JP2007013484A - Emergency data restoration system and method, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an emergency data restoration system for reading storage data even in emergency when a cryptographic key is lost by storing data encrypted by using the cryptographic key in a storage medium for protecting sensitive information. <P>SOLUTION: A user side data processor 1 for storing encryption data in a connected storage medium 14 and a restoration processor 2 for performing a restoration operation in emergency when the decryption of the encryption data is impossible are configured to restore data by sharing a load and cooperating with each other. The restoration processor 2 prepares a pair of a public key and a personal key, and transfers only the public key to the user side device 2, and the user side device 2 prepares a cryptographic key for encrypting data, and encrypts the cryptographic key by the public key, and writes it in the predetermined part of the storage medium 14. In case of emergency, the user side device 2 extracts the encrypted cryptographic key from the storage medium 14, and transfers it to the restoration processor 1, and the restoration processor 1 returns the cryptographic key decrypted by the personal key to the user side device 2, and the user side device 2 restores the data. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  Providing an emergency data recovery system that enables data stored in a storage medium to be read in the event of an emergency when the encryption key is lost, etc., in order to protect confidential information About.

  In the rapidly expanding information society, the importance of concealing personal information and confidential information within an organization is unquestionable. However, it is regrettable that leaks have occurred frequently and have become a serious social problem. For computer-related information, as one of the countermeasures, user authentication and access restriction are performed using a password, but the vulnerability of this method is recognized. For this reason, a method of encrypting and transmitting a user's document or the like or storing it in a storage medium has begun to spread. A typical example of transmission is SSL on the Internet, and manufacturers also provide respective encryption systems for storage media.

  However, unlike temporary transmission processing, writing / reading encrypted information to / from storage media requires thorough management and operation, and in that sense, it is still avoided by individual computer users. Tend. The biggest reason for patrol is probably due to anxiety and warning that decryption becomes impossible due to forgotten encryption keys such as passwords. Strangely enough, technical support for this is not at present, it is just at the preparedness level.

  In view of this situation, an object of the present invention is to provide computer users with technical support for removing such anxiety. That is, an object of the present invention is to provide a restoration service to a user of a storage device such as an HDD when decryption becomes impossible for the reasons described above.

  In order to realize such an object, the present invention provides a user side data processing apparatus installed on the user side that encrypts and manages data, and a recovery process when the encrypted data cannot be decrypted. An emergency data recovery system comprising a recovery processing device to perform, wherein the recovery processing device stores means for communicating with the user-side data processing device, and a key pair storage for storing and saving a public key and personal key pair Means, public key creation means for creating a public key / personal key pair and writing it to the key pair storage means, and the public key extracted from the key pair storage means encrypted by the public key The user-side data processing device includes a storage medium constituting a data storage unit that stores various data. A communication means for communicating with the recovery processing apparatus; a public key storage means for storing and saving a public key created by the recovery processing apparatus; and a data encryption key creating means for creating an encryption key for encrypting data And encryption key writing means for encrypting the encryption key with the public key extracted from the public key storage means and writing the encrypted encryption key in a predetermined location of the storage medium, and by the encryption key, Data reading means for reading out data stored encrypted in the data storage means, data writing means for encrypting data and writing the data in the data storage means, and an encryption key encrypted from a predetermined location of the storage medium And an encryption key reading means for reading out.

  According to such a configuration, the encryption key used by the user to encrypt the data is encrypted with the public key, and the decryption requires a personal key on the recovery processing device side. Even if the storage medium is stolen, information is fully protected. In addition, since the user does not need to be involved in the management of personal keys, which can be said to be the key point of this system, the burden on the user is reduced.

In the case of “emergency”, that is, “when the encrypted data can no longer be decrypted”, for example, the password as the base of the encryption key may be lost due to an accident or retirement of the person in charge. In addition, this also applies to a case where some trouble occurs in the computer connected to the encrypted storage medium and the decryption process becomes impossible.
When the “storage medium” in the present invention is accurately defined, it is referred to as “a storage medium that allows random read / write in units of sectors and on which an OS (operating system) can build a file system”. It will be. Therefore, tapes, read-only storage media, media for which device drivers are not provided, and the like are outside the scope of the present invention, and flexible disks, fixed hard disks, USB-specific removable storage media, and the like can be targeted. Therefore, in the following description of the embodiment, this storage medium is particularly referred to as a “protection target storage medium”.

According to the present invention, the recovery processing apparatus may include an encryption key reading unit, a data reading unit for decrypting data, and a writing unit for writing encrypted data.
According to such a configuration, even if the user's computer is out of order, the data in the storage medium can be recovered.

  In order to realize the object, the present invention is configured as a computer program for causing each of the user-side data processing device and the recovery processing device to perform storage and data recovery processing for preventing information leakage. You can also.

  Furthermore, the present invention provides a user-side data processing apparatus that handles data encryption as a normal operation and stores encrypted data in a connected storage medium as an emergency data recovery method, and the encrypted data cannot be decrypted. An emergency data recovery method for supporting sharing / collaboration with a recovery processing apparatus that performs recovery work in the event of an emergency, wherein the recovery processing apparatus creates a public key and a private key by creating a key pair consisting of a personal key Only to the user-side data processing device, the user-side data processing device creates an encryption key for encrypting the data, and encrypts the encryption key with the public key. While writing to the storage medium, the user-side data processing device or the recovery processing device retrieves the encryption key from the storage medium in an emergency, and the recovery processing device uses the personal key. The encryption key is decrypted, and the user-side data processing device or the recovery processing device decrypts the encrypted data that cannot be decrypted with the decrypted encryption key. is there.

  Since the encryption key is encrypted with the public key, it can be decrypted only with the personal key paired therewith. That is, if the management of the personal key is taken care of, the leakage of information can be avoided even if the storage medium is stolen. A situation where decryption becomes impossible due to the loss of the personal key can occur in the same way, but the individual used for this purpose is more difficult than the loss of the encryption key, that is, the password, etc. Key management is extremely easy. This is because passwords and the like must be managed individually for each user, but it is not necessary in the case of a personal key used in this application.

(First embodiment)
The configuration of the system according to the first embodiment will be described with reference to FIG.
The present embodiment includes a recovery processing device 1 and a user-side data processing device 2.
In the present embodiment, it is assumed that a manufacturer of a storage medium to be protected performs data recovery as a service for users of its own products. In this case, the recovery processing apparatus 1 is usually a computer of the manufacturer.

The recovery processing device 1 includes a storage unit 3, a processing unit 4, and a communication unit 5.
The storage unit 3 includes key pair storage means 6 for storing a public key / personal key pair.

  The processing unit 4 includes a public key creation unit 7 and an information decryption unit 8, and includes a unit that performs various control processes. Each means of the processing unit 4 is realized by reading a computer program stored in a ROM, an external storage medium, or the like onto a memory by the CPU, and executing a command on the memory by the CPU.

  The public key creation means 7 creates a key pair of the public key K1 and the personal key K2 under certain requirements, and stores this key pair in the key pair storage means 6. The personal key K2 is a key unique to the manufacturing company that manages the recovery processing apparatus 1, and is information that only this manufacturing company can know. On the other hand, the public key K1 is open to all users. Even if there are a plurality of users, only one type of key pair is required.

  The information decryption means 8 decrypts the information encrypted with the public key K1 by using the personal key K2 extracted from the key pair storage means 6. Any information can be decrypted as long as it is encrypted with the public key K1, but in this embodiment, an encrypted encryption key sent from the user in an emergency (hereinafter referred to as “encryption key”). Is the main target. Although the user has an encryption key K3 for encrypting data, it is dangerous to store the encryption key K3 as it is from the viewpoint of information security. Therefore, the encryption key K3 is encrypted with the public key K1, and the encryption key K4 is stored. If the data cannot be recovered due to reasons such as forgetting the encryption key K3, the encryption key K4 is decrypted by the information decryption means 8, and the encryption key K3 can be taken out.

The communication means 5 transmits / receives a signal to / from the user-side data processing device 2 via the communication line 9.
The communication line 9 may be a dedicated line or the Internet.
The restoration processing apparatus 1 includes an input unit and an output unit (not shown) as necessary.

Next, the configuration of the user side data processing apparatus 2 will be described.
The user-side data processing device 2 includes a storage unit 10, a processing unit 11, and a communication unit 12. In addition, input / output means (not shown) such as a keyboard and a display are provided as appropriate.

The storage unit 10 includes a public key storage unit 13 and a data storage unit 14.
The public key storage unit 13 stores the public key K1 created by the public key creation unit 7 of the recovery processing apparatus 1.
The data storage means 14 is means for storing and saving data created and managed by the user. From the viewpoint of information concealment, the data is encrypted and saved, and is decrypted and read.
In this embodiment, it is assumed that the data storage unit 14 is implemented by a protection target storage medium. Therefore, hereinafter, the “data storage unit 14” may be referred to as a “protection target storage medium 14”.

  The processing unit 11 includes a data encryption key creating unit 15, an encryption key writing unit 16, a data reading unit 17, a data writing unit 18, and an encryption key reading unit 19.

The data encryption key creation means 15 creates an encryption key K3 for encrypting data.
The encryption key writing unit 16 writes the encryption key K4 obtained by encrypting the encryption key K3 with the public key K1 extracted from the public key storage unit 13 in a predetermined location of the protection target storage medium 14.
The data reading means 17 reads the data encrypted and stored in the data storage means 14 with the encryption key K3 and reads the data writing means 18 encrypts the data with the encryption key K3 and the data storage means 14 Write to.
The encryption key reading unit 19 reads the encryption key K4 from a predetermined location of the protection target storage medium 14.

It is assumed that the user can also obtain a computer program for causing each of the processing means to perform each process with the acquisition of the protection target storage medium 14. The acquisition method does not ask | require.
This computer program is stored in the storage unit 10, developed on the memory (not shown) from the storage unit 10 when the user-side data processing device 2 is activated, and executed by a CPU (not shown).

Next, the operation of this embodiment will be described with reference to the processing flow of FIG.
The recovery processing device 1 of the manufacturing company of the protection target storage medium 14 creates a pair of its own public key K1 and personal key K2, and stores it in the key pair storage means 6 (S101). This personal key K2 is confidential information of the manufacturing company. Next, only the public key K1 is transmitted to the user-side data processing device 2 (S102). Usually, the data is sent from the communication means 5 to the communication means 12 of the user side data processing apparatus 2 via the communication line 9. However, it is not always necessary to use such electronic means. It may be written as data in a computer program attached to the protection target storage medium 14, or may be sent from the manufacturer to the user side by means such as mail or mail.

  The restoration processing device 1 sends the same public key K1 to all users. This is because even if the same public key K1 is distributed to each user, each user does not have the personal key K2, so that there is no possibility of information leaking between users.

The user connects the protection target storage medium 14 to his / her user data processing apparatus 2 and installs a necessary computer program (S201). Next, the public key K1 transmitted by the recovery processing device 1 in step S102 is stored in the public key storage unit 13 (S202).
Next, the data encryption key creation unit 16 creates an encryption key K3 used for encrypting / decrypting user data by a predetermined algorithm (S203). The method of creating the encryption key K3 includes, for example, a method based on a password, but is not particularly limited.

  Subsequently, the process proceeds to the encryption key writing unit 16 (S204). The public key K1 is extracted from the public key storage means 13, and the encryption key K3 is encrypted with the public key K1. The encryption key K4 obtained by the encryption is written in a predetermined location of the protection target storage medium 14.

Here, writing of the encryption key K4 to the protection target storage medium 14 will be described.
The OS creates a masked record or file under the root directory of the protection target storage medium 14. When notifying the OS of an area where a record or the like can be created by the OS, a size smaller than the area size that is actually secured is notified. An area corresponding to the difference between the secured size and the notified size may be used for writing the encryption key K4. Further, since this area portion is not a target of input / output by the OS, even if the system of this embodiment writes unique information here, there is a side effect that makes it impossible to use the storage medium 14 to be protected. Never give.
This technique can be realized in a normal file system construction environment. Further, in the present invention, the writing process to such a storage medium is indispensable. Therefore, as the “protection target storage medium 14”, “random read / write in units of sectors is possible and the OS is on that. The condition is that it is possible to build a file system.

  It should be noted here that the encryption key K3 itself is not stored and saved in the user-side data processing device 2. If the data is stored in the user-side data processing apparatus 2, information leakage cannot be prevented, and an emergency recovery measure as in the present invention is unnecessary. The encryption key K3 should be memorized by the user or recorded in the personal notebook of the user. Therefore, when this user changes jobs, the encryption key K3 may be lost. In order to avoid such inconvenience, the present invention stores an encryption key K4 obtained by encrypting the encryption key K3 with the public key K1. Since the user-side data processing device 2 does not have the personal key K2 for decrypting the encryption key K4, there is no worry of information leakage even if the user-side data processing device 2 is stolen. .

  The encryption key K4 is written in the protection target storage medium 14 itself when a failure or the like occurs in the data processing apparatus 2 on the user side or when the protection target storage medium 14 is connected to another computer. To prepare for import processing. Since the purpose of the encryption key K4 is such, the encryption key K4 is used only in the recovery work.

Next, when the input encryption key K3 is valid (YES in S205), the data read unit 17 decrypts the data read from the protection target storage medium 14, or the data write unit 18 encrypts the data. The written data is written into the protection target storage medium 14 (S206).
It goes without saying that any method for encrypting or decrypting these data may be used, for example, a well-known AES method or chaos method.

  If the input encryption key K3 is not valid (NO in S205), data cannot be read / written. In this case, if it is confirmed by some means that the user is a valid user, the encryption key reading means 19 performs encryption from a predetermined location of the protection target storage medium 14 according to a command via the input means. The key K4 is extracted (S207), and the encryption key K4 is transmitted to the recovery processing apparatus 1 via the transmission means 12 (S208). As a specific transmission method, a method using an attached file of an e-mail, a method using a Web site, or the like can be considered. Mail such as registered mail may be used.

  When the recovery processing device 1 receives the encryption key K4 from the user-side data processing device 2 (S103), the recovery processing device 1 takes out the personal key K2 paired with the public key K1 from the key pair storage unit 6 (S104). The information decryption means 8 decrypts the encryption key K4 using this personal key K2, and sends it back to the user side data processing apparatus 2 (S105).

  The decryption of the encryption key K4 with the personal key K2 is the encryption key K3 itself. When the user-side data processing device 2 receives the encryption key K3 from the recovery processing device 1 (S209), it stores the protection target memory. Data can be read from and written to the medium 14 again (S206). If the encryption key K3 is sent back and the data can be decrypted, the encryption key is changed and the data encrypted with the new encryption key K3 is replaced with the data encrypted with the old encryption key K3. . This is because, as long as the manufacturing company knows the encryption key K3 of the user, it is not desirable to keep using such an encryption key K3 from the viewpoint of information secrecy. Therefore, the system of the present invention must not only create a new encryption key K3 but also have a function to change it.

In the present embodiment, the emergency recovery processing is the processing from steps S103 to S105 performed by the recovery processing device 1.
This recovery process must be executed by another computer independent of the user-side data processing apparatus 2 as is applicable to all the embodiments of the present invention. This is a matter of course in view of the gist of the present invention, that is, compatibility between information security and emergency response.

(Second Embodiment)
The second embodiment shown in FIG. 3 differs from the first embodiment in that the recovery processing apparatus 1 includes an encryption key reading unit 20, a data reading unit 21, and a data writing unit 22. For this reason, in the figure, the same components as those in the first embodiment are denoted by the same reference numerals.
The function of the encryption key reading means 20 is the same as that of the encryption key reading means 19 of the user side data processing device 2, and the functions of the data reading means 21 and the data writing means 22 are respectively user side data processing. The same as the data reading means 17 and the data writing means 18 of the apparatus 2.

  This embodiment mainly assumes a case where the user-side data processing apparatus 2 cannot read / write data from / to the protection target storage medium 14 for some reason. It is delivered to the manufacturing company by flight and directly connected to the recovery processing apparatus 1 to perform the recovery processing.

  The recovery processing apparatus 1 reads the encryption key K4 from a predetermined location of the protection target storage medium 14 by the encryption key reading unit 20 and decrypts it by the information decryption unit 8 to obtain the encryption key K3. The data reading means 21 decrypts the data read from the protection target storage medium 14 using this encryption key K3. Further, the data writing means 22 can write the encrypted data to the protection target storage medium 14.

  In the second embodiment, the recovery processing apparatus 1 recovers in an emergency such as extraction of the encryption key K4, decryption of the encryption key K4 into the encryption key K3, and decryption of the encrypted data using the encryption key K3. Do all of the work. In this embodiment, when a failure occurs in the user-side data processing apparatus 2 to which the protection target storage medium 14 is connected, data recovery cannot be performed even if the protection target storage medium 14 itself has no abnormality. It may be applied to

  As in this embodiment, whether or not the recovery processing apparatus 1 also includes data encryption or decryption means should be determined in consideration of the operating environment of the system.

(Third embodiment)
In both the first embodiment and the second embodiment, when the user fails in data recovery, the manufacturer of the protection target storage medium 14 takes charge of the recovery process.
In the third embodiment, the recovery process is performed on the user side.

  For example, if the user belongs to a certain domain (any company, organization, etc.), the administrator of the domain may fulfill the role of the manufacturing company in the first or second embodiment in an emergency. That is, it is sufficient if there is one public key / personal key pair in the domain.

  As another example, a case where the user himself / herself plays the role of the manufacturing company of the above-described embodiment can be considered. In this case, it is assumed that the user prepares a computer for recovery processing separately from the computer for business processing for creating documents and the like. Since the business processing computer does not have information on the personal key, the confidentiality of the information can be ensured except in rare cases where the computer is stolen together with the recovery processing computer.

The embodiments disclosed above are illustrative in all respects and are not restrictive. Therefore, various modifications are possible. However, as long as the modification is based on the technical idea described in the claims, the modification is included in the technical scope of the present invention.

It is a figure which shows the system configuration | structure of 1st Embodiment. It is a figure which shows the processing flow of 1st Embodiment. It is a figure which shows the system configuration | structure of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recovery processing apparatus 2 User side data processing apparatus 5 Communication means 6 (of recovery processing apparatus 1) Key pair storage means 7 (of recovery processing apparatus 1) Public key creation means 8 (of recovery processing apparatus 1) (Recovery processing apparatus 1) Information decryption means 12 (user side data processing apparatus 2) communication means 13 (user side data processing apparatus 2) public key storage means 14 (user side data processing apparatus 2) data storage means, protection target storage medium 15 Data encryption key creation means 16 (of the user side data processing apparatus 2) Encryption key writing means 17 (of the user side data processing apparatus 2) Data reading means 18 (of the user side data processing apparatus 2) (User side) Data writing means 19 (of the data processing apparatus 2) Encryption key reading means 20 (of the user side data processing apparatus 2) Encryption key reading means 21 (of the recovery processing apparatus 1) Data (of the recovery processing apparatus 1) Reading means 22 Data writing means (of the recovery processing apparatus 1)

Claims (6)

An emergency data recovery system comprising a user-side data processing device installed on the user side for encrypting and managing data, and a recovery processing device for performing recovery processing when the encrypted data cannot be decrypted Because
The restoration processing device
Means for communicating with said user-side data processing device;
Key pair storage means for storing and storing a public key and a private key pair;
Public key creation means for creating a public key and private key pair and writing the key pair storage means;
An information decryption means for decrypting encrypted information encrypted by a public key with a personal key paired with the public key extracted from the key pair storage means,
The user side data processing device
A storage medium constituting data storage means for storing various data is provided,
Communication means for communicating with the recovery processing device;
Public key storage means for storing and storing the public key created by the recovery processing device;
A data encryption key creating means for creating an encryption key for encrypting data;
Encryption key writing means for encrypting the encryption key with the public key extracted from the public key storage means, and writing the encrypted encryption key in a predetermined location of the storage medium;
A data reading means for reading data stored encrypted by the data storage means by the encryption key; and a data writing means for encrypting data and writing to the data storage means;
An encryption key reading means for reading an encrypted encryption key from a predetermined location of the storage medium;
An emergency data recovery system comprising: In the emergency data recovery system according to claim 1,
The restoration processing device
An encryption key reading means for reading an encrypted key from a predetermined location of the storage medium of the user side data processing device;
A data reading means for decrypting data stored in the storage medium encrypted by the encryption key decrypted by the information decryption means, and a data document for encrypting the data and writing to the storage medium Including
Characterized by comprising. A computer program for causing a computer to function as a recovery processing device for performing recovery processing when it becomes impossible to decrypt encrypted data,
Create and store a public / private key pair,
When the encrypted information encrypted with the public key is input, the recovery processing device is caused to perform a process of decrypting the encrypted information with the personal key paired with the public key. Computer program. A computer program according to claim 3,
While reading the encryption information from a predetermined location of the storage medium storing the encryption information,
Using the information obtained by decrypting the encrypted information, decrypting the data encrypted and stored in the storage medium, or encrypting the data and writing the data to the storage medium to the restoration processing device It is characterized by being made to do. A computer program for causing a computer connected to a storage medium to function as a user-side data processing apparatus that encrypts and manages data,
When a public key that is paired with a specific personal key is given, the public key is stored and saved,
Create an encryption key according to a predetermined algorithm,
An encryption key obtained by encrypting this encryption key with the public key is written to a predetermined location of the storage medium, and
Storing the data encrypted by the encryption key in the storage medium;
While decrypting the data stored in the storage medium with the encryption key,
Read the encryption key from a predetermined location of the storage medium,
A computer program that causes another computer that manages the personal key to perform a process of transmitting the encryption key. Sharing of data encryption processing as a normal operation between the user-side data processing device that stores the encrypted data in the connected storage medium and the recovery processing device that performs recovery work in an emergency when the encrypted data cannot be decrypted・ Emergency data recovery method to support collaboration,
The recovery processing device creates a key pair composed of a public key and a personal key and passes only the public key to the user-side data processing device,
The user-side data processing device creates an encryption key for encrypting data, and writes the encryption key obtained by encrypting the encryption key with the public key to the storage medium,
The user side data processing device or the recovery processing device takes out the encryption key from the storage medium in an emergency,
The recovery processing device decrypts the encryption key with the personal key,
The emergency data recovery method, wherein the user side data processing device or the recovery processing device decrypts encrypted data that cannot be decrypted with the decrypted encryption key.

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