WO2016199554A1

WO2016199554A1 - Communication system

Info

Publication number: WO2016199554A1
Application number: PCT/JP2016/064732
Authority: WO
Inventors: 進一吉田
Original assignee: 株式会社東海理化電機製作所
Priority date: 2015-06-11
Filing date: 2016-05-18
Publication date: 2016-12-15
Also published as: JP2017005527A; JP6475096B2; CN107431650A

Abstract

Provided is a communication system including a plurality of control units that each function as a transmitting side and a receiving side, wherein communication frames are transmitted and received between the transmitting side and the receiving side. A plurality of frames (for example, three types of frame ID 1-3) are allocated to a control data block (A) transmitted by the transmitting side. In accordance with rules shared with the receiving side, the transmitting side transmits the control data block (A) while dynamically and regularly switching the frame ID by selecting one frame ID at a time from the plurality of frame IDs (ID 1-3).

Description

Communications system

The present invention relates to a communication system in which a frame ID (identification) is assigned to a control data block and a communication frame having a single frame structure is transmitted and received.

In recent years, the number of ECUs (electronic control units) installed in vehicles tends to increase, and in-vehicle communication networks are being promoted in order to share control data among a plurality of ECUs (for example, Patent Document 1). See). In such a communication system, when a specific communication frame is transmitted from a specific ECU to the network, the communication frame is shared among a plurality of ECUs that construct the network. When each ECU analyzes the communication frame and determines that it is a communication frame related to its own ECU, the ECU executes processing according to the communication frame.

Whether or not the communication frame is related to the own ECU is determined by checking the frame ID in the communication frame. A communication frame has a frame structure in which a frame ID is assigned to a control data block. When the frame ID is determined to be a communication frame related to the own ECU, the process is executed according to the contents of the control data block that forms the frame structure together with the frame ID.

JP 2006-42310 A

As shown in FIG. 5, in in-vehicle communication such as CAN (controller area network), frame IDs are normally assigned to control data blocks in a 1: 1 relationship. For example, frame ID 1 is assigned to control data block A, frame ID 2 is assigned to control data block B, and frame ID 3 is assigned to control data block C.

If the frame ID is fixed, communication analysis by a communication monitor or the like is facilitated, and as a result, there is a concern that it is susceptible to third party attacks such as impersonation and hacking. Although there is encryption as a countermeasure, there is a demerit that increases the hardware cost.

An object of the present invention is to provide a communication system that can improve information security without increasing costs.

According to one aspect, the communication frame includes a plurality of control units each functioning as a transmission side and a reception side, and a frame ID is assigned to the control data block to form a single frame structure between the transmission side and the reception side. In a communication system that transmits and receives data, a plurality of frame IDs are assigned to the control data block, and the transmitting side selects one of the plurality of frame IDs according to a rule shared with the receiving side. The control data block is transmitted while selecting the frame ID and switching the frame ID dynamically and regularly.

According to this configuration, when a control data block is transmitted, the risk of being easily analyzed by a third party is reduced by communicating with a variable frame ID. When the receiving side receives a frame ID that does not comply with the switching rule, it determines that it is abnormal (spoofing) and discards the data, thereby reducing the risk of information security. In addition, encryption is not required and this can be realized without an increase in cost. Therefore, information security can be improved without increasing the cost.

According to another aspect, the communication frame includes a plurality of control units each functioning as a transmission side and a reception side, and a frame ID is assigned to the control data block to form a single frame structure. A plurality of control data blocks are each assigned a plurality of frame IDs that are at least partially common among the plurality of control data blocks. For each block, set identifier information that allows the receiving side to uniquely identify the control data block in combination with the frame ID, and then select one frame ID from the plurality of frame IDs. Then, the control data block is transmitted while dynamically switching the frame ID.

According to this configuration, when transmitting one control data block in a limited frame ID, the risk of being easily analyzed by a third party is reduced by communicating with a variable frame ID. The Further, the risk can be reduced without increasing the number of assigned frame IDs. In addition, encryption is not required and this can be realized without an increase in cost. Therefore, information security can be improved without increasing the cost.

According to the present invention, information security can be improved without an increase in cost.

The figure which shows that three types of frame ID is allocated to one control data block in 1st Embodiment. The figure which shows the communication aspect of the transmission side and the receiving side in 1st Embodiment. The figure which shows that three types of common frame ID is allocated with respect to each of three types of control data blocks in 2nd Embodiment. The figure which shows that identifier information is set in the control data block in 2nd Embodiment. The figure which shows that frame ID is allocated by the relationship of 1: 1 with respect to the control data block conventionally.

(First embodiment)
Hereinafter, a first embodiment of a communication system will be described. The communication system includes a plurality of electronic control units (ECUs) that function as a transmission side and a reception side, respectively, and that transmit and receive communication frames via a network. For example, when one of a plurality of ECUs functions as a transmission side, one or a plurality of other ECUs that form a network together with the transmission side can function as a reception side. Each communication frame includes a control data block to which a frame ID is attached.
As shown in FIG. 1, in the communication system of this example, three types of frame IDs 1 to 3 are assigned to the control data block A transmitted by the ECU. The first communication frame is formed by assigning the frame ID 1 to the control data block A to form one frame structure. On the other hand, the frame ID2 is assigned to the control data block A to form one frame structure is the second communication frame. On the other hand, the frame ID3 is assigned to the control data block A to form one frame structure is the third communication frame.

The ECU selects frame IDs one by one in the order of frame ID 1 → frame ID 3 → frame ID 2 → frame ID 1 →... Dynamically and regularly according to the rules shared with the receiving side. The control data block A is transmitted while switching. That is, when transmitting the control data block A, the ECU transmits the communication frames in the order of the first communication frame → the third communication frame → the second communication frame → the first communication frame →. Become.

Although not shown, three types of frame IDs 4 to 6 are assigned to another control data block B, and three types of frame IDs 7 to 9 are assigned to another control data block C. The ECU selects frame IDs one by one in the order of frame ID 4 → frame ID 6 → frame ID 5 → frame ID 4 →... Dynamically and regularly according to the rules shared with the receiving side. The control data block B is transmitted while switching. In addition, the ECU selects frame IDs one by one in the order of frame ID 7 → frame ID 9 → frame ID 8 → frame ID 7 →... Dynamically and regularly in accordance with the rules shared with the receiving side. The control data block C is transmitted while switching the frame ID.

Next, the operation of the communication system will be described.
As shown in FIG. 2, when the switching rule of the frame IDs 1 to 3 shared between the transmission side and the reception side is “frame ID1 → frame ID3 → frame ID2”, the ECU on the transmission side transfers the control data block A to the control data block A. The first communication frame assigned with frame ID 1 is transmitted first. When receiving the frame ID 1 for the first time in accordance with the switching rule, the receiving ECU determines that it is normal (that is, the received communication frame is appropriate), and executes processing according to the contents of the control data block A.

Next, the transmission-side ECU transmits a third communication frame in which the frame ID 3 is assigned to the control data block A in accordance with the switching rule. When receiving the frame ID3 after the frame ID1 in accordance with the switching rule, the receiving ECU determines that the ECU is normal and executes the process according to the contents of the control data block A.

Next, the transmission-side ECU transmits a second communication frame in which the frame ID 2 is assigned to the control data block A in accordance with the switching rule. When receiving the frame ID2 after the frame ID3 in accordance with the switching rule, the receiving ECU determines that the ECU is normal and executes the process according to the contents of the control data block A.

After that, for example, when the ECU on the receiving side receives the frame ID2, unlike the switching rule, it means that the frame ID2 has been received twice in succession, so it is determined as abnormal (spoofing) and the data is discarded.

When the transmission-side ECU transmits the first communication frame in which the frame ID 1 is assigned to the control data block A in accordance with the switching rule, the receiving-side ECU transmits the previous normal frame in accordance with the switching rule. Since frame ID1 has been received next to ID2, it is determined to be normal, and processing is executed in accordance with the contents of control data block A.

Thereafter, when the transmission-side ECU transmits a third communication frame in which the frame ID 3 is assigned to the control data block A according to the switching rule, the receiving-side ECU follows the frame ID 1 according to the switching rule. Since frame ID 3 has been received, it is determined that the frame ID 3 is normal, and processing is executed according to the contents of the control data block A.

After that, when the transmission-side ECU transmits a second communication frame in which the frame ID 2 is assigned to the control data block A in accordance with the switching rule, the receiving-side ECU follows the frame ID 3 in accordance with the switching rule. Since the frame ID 2 is received, it is determined that the frame ID 2 is normal, and the process is executed according to the contents of the control data block A.

As described above, the receiving ECU determines that the frame ID is normal when receiving the frame ID in accordance with the switching rule, executes the process according to the contents of the control data block A, and receives the frame ID not in accordance with the switching rule. It is judged as abnormal (spoofing) and the data is discarded. Although not shown, the same applies to the control data block B or the control data block C.

As described above, according to the present embodiment, the following effects can be obtained.
(1) When transmitting a control data block, by communicating with a variable frame ID, it is possible to reduce the risk of communication analysis being easily performed by a third party.

(2) When the receiving side receives a frame ID that does not conform to the switching rule, it can determine that the reception side is abnormal (spoofing) and discard the data, thereby reducing the information security risk.
(3) The security hurdle is raised by communicating with variable frame IDs, and the hurdle is further raised by defining the order of frame IDs. Therefore, information security can be improved.

(4) No encryption is required to improve information security, and it can be realized without increasing costs. Therefore, information security can be improved without increasing the cost.

(Second Embodiment)
Next, a second embodiment of the communication system will be described.
As shown in FIG. 3, in the communication system of this example, three types of frame IDs 1 to 3 common to the control data blocks A to C are assigned to the three types of control data blocks A to C, respectively. ing. The first communication frame is formed by assigning the frame ID 1 to the control data block A to form one frame structure. On the other hand, the frame ID2 is assigned to the control data block A to form one frame structure is the second communication frame. On the other hand, the frame ID3 is assigned to the control data block A to form one frame structure is the third communication frame.

Similarly, the fourth communication frame is one in which the frame ID 1 is assigned to the control data block B to form one frame structure. On the other hand, the frame ID2 is assigned to the control data block B to form one frame structure is the fifth communication frame. On the other hand, the frame ID3 is assigned to the control data block B to form one frame structure is the sixth communication frame.

Similarly, the seventh communication frame has a frame structure in which the frame ID 1 is assigned to the control data block C. On the other hand, a frame ID2 assigned to the control data block C to form one frame structure is an eighth communication frame. On the other hand, the ninth communication frame has a frame structure in which the frame ID 3 is assigned to the control data block C.

The ECU selects the frame ID one by one from the frame IDs 1 to 3 for each control data block, and transmits the control data block while dynamically switching the frame ID. Alternatively, in combination with the first embodiment, a frame ID is selected one by one from the frame IDs 1 to 3 in accordance with a rule shared with the receiving side for each control data block. The control data block may be transmitted while switching the frame ID regularly. For example, the ECU selects the frame IDs one by one in the order of frame ID 1 → frame ID 3 → frame ID 2 → frame ID 1 →... And sends the control data block A while dynamically and regularly switching the frame ID. Also good.

As shown in FIG. 4, the ECU sets, for each control data block, identifier information that can uniquely identify the control data block on the receiving side in combination with the frame ID. Then, as described above, the ECU selects the frame IDs one by one from the frame IDs 1 to 3, and transmits the control data block while dynamically switching the frame IDs.

“Frame ID + identifier information” is called a control data identification ID, and this control data identification ID is confirmed on the receiving side to identify a control data block. For example, in the case of the control data block A, “control data identification ID = 100” is shared between the transmission side and the reception side. When the frame ID 1 assigned to the control data block A is “frame ID 1 = 90”, the transmission side sets “identifier information = 10”. If the frame ID 2 assigned to the control data block A is “frame ID 2 = 80”, “identifier information = 20” is set. When the frame ID 3 assigned to the control data block A is “frame ID 3 = 70”, “identifier information = 30” is set. When receiving the communication frame, the receiving side confirms the “frame ID” and “identifier information”, and when “control data specifying ID = 100”, the receiving side can specify the control data block A. That is, when the combination of “frame ID” and “identifier information” matches the “control data specifying ID” shared between the receiving side and the transmitting side, the receiving side specifies the received control data block. can do.

Similarly, in the case of the control data block B, for example, “control data identification ID = 110” is shared between the transmission side and the reception side. When the frame ID 1 assigned to the control data block B is “frame ID 1 = 90”, the transmission side sets “identifier information = 20”. When the frame ID 2 assigned to the control data block B is “frame ID 2 = 80”, “identifier information = 30” is set. When the frame ID 3 assigned to the control data block B is “frame ID 3 = 70”, “identifier information = 40” is set. When receiving the communication frame, the receiving side confirms the “frame ID” and “identifier information”, and when “control data specifying ID = 110”, the receiving side can specify the control data block B.

Similarly, in the case of the control data block C, for example, “control data identification ID = 120” is shared between the transmission side and the reception side. When the frame ID 1 assigned to the control data block C is “frame ID 1 = 90”, the transmission side sets “identifier information = 30”. When the frame ID 2 assigned to the control data block C is “frame ID 2 = 80”, “identifier information = 40” is set. When the frame ID 3 assigned to the control data block C is “frame ID 3 = 70”, “identifier information = 50” is set. When receiving the communication frame, the receiving side confirms the “frame ID” and “identifier information”, and when “control data specifying ID = 120”, the receiving side can specify the control data block C.

Next, the operation of the communication system will be described. Here, a case will be described in which the control data block A is transmitted not only dynamically changing the frame ID but also regularly switching the frame ID.

When the switching rule of the frame ID shared between the transmission side and the reception side is “frame ID1 → frame ID3 → frame ID2”, the ECU on the transmission side performs the first communication in which the frame ID1 is assigned to the control data block A. Send frame first. At this time, if “frame ID 1 = 90”, the transmission-side ECU sets “identifier information = 10” and then transmits the first communication frame. The ECU on the receiving side confirms the “frame ID” and “identifier information”, where “control data specifying ID = 100”, specifying the control data block A, and “frame ID 1 = 90”. Along with the first reception of frame ID 1 in accordance with the switching rule, it is determined to be normal, and the process is executed according to the contents of control data block A.

Next, the transmission-side ECU transmits a third communication frame in which the frame ID 3 is assigned to the control data block A in accordance with the switching rule. At this time, if “frame ID 3 = 70”, the ECU on the transmission side sets “identifier information = 30” and then transmits the third communication frame. The ECU on the receiving side confirms the “frame ID” and “identifier information”, where “control data specifying ID = 100”, specifying the control data block A, and “frame ID 3 = 70”. In accordance with the switching rule, when frame ID3 is received next to frame ID1, it is determined to be normal, and processing is executed according to the contents of control data block A.

Next, the transmission-side ECU transmits a second communication frame in which the frame ID 2 is assigned to the control data block A in accordance with the switching rule. At this time, if “frame ID2 = 80”, the transmission-side ECU sets “identifier information = 20” and then transmits the second communication frame. The ECU on the receiving side confirms the “frame ID” and “identifier information”, where “control data specifying ID = 100”, specifying the control data block A, and “frame ID 2 = 80”. In accordance with the switching rule, when frame ID2 is received next to frame ID3, it is determined to be normal, and processing is executed according to the contents of control data block A.

After that, for example, when the receiving ECU again receives the second communication frame in which the frame ID2 is assigned to the control data block A, the frame ID2 is received twice consecutively, unlike the switching rule. It is judged as abnormal (spoofing) and the data is discarded.

As described above, the receiving ECU determines that the frame ID is normal when receiving the frame ID in accordance with the switching rule, executes the process according to the contents of the control data block A, and receives the frame ID not in accordance with the switching rule. It is judged as abnormal (spoofing) and the data is discarded. The same applies to the control data block B or the control data block C.

As described above, according to the present embodiment, the following effects can be obtained.
(5) When transmitting one control data block among limited frame IDs (three types of frame IDs 1 to 3 in this example), it is possible to communicate with a third party by communicating with a variable frame ID. The risk of easily analyzing communications can be reduced.

(6) Although the first to ninth communication frames can be handled by three types of frame IDs 1 to 3, the risk can be reduced without increasing the number of assigned frame IDs.
It should be noted that each of the above embodiments can be modified and embodied as follows.

In the first embodiment, the switching rules for the three types of frame IDs 1 to 3 assigned to the control data block A are not limited to “frame ID 1 → frame ID 3 → frame ID 2”. For example, the same frame ID may be used twice or more in each routine, such as “frame ID 1 → frame ID 3 → frame ID 1 → frame ID 2”. The same applies to the control data block B or the control data block C.

In the first embodiment, two or more types of frame IDs may be assigned to the control data block A as long as a plurality of frame IDs are assigned to the control data block A. The same applies to the control data block B or the control data block C. An individual switching rule may be set for each control data block. For example, when two types of frame IDs 1 and 2 are assigned, the present invention is not limited to applying the switching rule of “frame ID 1 → frame ID 2” to each control data block. For example, a switching rule “frame ID 2 → frame ID 1 → frame ID 1” may be applied to the control data block B while a switching rule “frame ID 1 → frame ID 2” is applied to the control data block A.

In the first embodiment, a plurality of frame IDs with individual numbers may be assigned to each control data block. For example, two types of frame IDs may be assigned to the control data block A, three types of frame IDs may be assigned to the control data block B, and four types of frame IDs may be assigned to the control data block C.
In the first embodiment, “identifier information” may be set for each control data block as in the second embodiment. That is, a mechanism for setting “identifier information” combined with “frame ID” on the transmission side for each control data block while sharing the “control data specific ID” between the transmission side and the reception side is a plurality of control data blocks. The present invention is not limited to the embodiment in which a plurality of common frame IDs are assigned to each data block.

In the second embodiment, two or four or more types of frame IDs may be assigned to each of the control data blocks A to C as long as a plurality of common frame IDs are assigned. That is, the number (type) of the plurality of common frame IDs assigned to each of the plurality of control data blocks may not be the same as the number (type) of the plurality of control data blocks.

In the second embodiment described above, a plurality of frame IDs with individual numbers may be assigned to each of the control data blocks A to C. For example, two types of frame IDs may be assigned to the control data block A, three types of frame IDs may be assigned to the control data block B, and four types of frame IDs may be assigned to the control data block C.

In the second embodiment, the present invention is not limited to a configuration in which a plurality of completely common frame IDs are assigned to each of a plurality of control data blocks. The configuration may be such that at least one of the plurality of frame IDs individually assigned to each of the plurality of control data blocks is a common frame ID with any of the plurality of frame IDs assigned to the other control data blocks. That is, a plurality of frame IDs that are at least partially common among a plurality of control data blocks may be assigned to each of the plurality of control data blocks. In this case, the ECU on the transmission side sets, for each control data block, identifier information that can uniquely identify the control data block on the reception side in combination with the frame ID. Then, the ECU on the transmission side transmits the control data block while dynamically switching the frame ID by selecting one frame ID from the plurality of frame IDs for each control data block. Alternatively, in combination with the first embodiment, a frame ID is selected one by one from a plurality of frame IDs according to a rule shared with the receiving side for each control data block. The control data block is transmitted while switching the frame ID regularly.

-You may apply this invention to vehicle-mounted communication other than CAN. You may apply this invention to communication systems other than vehicle-mounted communication.
Next, technical ideas that can be grasped from the above embodiments and other examples will be described.

(Supplementary Note 1) A communication frame including a plurality of control units each functioning as a transmission side and a reception side and having a frame ID assigned to a control data block to form one frame structure between the transmission side and the reception side In a communication system for transmitting and receiving,
A plurality of frame IDs that are at least partially common among the plurality of control data blocks are assigned to each of the plurality of control data blocks,
The transmission side sets, for each control data block, identifier information that can uniquely identify the control data block on the reception side in combination with the frame ID, and then, among the plurality of frame IDs. The frame ID is selected one by one and the control data block is transmitted while dynamically switching the frame ID,
The communication system, wherein the number of the plurality of frame IDs assigned to each of the plurality of control data blocks is smaller than the number of the plurality of control data blocks.

(Supplementary Note 2) A communication frame including a plurality of control units each functioning as a transmission side and a reception side, and having a frame ID assigned to a control data block and forming one frame structure, is transmitted between the transmission side and the reception side. In a communication system for transmitting and receiving,
A plurality of frame IDs that are at least partially common among the plurality of control data blocks are assigned to each of the plurality of control data blocks,
The transmission side sets, for each control data block, identifier information that can uniquely identify the control data block on the reception side in combination with the frame ID, and then, among the plurality of frame IDs. The frame ID is selected one by one and the control data block is transmitted while dynamically switching the frame ID,
The communication system, wherein the number of the plurality of frame IDs assigned to each of the plurality of control data blocks is equal to or greater than the number of the plurality of control data blocks.

(Supplementary Note 3) A communication frame including a plurality of control units each functioning as a transmission side and a reception side and having a frame ID assigned to a control data block to form one frame structure between the transmission side and the reception side In a communication system for transmitting and receiving,
A plurality of frame IDs are assigned to each of the plurality of control data blocks,
The transmitting side selects a frame ID from the plurality of frame IDs one by one according to a rule shared with the receiving side, and dynamically and regularly switches the frame ID to control data block Send
The communication system, wherein the number of the plurality of frame IDs assigned to each of the plurality of control data blocks is equal to or greater than the number of the plurality of control data blocks.

(Supplementary Note 4) A communication frame including a plurality of control units each functioning as a transmission side and a reception side and having a frame ID assigned to a control data block to form one frame structure is transmitted between the transmission side and the reception side. In a communication system for transmitting and receiving,
For each of the plurality of control data blocks, a plurality of frame IDs with individual numbers are assigned,
The transmitting side selects a frame ID from the plurality of frame IDs one by one according to a rule shared with the receiving side, and dynamically and regularly switches the frame ID to control data block The communication system characterized by transmitting.

Claims

A communication system including a plurality of control units each functioning as a transmission side and a reception side, and transmitting and receiving a communication frame having a single frame structure with a frame ID assigned to a control data block between the transmission side and the reception side In
A plurality of frame IDs are assigned to the control data block,
The transmitting side selects a frame ID from the plurality of frame IDs one by one according to a rule shared with the receiving side, and dynamically and regularly switches the frame ID to control data block The communication system characterized by transmitting.
The communication system according to claim 1,
The transmitting side sets identifier information that allows the receiving side to uniquely identify the control data block in combination with the frame ID, and then sets a frame ID one by one from the plurality of frame IDs. A communication system, wherein a control data block is transmitted while selecting and dynamically switching a frame ID.
A communication system including a plurality of control units each functioning as a transmission side and a reception side, and transmitting and receiving a communication frame having a single frame structure with a frame ID assigned to a control data block between the transmission side and the reception side In
A plurality of frame IDs that are at least partially common among the plurality of control data blocks are assigned to each of the plurality of control data blocks,
The transmission side sets, for each control data block, identifier information that can uniquely identify the control data block on the reception side in combination with the frame ID, and then, among the plurality of frame IDs. A communication system characterized by selecting a frame ID one by one and transmitting a control data block while dynamically switching the frame ID.
The communication system according to claim 3,
The transmitting side selects a frame ID from the plurality of frame IDs one by one according to a rule shared with the receiving side for each control data block, and dynamically and regularly sets a frame ID. A control system that transmits control data blocks while switching between them.