JP5616810B2 - Drive recorder and drive recorder system - Google Patents

Description

  The present invention relates to a drive recorder that records data of a running vehicle, and more particularly to a drive recorder and a drive recorder system that prevent falsification of image data.

  A drive recorder that records driving data of a vehicle together with image data is mounted on the vehicle. The data recorded by the drive recorder serves as evidence of the cause of the vehicle accident, and requires data reliability and identity. Therefore, it is common to take measures to prevent data falsification.

  In Patent Document 1, in a drive recorder that stores travel data of a vehicle, an interface unit that connects to an in-vehicle LAN that transmits the travel data and acquires the travel data from the in-vehicle LAN, and encryption conversion that encrypts the acquired travel data A drive recorder is disclosed that includes a storage unit and a storage unit that stores encrypted travel data.

JP 2005-178494 A

  The conventional drive recorder encrypts the acquired traveling data and records it in the recording unit.

  On the other hand, when encrypting image data, the processing takes a very long time, and the cost increases when hardware for processing is installed. Therefore, in data including image data and travel data, it is common to encrypt only the travel data without encrypting the image data portion. In this case, since the image data itself is not encrypted, if the file structure is analyzed by a third party, the image data information may be obtained and the image data may be altered. was there.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a drive recorder and a drive recorder system that can prevent data tampering without increasing costs.

The present invention relates to an image information acquisition unit that acquires image information during vehicle travel, an impact detection unit that detects an impact generated in the vehicle, and an image acquired by the image information acquisition unit when the impact detection unit detects an impact. An image information recording means for recording information in the recording means, wherein the image information recording means encrypts only a part of the image information when recording the image information in the recording means And an encryption unit sets an encryption key and encrypts image information only to a predetermined size set to an indefinite length based on the set encryption key .

  According to the present invention, the time required for the encryption process can be shortened by minimizing the encrypted portion of the image information, and the processing capability required for the encryption process can be minimized, so that the drive Tampering of image information can be prevented without increasing the manufacturing cost of the recorder.

It is explanatory drawing of the drive recorder system containing the drive recorder of this invention of embodiment of this invention. It is a functional block diagram of the drive recorder of the embodiment of the present invention. It is a functional block diagram of the personal computer (PC) of the embodiment of the present invention. It is a sequence diagram which shows operation | movement of the drive recorder system of embodiment of this invention. It is explanatory drawing of the file which the drive recorder of embodiment of this invention records. It is explanatory drawing of an example of the table used when producing | generating the encryption key of embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an explanatory diagram of a drive recorder system 1 including a drive recorder 10 of the present invention.

  The drive recorder system 1 includes a drive recorder 10 mounted on a vehicle 11, a personal computer (hereinafter referred to as a PC) 20 installed in a business office, and a memory card 30 that records data acquired by the drive recorder 10. Is done.

  The drive recorder 10 acquires travel data (for example, vehicle speed, engine speed, latitude, longitude, etc.) from the vehicle 11 and records them at predetermined intervals together with the date and time. The drive recorder 10 is connected to a camera 12 and records image data captured by the camera 12. These travel data and image data are recorded in the memory card 30.

  The drive recorder 10 includes a memory card interface 170 that writes and reads data to and from the memory card 30 with the memory card 30 inserted, and a record button 180 that artificially records image data on the memory card 30. Is provided.

  The PC 20 includes a memory card interface 21 that writes data to and reads data from the memory card 30 with the memory card 30 inserted, a display unit 22 that includes a liquid crystal display that can display image data, and the like. And an input unit 23 including a keyboard and a mouse that can input instructions from.

  The memory card 30 is configured to be readable and writable by the memory card interfaces 170 and 21, and for example, a flash memory card such as SD (Source Digital) or CF (Compact Flash) is used.

  FIG. 2 is a functional block diagram of the drive recorder 10 according to the embodiment of the present invention.

  The drive recorder 10 includes a camera interface 120 that connects the camera 12, a vehicle interface 130 that acquires vehicle data by connecting to a vehicle CAN and the like, and a memory card interface 170 that reads and writes data with the memory card 30. A recording button 180 for recording image data and travel data on a memory card regardless of the occurrence of an event, which will be described later.

  In addition, the drive recorder 10 temporarily records image data, vehicle data, and the like, and also records a data 110 relating to control of the drive recorder 10 and an event for detecting occurrence of a predetermined event set in advance. The detection unit 140 includes an encryption key acquisition unit 150 that acquires an encryption key, which will be described later, and an encryption unit 160 that encrypts image data, travel data, and the like based on the encryption key.

  The control unit 100 controls the operations of these units in an integrated manner. More specifically, the control unit 100 sequentially records the image data acquired via the camera interface 120 and the travel data acquired via the vehicle interface 130 in the buffer of the recording unit 110. That is, the camera 12 and the control unit 100 constitute an image information acquisition unit.

  Here, when the event detection unit 140 detects a predetermined event, the control unit 100 determines the predetermined time before and after the time when the event is detected among the image data and the travel data recorded in the buffer of the recording unit 110. Extract only time (for example, 15 seconds before and after). The control unit 100 records the extracted data as a file on the memory card 30 via the memory card interface 170. That is, the memory card interface 170 and the control unit 100 constitute an image information recording unit.

  The event detection unit 140 includes an acceleration sensor. When the acceleration detected by the acceleration sensor exceeds a predetermined threshold (for example, when the front-rear G or the lateral G becomes 0.8 G or more), the event detection unit 140 shocks the vehicle. It is determined that has been added and an event is detected. That is, the event detection unit 140 constitutes an impact detection unit.

  The encryption unit 160 encrypts a part of the data written to the memory card 30 using the encryption key acquired by the encryption key acquisition unit 150. The encryption key acquisition unit 150 acquires the encryption key using the user ID and the file name, as will be described later.

  The record button 180 performs the same processing as when an event is detected when pressed by the driver, such as when the image detection is not performed by the event detection unit 140 and the image data is to be recorded in the memory card 30. Do. For example, even when the acceleration detected by the event detection unit 140 does not exceed a predetermined threshold value, data of a predetermined time before and after the time when the recording button 180 is pressed by pressing the recording button 180 by the driver. And this data can be recorded on the memory card 30.

  For connection between the camera 12 and the camera interface 120, an interface such as USB (Serial Universal Bus) is used. In the present embodiment, a configuration in which one camera 12 is connected to the drive recorder 10 is shown as an example. However, a plurality of cameras 12 are connected to the camera interface 120 and each camera is placed at an arbitrary position on the vehicle 11. May be installed. For example, one camera 12 may be installed so as to photograph the front of the vehicle, and the other camera 12 may be installed so as to photograph the rear of the vehicle and the vicinity of the driver in the passenger compartment.

  FIG. 3 is a functional block diagram of the personal computer (PC) 20 according to the embodiment of this invention.

  The PC 20 acquires the image data recorded on the memory card inserted into the memory card interface 21, acquires the same decryption key as the encryption key that encrypted the image data, decrypts the image data, and decrypts the image data. This is an image reproduction device for reproducing the converted image data.

  The PC 20 includes an external interface 270. The external interface 270 includes a memory card interface 21 that writes and reads data, a display unit 22 that includes a liquid crystal display that can display image data and the like, and an input that includes a keyboard and a mouse that can input instructions from the user. Are connected to each other.

  The PC 20 includes a vehicle information setting unit 230 that sets the drive recorder 10 using the input unit 23, a data acquisition unit 240 that acquires image data, travel data, and the like recorded in the memory card 30, and an encrypted image. A decrypting unit 250 that decrypts the data and the running data using the same decryption key as the encryption key.

  The control unit 210 comprehensively controls these units. The recording unit 220 includes a memory such as a ROM and a RAM, a hard disk, and the like, and records data used by each unit controlled by the control unit 210.

  In the PC 20, the control unit 210 reads the software recorded in the recording unit 220 and executes the software, whereby the vehicle information setting unit 230, the data acquisition unit 240, and the decryption unit 250 are configured.

  Further, for example, a USB or the like is used for connection between the external interface 270 and the memory card interface 21 or the input unit 23. For connection between the external interface 270 and the display unit 22, for example, an interface such as DVI (Digital Visual Interface) or HDMI (High-Definition Multimedia Interface) is used.

  Next, the operation of the drive recorder system 1 configured as described above will be described.

  FIG. 4 is a sequence diagram showing an operation of the drive recorder system 1 according to the embodiment of the present invention.

  First, the user inserts the memory card 30 into the memory card interface 21 of the PC 20 (S100), and sets vehicle information.

  In the PC 20, the vehicle information setting unit 230 displays a GUI on the display unit 22, and receives an input such as a user ID from a user (administrator) (S101). The vehicle information setting unit 230 writes the input user ID into the memory card 30 (S102). The memory card 30 records the written user ID (S103).

  The user ID set by the vehicle information setting unit 230 is an ID number that individually sets the vehicle 11 on which the drive recorder 10 is mounted. For example, a vehicle number unique to the vehicle 11 may be registered as a user ID, or information individually set for a driver driving the vehicle 11 may be added to the ID number.

  The user removes the memory card 30 from the PC 20 and inserts it into the memory card interface 170 of the drive recorder 10 (S104).

  In the drive recorder 10, when the control unit 100 detects that the memory card 30 is inserted into the memory card interface 170, the control unit 100 acquires the user ID recorded in the memory card 30 and records it in the recording unit 110 (S105). ).

  When the control unit 100 detects that the driving of the vehicle 11 is started with the memory card 30 inserted in the memory card interface 170, the control unit 100 starts recording the image data and the traveling data in the buffer of the recording unit 110 (S106). ). In addition, the control part 100 detects having started the driving | operation of the vehicle 11, when the vehicle speed acquired from the vehicle interface 130 exceeds 0 [km / h], for example.

  Further, the buffer of the recording unit 110 is configured as a FIFO, and when the recorded data reaches the upper limit of the buffer capacity, the data with the oldest recording time is discarded.

  When the event detection unit 140 detects an event during the driving of the vehicle 11 (S107), the control unit 100 detects before and after the time when the event is detected from the image data and the travel data recorded in the recording unit 110. The data for a predetermined time (for example, 15 seconds before and after) is extracted, and the extracted data is written in the memory card 30 as a file.

  Note that the event detection unit 140 detects that an event has occurred, for example, when the front and rear G or the lateral G is 0.8 G or more. If no event is detected, recording of image data and running data is continued (S107).

  When it is detected that an event has occurred, the control unit 100 extracts data for a predetermined time before and after the time when the event is detected, and assigns a file name to the extracted data. As the file name, for example, a character string that is unique in the memory card 30 such as date / time (day, hour, minute, second) or GPS latitude / longitude information is set.

  Next, the encryption key acquisition unit 150 acquires an encryption key from the user ID and the set file name. The encryption key acquisition unit 150 generates a unique numerical value from the character string included in the user ID and the file name, and generates this as an encryption key. The encryption unit 160 encrypts a part of the file using the generated encryption key (S108).

  Next, the control unit 100 writes the data encrypted by the encryption unit 160 to the memory card 30 as a file via the memory card interface 170 (S109). The memory card 30 records the written file (S110).

  After driving the vehicle, the user removes the memory card 30 from the drive recorder 10 and inserts it into the memory card interface 21 of the PC 20 (S111).

  In the PC 20, when the control unit 210 detects that the memory card 30 is inserted into the memory card interface 21, the control unit 210 acquires the user ID and the file name recorded in the memory card 30 (S112).

  Next, the decryption unit 250 obtains a decryption key from the obtained user ID and file name, and decrypts the file using the obtained decryption key (S113). The decryption unit 250 obtains the same decryption key as the encryption key from the file name and the user ID by the same process as the encryption key acquisition unit 150 described above, and is encrypted with this decryption key. Decrypt the file.

  Then, based on a request for image data reproduction from the user, the control unit 210 sequentially combines the files recorded on the memory card 30 and reproduces the image data (S114).

  Next, file encryption will be described.

  FIG. 5 is an explanatory diagram showing the structure of a file recorded on the memory card 30 by the drive recorder.

  The file mainly includes a travel data unit 50 that records travel data and an image data unit 60 that records image data. In the image data section 60, a plurality of JPEG image data 61 is continuously recorded in chronological order, and constitutes data that can be reproduced as a moving image by a series of JPEG image data.

  The travel data unit 50 includes a file name field 52 indicating a file name, a file size field 53 indicating the file size of the travel data unit 50, and a data unit 54 in which travel data acquired by the drive recorder 10 is recorded. .

  The image data part 61 includes a file name field 62 indicating a file name, a file size field 63 indicating a file size of the image data part 61, a JPEG data header part 64 in which information indicating JPEG data is stored, It comprises a JPEG data section 65 in which JPEG image data, which is image data acquired by the drive recorder 10, is recorded.

  Of the file structure generated in this way, the encryption unit 160 encrypts all of the travel data unit 50, the file name field 62, the file size field 63, and the JPEG data header unit 64 of the image data unit 61.

  The encryption unit 160 converts each byte in hexadecimal notation for the travel data unit 50, the file name field 62, the file size field 63, and the JPEG data header unit 64 into a character string shifted by the encryption key. Encryption. The encryption key is a numerical value of 0 to 255 as will be described later, and it is extremely difficult for a third party to decrypt the file by shifting each byte constituting the data by the encryption key. Data.

  Further, the encryption unit 160 encrypts only a predetermined number of bytes from the top of the JPEG data unit 65. Specifically, the number of bytes (1 to 256) corresponding to the encryption key of 0 to 255 from the top of the JPEG data portion 65 is converted into a character string shifted by the encryption key.

  In this way, the encryption unit 160 encrypts the head portion of the travel data unit 50 and all the image data 61 included in the file.

  This process makes it extremely difficult for a third party to obtain the boundary between the JPEG data header portion 64 and the JPEG data portion 65, which indicates JPEG data. Furthermore, since the file size field 63, which is information indicating the file size of JPEG data, which is an indefinite length file format, is also encrypted, it is extremely difficult for a third party to decrypt and acquire the JPEG data from the file. It becomes.

  FIG. 6 is an example of an encryption table used for acquiring the encryption key according to the embodiment of this invention.

  The encryption key acquisition unit 150 first sets a unique value from 0 to 255 from the set file name and user ID. This value is set by a known method using a hash function, for example. And the unique value of 0-255 is set from the set unique value using a table as shown in FIG.

  For example, a numerical value at a position shifted by a unique value set from the top of this table is extracted, and this value is acquired as an encryption key.

  As described above, since the encryption key is acquired not by the unique value set from the file name and the user ID but by a preset table, the encryption key is difficult to be decrypted.

  As described above, in the embodiment of the present invention, image data is acquired by the camera 12 provided in the running vehicle 11, and the image data is stored in the memory card when an event such as an impact is detected by the event detection unit 140. In the drive recorder for recording to 30, the file to be recorded is encrypted by the encryption unit 160 in order to prevent reading and falsification of the image data.

  Conventionally, image data has a large file size, so it takes a lot of time to encrypt the image data, and the cost increases due to the addition of hardware for high-speed encryption There was a problem.

  On the other hand, in the embodiment of the present invention, not all of the image data is encrypted, but only a part of the image data is encrypted.

  With this configuration, the time required for the image data encryption process can be shortened, and the processing capability required for the encryption process can be minimized, which increases the manufacturing cost of the drive recorder 10. Therefore, it is possible to prevent image data from being falsified.

  In particular, when the image data includes JPEG images, encryption is performed including the header information of the JPEG data and the boundary between the header information and the image information portion, and further, an indefinite length area is encrypted using the encryption key. Therefore, it becomes difficult for a third party to acquire the area and size of the image data included in the file, and the image data can be prevented from being falsified.

  In the above-described embodiment, an example in which a JPEG file is recorded as an example of the file format of image data has been described. However, other image formats can be similarly applied.

  For example, by recording image data in the MPEG file format and performing indefinite length encryption including the header information included in the MPEG file and the boundary portion of I-Picture, the area of the image data included in the file is It becomes difficult for a third party to obtain the size, and tampering of the image data can be prevented.

  It goes without saying that the present invention is not limited to the above-described embodiments, and includes various modifications and improvements that can be made within the scope of the technical idea.

1 Drive Recorder System 10 Drive Recorder 11 Vehicle 12 Camera 20 Personal Computer (PC)
30 Memory Card 100 Control Unit 150 Encryption Key Acquisition Unit 160 Encryption Unit 250 Decryption Unit

Claims (6)

Image information acquisition means for acquiring image information during vehicle travel, impact detection means for detecting an impact generated in the vehicle, and image information acquired by the image information acquisition means when the impact detection means detects an impact An image information recording means for recording the information on the recording means,
The image information recording means includes an encryption means for encrypting only a part of the image information when the image information is recorded in the recording means,
The drive recorder is characterized in that an encryption key is set, and the image information is encrypted only for a predetermined size set to an indefinite length based on the set encryption key . 2. The drive recorder according to claim 1, wherein the encryption unit sets the encryption key based on at least one of a date and a place where the impact detection unit detects an impact. The image information includes a JPEG image, and the encryption unit encrypts data including a boundary between the JPEG image and header information of the JPEG image. Drive recorder. 3. The image information according to claim 1 or 2, wherein the image information includes an MPEG moving image, and the encryption unit includes a boundary portion between the MPEG moving image and a header portion of the MPEG moving image. drive recorder.   Image information acquisition means for acquiring image information during traveling of the vehicle, impact detection means for detecting an impact generated in the vehicle, and image information acquired by the image information acquisition means when the impact detection means detects an impact Image information recording means for recording the image information on the recording means, and the image information recording means comprises encryption means for encrypting only a part of the image information when the image information is recorded on the recording means. The encryption means sets an encryption key, and encrypts the image information only to a predetermined size set to an indefinite length based on the set encryption key; and
  A decoding means for decoding the image information recorded in the recording means; an image reproduction apparatus for reproducing the image information decoded by the decoding means;
  A drive recorder system comprising: The encryption means encrypts only a predetermined size of the image information based on an encryption key set based on at least one of the date and place where the impact detection means detected the impact,
6. The decryption unit according to claim 5, wherein the decryption unit decrypts the image information based on a decryption key set based on information included in the image information recorded in the recording unit. Drive recorder system.