JP5116336B2 - Recording / reproducing system, recording / reproducing apparatus, control method for recording / reproducing system, and control method for recording / reproducing apparatus - Google Patents

Description

The present invention relates to a recording / reproducing system including a recording / reproducing apparatus such as a digital camera that encrypts / decrypts image data to record / reproduce, for example , a recording / reproducing apparatus, a control method for the recording / reproducing system, and a control method for the recording / reproducing apparatus. is there.

  In recent years, in a recording / reproducing apparatus such as a digital still camera, data to be handled has been diversified and a capacity of a recording medium has been increased. For this reason, when important data is leaked to a third party, it is more likely to be damaged than before, and the need to conceal the data is increasing in order to reduce this damage.

  As a method of concealing data, a method in which a user sets a password and requests input of the password at the time of reproduction, a method to require fingerprint verification at the time of reproduction by a fingerprint authentication device, an encryption key is stored in the recording / reproducing apparatus itself, There is a method of encrypting and recording data using an encryption key (see, for example, Patent Document 1).

JP 2006-3105050 A

  However, each of the above methods has various problems. In a method that requires the user to input a password, the password needs to be as simple as the user can remember, and the strength of the password is low. In addition, it is troublesome to input a password every time reproduction is performed, and data cannot be reproduced if the user forgets the password.

  In the method using the fingerprint authentication device, a space for mounting the device is required on the surface of the recording / reproducing apparatus, which hinders downsizing of the device.

  The method of storing the encryption key in the recording / reproducing apparatus itself is meaningless if the recording / reproducing apparatus itself is stolen.

  The present invention has been made in view of the above-described problems, and can perform encryption with sufficient strength without imposing a burden on the user, and even when the recording / reproducing apparatus itself is stolen. The purpose is to prevent data leakage.

The present invention includes a recording / reproducing apparatus that has an imaging unit, encrypts / decrypts data using an encryption key, records / reproduces, a battery that is detachable from the recording / reproduction apparatus, and a storage unit that stores the encryption key. And a charging / reproducing system configured to charge the battery, wherein the battery stores an encryption key stored in a storage unit of the charging device when connected to the charging device. The recording / reproducing apparatus includes a first recording means for recording the encryption key stored in the storage means in a built-in memory of the recording / reproducing apparatus, and an image acquired by the imaging means. Encryption means for encrypting data using the encryption key; and second recording means for recording the image data encrypted by the encryption means in an external memory detachable from the recording / reproducing apparatus. And the memory Is the encryption key stored in a public key and a private key, said first recording means records the public key to the internal memory of the cryptographic key stored in the storage means, in the internal memory When the public key is recorded, the encryption means encrypts image data using the public key recorded in the built-in memory .

The present invention is a recording / reproducing apparatus having an image pickup means and capable of encrypting or decrypting data using an encryption key, and mounting a battery having a storage means for storing information on the encryption key A first recording unit that records the encryption key stored in the storage unit in a built-in memory of the recording / reproducing device; and the image data acquired by the imaging unit is encrypted using the encryption key. wherein the encryption means, the image data encrypted by said encryption means, have a, a second recording means for recording the external memory detachable to the recording and reproducing apparatus, stored in said storage means The encryption key is a public key and a secret key, and the first recording unit records the public key among the encryption keys stored in the storage unit in the built-in memory, and the public key is recorded in the built-in memory. If it is Means is characterized by encrypting the image data by using the public key stored in the internal memory.

  According to the present invention, data can be encrypted and decrypted using an encryption key stored in a charging device that charges a battery that is detachable from the recording / reproducing device, and can be recorded and reproduced. Therefore, the encryption / decryption of data cannot be performed unless the power is directly or indirectly supplied to the recording / reproducing apparatus by the charging apparatus in which the encryption key is recorded. improves.

  Further, according to the present invention, the encryption key stored in the storage unit of the charging device can be copied to the storage unit of the battery, and the data can be encrypted and decrypted using the copied encryption key to be recorded and reproduced. Therefore, when charging the battery to drive the recording / reproducing device, the encryption key can be stored in the storage unit of the battery, and the data is encrypted / decrypted using the encryption key to be recorded / reproduced. Therefore, the burden of encryption / decryption is not imposed. Also, since data cannot be played back except for the battery that stores the encryption key, storing the battery separately from the recording / playback device prevents data leakage even if the recording / playback device is stolen. Can do.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
In the first embodiment, a case where the recording / reproducing apparatus according to the present invention is applied to the digital still camera body 2 and the recording / reproducing system according to the present invention is applied to the digital still camera 1 will be described. An operation in which the digital still camera body 2 encrypts / decrypts image data and records / reproduces it will be described. The encryption algorithm used in this embodiment is a public key cryptosystem, and the encryption key is composed of a pair of a public key and a secret key. Here, an example in which encryption is performed using a public key and decryption is performed using a secret key will be described.

  FIG. 1 is a block diagram illustrating a configuration of a digital still camera 1 according to the embodiment. A digital still camera 1 according to this embodiment includes a digital still camera body 2, a battery 3, a charging device 4, and a power adapter 5.

  In the digital still camera body 2, reference numeral 10 denotes an imaging unit that converts a subject into a video signal. Reference numeral 11 denotes a camera video signal processing circuit that processes the video signal converted by the imaging unit 10. A recording / playback data processing circuit 13 compresses the video signal processed by the camera video signal processing circuit 11 and processes image data played back from a memory card 16 described later.

  An encryption circuit 14 encrypts captured image data and decrypts image data read from the memory card 16. Reference numeral 15 denotes a liquid crystal panel that displays a captured image and a reproduced image. Reference numeral 16 denotes a memory card for recording image data. Reference numeral 17 denotes a USB interface for transferring image data to the outside. Reference numeral 18 denotes a flash memory (first non-volatile memory) as a storage unit for storing a public key for encryption. Reference numeral 19 denotes a control switch as an operation unit that allows the user to instruct image recording and reproduction. A system controller 20 controls each unit.

  The battery 3 removably attaches to and connects to the digital still camera body 2 to supply power to the digital still camera body 2. In the battery 3, 31 is a RAM (volatile memory) as a storage unit for storing the encryption key. Reference numeral 32 denotes a RAM erase switch as an operation unit for the user to erase the contents of the RAM 31.

  The charging device 4 can charge the battery 3 by connecting the battery 3. In the charging device 4, reference numeral 41 denotes a flash memory (second non-volatile memory) as a storage unit in which an encryption key is stored. Reference numeral 42 denotes a control microcomputer. Here, an encryption key (a pair of a public key and a secret key) is written and stored in the flash memory 41 of the charging device 4 at the time of production in a factory or the like. This encryption key is unique and desirably managed by a serial number at the time of production.

  The power adapter 5 supplies power to the digital still camera body 2. In the power adapter 5, 51 is a flash memory (third non-volatile memory) as a storage unit in which an encryption key is stored. Here, the same encryption key (a pair of public key and secret key) as that of the flash memory 41 of the charging device 4 is also stored in the flash memory 51 of the power adapter 5.

  Hereinafter, the processing operation in the digital still camera 1 according to the present embodiment will be described. First, the processing operation performed by the control microcomputer 42 in the charging device 4 when the battery 3 is connected to the charging device 4 will be described. FIG. 2 is a flowchart showing the processing operation of the charging device 4 to which the battery 3 is connected.

  In step S <b> 101, the control microcomputer 42 in the charging device 4 confirms whether or not the battery 3 is connected to the charging device 4. When the battery 3 is connected in step S101, the control microcomputer 42 reads the encryption key from the flash memory 41 in the charging device 4 and transmits the encryption key to the battery 3 in step S102. The battery 3 stores (copies) the received encryption key in the RAM 31 in the battery 3. Here, the configuration in which the encryption key of the flash memory 41 is copied to the RAM 31 in the battery 3 when the battery 3 is connected to the charging device 4 is referred to as encryption key copying means. Thereafter, in step S <b> 103, the control microcomputer 42 performs a charging process for the battery 3. If the battery 3 is not connected in step S101, step S101 is executed again after a certain period to confirm connection of the battery 3.

  The encryption algorithm used in this embodiment is a public key cryptosystem, and the encryption key copied from the charging device 4 to the battery 3 is a pair of a public key and a secret key.

  Next, a processing operation when the battery 3 is mounted and connected to the digital still camera body 2 and image data is recorded will be described. FIG. 3 is a flowchart showing the processing operation of the digital still camera body 2 at the time of shooting.

  In step S <b> 201, the system controller 20 determines whether a shooting operation has been performed by the control switch 19. If a shooting operation has been performed, the process proceeds to step S202 to perform a shooting process. If the photographing operation has not been performed, step S201 is executed again after a certain period.

  Next, in step S202, the system controller 20 controls each circuit to perform shooting processing. Specifically, the video signal converted by the imaging unit 10 is input to the camera video signal processing circuit 11 and converted into image data.

  Next, in step S203, the system controller 20 reads the contents of the RAM 31 in the battery 3 connected to the digital still camera body 2, and proceeds to step S204. In step S <b> 204, the system controller 20 determines whether or not a public key for encrypting image data is stored in the RAM 31 in the battery 3.

  If the public key is stored in the RAM 31 in step S204, the process proceeds to step S205. In step S205, the system controller 20 encrypts the image data created in step S202 by the encryption circuit 14 using the public key read from the RAM 31 in the battery 3. In step S206, the system controller 20 writes and stores the image data encrypted in step S205 in the memory card 16.

  On the other hand, if the public key is not stored in the RAM 31 in step S204, the process proceeds to step S207. In step S207, the system controller 20 writes the data in the memory card 16 as it is without encrypting the image data created in step S202.

  Next, a processing operation when image data is reproduced or transferred to an external device in the digital still camera body 2 will be described. FIG. 4 is a flowchart showing an operation process of the digital still camera body 2 when image data is reproduced or transferred to an external device.

  In step S <b> 301, the system controller 20 reads image data stored in the memory card 16. Next, in step S302, it is checked whether or not the image data read from the memory card 16 is encrypted. If it is encrypted, the process proceeds to step S303, and if it is not encrypted, the process proceeds to step S306. .

  In step S303, the system controller 20 reads the contents of the RAM 31 in the battery 3 connected to the digital still camera body 2, and proceeds to step S304. In step S <b> 304, the system controller 20 determines whether or not a secret key for decrypting the image data is stored in the RAM 31 in the battery 3.

  If the secret key is stored in the RAM 31 in step S304, the process proceeds to step S305. In step S 305, the system controller 20 decrypts the encrypted image data using the secret key read from the RAM 31 in the battery 3, and sends it to the recording / reproduction data processing circuit 13.

  In step S306, the system controller 20 converts the image data into a video signal by the recording / reproduction data processing circuit 13 and outputs it to the LCD panel 15. When connecting to an external device such as a personal computer (PC) or a printer, the image data can be directly transferred to the external device using the USB interface 17 without passing through the recording / reproducing data processing circuit 13. Here, the configuration in which the system controller 20 decrypts the image data using the encryption key stored in the RAM 31 and transfers it to the external device is referred to as decryption transfer means.

  On the other hand, if the secret key is not stored in the RAM 31 in step S304, the process proceeds to step S307. In step S307, a warning is displayed on the LCD panel 15 that reproduction / transfer is impossible.

  As described above, according to the present embodiment, the encryption key is copied from the charging device 4 to the battery 3 when the battery 3 is charged. In a state where the battery 3 is mounted on the digital still camera body 2, image data can be automatically encrypted and recorded using an encryption key (public key) without any particular awareness of the user at the time of shooting. Since this encryption uses a public key cryptosystem, its strength is sufficient. Further, at the time of reproduction or transfer, the image data can be automatically decrypted using the encryption key (secret key) without being particularly conscious of the user, and can be reproduced or transferred to an external device.

  The encryption key for reproducing the encrypted image data is stored in the RAM 31 in the battery 3 and is automatically deleted (disappears) when the remaining amount of the battery 3 is exhausted. Therefore, even if a camera that has not been used for a long time is stolen, leakage of image information can be prevented if the remaining battery level is exhausted. Further, if the digital still camera body 2 and the battery 3 are stored separately, the leakage of image information can be prevented when only the digital still camera body 2 is stolen.

  In the present embodiment, the contents (encryption key) of the RAM 31 in the battery 3 can be erased by operating the RAM erase switch 32 provided in the battery 3. In other words, it is possible to make it impossible for the user to reproduce the intentionally encrypted image data. Further, the contents of the RAM 31 of the battery 3 can be erased by the control switch 19 from the menu of the digital still camera body 2 or the like. As described above, since the contents of the RAM 31 can be erased, when a third party is requested to take a picture, it is possible to immediately make the reproduction impossible. The possibility can be reduced. Here, the configuration for erasing the encryption key stored in the RAM 31 is referred to as erasing means.

  In this embodiment, the case where the battery 3 is mounted has been described. However, when the charging device 4 is directly connected to the digital still camera body 2, the encryption key is read from the flash memory 41 of the charging device 4, and the image is displayed. Data can be encrypted and decrypted.

  The flash memory 51 of the power adapter 5 stores the same encryption key as the encryption key stored in the flash memory 41 of the charging device 4. That is, when the power adapter 5 is connected to the digital still camera body 2, the encryption key can be read from the flash memory 51 in the power adapter 5 and the image data can be encrypted and decrypted.

(Second Embodiment)
In the first embodiment, the battery 3 storing the encryption key is used both at the time of shooting and at the time of reproduction (or at the time of transfer). In the present embodiment, a digital still camera 1 that can be encrypted and recorded even when the battery 3 without the encryption key is used at the time of shooting after the battery 3 storing the encryption key is once mounted will be described. Note that the block diagram of the digital still camera 1 according to the present embodiment is the same as that of the first embodiment, and a description thereof will be omitted. Further, the operation when the battery 3 is connected to the charging device 4 is the same as that of the first embodiment, and therefore the description thereof is omitted.

  A processing operation when the battery 3 is attached to and connected to the digital still camera body 2 and image data is recorded will be described. FIG. 5 is a flowchart showing the processing operation of the digital still camera body 2 at the time of shooting.

  In step S <b> 401, the system controller 20 determines whether a shooting operation has been performed by the control switch 19. If a shooting operation has been performed, the process proceeds to step S402 to perform a shooting process. If the photographing operation is not performed, step S401 is executed again after a certain period.

  Next, in step S402, the system controller 20 controls each circuit to perform shooting processing. Specifically, the video signal converted by the imaging unit 10 is input to the camera video signal processing circuit 11 and converted into image data.

  Next, in step S403, the system controller 20 reads the contents of the RAM 31 in the battery 3 connected to the digital still camera body 2, and proceeds to step S404. In step S <b> 404, the system controller 20 determines whether or not a public key for encrypting image data is stored in the RAM 31 in the battery 3.

  If the public key is stored in the RAM 31 in step S404, the process proceeds to step S405. In step S405, the system controller 20 copies the read public key to the flash memory 18 of the digital still camera body 2. Here, the configuration for copying the public key to the flash memory 18 is called public key copying means. In this case, only the public key for encryption is copied, and the private key for decryption used at the time of reproduction is not copied.

  Next, in step S406, the system controller 20 encrypts the image data created in step S402 by the encryption circuit 14 using the public key copied to the flash memory 18. In step S407, the system controller 20 writes and stores the image data encrypted in step S406 in the memory card 16.

  On the other hand, if the public key is not stored in the RAM 31 in step S404, the process proceeds to step S408. In step S408, the system controller 20 confirms whether or not the public key for encryption is stored in the flash memory 18 of the digital still camera body 2. If the public key is stored in the flash memory 18, the process advances to step S406 to perform image data encryption processing. Accordingly, if the digital still camera body 2 has once stored the public key for encryption, the image data can be encrypted and recorded even when the battery 3 in which the public key is not stored is used. . On the other hand, if the public key is not stored in the flash memory 18, the process proceeds to step S409. In step S409, the system controller 20 writes the data in the memory card 16 as it is without encrypting the image data created in step S402.

  Here, the operation process at the time of reproduction is the same as that in the first embodiment, and thus the description thereof is omitted. In step S405, since only the public key for encryption is copied to the first flash memory 18 in the digital still camera body 2, the private key for decryption is stored for reproduction. The battery 3 is required.

  As described above, according to the present embodiment, once the public key for encryption is stored in the digital still camera body 2, the image data is encrypted even in combination with a battery that does not store the public key. Can be recorded. Therefore, even when the remaining battery level is exhausted at a travel destination or the like, if a commercially available dry battery or the like can be used for the digital still camera main body 2, it is possible to encrypt and record the image data.

  In addition, two types of battery 3 that stores the encryption key and battery 3 that does not hold the encryption key using the RAM erase switch 32 are prepared, and the battery 3 without the encryption key is used at the time of shooting. The battery 3 holding the encryption key is used only during reproduction. Thereby, the possibility of leakage of image information when the digital still camera body 2 and the attached battery 3 are stolen at the same time can be reduced.

  In the first and second embodiments described above, the case where image data is encrypted and decrypted has been described. However, the data is not limited to image data, and data such as audio data may be encrypted and decrypted. In the first embodiment and the second embodiment described above, image data is both encrypted and decrypted. However, at least one of encryption and decryption is performed. Also good.

  Each step of the recording / reproducing apparatus, the recording / reproducing system, and the control method of the recording / reproducing apparatus and the recording / reproducing system in the embodiment of the present invention described above is a program stored in the RAM, ROM, etc. of the computer. Can be realized by operating. This program and a computer-readable recording medium recording the program are included in the present invention. Further, the present invention can be embodied as a system, apparatus, method, program, recording medium, or the like.

  The present invention supplies a software program for realizing the functions of the above-described embodiments directly or remotely to a system or apparatus. In addition, this includes a case where the system or the computer of the apparatus is also achieved by reading and executing the supplied program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention. In that case, as long as it has the function of a program, it may be in the form of object code, a program executed by an interpreter, script data supplied to the OS, and the like.

  Further, the functions of the above-described embodiments are realized by the computer executing the read program. Furthermore, based on the instructions of the program, the OS or the like running on the computer performs part or all of the actual processing, and the functions of the above-described embodiments can be realized by the processing.

  As another method, the program read from the recording medium is first written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer. Then, based on the instructions of the program, the CPU or the like provided in the function expansion board or function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are also realized by the processing.

It is a block diagram which shows the structure of the digital still camera which concerns on embodiment. It is a flowchart which shows the operation processing of the charging device which connected the battery. It is a flowchart which shows the processing operation of the digital still camera main body at the time of imaging | photography in 1st Embodiment. It is a flowchart which shows the operation processing of the digital still camera main body at the time of reproducing | regenerating image data or transferring to external equipment. It is a flowchart which shows the processing operation of the digital still camera main body at the time of imaging | photography in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital still camera 2 Digital still camera main body 3 Battery 4 Charging device 5 Power supply adapter 10 Imaging part 11 Camera video signal processing circuit 13 Recording / reproduction data processing circuit 14 Encryption circuit 15 Liquid crystal panel 16 Memory card 17 USB interface 18 Flash memory 19 Control switch 20 System controller 31 RAM
32 RAM erase switch 41 Flash memory 42 Charger control microcomputer 51 Flash memory

Claims (9)

A recording / reproducing apparatus that has an imaging unit, and that records and reproduces data by encrypting and decrypting data using an encryption key;
A battery removable from the recording / reproducing device;
A recording / reproducing system including a storage unit storing an encryption key and charging the battery,
The battery is
A storage unit that stores an encryption key stored in a storage unit of the charging device when connected to the charging device;
The recording / reproducing apparatus comprises:
First recording means for recording the encryption key stored in the storage means in a built-in memory of the recording / reproducing apparatus;
Encryption means for encrypting the image data acquired by the imaging means using the encryption key;
The image data encrypted by said encryption means, have a, a second recording means for recording the external memory detachable to the recording and reproducing apparatus,
The encryption key stored in the storage means is a public key and a secret key,
The first recording means records a public key among the encryption keys stored in the storage means in the built-in memory,
When the public key is recorded in the built-in memory, the encryption unit encrypts image data using the public key recorded in the built-in memory . The recording / reproducing apparatus comprises:
2. The reproduction apparatus according to claim 1 , further comprising a decrypting unit configured to decrypt the encrypted image data recorded in the external memory using the secret key stored in the storage unit. The recording / reproducing system described. The battery recording and reproducing system according to claim 1 or 2, characterized in that it has an erase means for erasing the encryption key stored in the storage means. The recording and reproducing apparatus, in a state in which the battery is mounted, the recording and reproducing system according to claim 1 or 2, characterized in that it has an erase means for erasing the encryption key stored in the storage means. The recording and reproducing apparatus, recording and reproducing system according to claim 2, characterized in that it comprises a decoding transfer means for transferring to the external device decodes the image data by using the secret key stored in said storage means . A recording / reproducing apparatus having an imaging means and capable of encrypting or decrypting data using an encryption key,
A mounting unit for mounting a battery having storage means for storing information on the encryption key;
First recording means for recording the encryption key stored in the storage means in a built-in memory of the recording / reproducing apparatus;
Encryption means for encrypting the image data acquired by the imaging means using the encryption key;
The image data encrypted by said encryption means, have a, a second recording means for recording the external memory detachable to the recording and reproducing apparatus,
The encryption key stored in the storage means is a public key and a secret key,
The first recording means records a public key among the encryption keys stored in the storage means in the built-in memory,
When the public key is recorded in the built-in memory, the encryption means encrypts image data using the public key recorded in the built-in memory . 7. The apparatus according to claim 6 , further comprising decryption means for decrypting the encrypted image data recorded in the external memory using the secret key stored in the storage means. The recording / reproducing apparatus as described. A recording / reproducing apparatus that has an imaging unit, and that records and reproduces data by encrypting and decrypting data using an encryption key;
A battery having a storage unit and detachable from the recording / reproducing apparatus;
A control method for a recording / reproducing system including a storage unit having an encryption key stored therein and a charging device for charging the battery,
The charging device is:
A storage step of storing the encryption key stored in the storage unit of the charging device in the storage unit of the battery when the battery is connected;
The recording / reproducing apparatus comprises:
A first recording step of recording the encryption key stored in the storage means in a built-in memory of the recording / reproducing apparatus;
An encryption step of encrypting the image data acquired by the imaging means using the encryption key;
The encrypted image data in the encrypting step, have a, a second recording step of recording in the external memory detachable to the recording and reproducing apparatus,
The encryption key stored in the storage means is a public key and a secret key,
In the first recording step, a public key of the encryption key stored in the storage unit is recorded in the built-in memory,
When the public key is recorded in the built-in memory, in the encryption step, the image data is encrypted using the public key recorded in the built-in memory . Control method for recording / reproducing apparatus comprising: a mounting unit for mounting a battery capable of encrypting or decrypting data using an encryption key and having a storage unit for storing information on the encryption key; and an imaging unit Because
A first recording step of recording the encryption key stored in the storage means in a built-in memory of the recording / reproducing apparatus;
An encryption step of encrypting the image data acquired by the imaging means using the encryption key;
The encrypted image data in the encrypting step, have a, a second recording step of recording in the external memory detachable to the recording and reproducing apparatus,
The encryption key stored in the storage means is a public key and a secret key,
In the first recording step, a public key of the encryption key stored in the storage unit is recorded in the built-in memory,
When the public key is recorded in the built-in memory, in the encryption step, the image data is encrypted using the public key recorded in the built-in memory .

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