JP3903629B2 - Information processing apparatus and storage medium storing program used for information processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information processing apparatus having a security function for ensuring the safety and reliability of information, and a storage medium storing a program used for the information processing apparatus.
[0002]
[Prior art]
In recent years, various types of information are managed in information processing apparatuses such as personal computers, and include information (secret information) that can only be handled by a person with a specific right (right holder). Has also increased.
[0003]
Conventionally, as a method to prevent anyone other than the right holder from handling confidential information in the computer, when the secret information can be confirmed by encrypting the secret information and presenting the password when decrypting it There was a method of performing decryption or attaching an IC card storing private key data to the computer when decrypting and decrypting using the private key data read from the IC card. .
[0004]
[Problems to be solved by the invention]
However, in the case of the method of presenting the password at the time of decryption, since the length of the password is limited so that it can be stored, it is easy to guess, and since the password data is stored on the computer, the data can be analyzed. There is sex.
[0005]
Also, the method of putting the secret key data in the IC card is inconvenient because the IC card must be mounted on the computer every time it is decrypted. Because of this inconvenience, there may be a user who keeps the IC card attached to the computer. This is especially true for mobile computers that are used exclusively by one person. If the IC card is still attached to the mobile computer, the secret information and the secret key data in the computer are acquired by the other party at the same time, and the secret information is easily acquired by the other party.
[0006]
Also, if you leave the computer for a short time while decrypting and reading the secret information, the decrypted data will remain on the computer, so that others can operate the computer in that state. If stolen or stolen, secret data can be easily read.
[0007]
However, when you leave the computer for a short time, it is very difficult to operate the computer sequentially, encrypt the decrypted secret information again, delete it from the decrypted data computer, and decrypt it again when you return It is troublesome.
[0008]
Some screen savers are locked with a password on the condition that the computer has not been operated for a certain period of time. However, depending on the password, if the password is analyzed in the same way as described above, it is safe. Will be lower. In addition, when the time until the screen saver is displayed is short, it is inconvenient in use of the computer. On the other hand, when the time is long, there is a high possibility that it will be seen by others and the security will be lowered.
[0009]
The present invention has been made in view of the above problems, and an information processing apparatus capable of reliably securing confidentiality protection for confidential information managed on the information processing apparatus without imposing a work burden, and It is an object of the present invention to provide a storage medium storing a program used for the information processing apparatus.
[0010]
[Means for Solving the Problems]
The present invention relates to a wireless communication means that wirelessly communicates within a predetermined communication range with a proving device that stores access authority information, and an access received from the proving device within the predetermined communication range via the wireless communication means. A recognition means for recognizing the legitimacy of the user who owns the certification device based on the authority information; Key storage means for storing an encrypted encryption key, information storage means for storing encrypted information, When the recognition means recognizes the legitimacy of the user, The encrypted encryption key stored in the key storage means is decrypted using the proving device, and the encrypted encryption key stored in the information storage means is decrypted using the decrypted encryption key. The Decryption means for decrypting information and detecting that the proving device is away from a predetermined communication range To generate a new encryption key and Information decrypted by the decryption means The newly generated encryption key is encrypted and stored in the information storage means, and the encryption key is also encrypted and stored in the key storage means And encryption means.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
FIG. 1 shows a system configuration for realizing the secret information protection method of the present invention. In this embodiment, a mobile computer 10 with a wireless communication function, which is configured as a small and easy to carry as an information processing apparatus, The example of a structure which each uses the electronic wristwatch 12 with a wireless communication function as a certification | authentication apparatus is shown. In addition to the mobile computer 10, the information processing device can be a desktop computer, as well as various computers. The identity verification device is not only the wristwatch 12, but glasses, a tie pin, a dedicated terminal, and the like. Any configuration may be used as long as the functions described later can be mounted.
[0015]
In this system, the secret information handled in the mobile computer 10 can be handled by decrypting it when it can be detected that the wristwatch 12 held by a person authorized to handle the secret information exists near the mobile computer 10. If it is detected that it has been separated, it is encrypted and managed so as not to be used by others.
[0016]
FIG. 2 is a block diagram showing a configuration of an electronic circuit of a portion related to the present invention of the wristwatch 12 shown in FIG.
[0017]
As shown in FIG. 2, the wristwatch 12 in this embodiment includes a CPU 20, a RAM 21, a nonvolatile memory 22 (including security-related data 23), an encryption processing unit 24, a display unit 25, an input unit 26, and a time counting unit 27. The wireless communication unit 28 and the wireless communication activation unit 29 are connected to each other.
[0018]
The CPU 20 controls the entire electronic circuit, and executes wristwatch side mutual authentication processing and wristwatch security processing in order to ensure the security of secret information managed by the mobile computer 10. Normally, the CPU 20 stops its operation in order to reduce current consumption, and operates only when it is necessary to execute processing. The CPU 20 is activated by the functions of the time counting unit 27, the display unit 25, and the input unit 26 that are operating regardless of whether the CPU 20 is operating.
[0019]
The RAM 21 temporarily stores various data as a work area when the CPU 20 executes processing such as wristwatch side mutual authentication processing and wristwatch security processing.
[0020]
The non-volatile memory 22 is a memory for holding data that should not be deleted even when the battery is replaced. In this embodiment, security-related data 23 (access authority information) including secret key data is stored. Is done. Details of the security-related data 23 will be described later (FIG. 4A).
[0021]
The cryptographic processing unit 24 performs cryptographic processing using the security-related data 23 stored in the nonvolatile memory 22 under the control of the CPU 20, and in this embodiment, cryptographic processing and decryption processing using a public key cryptosystem. I do. The encryption processing unit 24 normally stops its operation and is activated when the wristwatch side mutual authentication process and the watch security process are executed.
[0022]
The display unit 25 displays time for providing various information in addition to displaying time as a clock function.
[0023]
The input unit 26 receives an input by a user operation on a button (not shown) and notifies the CPU 20 of the input.
[0024]
The time counting unit 27 counts time in order to notify the current time or a preset time interval.
[0025]
The wireless communication unit 28 performs processing for performing wireless communication with the mobile computer 10 in cooperation with the CPU 20, and is executed in the mobile computer 10 when the wristwatch side mutual authentication processing and watch security processing are executed. Various kinds of processing at predetermined timing in cooperation with mobile computer-side mutual authentication processing and mobile computer processing (file open processing (FIG. 8), encrypted file work in-process (FIG. 9), encrypted file work restart processing (FIG. 10)) (The details will be described later). The wireless communication unit 28 is activated by the wireless communication activation unit 29 and starts wireless communication with the mobile computer 10. The wireless communication unit 28 normally stops its operation, and is activated by the wireless communication activation unit 29 when the wristwatch side mutual authentication process and the wristwatch security process are executed.
[0026]
When receiving a communication request signal from the mobile computer 10, the wireless communication activation unit 29 activates the wireless communication unit 28 to cause subsequent communication with the mobile computer. By making the communication request signal from the mobile computer into a simple radio wave, the current consumption of the wireless communication activation unit 29 when waiting for this can be reduced.
[0027]
FIG. 3 is a block diagram showing the configuration of the electronic circuit of the mobile computer 10 shown in FIG.
[0028]
As shown in FIG. 3, the mobile computer 10 according to the present embodiment is configured by connecting a RAM 31, a hard disk 32 (security related data 36), a display unit 33, an input unit 34, and a wireless communication unit 35 to a CPU 30. Yes.
[0029]
The CPU 30 controls the entire mobile computer 10 and executes various processes by executing programs stored in the RAM 31. The CPU 30 executes a mobile computer side mutual authentication process and a mobile computer process in order to ensure the security of the secret information managed by the mobile computer 10.
[0030]
The RAM 31 is used to temporarily store various data as a work area when the CPU 30 executes processing such as mobile computer side mutual authentication processing and mobile computer processing, and is also used to hold data for a certain period of time. The
[0031]
The hard disk 32 is a nonvolatile large-capacity storage device, and stores various programs and data. In the present embodiment, security-related data 36 including secret key data and encrypted files (secret information) is stored. Details of the security-related data 36 will be described later (FIG. 4B).
[0032]
The display unit 33 is configured by an LCD (liquid crystal display) or the like, and displays various kinds of information as a result of various processes executed by the mobile computer 10.
[0033]
The input unit 34 is configured by a keyboard, a touch panel, and the like, and is a device that accepts input of instructions, data, and the like to the mobile computer 10 by user operations.
[0034]
The wireless communication unit 35 performs processing for performing wireless communication with the wristwatch 12 in cooperation with the CPU 30. The wristwatch executed by the wristwatch 12 when the mobile computer side mutual authentication processing and mobile computer processing are executed. Various information is transmitted and received at a predetermined timing in cooperation with the side mutual authentication process and the wristwatch security process (details will be described later).
[0035]
Note that the wireless communication unit 28 (FIG. 2) provided on the wristwatch 12 and 35 (FIG. 3) provided on the mobile computer 10 are both short distances (persons with access rights directly grasp the state of the mobile computer 10). It is configured so that it can only communicate at a distance). For example, by making communication possible only when the distance between the two is within 50 cm, the processing described later can be executed only when the wristwatch 12 is in the vicinity of the mobile computer 10. 10 so that the secret information managed in the server 10 can be handled.
[0036]
FIG. 4 shows an example of security-related data used in the mobile computer 10 and the wristwatch 12 to ensure the security of secret information.
[0037]
FIG. 4A shows security-related data 23 stored in the nonvolatile memory 22 in the wristwatch 12, and includes a wristwatch authentication private key 40, a computer authentication public key 41, and an encryption private key 42. .
[0038]
FIG. 4B shows security-related data 36 stored in the hard disk 32 in the mobile computer 10. In addition to the wristwatch authentication public key 50, the computer authentication private key 51, the encryption public key 52, the secret information body It is included. The secret information body is an encrypted file 531a, 532a,..., 53na,... For each file (file-1, file-2,..., File-n,. Data 531b, 532b,..., 53nb,... Obtained by encrypting a file encryption common key obtained by encrypting (file-1, file-2,..., File-n,...) With the encryption public key 52 are included. Yes.
[0039]
The wristwatch authentication private key 40 and the wristwatch authentication public key 50 are a pair of public key cryptosystems. The wristwatch authentication private key 40 is data stored only in one wristwatch 12 and is guaranteed not to be known by any other person. Encrypting data using the wristwatch authentication private key 40 corresponds to a signature. If the encrypted data can be correctly decrypted by the wristwatch authentication public key 50, it is definitely stored in the wristwatch 12. It can be seen that the one encrypted with the wristwatch authentication private key 40 is obtained. Thus, it can be authenticated that the wristwatch 12 is valid.
[0040]
The computer authentication private key 51 and the computer authentication public key 41 are keys that form a pair of public key cryptosystems. The computer authentication private key 51 is data stored only in one mobile computer 10 and is guaranteed not to be known by anyone else. Encrypting data using the computer authentication private key 51 is equivalent to a signature, and if the encrypted data can be correctly decrypted by the computer authentication public key 41, the mobile computer 10 will definitely be notified. It can be seen that what is encrypted with the stored computer authentication private key 51 is. Thus, it can be authenticated that the mobile computer 10 is valid.
[0041]
Similarly, the encryption private key 42 and the encryption public key 52 are a pair of public key cryptosystems. However, it is not used for authenticating the other party, but used for encryption and decryption of secret information (file). In other words, information encrypted with the encryption public key 52 can be correctly decrypted only with the encryption private key 42.
[0042]
It should be noted that the file body is encrypted not by public key encryption but by common key encryption. Therefore, encryption and decryption for one file are performed using the same file encryption common key. A file encryption common key for encrypting a file is generated separately and randomly for each file so that it is different for each file. This file encryption common key is encrypted with the encryption public key 52 and stored in correspondence with the corresponding encrypted file (531b, 532b,..., 53nb,...).
[0043]
The file encryption common key encrypted with the encryption public key 52 cannot be decrypted without the encryption private key 42. Therefore, the file encryption common key can be decrypted only when the wristwatch 12 having the encryption secret key 42 is in the vicinity of the mobile computer 10 and the encryption secret key 42 can be obtained. The encrypted file body cannot be decrypted unless the file encryption common key is decrypted.
[0044]
Next, the operation of the system configured as described above will be described with reference to the flowcharts shown in FIGS.
[0045]
FIG. 5 is a flowchart showing mobile computer side mutual authentication processing by the mobile computer 10, and FIG. 6 is a flowchart showing wristwatch side mutual authentication processing by the wristwatch 12. By this mobile computer side mutual authentication process and wristwatch side mutual authentication process, the mobile computer 10 and the wristwatch 12 mutually authenticate each other and confirm whether or not the combination is definitely compatible.
[0046]
The wristwatch 12 waits for the wireless communication activation unit 29 to receive a communication request signal transmitted from the mobile computer 10 (step B1 in FIG. 6). Here, when a communication request signal is transmitted from the mobile computer 10 (FIG. 5, step A1) and received by the wireless communication activation unit 29 of the wristwatch 12, the wireless communication activation unit 29 connects the wireless communication unit 28 and the CPU 20 together. Start (step B2 in FIG. 6).
[0047]
That is, when the person wearing the wristwatch 12 comes near the mobile computer 10 (for example, within 50 cm), the mutual authentication is started when the wristwatch 12 and the mobile computer 10 become capable of wireless communication with each other. Is done.
[0048]
The CPU 20 of the wristwatch 12 generates a random number (R1) and transmits it via the wireless communication unit 28 (FIG. 6, step B3). On the other hand, when the mobile computer 10 receives the random number (R1) transmitted from the wristwatch 12, the mobile computer 10 encrypts it using the computer authentication private key 51 in the security-related data 36, and transmits the encrypted random number (C1). (FIG. 5, step A2).
[0049]
When the wristwatch 12 receives the encrypted random number (C1) from the mobile computer 10, the wristwatch 12 decrypts it using the computer authentication public key 41 in the security-related data 23 and obtains the decrypted random number (P1) (FIG. 6, Step B4).
[0050]
The CPU 20 of the wristwatch 12 compares the random number (R1) transmitted to the mobile computer 10 with the random number (P1) encrypted by the mobile computer 10 and decrypted using the computer authentication public key 41, and they match. It is determined whether or not (step B5).
[0051]
If the random number (R1) matches the decrypted random number (P1), the wristwatch 12 transmits an OK signal to the mobile computer 10 assuming that the mobile computer 10 is a valid partner (step) B6).
[0052]
When the CPU 30 of the mobile computer 10 receives the OK signal (step A3), the CPU 30 confirms that the wristwatch 12 is authenticated as a legitimate partner, and then authenticates the wristwatch 12 with a random number ( R2) is generated and transmitted via the wireless communication unit 35 (step A4 in FIG. 5). On the other hand, when receiving the random number (R2) transmitted from the mobile computer 10, the wristwatch 12 encrypts it using the wristwatch authentication private key 40 of the security-related data 23, and transmits the encrypted random number (C2). (FIG. 6, step B7).
[0053]
When the mobile computer 10 receives the encrypted random number (C2) from the wristwatch 12, the mobile computer 10 decrypts it using the wristwatch authentication public key 50 in the security-related data 36 to obtain the decrypted random number (P2) (FIG. 5, Step A5).
[0054]
The CPU 30 of the mobile computer 10 compares the random number (R2) transmitted to the wristwatch 12 with the random number (P2) encrypted by the wristwatch 12 and decrypted using the wristwatch authentication public key 50. It is determined whether or not there is (step A6).
[0055]
Here, when the random number (R2) matches the decrypted random number (P2), the mobile computer 10 transmits an OK signal to the mobile computer 10 assuming that the wristwatch 12 is a legitimate partner (step). A7). As a result, the mobile computer 10 considers that the mutual authentication has been successful, and continues to execute the mobile computer processing described later.
[0056]
Further, when the wristwatch 12 receives the OK signal transmitted from the mobile computer 10 (step B8), the wristwatch 12 regards that the mutual authentication has been successful, and continues to perform wristwatch security processing (FIG. 7) described later.
[0057]
If the mobile computer 10 does not receive the random number (R1) from the wristwatch 12 despite the transmission of the communication request signal (step A2), it is OK despite the transmission of the encrypted random number (C1). When the signal is not received (step A3) and when the encrypted random number (C2) is not received despite the transmission of the random number (R2) (step A5), the communication is interrupted. It is assumed that the person who wears the wristwatch 12 has left the mobile computer 10 and the mutual authentication has failed. Also, when the random number (R2) and the decrypted random number (P2) do not match (step A6), it is considered that the mutual authentication has failed.
[0058]
If the mutual authentication fails, the mobile computer 10 encrypts the file being worked using the file encryption common key (step A8) and deletes the file before encryption (step A9). Make it impossible for a person to handle confidential information.
[0059]
Further, when the wristwatch 12 does not receive the encrypted random number (C1) from the mobile computer 10 in spite of transmitting the random number (R1) (step B4), the random number (R1) is transmitted despite the OK signal being transmitted. When R2) is not received (step B7), and when the encrypted random number (C2) is transmitted but the OK signal is not received (step B8), the communication is interrupted. Therefore, it is considered that the mutual authentication has failed because the person wearing the wristwatch 12 has left the mobile computer 10. Also, if the random number (R1) does not match the decrypted random number (P1) (step B5), it is considered that mutual authentication has failed.
[0060]
If the mutual authentication fails, the wristwatch 12 stops the wireless communication unit 28 and the CPU 20 (step B9).
[0061]
In this way, both the mobile computer 10 and the wristwatch 12 generate random numbers, transmit and receive each other, encrypt with the private key of only the other party, and only when it can be decrypted with the corresponding public key It can be considered as mutual authentication. Further, when communication is interrupted on the way, such as when a person wearing the wristwatch 12 leaves the mobile computer 10, it can be determined that mutual authentication has failed at that time.
[0062]
Next, wristwatch security processing in the wristwatch 12 will be described with reference to the flowchart shown in FIG. In addition, although the process as a normal timepiece is executed in parallel with the wristwatch security process, the description is omitted here.
[0063]
The wristwatch 12 always performs the above-described wristwatch-side mutual authentication process (FIG. 6) until the mutual authentication with the mobile computer 10 that is a legitimate partner is successful (step C1). As a result, it is possible to respond to any request for communication from the mobile computer 10.
[0064]
Note that the wristwatch 12 stops the operations of the wireless communication unit 28 and the CPU 20 until the communication request signal transmitted from the mobile computer 10 is received in the wristwatch-side mutual authentication process. As a result, low power consumption can be realized even when waiting for signal reception from the mobile computer 10 at all times.
[0065]
After mutual authentication succeeds by the wristwatch side mutual authentication process, when the CPU 20 receives the command transmitted from the mobile computer 10 by the wireless communication unit 28 (step C2), the CPU 20 branches to a process corresponding to the received command (step C3). ). The command transmitted from the mobile computer 10 will be described in a mobile computer process (FIGS. 8, 9, and 10) described later.
[0066]
When the file encryption common key decryption command is received, the CPU 20 receives the encrypted file encryption common key (CKn) (step C4), and the encrypted file encryption common key (step C4). CKn) is decrypted using the encryption private key 42 of the security-related data 23. The CPU 20 transmits the decrypted file encryption common key (Kn) from the wireless communication unit 28 to the mobile computer 10 (step C5). As a result, the mobile computer 10 can handle the secret information by decrypting the encrypted file using the decrypted file encryption common key (Kn).
[0067]
In addition, what was described as n, such as CKn and Kn described above, does not indicate a specific n, but indicates a general number and corresponds to n or m in the description to be described later.
[0068]
Next, details of mobile computer processing (file open processing, encrypted file work in progress process, encrypted file work restart process) in the mobile computer 10 will be described. The mobile computer process is a process related to the present invention when a file is opened on the mobile computer 10 and the file is being processed.
[0069]
First, the file open process will be described with reference to the flowchart shown in FIG.
[0070]
First, the CPU 30 determines whether or not the file to be processed is an encrypted file (step D1). Here, if the file is not encrypted, the file to be opened is set as a work file (step D2), and processing corresponding to an instruction input from the input unit 34 is executed on the work target file (step S2). Step D9).
[0071]
Process A in step D9 means all the operations performed by operating the mobile computer for the opened file. In the case of document creation work, it means the work of adding / deleting / editing a sentence and encrypting and saving the sentence when the sentence is encrypted and saved. (Although encryption processing here also uses the processing related to encryption shown in the present embodiment, it is out of the main point of the present invention and will not be described here.) This work also includes cases where the file contents are simply referenced.
[0072]
After the work on the file is completed, the CPU 30 stops any thread executing an encrypted file work process to be described later, and ends the file open process (step D10).
[0073]
On the other hand, when the file to be opened as an object to be processed is an encrypted file (step D1), the CPU 30 performs a corresponding process depending on whether or not the mutual authentication is successful as a result of the above-described mutual authentication process on the mobile computer side. Execute.
[0074]
For example, if the mutual authentication has failed, the CPU 30 displays a warning “No authority to open this encrypted file” on the display unit 33, for example, and stops the processing (step D11).
[0075]
On the other hand, if the mutual authentication is successful, the CPU 30 transmits a file encryption common key decryption command via the wireless communication unit 35 (step D4). As a result, the wristwatch 12 receives the encrypted file encryption common key (CKn) to be transmitted next (see steps C3 and C4 in FIG. 7).
[0076]
After transmitting the file encryption common key decryption command, the CPU 30 transmits the encrypted file encryption common key (CKn) of the file (step D5). When the wristwatch 12 receives the encrypted file encryption common key (CKn), the encrypted file encryption common key (CKn) is decrypted using the encryption secret key 42 of the security-related data 23. And returned (see step C5 in FIG. 7).
[0077]
The mobile computer 10 receives the decrypted file encryption common key (Kn) of the file (step D6). If the decrypted file encryption common key (Kn) is not received, the CPU 30 proceeds to the process of step D11 and stops the process.
[0078]
On the other hand, when receiving the decrypted file encryption common key (Kn), the CPU 30 decrypts the file with the received file encryption common key (Kn) to obtain a work file (step D7), and performs the encrypted file work. Medium processing (described later) is started as a separate thread (step D8).
[0079]
The CPU 30 executes a process corresponding to an instruction input from the input unit 34, for example, on the work target file (step D9). The contents of the work on the work target file are as described above.
[0080]
After the work on the file is completed, the CPU 30 stops any thread executing an encrypted file work process to be described later, and ends the file open process (step D10).
[0081]
Next, the encrypted file work process will be described with reference to the flowchart shown in FIG. 9, and the encrypted file work restart process will be described with reference to the flowchart shown in FIG. The encrypted file work process and the encrypted file work restart process are a series of processes, and are activated as separate threads in the above-described file open process (FIG. 8). After startup, it operates in parallel with the file open process until it is stopped.
[0082]
As described for the file open process (see FIG. 8), when the file to be opened is an encrypted file, it can be mutually authenticated with the pair of watches 12 and the file encryption common key can be decrypted. Only the file can be decrypted and opened. Then, only when the encrypted file is opened for work, the encrypted file work process is started in another thread (FIG. 8, step D8).
[0083]
That is, when the mutual authentication is successful by the mobile computer side mutual authentication process (step E1), the CPU 30 transmits a NOP command via the wireless communication unit 35 (step E2), for a certain time (for example, 3 seconds). By waiting (step E3), mutual authentication is repeated with the wristwatch 12 paired at regular intervals. Note that the predetermined time is determined in consideration of the required security level and power consumption. Shortening this time increases security but increases power consumption.
[0084]
On the other hand, if the mutual authentication fails, the CPU 30 stops the process on the work target file (step E4), and utters a new file encryption common key (Km) using a random number, and encrypts the work target file. Then, it is stored in the RAM 31 or the hard disk 32 as a temporary storage file (step E5). Further, the CPU 30 encrypts the new file encryption common key (Km) with the encryption public key, and stores the encrypted file encryption common key (CKm) (step E6). Then, the CPU 30 deletes the work target file before encryption (step E7).
[0085]
The CPU 30 erases the file encryption common key (Km) before encryption (step E8) and displays, for example, “The file operation is interrupted because the access condition for this file is no longer satisfied” on the display unit 33. Is displayed to notify that the file operation cannot be performed (step E9).
[0086]
In this way, even if the person wearing this watch 12 moves away from the mobile computer 10 while working while decrypting the encrypted file, the contents of the file being worked on can be changed. Since it becomes impossible for the person to know, security can be ensured.
[0087]
When mutual authentication can be performed again, the work target file is automatically decrypted by the encrypted file work restart process as follows.
[0088]
That is, when the mutual authentication is successful by the mobile computer side mutual authentication process (step F1), the CPU 30 transmits a file encryption common key decryption command (step F2).
[0089]
Further, the CPU 30 transmits the encrypted file encryption common key (CKm) corresponding to the temporarily saved file that has been temporarily saved in the encrypted file work process (step E5 in FIG. 9) (step F3). . Upon receiving the encrypted file encryption common key (CKm), the wristwatch 12 decrypts the encrypted file encryption common key (CKm) using the encryption private key 42 of the security-related data 23. And returned (see step C5 in FIG. 7).
[0090]
When the CPU 30 receives the decrypted file encryption common key (Km) corresponding to the temporarily saved file (step F4), the CPU 30 decrypts the temporarily saved file with the received file encryption common key (Km), and the work target file (Step F5).
[0091]
Further, the CPU 30 deletes the encrypted file encryption common key corresponding to the temporarily saved file, and displays a message such as “The operation can be resumed because the access condition to this file is satisfied again” on the display unit 33. Is displayed to notify that the file operation is possible (step F8). Then, the CPU 30 reunite the processing for the work target file (step F9).
[0092]
As described above, since the person wearing the wristwatch 12 comes again near the mobile computer 10 and the file being worked on is automatically decrypted, the work can be resumed without troublesome procedures. Can do.
[0093]
In addition, in mobile computer processing, mutual authentication is performed only when an encrypted file is opened and worked, so it is necessary to communicate with each other in normal operations such as when working with an unencrypted file. In addition, both the wrist watch 12 and the mobile computer 10 consume less power.
[0094]
In this embodiment, in order to simplify the description, the encrypted information is a condition that is confidential information that should not be known to others, but this is not sufficient in practice. . For example, when you start to create a sentence for the first time, there is no encrypted file because there is no file before work. However, there is a case where a sentence that has been created is content that should be confidential information, and it is necessary to prevent others from seeing the sentence being created. In such a case, it is possible to use a method of designating that the information is secret information. For example, it is possible to use a method such as specifying in advance whether or not the information is secret information when creating a new file, or setting in advance that a file under a specific directory is secret information.
[0095]
In this way, when mutual authentication by short-range wireless communication with a predetermined object (watch 12) worn by the user is not possible, the decrypted one is deleted from the encrypted file. Even when the user is away from the mobile computer 10, the content of the confidential information cannot be illegally known by another person.
[0096]
At this time, the working file decrypted from the encrypted file is automatically encrypted and stored, and mutual authentication is performed by short-range wireless communication with a predetermined object (watch 12) worn by the user. When the file becomes available again, the encrypted working file is automatically decrypted, so that the user can continue working without any additional inconvenience.
[0097]
Further, since wireless communication is performed only while the encrypted file is opened and the work is performed, the power consumption can be reduced when a normal computer is used.
[0098]
In addition, since reception of a communication request signal that can be received by a low-power-consumption receiving device and subsequent complicated data transmission / reception are provided separately, it can be realized with low power consumption even when waiting for a communication request at all times.
[0099]
In addition, an encryption private key that is indispensable when decrypting an encrypted file is in a different object (watch 12) from the mobile computer 10 having the encrypted file, and the object is usually worn by the user. It is difficult for others to obtain the computer and this object at the same time because there is no need to attach it to the computer, and as a result, there is no risk of unauthorized decryption of the encrypted file Lower.
[0100]
In addition, because mutual authentication uses information (secret key) that cannot be known by others, a random number encrypted with that information is sent and the information itself is not sent. However, the information cannot be known and it is difficult to create a bogus person.
[0101]
Since the public key cryptosystem is used to encrypt the file encryption common key, the file encryption common key can be encrypted after communication with the wristwatch 12 becomes impossible, and the decryption must be performed by the corresponding wristwatch 12. I can't do it.
[0102]
Further, since the wristwatch 12 is used, the power supply of the wristwatch 12 can be used to realize the operation of the present invention. Therefore, it is not necessary to provide a new power source for the operation of the present invention. There is also an effect that the distance from the computer is reduced, and that it can be realized by wireless communication with a small output.
[0103]
In the above description, the wristwatch 12 is used, but other watches may be used as long as they can be worn by the user. In that case, it is usually better to wear it all the time and get closer to the computer naturally when operating the computer. For example, there are glasses, rings, bracelets, necklaces, ID cards generally attached to the chest.
[0104]
Furthermore, it can also be executed in combination with other authentication methods using passwords or fingerprint authentication. For example, a password may be input when decrypting an encrypted file. At this time, password data to be referred to may be stored in the wristwatch 12.
[0105]
Further, the public key cryptosystem and the common key cryptosystem may be used in different combinations or only one of them may be used.
[0106]
Moreover, although it demonstrated as what communicates with the mobile computer 10 using the power supply of the wristwatch 12, you may receive communication by receiving power supply with the electromagnetic waves from a computer. In that case, an electromagnetic wave for power supply can be configured to serve as a communication request signal.
[0107]
Further, although only two combinations of the mobile computer 10 and the wristwatch 12 are used, an authentication method using information obtained from another object (such as an IC card) may be used in combination.
[0108]
In addition, although the mutual authentication is performed in each of the mobile computer 10 and the wristwatch 12, the security is slightly lowered, but only one of the authentications may be performed.
[0109]
In addition, the keys used by sharing the secret key and public key described above may be reduced, or conversely, the keys used may be increased.
[0110]
Further, although wireless communication using electromagnetic waves is used, other methods such as infrared rays may be used.
[0111]
Further, the working file is automatically decrypted when the person with the wristwatch 12 returns, but this process may not be automated. In that case, although the inconvenience comes out when the work is resumed, the security intended by the present invention is similarly secured.
[0112]
The procedure for resuming the work may be changed depending on the time until the person wearing the wristwatch 12 returns. For example, when it returns within 5 minutes, it automatically decrypts and restarts the working file, but when it returns after more time has passed, do not automatically decrypt the working file. Also good.
[0113]
Moreover, although the example of the one-to-one relationship between the mobile computer 10 and the wristwatch 12 has been shown, a plurality of correspondence relationships can be set. For example, a plurality of people can access the secret information of one computer, or one person can access the secret information of a plurality of computers. In this case, it can be realized by providing the computer or the wristwatch 12 with a plurality of authentication keys or encryption keys having different roles.
[0114]
Note that each processing method described in the above-described embodiment is a program that can be executed by a computer, such as a magnetic disk (floppy disk, hard disk, etc.), an optical disk (CD-ROM, DVD, etc.), a semiconductor memory, or the like. It can be written on a medium and provided to various devices. It is also possible to transmit to a variety of devices by transmitting via a communication medium. A computer that implements this apparatus reads the program recorded on the recording medium or receives the program via the communication medium, and the operation is controlled by this program, thereby executing the above-described processing.
[0115]
【The invention's effect】
As described above, according to the present invention, while working on confidential information that should not be known to others, an object worn by a person who has the right to access the information (having access authority information). Device) and short-range wireless communication, it is detected whether the person with access right is nearby, and when it detects that the person with access right has left, the secret information during the work is automatically Is managed on the information processing device without imposing a burden on the work, so that others cannot know the secret information by automatically erasing and automatically erasing the secret information before encryption. Confidentiality protection can be ensured for confidential information.
[Brief description of the drawings]
FIG. 1 is a diagram showing a system configuration for realizing a secret information protection method of the present invention.
2 is a block diagram showing a configuration of an electronic circuit of a portion related to the present invention of the wristwatch 12 shown in FIG. 1;
3 is a block diagram showing a configuration of an electronic circuit of the mobile computer 10 shown in FIG.
FIG. 4 is a diagram showing an example of security-related data used to ensure security of secret information in the mobile computer 10 and the wristwatch 12;
FIG. 5 is a flowchart showing mobile computer side mutual authentication processing by the mobile computer 10;
FIG. 6 is a flowchart showing wristwatch side mutual authentication processing by the wristwatch 12;
FIG. 7 is a flowchart showing watch security processing in the watch 12;
FIG. 8 is a flowchart showing file open processing;
FIG. 9 is a flowchart showing encrypted file work processing;
FIG. 10 is a flowchart showing encrypted file work restart processing.
[Explanation of symbols]
10 ... Mobile computer,
12 ... watch,
20, 30 ... CPU,
21, 31 ... RAM,
22: Non-volatile memory,
23, 36 ... security related data,
24. Encryption processing unit,
25, 33 ... display section,
26, 34 ... input section,
27: Time counting part,
28, 35 ... wireless communication unit,
29 ... wireless communication starting part,
32: Hard disk.

Claims (3)

Wireless communication means for wirelessly communicating within a predetermined communication range with a certification device storing access authority information;
Recognizing means for recognizing the legitimacy of the user who owns the certification device based on the access authority information received from the certification device within a predetermined communication range via the wireless communication means;
Key storage means for storing the encrypted encryption key;
Information storage means for storing encrypted information;
When the recognizing means recognizes the legitimacy of the user, the encrypted encryption key stored in the key storage means is decrypted using the proving device, and the decrypted encryption key Decrypting means for decrypting encrypted information stored in the information storage means using
By detecting that the certification device is separated from the predetermined communication area, and encrypted using the encryption key to generate a new encryption key, and generates new information decoded by pre-Symbol decoding means An information processing apparatus comprising: an encryption unit that stores the information in the information storage unit and encrypts the encryption key in the key storage unit . The encryption key, the information processing apparatus according to claim 1, characterized in that it is produced on the basis of random numbers generated for each information. A storage medium having a computer readable program code for ensuring security and managing information,
A communication means for causing a computer to communicate within a predetermined communication range with a certification device storing access authority information using a wireless communication device;
Recognition means for recognizing the legitimacy of the user who owns the certification device based on the access authority information received from the certification device within a predetermined communication range via the communication means;
Key storage means for storing the encrypted encryption key;
Information storage means for storing encrypted information;
When the recognizing means recognizes the legitimacy of the user, the encrypted encryption key stored in the key storage means is decrypted using the proving device, and the decrypted encryption key Decrypting means for decrypting encrypted information stored in the information storage means using
By detecting that the certification device is separated from the predetermined communication area, and encrypted using the encryption key to generate a new encryption key, and generates new information decoded by pre-Symbol decoding means A storage medium storing a program code for storing the information in the information storage unit, and encrypting the encryption key and storing it in the key storage unit .

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