KR20090046607A - Data storage device, mobile communication device and service provider system for automatically user information backup - Google Patents

Abstract

Disclosed are an information storage device, a mobile communication device, and an operator system for automatic backup of user information. The information storage device includes a data storage unit for storing data, an authentication unit for unidirectionally or mutually authenticating with another information storage device, a session key generator for generating a session key corresponding to the other information storage device, and the session key. And an encryption unit for encrypting data.

Subscriber Identity Module (SIM), Data Backup, Mobile Devices, Wireless Personal Area Network (WPAN), Bluetooth

Description

DATA STORAGE DEVICE, MOBILE COMMUNICATION DEVICE AND SERVICE PROVIDER SYSTEM FOR AUTOMATICALLY USER INFORMATION BACKUP}

The present invention relates to an information storage device, a mobile communication device and an operator system used for automatically backing up user information.

Subscriber Identity Module (SIM) is a module in the form of a card that can be used in a mobile phone, etc., and means a module that stores personal information to provide various services such as subscriber authentication, billing, and security functions. For example, these SIMs allow you to freely use your mobile phone anywhere in your area regardless of mobile phone technical specifications, such as code division multiple access (CDMA) or global mobile communication system (GSM). have. In addition, a certain amount of SIM cards can be reduced in charge every time a call is made and can be recharged. The subscriber identification module for the universal mobile communication system (UMTS), which is the third generation of mobile communication, is called the universal subscriber identity module (USIM).

In the prior art, in order to back up data through an information storage device such as a SIM card or a smart card, the information storage device being used is inserted into a separate backup system, the data of the information storage device is acquired from the backup system, and then backed up again. Data obtained by inserting the information storage device into the backup system should be stored in the information storage device for backup.

The present invention provides a one-way or mutual authentication of another information storage device associated with a backup communication device for backup by using an air interface of a mobile communication device connected without a separate backup system or a separate user intervention. An information storage device for backing up data of another information storage device or backing up its data to the other information storage device is provided.

The present invention provides authentication data or backup with the backup communication device through the air interface such as a wireless personal area network (WPAN) according to a predetermined period, a period set by a user, or a data change of the information storage device. It provides a mobile communication device for transmitting and receiving data to be.

The present invention stores and maintains identifiers of a mobile communication device, a main information storage device, and a backup information storage device in association with each other, and identifies an identifier of an information storage device associated with the mobile communication device when the mobile communication device approaches a communication network. By confirming, the main information storage device which is lost or replaced is automatically deactivated, and the backup information storage device is automatically activated so that the user can receive the service at any time by using the information storage device for backup. Provided is an operator system that can immediately respond to the loss or replacement of the information storage device.

An information storage device according to an embodiment of the present invention includes a data storage unit for storing data, an authentication unit for unidirectionally or mutually authenticating with another information storage device, and a session key generation unit for generating a session key corresponding to the other information storage device. And an encryption unit for encrypting the data through the session key.

According to an aspect of the present invention, the authentication unit may be one-way or mutually authenticated with the other information storage device based on the first authentication data further stored by the data storage unit or the second authentication data stored by the other information storage device. have.

According to an aspect of the present invention, the session key generation unit and the other information storage device may generate the same session key when one-way or mutual authentication.

According to an aspect of the present invention, the encrypted data may be transmitted to a second mobile communication device associated with the other information storage device through an air interface of the associated first mobile communication device. The second mobile communication device can transfer the encrypted data to the other information storage device.

According to an aspect of the invention, the information storage device may further include a decryption unit for decrypting the encrypted data based on the corresponding session key, when the encrypted data is received from the other information storage device, The data storage unit may store the decoded data or update the data based on the decoded data.

According to an embodiment of the present invention, a mobile communication device may include a first interface for transmitting encrypted data to a backup communication device, a second interface for receiving the encrypted data from a main information storage device, and the first interface according to a predetermined condition. And a control unit controlling a backup of data stored in the main information storage device by controlling a first interface and the second interface.

An operator system according to an embodiment of the present invention includes an identifier storage unit for storing and maintaining identifiers of a mobile communication device, a main information storage device, and a backup information storage device in association with each other, and an identifier of an information storage device associated with the mobile communication device. And a change confirming unit confirming whether or not the information storage device has been changed. In this case, when the identifier of the information storage device is the same as the identifier of the backup information storage device, the operator system deactivates the main information storage device and activates the backup information storage device. The changer may further include.

Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

1 is an example for explaining an overview of a method for backing up user information according to an embodiment of the present invention. 1 is a diagram illustrating an example of a method of automatically backing up user information stored by the information storage device 101 without requiring a user. More specifically, FIG. 1 illustrates a method of backing up the user information by communicating with another information storage device 104 associated with the backup communication device 103 through the mobile communication device 102 associated with the information storage device 101. It is an example to explain.

In this case, the information storage device 101 storing the user information may be inserted into or included in the mobile communication device 102 of the user, and within the air interface and the effective communication distance of the mobile communication device 102. It is possible to communicate with the other information storage device 104 in a secure channel through the backup communication device 103 located.

Here, one of all devices capable of wireless communication may be used as the mobile communication device 102 and the backup communication device 103, and the information storage device 101 and the other information storage device 104 are respectively main. As a device that performs the role of the information storage device and the information storage device for backup, it may have the same function as each other or may have a function specialized for each of the main and backup.

For example, when the mobile communication device 102 is a mobile phone, the information storage device 101 may use a subscriber identity module (SIM) card, and the SIM card is backed up through the air interface of the mobile phone. Communication with another information storage device 104 associated with the communication device 103 becomes possible. In this case, a wireless personal area network (WPAN) air interface technology such as Radio Frequency Identification (RFID), ZigBee, Bluetooth, or Near Field Communication (NFC) may be used as the air interface.

In addition, the backup communication device 103 may be implemented in the form of a small device that can communicate with a smart card that can be carried in a wallet or the like, or in the form of a convenient device such as a watch, or a device such as a PDA that a user carries. It may be configured to conveniently maintain a constant distance between the main information storage device and the backup information storage device around the user at all times. That is, when the main information storage device and the backup information storage device exist within the effective communication distance, the main information storage device may simply perform communication for backup through the air interface.

The information storage device 101 generates a session key after one-way or mutual authentication when starting communication with the other information storage device 104, encrypts data to be backed up with the user information through the session key, and encrypts the data. send. In this case, the authentication between the information storage device 101 and the other information storage device 104 may be performed using first authentication data stored in the information storage device 101 or second authentication data stored in the other information storage device 104. Can be. For example, by transmitting the second authentication data in response to a request of the information storage device 101 from another information storage device 104, the information storage device 101 unidirectionally authenticates the other information storage device 104. It becomes possible.

The other information storage device 104 receives the encrypted data and decrypts and stores the encrypted data using a session key generated in the same manner as the information storage device 101 so that the user information can be backed up. Can be. In this case, the first authentication data, the second authentication data and the encrypted data may be transmitted using an air interface included in the mobile communication device 102 and the backup communication device 103.

Such a data backup between the information storage device 101 and the other information storage device 104 is intermittently performed without a user's special command, is performed when switching from a non-communicable state to a communicable state, or periodically according to a user's setting. It may be performed each time the data of the information storage device 101 is changed.

The data backup is to prepare for the loss, damage or replacement of the information storage device 101. When the information storage device 101 is lost, damaged or replaced, the user may change another information storage device 104 to the main. It can be used as an information storage device. That is, in order for another information storage device 104 to be used as the main information storage device, the information storage device 101 and the other information storage device 104 may have the same function as described above. Therefore, by inserting another information storage device 104 in place of the information storage device 101 in the mobile communication device 102, it is possible to immediately cope with the loss, damage or replacement of the information storage device 101.

In addition, the operator system 105 is the first mobile communication device 102, the main information storage device that is the information storage device 101 and other information storage devices for the replacement between the information storage device 101 and the other information storage device 104. An identifier of each of the backup information storage devices 104 may be stored in association with each other. Subsequently, when the mobile communication device 102 approaches the communication network, the operator system 105 receives an identifier of the associated information storage device from the mobile communication device 102 and loses or damages the main information storage device through the identifier. Or you can check the replacement.

That is, the operator system 105 continuously provides a service when the identifier is the same as the identifier of the main information storage device, and the information is the main information storage device when the identifier is the same as the identifier of the backup information storage device. The storage device 101 may be determined to be lost, damaged, or replaced, thereby deactivating the information storage device 101, and activating another information storage device 104 to continuously provide a service.

A new backup information storage device may be allocated to a user who has lost the main information storage device. The operator system 105 may use another information storage device 104 as the main information storage device as the main information storage device. An information storage device can be set as the backup information storage device. That is, the operator system 105 may store and maintain identifiers of the mobile communication device 102, the other information storage device 104, and the new backup information storage device in association with each other. Thereafter, the other information storage device 104 may perform data backup in the same manner as the existing information storage device 101. To this end, the other information storage device 104 may perform the same function as the information storage device 101. For example, the other information storage device 104 encrypts its data with the new backup information storage device and uses the air interface of the associated mobile communication device 102 to backup the data storage device associated with the new backup information storage device. It may transmit to the communication device 103.

As such, the information storage device, the mobile communication device, and the operator system used for the data backup will be described in more detail with reference to FIGS. 2 to 5.

2 is a block diagram illustrating an internal configuration of an information storage device according to an exemplary embodiment of the present invention. Here, the information storage device 200 may include a data storage unit 201, an authentication unit 202, a session key generation unit 203, an encryption unit 204, and a decryption unit 205.

The data storage unit 201 stores data to be backed up, such as user information. In addition, the data storage unit 201 may further include authentication data to be used for authentication.

The authenticator 202 authenticates one-way or mutually with another information storage device. In this case, the authentication unit 202 may perform one-way or mutual authentication with the other information storage device based on the first authentication data which is the authentication data further stored by the data storage unit or the second authentication data stored by the other information storage device. Can be.

For example, the authentication unit 202 transmits an authentication request message to the other information storage device through the air interface of the associated first mobile communication device, and the other information storage device may transmit air of the associated second mobile communication device. By transmitting the second authentication data to the authentication unit 202 through an interface, one-way authentication between the information storage device 200 and the other information storage device may be performed. Alternatively, mutual authentication between the information storage device 200 and the other information storage device may be performed by exchanging the first authentication data and the second authentication data with each other.

The session key generation unit 203 generates a session key corresponding to the other information storage device. In this case, the other information storage device may also generate the session key in the same manner. In other words, the session key generation unit 203 and the other information storage device (or the session key generation unit included in the other information storage device) may generate the same session key when one-way or mutually authenticated.

An encryption unit 204 encrypts the data through the session key. The information storage device 200 may operate as the main information storage device described with reference to FIG. 1. That is, the information storage device 200 may allow the data to be encrypted through the encryption unit 204 to back up its data. In this case, the encrypted data may be transmitted to a second mobile communication device connected to the other information storage device through an air interface of the associated first mobile communication device, and the second mobile communication device may be transferred to the other information storage device. The encrypted data can be delivered. The other information storage device may back up the data by decrypting and storing the encrypted data through the session key.

When the encrypted data is received from the other information storage device, the decryption unit 205 decrypts the encrypted data based on the corresponding session key. In FIG. 1, a backup information storage device may be used as a main information storage device. That is, the information storage device 200 and the other information storage device may include the same function, so that the information storage device 200 also stores information for backup that decrypts and stores the encrypted data received through the session key. It may further include a decoder 205 which is a function of the device. In this case, the data storage unit 201 may store the decoded data or update the data based on the decoded data.

The information storage device 200 may further include a communication interface 206 for communicating with the first mobile communication device for transmission of the first authentication data and the encrypted data or reception of the second authentication data and the encrypted data. ) May be further included.

3 is a block diagram illustrating an internal configuration of a mobile communication device according to an embodiment of the present invention. Here, the mobile communication device 300 includes a first interface 301, a second interface 302, and a controller 303 as shown in FIG. 3.

The first interface 301 transmits the encrypted data to the backup communication device 310, and the second interface 302 receives the encrypted data from the main information storage device 320.

In this case, the controller 303 may control the first interface 301 and the second interface 302 according to a predetermined condition to process the backup of the data stored in the main information storage device 320. In more detail, the controller 303 may be configured according to at least one of a change of the data stored in the main information storage device 320, a cycle according to a user's setting, a predetermined cycle, and a transition from a non-communicable state to a communicable state. The backup process of the data can be started.

For example, when the data stored in the main information storage device 320 is changed, the controller 303 recognizes the change of the data and controls the main information storage device 320 to perform a backup according to the change of the data. can do. Alternatively, the backup may be controlled to be performed every cycle set by the user, or the backup may be performed at the time when the communication is switched from a state in which communication is not possible due to power shutdown or departure of the communication area. As such, since the data stored in the main information storage device 320 is backed up to the backup information storage device 330 according to various conditions, the loss of data may be minimized even when the main information storage device 320 is lost or damaged. Or you can eliminate it.

For the backup, the backup information storage device 330 and the main information storage device 320 associated with the backup communication device 310 may perform one-way or mutual authentication, and then backup data encrypted by the session key in the main information storage device 320. It is necessary to receive, decode and store the information in the information storage device 330.

First, for one-way or mutual authentication, the controller 303 receives first authentication data from the backup communication device 310 through the first interface 301 and receives the main information storage device through the second interface 302. 320, the second authentication data stored in the main information storage device 320 may be received through the second interface 302, and then transmitted to the backup communication device 310 through the first interface 301. In addition, the backup communication device 310 receives the first authentication data from the associated backup information storage device 330 and transmits it to the first interface 301 or the second authentication data through the first interface 301. It may be received and transmitted to the backup information storage device 330.

In other words, the controller 303 receives the first authentication data stored by the backup information storage device 330 through the backup communication device 310 and the first interface 301, and through the second interface 302. By transmitting to the main information storage device 320, the main information storage device 320 controls the one-way authentication of the backup information storage device 330 through the first authentication data or the main information storage device 320 stores the information. The second authentication data is received through the second interface 302 and transmitted to the backup information storage device through the first interface 301 and the backup communication device 310, thereby allowing the backup information storage device 330 to receive the second authentication data. The main information storage device 320 may be controlled to be one-way authenticated through the authentication data. In addition, the controller 303 may control the main information storage device 320 and the backup information storage device 330 to mutually authenticate each other by performing the above two processes.

In addition, the controller 303 may store the data encrypted from the main information storage device 320 through the second interface 302 to back up the data stored in the main information storage device 320 to the backup information storage device 330. It may be received and transmitted to the backup communication device 310 via the first interface 301. In this case, the backup communication device 310 transmits the encrypted data to the backup information storage device 330, and the backup information storage device 330 uses the session key generated in the same manner as the main information storage device 320. By decrypting and storing the encrypted data, the data can be backed up.

Here, the backup communication device 310 is embodied in the form of a small device that can communicate with a smart card that can be carried in a wallet or the like or a device that is convenient to carry, such as a watch as described with reference to FIG. It may be implemented in a device such as a PDA. The backup communication device 310 receives the encrypted data or authentication data from the mobile communication device 300 from the main information storage device 320 and transmits the data or authentication data to the backup information storage device 330 or the backup information storage device 320. The first interface 311, the second interface 312, and the controller 313 may be included as illustrated in FIG. 3 to receive the authentication data of FIG. 3 and transmit the authentication data to the mobile communication device 300.

That is, the first interface 311 receives encrypted data from the mobile communication device 300, and the second interface 312 transmits the encrypted data to the backup information storage device 330.

The controller 313 controls the backup of the encrypted data by controlling the first interface and the second interface. At this time, the controller 313 is a main information storage device from the mobile communication device 300 through the first interface 311 for the one-way or mutual authentication between the main information storage device 320 and the backup information storage device 330. The first authentication data, which is authentication data of 320, may be received and transmitted to the backup information storage device 330 through the second interface 312.

Alternatively, the second authentication data, which is authentication data of the backup information storage device 330, may be received through the second interface 312 and transmitted to the mobile communication device 300 through the first interface 311.

In this case, the main information storage device 320 may divide and transmit the encrypted data when the encrypted data exceeds a size that can be transmitted at one time, and the controller 303 temporarily stores the divided encrypted data. When all the encrypted data is received, the encrypted data may be controlled to be transmitted to the backup communication device 310 through the first interface 301. For example, when the above-described SIM card is used as the main information storage device 320 and the backup information storage device 330, the size of the SIM card that can be transmitted at a time may be limited to 256 bytes. In this case, when the size of the encrypted data to be encrypted and transmitted exceeds 256 bytes, the SIM card cannot transmit the encrypted data at once. Therefore, the SIM card divides and transmits the encrypted data in 256-byte units, and the control unit 303 temporarily stores the divided data in 256-byte units, and then receives all of the encrypted data. It can be combined and transmitted as encrypted data.

4 is a block diagram illustrating an internal configuration of a service provider system according to an embodiment of the present invention. Here, the operator system 400 may include an identifier storage unit 410, a change confirmation unit 420, and an information storage device change unit 430 as shown in FIG. 4.

The identifier storage unit 410 stores and maintains identifiers of the mobile communication device, the main information storage device, and the backup information storage device in association with each other. For example, each field for storing identifiers of the mobile communication device, the main information storage device and the backup information storage device may be generated, and an identifier corresponding to the corresponding field may be stored and maintained. The method of storing and maintaining the identifiers in association with each other in the identifier storage unit 410 will be described in more detail with reference to FIG. 5.

The change confirming unit 420 confirms whether or not the information storage device is changed based on an identifier of the information storage device associated with the mobile communication device. To this end, the change confirming unit 420 is an identifier receiving unit for receiving an identifier of the mobile communication device and the information storage device from the mobile communication device, when the mobile communication device is connected to the communication network as shown in FIG. 421 and the information storage device change checking unit 422 confirming that the information storage device is changed when the identifier of the information storage device is different from the identifier of the main information storage device.

When the identifier of the information storage device is the same as the identifier of the backup information storage device, the information storage device changing unit 430 deactivates the main information storage device and activates the backup information storage device. . To this end, the information storage device changing unit 430 updates the identifier of the main information storage device stored in the identifier storage unit 410 with the identifier of the information storage device for backup, and updates the identifier of the information storage device for backup. It can be updated with the identifier of the information storage device.

5 is an example for explaining the method of handling the loss of the information storage device. Here, the table 510 shows an example of storing identifiers of the mobile communication device, the main information storage device, and the backup information storage device in association with each other. In this case, when the main information storage device having the identifier 'SIM_ID-A' 511 is lost, the user may identify the backup information storage device having the identifier 'SIM_ID_B' 512 with the identifier '011-1234-5678' 513. The mobile communication device may be inserted into a mobile communication device, and the operator system may receive an identifier of an associated information storage device from the mobile communication device when the mobile communication device accesses a communication network. In this case, the identifier is an identifier 'SIM_ID_B' 512 which is an identifier of the backup information storage device, and through this, the operator system may confirm that the main information storage device is lost, damaged or replaced.

The operator system updates the identifier 'SIM_ID-A' 511 of the main information storage device with the identifier 'SIM_ID_B' 512 of the backup information storage device, and updates the identifier 'SIM_ID_B' 512 of the backup information storage device. May be updated with an identifier of a new backup information storage device.

That is, the table 520 shows an example in which the identifier of the main information storage device is updated with the identifier 'SIM_ID_B' 512 in the table 510, and the identifier of the backup information storage device is updated with the identifier of the new information storage device for backup. Indicates. Accordingly, the user of the mobile communication device having the identifier '011-1234-5678' 513 can receive the continuous service simply by inserting the backup information storage device having the identifier 'SIM_ID_B' 512 into the mobile communication device. have.

As described above, the present invention has been described by specific embodiments such as specific components and the like, but the embodiments and drawings are provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things that are equivalent to or equivalent to the claims as well as the following claims will belong to the scope of the present invention. .

1 is an example for explaining an overview of a method for backing up user information according to an embodiment of the present invention.

2 is a block diagram illustrating an internal configuration of an information storage device according to an exemplary embodiment of the present invention.

3 is a block diagram illustrating an internal configuration of a mobile communication device according to an embodiment of the present invention.

4 is a block diagram illustrating an internal configuration of a service provider system according to an embodiment of the present invention.

5 is an example for explaining the method of handling the loss of the information storage device.

<Explanation of symbols for the main parts of the drawings>

200: information storage device

201: data storage

202: certification unit

203: session key generation unit

204: encryption unit

205: decoder

Claims (22)

A data storage unit for storing data; An authenticator configured to unidirectionally or mutually authenticate with another information storage device; A session key generator for generating a session key corresponding to the other information storage device; And An encryption unit for encrypting the data through the session key Information storage device comprising a. The method of claim 1, The authentication unit, And one-way or mutual authentication with the other information storage device based on the first authentication data further stored by the data storage unit or the second authentication data stored by the other information storage device. The method of claim 1, And the session key generator and the other information storage device generate the same session key when one-way or mutually authenticated. The method of claim 1, The encrypted data is transmitted to a second mobile communication device connected to the other information storage device through an air interface of the first mobile communication device connected thereto, And the second mobile communication device transfers the encrypted data to the other information storage device. The method of claim 1, Decryption unit for decrypting the encrypted data based on the corresponding session key when the encrypted data is received from the other information storage device More, The data storage unit, And store the decoded data or update the data based on the decoded data. A first interface for transmitting encrypted data to a backup communication device; A second interface for receiving the encrypted data from a main information storage device; And A control unit controlling the backup of the data stored in the main information storage device by controlling the first interface and the second interface according to a predetermined condition; Mobile communication device comprising a. The method of claim 6, The predetermined condition may include at least one of a change of the data stored in the main information storage device, a period according to a user's setting, a predetermined period, and a transition from a non-communicable state to a communicable state. Mobile communication device. The method of claim 6, The control unit, Receiving first authentication data from the backup communication device through the first interface and transmitting the first authentication data to the main information storage device through the second interface, or second authentication data stored in the main information storage device through the second interface. The mobile communication device, characterized in that for receiving and transmitting to the backup communication device via the first interface. The method of claim 8, The backup communication device receives the first authentication data from an associated backup information storage device and transmits the first authentication data to the first interface, or receives the second authentication data through the first interface and transmits the second authentication data to the backup information storage device. Mobile communication device, characterized in that. The method of claim 9, And the main information storage device authenticates the backup information storage device through the first authentication data. The method of claim 9, And the backup information storage device authenticates the main information storage device through the second authentication data. The method of claim 6, The control unit, And receiving encrypted data from the main information storage device through the second interface and transmitting the encrypted data to the backup communication device through the first interface. The method of claim 12, The backup communication device transmits the encrypted data to an associated information storage device for backup. And the backup information storage device decrypts and stores the encrypted data using a session key generated in the same manner as the main information storage device. The method of claim 6, The main information storage device divides and transmits the encrypted data when the encrypted data exceeds a size that can be transmitted at one time. The control unit And temporarily storing the divided encrypted data, and transmitting the encrypted data to the backup communication device through the first interface when all of the encrypted data is received. An identifier storage unit for storing and maintaining identifiers of a mobile communication device, a main information storage device, and a backup information storage device in association with each other; And A change confirming unit confirming whether or not the information storage device is changed based on an identifier of the information storage device associated with the mobile communication device; Operator system comprising a. The method of claim 15, The change confirmation unit, An identifier receiver configured to receive identifiers of the mobile communication device and the information storage device from the mobile communication device when the mobile communication device accesses a communication network; And If the identifier of the information storage device is different from the identifier of the main information storage device, the information storage device change confirming unit confirming that the information storage device is changed. Operator system comprising a. The method of claim 15, When the identifier of the information storage device is the same as the identifier of the backup information storage device, the information storage device change unit for deactivating the main information storage device and activating the backup information storage device. Operator system further comprising. The method of claim 17, The information storage device change unit, And updating the identifier of the main information storage device stored in the identifier storage unit with the identifier of the backup information storage device, and updating the identifier of the backup information storage device with the identifier of the new backup information storage device. A first interface for receiving encrypted data from a mobile communication device; A second interface for transmitting the encrypted data to a backup information storage device; And Control unit for controlling the backup of the encrypted data by controlling the first interface and the second interface Backup communication device comprising a. The method of claim 19, The control unit, Receive authentication data of the main information storage device from the mobile communication device through the first interface and transmit the authentication data to the backup information storage device through the second interface, or authentication data of the backup information storage device through the second interface. Receiving and transmitting the received data to the mobile communication device through the first interface. The method of claim 20, The backup information storage device is a backup communication device, characterized in that for authenticating the main information storage device through the authentication data of the main information storage device. The method of claim 19, The mobile communication device is associated with a main information storage device, And the encrypted data is encrypted by the session key generated in the main information storage device and decrypted by the session key generated in the same manner in the backup information storage device.

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