JP4181246B2 - ENCRYPTION SYSTEM IN NETWORK COMPUTING SYSTEM, ENCRYPTION KEY MANAGEMENT METHOD IN THE SYSTEM, AND STORAGE MEDIUM - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an encryption system in a network computing system for improving management of encryption keys used when encrypting / decrypting data on a terminal device connected to a network, and network computing The present invention relates to an encryption key management method in a storage system and a computer-readable storage medium storing the method.
[0002]
[Prior art]
Conventionally, when data on a terminal device connectable to a network is encrypted / decrypted, for example, a key used for encryption or decryption, a so-called encryption key is managed on the terminal device side.
[0003]
In such a conventional management method, the encryption key is destroyed due to a hardware failure or software failure of the terminal device, or the terminal device is lost or stolen by a third party. There was a risk of security.
[0004]
In particular, the latter problems such as loss and theft are serious, and with the rapid spread of highly portable terminal devices in recent years, for example, a public network is being used for server computers installed in offices while moving or away from home. It is natural that the above problem will continue to increase in the form of access via the Internet, that is, mobile computing is becoming established.
[0005]
[Problems to be solved by the invention]
In the above-described prior art, the user of the terminal device manages the encryption key at his / her own risk, and the encryption key is stored in an external storage medium different from the terminal device in preparation for destruction of the encryption key, such as a floppy disk or an IC. Since it is necessary to back up to a card, etc., if you forget to back up or forget where you backed up, you can use this encryption key to decrypt the encrypted data again. Serious data leaks to third parties due to loss or theft of encryption keys that are lost or stored on the terminal device or backed up on an external storage medium together with the terminal device There was a fear.
[0006]
Therefore, the present invention has been made in consideration of the above circumstances, and solves the above problems, and in addition to the local key management function for managing the encryption key on the terminal device, the network key is managed on the server via the network. By realizing the management function and the function to identify whether the data on the terminal device is encrypted with the encryption key of the local key or the network key, the highly reliable encryption key management function is realized and the encryption Implementation of an encryption key management system according to the confidentiality level of data to be encrypted, that is, high-level data at the confidentiality level uses a network key management method. Data that is frequently used closed is used in a network computing system that can use the local key management method. And to provide that encryption system, and in the encryption key management method in a network computing TIG systems, and computer-readable storage medium storing a same way.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present invention stores a terminal device that stores data encrypted using an encryption key, and an information processing device that stores the encryption key used when encrypting data on the terminal device. Used in network computing system to connect An encryption system on the information processing apparatus First Encryption key On the information processing device Generate and store First Encryption key management means; Second encryption key management means for generating and storing a second encryption key on the terminal device; On the terminal device The first or second Encryption key above First or second From encryption key management means Each An encryption key acquisition means to acquire and acquired from the encryption key acquisition means on the terminal device The first or second An encryption means for encrypting and storing data using an encryption key; Connection confirmation means for determining whether the terminal device is connected to the network on the terminal device; Equipped with The encryption unit is encrypted and connected using the second encryption key when it is determined by the connection confirmation unit that the terminal device is disconnected from the network. If it is determined, the first encryption key is used for encryption. It is characterized by Encryption system is provided .
[0010]
According to such a configuration, the encryption key for encrypting the data on the client terminal is managed on the server computer or on the terminal, so that the encryption key matched with the safety of the data on the terminal device can be obtained. Management can be provided, and a more flexible encryption system can be provided.
[0020]
Also, According to such a configuration, the encryption key on the server computer is used only when the client is connected to the network, and the encryption key on the terminal is used when the client is disconnected. There is no need to select whether to use it.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing the overall configuration of an encryption system in a network computing system according to the present embodiment.
[0022]
As shown in FIG. 1, the terminal device 1 is connected to a public network 2 such as a WAN (Wide Area Network), for example. The other terminal devices 4 and the server computer 5 are connected to a LAN (Local Area Network) 3. Here, the LAN 3 is connected to the WAN 2, and the terminal device 1 and the terminal device 4 are connected to the server computer 5.
[0023]
The terminal device 1 includes a CPU 11 that performs various controls of the terminal device, a memory 12 that stores various information, a screen display device 13 such as an LCD that outputs and displays various information, and an input such as a keyboard and a mouse that input various information. A device 14 and an external storage device 15 such as a disk device are provided internally.
[0024]
On the memory 12, any unencrypted data 121 in the unencrypted data set 151 on the external storage device 15 is encrypted into the encrypted data 122, or vice versa. Management program for decrypting the encrypted data 122 to the unencrypted data 121, the local key 124 on the local key management table 153, and the key management client for transmitting / receiving the network key 125 to / from the server computer 5 A program 126, a screen control program 127 for controlling a screen displayed on the screen display device 13, and a screen operation data 128 for storing data displayed on the screen display device 13 and data of various icons are stored. .
[0025]
The local account 1531, the local password 1532, and the local key 1533 on the local key management table 153 are scrambled or encrypted in order to protect from an external attack at the time of writing, and unscrambled or decrypted at the time of reading.
[0026]
Since the screen control program 127 and the screen operation data 128 are always controlled when a display or input request is received from the key management client program 126, the description thereof will be omitted each time.
[0027]
The terminal device 4 has the same configuration as that of the terminal device 1 and differs only in whether the connected network is a LAN or a WAN, and there is no difference in data encryption processing and decryption processing. The subsequent description of the operation of the terminal device 4 is the same as the operation of the terminal device 1 and is therefore omitted.
[0028]
The server computer 5 includes a network key management server program 52 that manages the network key 125 on the network key management table 51, and the network key management server program 52 communicates with the key management client program 126 on the terminal device 1. The key 125 is transmitted and received.
[0029]
The setting program 53 is a program for the operator of the terminal device 1 to set an authentication network account, a password, a network key, and the like in the network key management table 51 in advance of encryption processing.
[0030]
The network account 511, the network password 512, and the network key 513 on the network key management table 51 are scrambled or encrypted to protect against external attacks at the time of writing, and unscrambled or decrypted at the time of reading.
[0031]
FIG. 2 shows a key selection screen 200 for allowing the operator of the terminal device 1 to select whether the key management client program 126 is a local key or a network key.
[0032]
The key selection screen 200 has a local key management icon 221 for instructing the key management client program 126 to use a local key, and a network key management for instructing the key management client program 126 to use a network key. It is composed of icons 222.
[0033]
The local key management icon 221 indicates that the local key 124 is active (meaning that data can be encrypted or decrypted) while the local key 124 exists on the memory 12. For example, an X mark is not added, and if it does not exist, it indicates an inactive state (meaning that data cannot be encrypted or decrypted). For example, an X mark is added as in the local key management icon 223. . The same applies to the network key management icon 222.
[0034]
The activation time of the local key 124 or the network key 125 on the memory 12 is specified by the operator of the terminal device 1. In the case of the local key 124, the activation time is stored in the local key management table 153, and in the case of the network key 125, the network key Stored in the management table 51. The activation time is the activation time from when the local key 124 or the network key 125 is placed on the memory 12 until it disappears. When the activation time has elapsed, the key management client program 126 is deleted from the memory 12 in order to deactivate it.
[0035]
FIG. 3 shows that when the local key management icon 221 is selected, the key management client program 126 allows the operator to input the local account 331 and the local password 332 of the operator of the terminal 1 to set the local key, It is a local key setting / acquisition screen 300 for acquiring a local key set in the local key management table 153.
[0036]
The local account 331 is an identifier for identifying the operator of the terminal device 1, and when the identifier does not exist in the local key management table 153, the key management client program 126 together with the local password 332 has the local key management table 126. 153.
[0037]
The local password 332 is used for generating a local key together with information such as the local account 331 as well as being used for a security check. The key management client program 126 stores the generated local key 124 in the memory 12. And stored in the local key management table 153.
[0038]
4, when the network key management icon 222 is selected, the key management client program 126 causes the operator of the terminal device 1 to input the network account 441 and the network password 442 to set the network key. This is a network key setting / acquisition screen 400 for acquiring a network key already set in the network key management table 51.
[0039]
The network account 441 is an identifier for identifying the operator of the terminal device 1 over the network, and inquires of the network key management server program 52 whether the identifier exists in the network key management table 51. If it does not exist, the key management client program 126 requests the network key management server program 52 to store it in the network key management table 51 together with the network password 442.
[0040]
The network password 442 is used for generating a network key together with information such as the network account 441 at the same time as the security check. The key management client program 126 stores the generated network key 125 in the memory 12. And stored in the network key management table 51 via the network key management server 51.
[0041]
When the local key management client program 126 makes an inquiry to the network key management server program 52, it is checked whether the terminal device 1 is connected to the server computer 5 via the WAN 2 such as a public network. If there is no connection, the key management client program 126 issues a connection request to complete the connection and the connection state is established, or if already connected, the network key management server program 52 is requested to perform setting and acquisition processing. .
[0042]
When the operator of the terminal device 1 makes an encryption request to any unencrypted data 121 from the unencrypted data set 151 stored on the external storage device 15, the encryption program 123 The local key 124 or the network key 125 stored on the memory 12 is acquired from the key management client program 126. Which key is to be acquired is determined by the encryption program 123 checking the attribute of the target data. This attribute is stored on the external storage device 15 together with each target data, and the encryption program 123 reads it together on the memory 12.
[0043]
The encryption program 123 encrypts the non-encrypted data 121 into the encrypted data 122 using either the acquired local key 124 or the network key 125. Similarly, in the case of decryption, when the operator makes a decryption request to any encrypted data 122 from the encrypted data set 152 stored on the external storage device 15, the encrypted data 122 Is decrypted into the non-encrypted data 121. The encryption or decryption instruction by the operator is given to the encryption program 123 using the input device 14 such as a mouse.
[0044]
5 and 6 are an encryption instruction screen 551 and a decryption number instruction screen 661 for an operator to give an encryption or decryption instruction to the encryption program 123. The unencrypted data set 151 or the encryption An example in which the encryption menu 551 and the decryption menu 661 are displayed when the mouse pointer is clicked on the arbitrary target data 551a, 551b, 551c,..., 661x, 661y, 661z in the encrypted data set 152 is clicked. is doing.
[0045]
When the operator selects and clicks one of the menus with the mouse, one of the instructions is transmitted to the encryption program 123, and the encryption program 123 receives this and receives the local management information obtained from the key management client program 126. The key 124 or the network key 125 is used to encrypt or decrypt the selected target data 551b or 6611y.
[0046]
FIG. 7 shows a flowchart for storing the local key 124 on the memory 12.
When the operator of the terminal device 1 clicks the inactive local key management icon 223 with the mouse (step S71), the key management client program 126 displays the input screen 300 for the local account 331 and the local password 332 (step S72) and uses it. It is checked whether the local account 331 and the local password 332 entered by the user are stored in the local key management table 153 (step S73).
[0047]
Here, if it does not exist (NO in step S73b), the local key 124 is generated using the input local account 331, the local password 332, and information such as time, and stored in the memory 12 at the same time. 331 and the local password 332 are stored in the local key management table 153, and the process proceeds to step S76 (step S74).
[0048]
On the other hand, if it exists (YES in step S73b), the corresponding local key 124 is acquired from the local key management table 153, stored in the memory 12 (step S75), and the inactive local key management icon 223 is activated. The change display is performed on the local key management icon 221 (step S76).
[0049]
Next, FIG. 8 shows a flowchart for storing the network key 125 in the memory 12.
When the operator of the terminal device 1 clicks the inactive network key management icon 224 with the mouse (step S81), the key management client program 126 displays the input screen 400 for the network account 441 and the network password 442 (step S82), and is used. It is checked by inquiring to the network key management server program 52 whether the network account 441 and the network password 442 entered by the user are stored in the network key management table 51 (step S83).
[0050]
If it does not exist (NO in step S83b), the network key 125 is generated using the input network account 441, network password 442, and information such as time, and stored in the memory 12 at the same time. 441 and the network password 442 are stored in the network key management table 51 via the network key management server program 52, and the process proceeds to step S86 (step S84).
[0051]
On the other hand, if it exists (YES in step S83b), the corresponding network key 125 is acquired from the network key management table 51, stored in the memory 12 (step S85), and the inactive network key management icon 224 is set to the active network. The change is displayed on the key management icon 222 (step S86).
[0052]
Next, FIG. 9 is a flowchart showing an encryption process of the unencrypted data 121 using the local key 124 when the local key management icon 221 is in an active state.
[0053]
In the encryption / decryption instruction screen 551 displayed by the key management client program 126, for example, when the operator of the terminal device 1 clicks and selects the data 551b on the unencrypted data set 151 as the target data (step S91). ), The key management client program 126 displays the encryption instruction icon 552.
[0054]
When the operator clicks on it (step S92), the local key 124 and data 551 on the external storage device 15 (file name, etc.) are sent to the encryption program 123 (step S93). Receiving this, the encryption program 123 reads the data 551b from the unencrypted data set 151 on the external storage device 15 as unencrypted data 121 on the memory 12 (step S94), and encrypts it using the local key 124. (Step S95). And it writes out as 1 data of the encryption data set 152 on the external storage device 15 (step S96).
[0055]
FIG. 10 is a flowchart showing a decryption process of the encrypted data 122 using the local key 124 when the local key management icon 221 is in the active state.
On the decryption instruction screen 661 displayed by the key management client program 126, when the operator of the terminal device 1 clicks and selects, for example, the data 661y on the encrypted data set 152 as the target data (step S1001). The key management client program 126 displays a decryption instruction icon 662.
[0056]
When the operator clicks on the decryption instruction icon 662 (step S1002), the local key 124 and information (file name etc.) on the external storage device 15 of the data 661y are sent to the encryption program 123 (step S1003).
[0057]
Receiving this, the encryption program 123 reads the data 661y as the encrypted data 122 from the encrypted data set 152 on the external storage device 15 (step S1004) and decrypts it using the local key 124. (Step S1005). And it writes out as 1 data of the non-encrypted data set 151 on the external storage device 15 (step S1006).
[0058]
Here, the display of the encryption / decryption instruction screen shown in FIGS. 5 and 6 is not necessarily performed by the key management client program 126, and may be a file operation program supported by the operating system, for example. Also, regarding the data attribute of whether or not it is encrypted, it is not always necessary to have an encryption attribute as an attribute of the entire data set such as a file directory, and a file extension is added as an encryption attribute for each data unit. It is also possible to identify it.
[0059]
FIG. 11 is a flowchart showing an encryption process of the unencrypted data 121 using the network key 125 when the network key management icon 222 is in an active state.
[0060]
On the encryption / decryption instruction screen (FIGS. 5 and 6) displayed by the key management client program 126, the operator of the terminal device 1 clicks the data 551b on the unencrypted data set 151 as the target data, for example. When selected (step S1101), the key management client program 126 displays an encryption instruction icon 552.
[0061]
When the operator clicks on it (step S1102), the network key 125 and information (file name etc.) on the external storage device 15 of the data 551b are sent to the encryption program 123 (step S1103).
[0062]
Upon receiving this, the encryption program 123 reads the data 551b from the unencrypted data set 151 on the external storage device 15 as the unencrypted data 121 into the memory 12 (step S1104), and uses the network key 125. Encryption is performed (step S1105). And it writes out as 1 data of the encryption data set 152 on the external storage device 15 (step S1106).
[0063]
FIG. 12 is a flowchart showing a process of decrypting the encrypted data 122 using the network key 124 when the network key management icon 222 is in an active state.
[0064]
On the encryption / decryption instruction screen (FIGS. 5 and 6) displayed by the key management client program 126, the operator of the terminal device 1 clicks the data 661y on the encrypted data set 152 as the target data, for example. When selected (step S1201), the key management client program 126 displays a decryption instruction icon 662.
[0065]
When the operator clicks on the decryption instruction icon 662 (step S1202), the network key 125 and information (file name etc.) on the external storage device 15 of the data 661y are sent to the encryption program 123 (step S1203).
[0066]
Receiving this, the encryption program 123 reads the data 661y as the encrypted data 122 from the encrypted data set 152 on the external storage device 15 into the memory 12 (step S1204), and decrypts it using the network key 125. (Step S1205).
[0067]
And it writes out as 1 data of the non-encrypted data set 151 on the external storage device 15 (step S1206).
Here, the identification of whether the data in the encrypted data set 151 is encrypted by the local key 124 or the network key 125 is set by changing the type of the file extension, for example. Can also be done.
[0068]
【The invention's effect】
As described above in detail, according to the present invention, in addition to the local key management function for managing the encryption key on the terminal device, the network key management function for managing the encryption key on the server via the network, and the data on the terminal device are stored locally. By realizing the function to identify whether the key is encrypted with the encryption key of the key or the network key, a highly reliable encryption key management function is realized and the encryption according to the confidentiality level of the data to be encrypted Realization of a key management system, that is, high-level data at the secret level uses the network key management method, and data that is not so high or data that is frequently used by being disconnected from the network and closed on the terminal is used by the local key management It becomes possible.
[0069]
In particular, according to the present invention, since the network key management method is improved, that is, the encryption key for encrypting the data on the client terminal is managed on the server computer, the encryption on the terminal can be performed even if the terminal is stolen. Since the encrypted data cannot be decrypted, a stronger encryption system can be provided.
[0070]
In addition, according to the present invention, the combination of the local key management method and the network key management method is improved, that is, the encryption key for encrypting the data on the client terminal is managed on the server computer or on the terminal. By providing encryption key management that matches the security of data on the terminal, a more flexible encryption system can be provided. In other words, when the client terminal is carried away from the network, processing such as line connection is required to obtain the encryption key on the server computer, which reduces the operability, but in this system, it is managed on the terminal Since the encryption key can be used, convenience is enhanced.
[0071]
Furthermore, according to the present invention, the combination of the local key management method and the network key management method and the improvement of the method for explicitly selecting either one, that is, the encryption key for encrypting the data on the client terminal is provided on the server computer. Alternatively, by managing on the terminal, it is possible to provide a more flexible encryption system by providing encryption key management in accordance with the security of data on the terminal device. In other words, when the client terminal is carried away from the network, processing such as line connection is required to obtain the encryption key on the server computer, which reduces the operability, but in this system, it is managed on the terminal Since the encryption key can be used, convenience is enhanced. Whether to use an encryption key managed on the terminal device or an encryption key managed on the server computer is determined by using two types of key management icons on the terminal device.
[0072]
Furthermore, according to the present invention, the combination of the local key management method and the network key management method is improved, that is, the encryption key for encrypting data on the client terminal is not only managed on the client terminal, but also on the server computer. However, by managing twice, it is possible to prepare for loss or destruction of the encryption key on the terminal device.
[0073]
Furthermore, according to the present invention, by specifying an effective time during which the encryption key for encrypting data on the client terminal can be held on the terminal device, the terminal device is passed to a third party in the event of theft. However, since the encryption key is automatically invalidated after a lapse of time, the encrypted data cannot be decrypted, and a more secure encryption system can be provided.
[0074]
Furthermore, according to the present invention, the combination of the local key management method and the network key management method is improved, that is, the encryption key on the server computer is used only when the client is connected to the network and is disconnected. By using the encryption key on the terminal device, it is not necessary to select which encryption key to use.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the overall configuration of an encryption system in a network computing system according to an embodiment of the present invention.
FIG. 2 is an exemplary view showing a key selection screen for allowing the terminal device side to select either a local key or a network key by the key management client program according to the embodiment.
FIG. 3 is an exemplary view showing a display screen for local key setting / acquisition according to the embodiment.
FIG. 4 is an exemplary view showing a network key setting / acquisition display screen according to the embodiment.
FIG. 5 is a view showing an encryption instruction screen according to the embodiment.
FIG. 6 is an exemplary view showing a composite instruction screen according to the embodiment.
FIG. 7 is a flowchart showing processing for storing a local key on the memory according to the embodiment;
FIG. 8 is a flowchart showing processing for storing a network key in the memory according to the embodiment;
FIG. 9 is a flowchart showing a process for encrypting unencrypted data using a local key when a local key management icon according to the embodiment is in an active state.
FIG. 10 is a flowchart showing decryption processing of encrypted data using a local key when a local key management icon according to the embodiment is in an active state.
FIG. 11 is a flowchart showing an encryption process of unencrypted data using a network key when a network key management icon according to the embodiment is in an active state.
FIG. 12 is a flowchart showing the sum of decryption processing of encrypted data using a network key when the network key management icon according to the embodiment is in an active state.
[Explanation of symbols]
1, 4 ... Terminal equipment
2 ... WAN (public network)
3 ... LAN
5 ... Server computer
11 ... CPU
12 ... Memory
13. Screen display device
14 ... Input device
15 ... External storage device
51. Network key management table
52 ... Key management server program
53 ... Setting program
121 ... unencrypted data
122 ... Encrypted data
123 ... Encryption program
124 ... Local key
125 ... Network key
126 ... Key management client program
151: Unencrypted data set
152 ... Encrypted data set
153 ... Local key management table

Claims (3)

Encryption system used in a network computing system that connects a terminal device that stores data encrypted using an encryption key and an information processing device that stores the encryption key used when encrypting data on the terminal device Because
A first encryption key managing means for storing a first encryption key be on the information processing apparatus is generated on the information processing apparatus,
Second encryption key management means for generating and storing a second encryption key on the terminal device;
An encryption key obtaining means for each acquired from the first or the second the first or the encryption key of the second encryption key management unit be on the terminal equipment,
Encryption means for storing encrypted data using the first or second cryptographic key obtained from the encryption key acquisition means be on the terminal equipment,
Connection confirmation means for determining whether the terminal device is connected to the network on the terminal device ,
The encryption means encrypts using the second encryption key when it is determined that the terminal device is disconnected from the network as a result of the determination by the connection confirmation means. If determined, encrypt using the first encryption key.
An encryption system in a network computing system. A terminal device that stores data encrypted using an encryption key and includes second encryption key management means, encryption key acquisition means, connection confirmation means, and encryption means, and is used when encrypting data on this terminal equipment An encryption key management method executed by an encryption system used in a network computing system for storing an encrypted key and connecting an information processing apparatus having a first encryption key management means ,
The first encryption key management means generating and storing a first encryption key on the information processing apparatus;
The second encryption key management means generating and storing a second encryption key on the terminal device;
The encryption key acquisition means acquiring the first or second encryption key from the first or second encryption key management means, respectively;
The encryption means encrypts and stores the data using the acquired first or second encryption key;
The connection confirmation means determining whether the terminal device is connected to a network;
Comprising
In the step of encrypting and storing, the encryption means encrypts using the second encryption key when the terminal device is determined to be disconnected from the network as a result of the determination, and connects If it is determined that it has been encrypted, the first encryption key is used for encryption.
An encryption key management method characterized by the above. And a terminal device that stores the encrypted data using the encryption key is used in a network computing TIG system for connecting the storing information processing apparatus an encryption key used when encrypting the data on the terminal device,
A function of generating and storing a first encryption key on the information processing apparatus in the information processing apparatus;
A function of generating and storing a second encryption key on the terminal device in the terminal device;
A function for acquiring the first or second encryption key from the first or second encryption key management means in the terminal device;
A function of encrypting and storing data in the terminal device using the acquired first or second encryption key;
A function for determining whether the terminal device is connected to the network.
Realized,
The function of encrypting and storing is determined to be encrypted and connected using the second encryption key when the terminal device is determined to be disconnected from the network as a result of the determination. If it does, it includes a function to encrypt using the first encryption key.
The computer-readable storage medium which memorize | stored the program characterized by the above-mentioned.

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