit” may be realized by firmware stored in the ROM 913.
Alternatively, it may be implemented only by software, or only by hardware such as elements, devices, substrates, and wirings, by a combination of software and hardware, or by a combination of firmware.
Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD.
The program is read by the CPU 911 and executed by the CPU 911.
That is, the program causes the computer to function as “to part” in the first to fifth embodiments. Alternatively, the computer executes the procedure and method of “to part” in the first to fifth embodiments.

As described above, the communication device 1 shown in the first to fifth embodiments includes a CPU as a processing device, a memory as a storage device, a magnetic disk, a console as an input device, a communication board, a display device as an output device, a communication board, and the like. Computer.
Then, as described above, the functions indicated as “˜units” are realized using these processing devices, storage devices, input devices, and output devices.

  1 communication device, 2 communication device, 3 distribution information processing unit, 4 authentication information processing unit, 5 communication unit, 6 counter, 7 storage unit, 20 first authentication information, 21 data identification information, 22 distribution information, 23 second Authentication information, 24 identification information of first authentication information, 31 transmission processing unit, 32 reception processing unit, 50 reception ID storage unit, 51 transmission flag, 52 reception flag, 55 first reception ID storage unit, 56 second Reception ID storage unit, 57 record flag, 70 navigation device, 71 on-vehicle device communication unit, 80 on-vehicle device, 81 navigation communication unit.

Claims (16)

A communication device that repeatedly transmits distribution information and repeatedly transmits related information related to the distribution information,
For each transmission timing that repeatedly arrives, a transmission target designating unit that designates whether to transmit the related information or to transmit identification information of the related information instead of the related information;
At the transmission timing at which transmission of the related information is designated by the transmission target designating unit, at least the related information is transmitted, and at the transmission timing at which transmission of identification information of the related information is designated by the transmission target designating unit, A communication apparatus comprising: a communication unit that transmits identification information of related information and the distribution information in association with each other. The communication device
Repeatedly transmitting distribution information and second authentication information used for verification of the distribution information, and repeatedly transmitting first authentication information used for verification of the second authentication information as the related information,
The transmission target designating unit
For each transmission timing that repeatedly arrives, specify whether to transmit the first authentication information or to transmit the identification information of the first authentication information instead of the first authentication information,
The communication unit is
At the transmission timing at which transmission of the first authentication information is specified by the transmission target specifying unit, at least the first authentication information is transmitted, and transmission of identification information of the first authentication information is performed by the transmission target specifying unit 2. The communication apparatus according to claim 1, wherein identification information of the first authentication information, the distribution information, and the second authentication information are transmitted in association with each other at a transmission timing in which is specified. The communication device further includes:
A counter that counts the number of arrivals of transmission timing each time transmission timing arrives,
The transmission target designating unit
With reference to the counter value of the counter, transmission of the first authentication information is designated once every N (N is an arbitrary integer of 2 or more) times, and the first authentication information is designated (N-1) times. The communication apparatus according to claim 2, wherein transmission of identification information is designated. The communication device further includes:
When a communication device that can receive the distribution information in a period between transmission timings is detected and a communication device that has not been detected is newly detected, the transmission target is detected as a new communication device. It has a device detection unit that notifies the specified unit,
The transmission target designating unit
4. The communication apparatus according to claim 2, wherein transmission of the first authentication information is designated with respect to a transmission timing that arrives after notification of detection of a new communication device by the device detection unit. . The transmission target designating unit
When the transmission timing has arrived and the detection of a new communication device is not notified by the device detection unit, the transmission of identification information of the first authentication information is specified for the transmission timing. The communication device according to claim 4. The device detection unit is
The communication apparatus according to claim 4 or 5, wherein after detecting one new communication device, the operation of detecting a new communication device is stopped. The transmission target designating unit
After the notification of the detection of a new communication device by the device detection unit, the first authentication is performed with respect to the transmission timing next to the transmission timing specified to transmit the identification information of the first authentication information. The communication apparatus according to claim 4, wherein transmission of information is designated. The transmission target designating unit
The transmission of the first authentication information is specified for the next transmission timing when the detection of a new communication device is notified by the device detection unit. Communication device. The communication unit is
Transmitting the first authentication information without transmitting the distribution information and the second authentication information at a transmission timing at which transmission of the first authentication information is specified by the transmission target specifying unit; The communication device according to claim 2, wherein the communication device is characterized in that: The communication unit is
The first authentication information, the distribution information, and the second authentication information are transmitted in association with each other at a transmission timing at which transmission of the first authentication information is designated by the transmission target designating unit. The communication device according to claim 2. The communication device
Receiving distribution information and second authentication information used for verification of the distribution information from the communication device,
The distribution information meeting a predetermined condition is selected from the received distribution information, and verification using the second distribution information is performed only on the selected distribution information. The communication device described. The communication device
Receiving distribution information and second authentication information used for verification of the distribution information from the communication device,
When the first authentication information used for verification of the second authentication information is held, the expiration date of the held first authentication information is confirmed. The communication apparatus according to any one of claims 2 to 11, wherein the second authentication information is verified using authentication information, and the first authentication information is deleted if it is outside the expiration date. The communication device
It is mounted on a roadside machine installed on the roadside,
The communication apparatus according to claim 1, wherein distribution information is transmitted to a communication device mounted on a vehicle traveling on the road. The communication device
Mounted on vehicles traveling on the road,
The distribution information is transmitted to at least one of a communication device mounted on another vehicle traveling on the road and a communication device mounted on a roadside device installed on the roadside of the road. The communication device according to claim 1. A communication method performed by a computer that repeatedly transmits distribution information and repeatedly transmits related information related to distribution information,
A transmission target designating step for designating whether the computer repeatedly transmits the related information or transmits the identification information of the related information instead of the related information for each transmission timing that repeatedly arrives;
The computer transmits at least the related information at a transmission timing at which transmission of the related information is designated by the transmission target designation step, and transmission at which transmission of identification information of the related information is designated by the transmission target designation step And a communication step of transmitting the identification information of the related information and the distribution information in association with each other at a timing. A computer that repeatedly transmits distribution information and repeatedly transmits related information related to the distribution information.
A transmission target designating step for designating whether to transmit the related information or to transmit the identification information of the related information instead of the related information for each transmission timing that repeatedly arrives;
At the transmission timing at which transmission of the related information is designated by the transmission target designation step, at least the related information is transmitted, and at the transmission timing at which transmission of identification information of the related information is designated by the transmission target designation step, A program for executing a communication step of transmitting identification information of related information and the distribution information in association with each other.

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