JP2005080131A - Secret data communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secret data communication system capable of using latest secret data maintained always, transmitting and receiving the secret data safely via an open communication line by a method of obtaining reliance from a recipient, having only the terminal of a specific recipient receive the secret data, and conducting tracking if the secret data are leaked. <P>SOLUTION: Secret data are encrypted with a long key, and the key of encryption is passed to a recipient by a safe means. The encrypted secret data are received by the terminal of the recipient, and it is decoded automatically for the utilization of the secret data. A terminal other than the terminal of the recipient cannot transmit, receive, or decode the secret data, since a value unique to the terminal of the recipient is used. Trace information is put into the secret data for each recipient. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to a communication line application system or an Internet application system that securely communicates secret data via a communication line or the Internet.

In order for an unspecified number of people to send and receive confidential data,
1) In most cases, a short key of 128 bits or less is exchanged and encrypted at the time of data transmission / reception.
Or for a specific person to connect to the server at any time or periodically to send and receive confidential data,
2) A system for communicating secret data by accessing a server using a communication line (private line) of a closed line network,
3) A system for restricting access to Internet servers and communicating and using secret data,
4) Some use secret data by sending and receiving data through a communication line using a VPN (Virtual Private Network-Virtual Private Line).
In addition, in order for a specific person to send and receive confidential data at any time or periodically without connecting to the server,
5) Putting secret data into a recording medium without connecting to a server, delivering the recording medium, and sending / receiving the secret data.
6) There is a method in which secret data and dedicated software are put in a recording medium without connecting to a server, and the secret data is transmitted / received and searched and browsed by a terminal.

Encryption and Key Length Current encryption is often made on the premise that an unspecified number of parties exchange data when communicating data. Therefore, the public key is used or the key length is limited. There are also circumstances where the key length cannot be increased due to restrictions. The encryption method itself uses a known method that can be used by an unspecified party to communicate between unspecified parties.
If the data length to be transmitted / received exceeds 128 bits and a key longer than the data length to be transmitted / received is generated, exchanged, and encrypted, it is difficult to break the encryption with the current technology.
Even if the data length is too long, it is impossible to break the encryption if the key length is made longer than enough, for example, 128 kilobytes (1 Mbit). This length can be made as long as you like, but it makes no sense to make it longer than the data length. By exchanging and preparing a sufficiently long key in advance before communication between the parties, and then transmitting and receiving data by communication, it is possible to construct a system in which data cannot be taken out even if eavesdropping or data is leaked.
In addition, since the key length is not fixed in the method of exchanging keys in advance, a key having an arbitrary length can be exchanged as needed. The encryption method may be performed by a method determined between specific parties. If the key length is sufficiently long, the key length is arbitrary, and the encryption method is unique, the encrypted data cannot be technically decrypted.

The purpose is to construct a safe system without incurring costs in a system in which a specific person connects to a periodic server or sends / receives secret data to view and use it.
A closed communication network is cost-effective and has a slow line speed and equipment. Compared to open communication networks such as the Internet, communication costs are also increased. VPN also requires a dedicated device, and the cost including setting up is high. These problems can be prevented by securely sending and receiving secret data over an open communication network.
Although some problems can be solved by restricting access to Internet servers, putting confidential data on the Internet is unreliable and avoided because of the openness of the Internet. Also, since there are problems such as eavesdropping and hacking, it is dangerous to send secret data over a communication line or store it on a server. Existing encryption methods have a short key length and are widely known, so they can be decrypted. Since many key exchanges are performed through communication lines, they are not safe. In some cases, the length of a key is also regulated like a public key. This system solves these problems and sends and receives secret data dramatically and safely via a communication line.
It is safe to store secret data in a storage medium, distribute it, and search and use it on the recipient's terminal, but maintenance of the secret data is not easy and costs high. By keeping the secret data up-to-date at all times, the server can easily keep the data viewed and used up-to-date.
It also facilitates management of secret data. Even when secret data is collected from a base, a method of storing the data in a recording medium, delivering the recording medium to the center, and collecting the data is also used. However, management of the recording medium that must be eliminated is complicated.
Only certain devices can receive secret data. Even if the key is leaked, if only certain devices can send and receive secret data, the security will be further increased.
Capability to track leaks of confidential data. Enables tracking when confidential data is leaked intentionally or accidentally by the recipient.

The secret data is stored on the server so that the receiver can use it for easy maintenance of the secret data. Therefore, it is safe even if secret data is stored on the server. For this purpose, the secret data is encrypted using a key with a bit number that is long enough to be judged to be sufficient and stored in the server, and the decryption key that is inevitably long is passed to the receiver by a secure means. The terminal can be read by the terminal. The receiver requests secret data from the server at the terminal, the server sends the encrypted secret data to the receiver terminal, and the receiver terminal automatically uses the decryption key. Decrypt it and make it available to the recipient.
In this way, the secret data is encrypted anywhere on the server (communication line) other than the recipient's terminal, and the encryption can be performed by a unique method. The key length can also be set freely, it is easy to encrypt with a sufficiently long key, for example, a megabit length, and the encryption is not broken due to technical factors.
Only a specific device can receive or decrypt the secret data by using the unique value of the receiving terminal.
Tracking in the case of omission is possible by putting different tracking information for each receiver in secret data. Safety is further enhanced by limiting the terminals connected.

Embodiments of the present invention will be described based on examples with reference to the drawings.
A method for transmitting and receiving secret data via a communication line will be described with reference to FIG.
a) Prior to sending / receiving the secret data, the secret data sender (X) and the secret data receiver (B) decide in advance to send / receive the secret data (H1) via the communication line. The above arrangement is a method such as presenting the information of the receiver (B) and applying to the sender (X), or meeting in advance between the sender (X) and the receiver (B) to send and receive secret data To do. The sender (X) and the recipient (B) are not unspecified, but are a specific single / plurality of senders (X) and a single / plurality of recipients (B).
b) A long key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and an encryption key is set for the sender (X). (C1) Exchange the decryption key (C2) to the recipient (B).
When there are many recipients (B) as in the case where the center distributes and browses the secret data (H1) to the members, the sender (X) generates the encryption / decryption keys (C1, C2) and the recipients ( When the decryption key (C2) is distributed to B) and there are many senders (X) as in the case where the center collects secret data (H1) from the base, the receiver (B) is the encryption / decryption key. It is convenient to generate (C1, C2) and distribute the encryption key (C1) to the sender (X).
It is important to exchange the encryption / decryption keys (C1, C2) safely by using a transport means, using a communication line that is not open, or limiting the connection time of the communication line.

c) The secret data recipient (B) takes the exchanged decryption key (C2) into the receiver's terminal (A) or the main storage device, or the decryption key (C2) The stored electronic recording medium is set in an electronic recording medium reader so that it can be read by the recipient's terminal (A).
d1) The secret data sender (X) encrypts the secret data (H1) with the exchanged encryption key (C1), and d2) the encryption on the server (Z) connectable via the communication line. The secret data (H2) is stored.
For safety reasons, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line during the encryption. Also, the encryption key (C1) and the decryption key (C2) should not be stored on the server (Z).
The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.
If there is a plurality of encrypted data (H2), the encrypted data (H2) is uniquely identified by creating a single file for each data or storing the encrypted data in a database with an identifier. Give it an identifier so you can.

e1) The receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line and requests secret data (H1), and e2) the server (Z) stores the storage The requested secret data (H1) is received in the terminal (A) of the receiver (B) via the communication line while being encrypted (H2).
When there are a plurality of secret data (H1), the request is made by designating an identifier, or the search condition is presented and the matching data is requested.
f) The terminal (A) of the recipient (B) uses the decryption key (C2) that enables the terminal (A) to read the received encrypted secret data (H2). It is decrypted and displayed on the display device (D) of the terminal (A) and viewed by the receiver (B), or the decrypted secret data (F) is used.
The above e) and f) use the server (Z) connectable via the communication line as the WWW server, display the home page of the server, request the secret data (H1), and are encrypted in the response The secret data (H2) is received and displayed on the browser (browsing software) of the terminal (A), or the secret data (F) is stored and used by the receiver (B) of the terminal (A). This is easy to realize. Decryption can be easily realized by using a decoder incorporated in a dedicated browser or by incorporating a plug-in program (embedded program) in a general-purpose browser.
Of course, it can also be realized by a dedicated communication program of the server client.

A method for transmitting and receiving secret data using the management ID will be described with reference to FIG.
a1) Arrange in advance between the secret data sender (X) and the secret data receiver (B) to send and receive the secret data (H1) via the communication line, and a2) between the two (X, B) A management ID (R) is set for each recipient (B) or each recipient's terminal (A).
The above arrangement is a method such as presenting the information of the receiver (B) and applying to the sender (X), or meeting in advance between the sender (X) and the receiver (B) to send and receive secret data To do. The sender (X) and the recipient (B) are not unspecified, but are a specific single / plurality of senders (X) and a single / plurality of recipients (B).
The management ID (R) is a serial number that can be managed uniquely by the sender (X) or the receiver (B). The name, phone number, name and date of birth of the receiver (B), member The receiver (B) connects to the server (Z) and freely inputs the ID, and if it is duplicated, it is re-entered and used with the password. The sender (X) 's server (Z) obtains the eigenvalue it has, and the sender (X) or the receiver (B) notifies the other party of the value determined by a method such as generating a long random number. Set between (X) and recipient (B).

b) The secret data sender (X) stores the management ID (R) on the server (Z) connectable via a communication line.
The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.
c) A long key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and an encryption key ( C1), and exchange the decryption key (C2) to the recipient (B).
When there are many recipients (B) as in the case where the center distributes and browses the secret data (H1) to the members, the sender (X) generates the encryption / decryption keys (C1, C2) and the recipients ( When the decryption key (C2) is distributed to B) and there are many senders (X) as in the case where the center collects secret data (H1) from the base, the receiver (B) is the encryption / decryption key. It is convenient to generate (C1, C2) and distribute the encryption key (C1) to the sender (X).
It is important to exchange the encryption / decryption keys (C1, C2) safely by using a transport means, using a communication line that is not open, or limiting the connection time of the communication line.

d) The receiver (B) of the secret data takes the exchanged decryption key (C2) into the external or main storage of the receiver terminal (A), or the decryption key (C2) Is set in an electronic recording medium reading device so that the terminal (A) of the recipient can read the electronic recording medium.
e1) The receiver (B) of the secret data uses the terminal (A) to connect to the server (Z) via a communication line, presents the management ID (R), and presents the terminal (A). Request registration of unique ID (T), e2) The server (Z) acquires or sets the unique value of the connected terminal (A) as the unique ID (T), and the unique ID (T) ID (T) and the management ID (R) are linked and stored on the server (Z).
Specific values of the terminal (A) include a hard disk serial number, a CPU ID, a MAC address of the terminal (A), a cookie that the server (Z) uniquely sets for each terminal (A), and an IPV6 terminal. The terminal (A) hardware, such as the IP address assigned to each machine, is set for each user of the terminal (A) or the terminal (A), and is not held by other terminals. A value that is difficult for the person (A) to set arbitrarily is used.
Since the unique ID (T) of the receiver terminal (A) is stored in association with the receiver (B) or the management ID (R) for each receiver terminal (A), the management ID is stored. If it is confirmed whether or not the unique ID of the terminal (A) that is already linked to (R) is stored, the safety is further deepened. If the unique management ID (T) associated with the management ID (R) is not stored on the server (Z), the registration of the unique ID (T) of the terminal is explicitly performed. The convenience is enhanced by the server (Z) acquiring or setting and storing the unique ID (T) without requesting it.
The management ID (R) is presented when the recipient (B) connects to the server (Z) using the terminal (A), and the program for connection transmits the management ID (R) as a parameter. Thus, convenience can be improved by causing the receiver (B) to present it without being aware of it.
f1) The secret data sender (X) encrypts the secret data (H1) with the exchanged encryption key (C1), and f2) the encryption on the server (Z) connectable via a communication line. The secret data (H2) is stored.
For encryption, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line at the time of encryption. Also, the encryption key (C1) and the decryption key (C2) should not be stored on the server (Z).
If there is a plurality of encrypted data (H2), the encrypted data (H2) is uniquely identified by creating a single file for each data or storing the encrypted data in a database with an identifier. Give it an identifier so you can. In addition, when a search is necessary, the search is facilitated by not encrypting the items to be searched.

g1) The receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line to request secret data (H1), and g2) the server connects to the server (Z). A unique ID (T) of the terminal (A) is acquired, g3) whether the acquired unique ID (T) is stored in the server (Z), and g4) is stored Makes the requested secret data (H1) encrypted (H2) received by the receiver terminal (A) via the communication line.
When there are a plurality of secret data (H1), the request is made by designating an identifier, or the search condition is presented and the matching data is requested.
h) The terminal (A) of the recipient (B) uses the decryption key (C2) that enables the terminal (A) to read the received encrypted secret data (H2). It is decrypted and displayed on the display device (D) of the terminal (A) to be viewed by the recipient (B), or the decrypted secret data (F) is used.
The above g) and h) use the server (Z) connectable via the communication line as the WWW server, display the home page of the server, request the secret data (H1), and are encrypted in the response The secret data (H2) is easily received and displayed on the browser (browsing software) of the terminal (A). Decryption can be easily realized by using a decoder incorporated in a dedicated browser or by incorporating a plug-in program (embedded program) in a general-purpose browser.
Of course, it can also be realized by a dedicated communication program of the server client.
In order for the server (Z) to connect the hard disk serial number, the CPU ID, and the MAC address of the terminal (A) among the unique ID (T) of the terminal, a plug-in program (additional incorporation) Program) or by using a dedicated browser or a dedicated communication program.
Depending on the strength of the security, a unique ID (T ) Can be substituted.
Since the terminal that can receive the secret data (H1) can be restricted by using the unique ID (T), the decryption key (C2) can be obtained illegally and read by another terminal. However, the secret data (H1) cannot be browsed and used.

A method for transmitting and receiving secret data using a unique ID will be described with reference to FIG.
a1) The receiver (B) of the secret data uses the terminal (A) to connect to the server (Z) of the sender (X) of the secret data via the communication line and present the information of the receiver (B) A notification is sent in advance that secret data (H1) is sent and received via a communication line, and a2) the server (Z) assigns a unique value of the connected terminal (A) to the unique ID (T ) Is acquired or set and stored on the server (Z).
Specific values of the terminal (A) include a hard disk serial number, a CPU ID, a MAC address of the terminal (A), a cookie that the server (Z) uniquely sets for each terminal (A), and an IPV6 terminal. The terminal (A) hardware, such as the IP address assigned to each machine, is set for each user of the terminal (A) or the terminal (A), and is not held by other terminals. A value that is difficult for the person (A) to set arbitrarily is used.
b) A long key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and an encryption key ( C1) Exchange the decryption key (C2) to the recipient (B).
When there are many recipients (B) as in the case where the center distributes and browses the secret data (H1) to the members, the sender (X) generates the encryption / decryption keys (C1, C2) and the recipients ( When the decryption key (C2) is distributed to B) and there are many senders (X) as in the case where the center collects secret data (H1) from the base, the receiver (B) is the encryption / decryption key. It is convenient to generate (C1, C2) and distribute the encryption key (C1) to the sender (X).
It is important to exchange the encryption / decryption keys (C1, C2) safely by using a transport means, using a communication line that is not open, or limiting the connection time of the communication line.
Usually, the encryption key (C1) and the decryption key (C2) are generated as a pair or are exactly the same.

c) The receiver (B) of the secret data takes the exchanged decryption key (C2) into the external or main storage of the receiver terminal (A) or the decryption key (C2). Is set in an electronic recording medium reading device so that the terminal (A) of the recipient can read the electronic recording medium.
d1) The secret data sender (X) encrypts the secret data (H1) with the exchanged encryption key (C1), and d2) the encryption on the server (Z) connectable via the communication line. The secret data (H2) is stored.
For safety reasons, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line during the encryption. Also, the encryption key (C1) and the decryption key (C2) should not be stored on the server (Z). The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.
If there is a plurality of encrypted data (H2), the encrypted data (H2) is uniquely identified by creating a single file for each data or storing the encrypted data in a database with an identifier. Give it an identifier so you can.

e1) The receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line to request secret data (H1), and e2) the server connects to the server (Z). A unique ID (T) of the terminal (A) is acquired, e3) whether the acquired unique ID (T) is stored in the server (Z), and e4) is stored Makes the requested secret data (H1) encrypted (H2) received by the receiver terminal (A) via the communication line.
When there are a plurality of secret data (H1), the request is made by designating an identifier, or the search condition is presented and the matching data is requested.
f) The terminal (A) of the recipient (B) uses the decryption key (C2) that enables the terminal (A) to read the received encrypted secret data (H2). It is decrypted and displayed on the display device (D) of the terminal (A) to be viewed by the recipient (B), or the decrypted secret data (F) is used.
The above e) and f) use the server (Z) connectable via the communication line as the WWW server, display the home page of the server, request the secret data (H1), and are encrypted in the response The secret data (H2) is easily received and displayed on the browser (browsing software) of the terminal (A). Decryption can be easily realized by using a decoder incorporated in a dedicated browser or by incorporating a plug-in program (embedded program) in a general-purpose browser.
Of course, it can also be realized by a dedicated communication program of the server client.
In order for the server (Z) to connect the hard disk serial number, the CPU ID, and the MAC address of the terminal (A) among the unique ID (T) of the terminal, a plug-in program (additional incorporation) Program) or by using a dedicated browser or a dedicated communication program.
Depending on the strength of the security, a unique ID (T ) Can be substituted.
By using the unique ID (T), it is possible to limit the terminals that can view the secret data (H1). For example, the decryption key (C2) can be obtained illegally and read by another terminal. However, the secret data (H1) cannot be browsed and used.

With reference to FIG. 4, a method for transmitting / receiving secret data encrypted twice will be described.
a1) Arrange in advance between the secret data sender (X) and the secret data receiver (B) to send and receive the secret data (H1) via the communication line, and a2) between the two (X, B) A management ID (R) is set for each recipient (B) or each recipient's terminal (A).
The above arrangement is a method such as presenting the information of the receiver (B) and applying to the sender (X), or meeting in advance between the sender (X) and the receiver (B) to send and receive secret data To do. The sender (X) and the recipient (B) are not unspecified, but are a specific single / plurality of senders (X) and a single / plurality of recipients (B).
The management ID (R) is a serial number that can be managed uniquely by the sender (X) or the receiver (B). The name, phone number, name and date of birth of the receiver (B), member The receiver (B) connects to the server (Z) and freely inputs the ID, and if it is duplicated, it is re-entered and used with the password. The sender (X) 's server (Z) obtains the eigenvalue it has, and the sender (X) or the receiver (B) notifies the other party of the value determined by a method such as generating a long random number. Set between (X) and recipient (B). This can also be realized by a method in which the server (Z) issues a cookie.
b) An individual encryption / decryption key (D1, D2) is set for each of the set management ID (R) between the secret data sender (X) and the secret data receiver (B). The individual encryption / decryption key (D1) is exchanged so that the encryption key (D1) is passed to the sender and the decryption key (D2) is passed to the receiver.

c) The secret data sender (X) associates and stores the management ID (R) and the individual encryption key (D2) on the server (Z) connectable via a communication line.
The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.
d) A long encryption / decryption key (C1, D1) common to all the secret data sender / receiver is set between the secret data sender (X) and the secret data receiver (B), and the sender (X) Exchange the encryption key (C1) to the recipient (B) and the decryption key (D1) to the recipient (B).
In the exchange of keys in b and d above, when there are many recipients (B) as in the case where the center distributes and browses the secret data (H1) to the members, the sender (X) uses the encryption / decryption key (C1 , C2) and distributing the decryption key (C2) to the receiver (B), and when there are many senders (X) as in the case where the center collects secret data (H1) from the base, the receiver ( It is convenient for B) to generate the encryption / decryption keys (C1, C2) and distribute the encryption key (C1) to the sender (X).
Also, it is important to exchange encryption / decryption keys (C1, C2) safely by using transport means, using a communication line that is not open, or limiting the connection time of the communication line.

e) The secret data recipient (B) sends the exchanged common decryption key (D1) and the individual decryption key (D2) to the outside of the receiver (B) terminal (A) or the main It can be read by the terminal (A) of the recipient (B) by taking it into a storage device or setting an electronic recording medium in which the decryption keys (C2, D2) are stored in the electronic recording medium reader. To.
f1) The secret data sender (X) encrypts the secret data (H1) with the exchanged common encryption key (c1), and f2) on the server (Z) connectable via a communication line. The encrypted secret data (H2) is stored.
For safety reasons, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line during the encryption. Also, the common encryption key (C1) and the common decryption key (C2) should not be stored on the server (Z).
If there is a plurality of encrypted data (H2), the encrypted data (H2) is uniquely identified by creating a single file for each data or storing the encrypted data in a database with an identifier. Give it an identifier so you can.

g1) The secret data receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line to request the secret data (H1), and g2) the server receives the management ID. (R) is acquired.
At this time, the management ID (R) set in the a2 is automatically set from the terminal (A) of the receiver (B) to the server (Z) by issuing a cookie and setting the management ID automatically. It is convenient if the server (Z) automatically acquires the management ID (R) by a parameter or the like, and the server (Z) automatically acquires it. This can also be easily realized by setting the server (Z) as a WWW server and allowing the recipient (B) to input the management ID (R) in the input form returned by the server (Z).
If there are a plurality of secret data (H1), a request is made by specifying an identifier, or a search condition is presented and a matching one is requested.
h1) The server (Z) uses the individual encrypted key (D2) stored in association with the requested secret data (H2) as encrypted and associated with the acquired management ID (R). Further, encryption is performed, and h2) the double-encrypted data (H3) is received by the receiver (B) terminal (A) via the communication line.
i) The terminal (A) of the receiver (B) can decrypt the received double-encrypted secret data (H3) by the terminal (A). Using the encryption key (C2, D2) and displaying it on the display device (D) of the terminal (A) for viewing by the recipient (B), or the decrypted secret data (F) Let me use it.
The above g, h, i are encrypted in the response by requesting the secret data (H1) by displaying the homepage of the server (Z) that can be connected via the communication line as the WWW server. It is easy to realize by receiving the secret data (H3) and displaying it on the browser (browsing software) of the terminal (A). Decryption can be easily realized by using a decoder incorporated in a dedicated browser or by incorporating a plug-in (embedded program) in a general-purpose browser.

With reference to FIG. 5, a method for transmitting and receiving secret data by double encryption using eigenvalues will be described.
a1) Arrange in advance between the secret data sender (X) and the secret data receiver (B) to send and receive the secret data (H1) via the communication line, and a2) between the two (X, B) A management ID (R) is set for each recipient (B) or each recipient's terminal (A).
The above arrangement is a method such as presenting the information of the receiver (B) and applying to the sender (X), or meeting in advance between the sender (X) and the receiver (B) to send and receive secret data To do. The sender (X) and the recipient (B) are not unspecified, but are a specific single / plurality of senders (X) and a single / plurality of recipients (B).
The management ID (R) is a serial number that can be managed uniquely by the sender (X) or the receiver (B). The name, phone number, name and date of birth of the receiver (B), member The receiver (B) connects to the server (Z) and freely inputs the ID, and if it is duplicated, it is re-entered and used with the password. A value determined by a method in which the server (Z) of the sender (X) acquires a unique value, or a long random number that does not overlap even if the sender (X) or the receiver (B) generates it arbitrarily. Is set between the sender (X) and the receiver (B). It can also be realized by a method in which the server (Z) is a WWW server and the server issues a cookie.

b) The secret data sender (X) or the receiver (B) acquires a unique value (V) of the terminal (A) of the secret data receiver (B) for each set management ID (R). Then, an individual encryption / decryption key (D1, D2) is generated using the acquired unique value (V), and a method of generating the decryption key (D2) is set to the receiver (B). The individual encryption key (D1) generated is notified to the sender (X).
As the unique value (V) of the terminal (A), the hard disk serial number, the CPU ID, the MAC address of the terminal (A), the cookie that the server (Z) uniquely sets for each terminal (A), The terminal (A) hardware, such as an IP address assigned to each terminal by the IPV6, is set for each user of the terminal (A) or the terminal (A) and is not held by another terminal. Further, a value that is difficult for the receiver (A) to set arbitrarily is used.
The receiver's terminal (A) can generate the individual decryption key (D2) by the generation method notified from the eigenvalue (V). Thus, when the decryption key (D2) is generated from the eigenvalue (V) of the receiver (B) terminal (A) as necessary, decryption is performed except for the receiver (B) terminal (A). become unable.
When setting the decryption key from the unique value (V) of the terminal (A), the server (Z) is accessed from the general-purpose browser of the terminal (A) to the server (Z) as the WWW server. This is realized by a method such that Z) acquires the eigenvalue (V) of the terminal (A) using a plug-in, or acquires the eigenvalue (V) of the terminal (A) using a dedicated communication program.

c) The secret data sender (X) associates and stores the management ID (R) and the individual encryption key (D2) on the server (Z) connectable via a communication line.
The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.
d) A long encryption / decryption key (C1, D1) common to all the secret data sender / receiver is set between the secret data sender (X) and the secret data receiver (B), and the sender (X) Exchange the encryption key (C1) to the recipient (B) and the decryption key (D1) to the recipient (B).
In the exchange of keys in b and d above, when there are many recipients (B) so that the center distributes and browses the secret data (H1) to the members, the sender (X) can use the encryption / decryption keys (C1, C2) is generated and distributed, and when there are many senders (X) so that the center collects secret data (H1) from the base, the receiver (B) generates encryption / decryption keys (C1, C2). Easy to distribute.
Also, it is important to exchange encryption / decryption keys (C1, C2) safely by using transport means, using a communication line that is not open, or limiting the connection time of the communication line.

e1) The secret data receiver (B) imports the exchanged common decryption key (D1) into the outside of the receiver (B) terminal (A) or the main storage device, or The electronic recording medium in which the key (D2) is stored is set in the electronic recording medium reader so that it can be read by the terminal (A) of the receiver (B), e2) and the receiver (B) The individual decryption by the notified method from the unique value of the terminal (A) so that the individual decryption key (D2) can be generated by the notified generation method using the terminal (A). A program for generating the key (D2) is installed. The individual decryption key (D2) is generated, for example, by hashing the eigenvalue.
f1) The secret data sender (X) encrypts the secret data (H1) with the exchanged common encryption key (c1), and f2) on the server (Z) connectable via a communication line. The encrypted secret data (H2) is stored.
For safety reasons, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line during the encryption. Also, the common encryption key (C1) and the common decryption key (C2) should not be stored on the server (Z).
If there is a plurality of encrypted data (H2), the encrypted data (H2) is uniquely identified by creating a single file for each data or storing the encrypted data in a database with an identifier. Give it an identifier so you can.

g1) The secret data receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line to request the secret data (H1), and g2) the server receives the management ID. (R) is acquired.
At this time, the management ID (R) set in the a2 is automatically set from the terminal (A) of the receiver (B) to the server (Z) by issuing a cookie and setting the management ID automatically. It is convenient if the server (Z) automatically acquires the management ID (R) by a parameter or the like, and the server (Z) automatically acquires it. This can also be easily realized by setting the server (Z) as a WWW server and allowing the recipient (B) to input the management ID (R) in the input form returned by the server (Z).
If there are a plurality of secret data (H1), a request is made by specifying an identifier, or a search condition is presented and a matching one is requested.
h1) The server (Z) uses the individual encrypted key (D2) stored in association with the requested secret data (H2) as encrypted and associated with the acquired management ID (R). Further, encryption is performed, and h2) the double-encrypted data (H3) is received by the receiver (B) terminal (A) via the communication line.
i1) The terminal (A) of the receiver (B) can generate the received double-encrypted secret data (H3) using the terminal (A). A key (D2) is generated and decrypted; i2) is decrypted with the common decryption key (C2) that can be read, and is displayed on the display device (D) of the terminal (A). Let the recipient (B) browse or use the decrypted secret data (F).
The above g, h, i are encrypted in the response by requesting the secret data (H1) by displaying the homepage of the server (Z) that can be connected via the communication line as the WWW server. It is easy to realize by receiving the secret data (H3) and displaying it on the browser (browsing software) of the terminal (A). Generation of individual decryption key (D2) and decryption of data can be easily realized by using a generator and decryptor built in a dedicated browser, or by incorporating a plug-in (embedded program) in a general-purpose browser It is.

With reference to FIG. 6, a method for transmitting / receiving corresponding secret data using a database will be described.
a) Prior to sending / receiving the secret data, the secret data sender (X) and the secret data receiver (B) decide in advance to send / receive the secret data (H1) via the communication line. The above arrangement is a method such as presenting the information of the receiver (B) and applying to the sender (X), or meeting in advance between the sender (X) and the receiver (B) to send and receive secret data To do. The sender (X) and the recipient (B) are not unspecified, but are a specific single / plurality of senders (X) and a single / plurality of recipients (B).
b) A long key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and an encryption key is set for the sender (X). (C1) Exchange the decryption key (C2) to the recipient (B).
When there are many recipients (B) as in the case where the center distributes and browses the secret data (H1) to the members, the sender (X) generates the encryption / decryption keys (C1, C2) and the recipients ( When the decryption key (C2) is distributed to B) and there are many senders (X) as in the case where the center collects secret data (H1) from the base, the receiver (B) is the encryption / decryption key. It is convenient to generate (C1, C2) and distribute the encryption key (C1) to the sender (X).
It is important to exchange the encryption / decryption keys (C1, C2) safely by using a transport means, using a communication line that is not open, or limiting the connection time of the communication line.

c) The secret data recipient (B) takes the exchanged decryption key (C2) into the receiver's terminal (A) or the main storage device, or the decryption key (C2) The stored electronic recording medium is set in an electronic recording medium reader so that it can be read by the recipient's terminal (A).
d1) The secret data sender (X) encrypts the secret data (H1) with the exchanged encryption key (C1), and d2) the encryption on the server (Z) connectable via the communication line. An identifier (S) for specifying the secret data is associated with the individual secret data (H1) and stored.
For safety reasons, it is preferable to use a local terminal (Y) that cannot be connected via the communication line without using the server (Z) that can be connected via the communication line during the encryption. Also, the encryption key (C1) and the decryption key (C2) should not be stored on the server (Z).
The server (Z) that can be connected via the communication line does not need to be a server that is directly connected via the communication line, but is indirectly connected via the server that is directly connected via the communication line. It is a server that can send and receive data via the Internet.

e) At the same time, the secret data sender (X) sends a part of the secret data (H1) or / and summary data of the secret data (H1) and the identifier (S) necessary for retrieving the secret data (H1). The search secret data (K) is stored in the server (Z) or a database on a server to which the server can be connected.
The search secret data (K) is a partial item of the secret data (H1) necessary for the search, or summary data of the partial item of the secret data. Of the secret data, for example, binary data items such as photo data are unlikely to become search conditions. The summary data is coarser information of items with secret data. For example, the address is not an address with a detailed address, but an address such as a city or a prefecture.
f) The receiver (B) uses the terminal (A) to connect to the server (Z) via a communication line, presents search conditions, and requests secret data (H1).
g1) The server (Z) uses the database of the search secret data (K) to make a selection based on the search condition, obtains the identifier (S) of the corresponding secret data (H1), and g2) the identifier The corresponding secret data (H1) associated with (S) is received by the receiver's terminal (A) via the communication line (H2) while being encrypted.
h) The terminal (A) of the recipient (B) uses the decryption key (C2) that enables the terminal (A) to read the received encrypted secret data (H2). It is decrypted and displayed on the display device (D) of the terminal (A) to be viewed by the recipient (B), or the decrypted secret data (F) is used.
The above-mentioned f thru | or h display the homepage which consists of a form with the input item of the server (Z) by making the server (Z) connectable via the said communication line into a WWW server, and a receiver (B) makes the form The search condition is used to request the secret data (H1), the server (Z) searches using the search database, receives the encrypted secret data (H2) in response, and the terminal (A) It is easy to display and display on a browser (browsing software). Decryption can be easily realized by using a decoder incorporated in a dedicated browser or by incorporating an embedded program in a general-purpose browser.
If the secret data (H1) is changed even after reaching the step of transmitting and receiving the secret data (H1) after communication, the secret data sender (X) encrypts the latest secret data (H1) and encrypts the server (Z). By storing it above, the secret data (H1) can be kept up-to-date. Also in this case, the secret data (H1) can be transmitted and received without any change in the communication method.
It is easy to realize in the system.

A method of distributing a recording medium and distributing a decryption key will be described with reference to FIG.
a) A key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and the encryption / decryption key is set to the electronic recording medium (M). And the electronic recording medium (M) is distributed to the sender so that the encryption key is passed to the sender and the decryption key is passed to the receiver.
When there are a large number of recipients (B), such as when the center distributes and browses secret data (H1) to members, the sender (X) generates encryption / decryption keys (C1, C2) and decrypts them. The key (C2) is stored in the electronic recording medium (M), and the electronic recording medium (M) is distributed to the recipient (B). Conversely, when there are many senders (X) so that the center collects secret data (H1) from a plurality of bases, the receiver (B) generates encryption / decryption keys (C1, C2) and encrypts them. It is convenient to store the key (C1) in the electronic recording medium (M) and distribute the electronic recording medium (M) to the sender (X).
b) The secret data receiver (B) sets the electronic recording medium (M) in which the decryption key (C2) is stored in the electronic recording medium reader of the terminal (A) of the receiver (B), The decryption key (C2) is stored in the terminal (A) so that it can be read by the terminal (A).
Since the encryption / decryption keys (C1, C2) are distributed in the electronic recording medium (M) and distributed, the encryption / decryption keys (C1, C2) can be made as long as possible. If the decryption key (C2) is sufficiently long, the encrypted secret data (H2) cannot be decrypted except by the terminal (A) that can read the decryption key (C2). Be drunk.
In addition, the electronic recording medium (M) cannot be distributed by communication means, so it is delivered. This reduces the risk of loss due to leakage.

A method of distributing a decryption key using a restricted server will be described with reference to FIG.
In the following description, the sender (X) generates an encryption / decryption key (C1, C2), stores the decryption key (C2) in the server (Z) of the sender, and the receiver (B) The receiving method is described in (A). The receiver (B) generates encryption / decryption keys (C1, C2) and stores the encryption key (C1) in the receiver's server. The same can be realized when (X) is received at the sender's terminal.
a) A key (C1, C2) for encrypting / decrypting data is set between the secret data sender (X) and the secret data receiver (B), and the encryption / decryption keys (C1, C2) are set, Save in advance on a server (Z) that can be connected via a communication line,
b) Notifying the other party of the information on the storage location and the method (P) for connecting to the storage location, which uses the terminal (A) on the server (Z) via the communication line The encryption / decryption key (C1, C2) is connected to the storage location (Q) using the connection method, and the decryption key (C2) is received and stored by the terminal (A). Are exchanged so that the encryption key (C1) is passed to the sender (X) of the secret data (H1) and the decryption key (C2) is passed to the receiver (B) of the secret data.
When there are many recipients (B), such as when the center distributes and browses the secret data (H1) to the members, the sender (X) uses the encryption / decryption keys (C1, C2) as shown in FIG. And the decryption key (C2) is stored in the storage location (Q) of the server (Z) that can be connected via the communication line, and the storage location and connection method are notified to the receiver (B). Conversely, when there are many senders (X), such as when the center collects secret data (H1) from a plurality of bases, the receiver (B) generates encryption / decryption keys (C1, C2) and encrypts them. It is convenient to store the encryption key (C1) in the storage location (Q) of the server (Z) that can be connected via a communication line and notify the sender (X) of the storage location and connection method.
Information on key storage location and notification of connection method (P) can be safely done by mail, delivery, etc., or by using classic communication means such as FAX and telephone, without using public communication lines such as interviews. Desirable above.
The connection method to the server storing the encryption / decryption keys (C1, C2) is limited by ID and password, or directly connected to the server by dial-up connection using VPN (Virtual Private Network). The number of calling party is picked up and restricted, dial-up is called back and connected, a dedicated line is used, the connection source IP is restricted, and the server can be connected based on the request from the other party in advance. Safety is enhanced by limiting the line. It is also effective to limit the time so that only a specific time can be connected. If you combine the above, it will be safer.
Once the decryption key (C2) has been obtained, when the decryption key (C2) is changed, the next decryption key is encrypted and sent as encrypted secret data (H2). The decryption key (C2) can be sent. The next decryption key (C2) may be used after a deadline is determined. This method is also a method of distributing the decryption key (C2) via the communication line, and the safety is dramatically increased by combining with this method.

A method for adding data by separating connections to the server will be described with reference to FIG.
a) When the receiver (B) connects to the server (Z) of the sender (X) of the secret data (H) and requests the secret data (H), the server (Z) is connected to the receiver (B) or terminal (A) is separated,
b) Data (E) that is different for each of the sorted recipient (B) or terminal (A) is added to the encrypted secret data (H2) received by the receiver (B) of the terminal (A).
c) The terminal (A) of the receiver (B) separates the added data (E) and decrypts the encrypted secret data (H2), and d) converts the decrypted secret data (H1) into the decrypted secret data (H1). The added data (E) is added again so as not to affect the browsing and use of the secret data (H1).
Since the decrypted secret data (H1) is added with different data (E) for each receiver (B) or receiver terminal (A) requested by connecting to the server (Z), the secret data is added. When (H1) is leaked, it can be traced from which recipient or from which terminal.
For this purpose, the server (Z) must store the additional data (E) and the sorted terminal information in association with each other.
When re-adding the different data (E) to the secret data (H1), a location determined in advance in the secret data (H1) is used, or when the secret data (H1) is general-purpose image data, It is added to a comment area (an area predetermined for secret data) possessed by general-purpose image data or the like so as not to affect the browsing and use of the secret data (H1).
The above is easy to implement with the CGI of the WWW server by connecting the server (Z) of the sender of the secret data (H1) as a WWW server and connecting from the browser of the terminal (A) of the receiver (B). Here, CGI refers to all programs that are processed by a server in a broad sense. Decryption can be easily realized by using a dedicated browser in the terminal (A) or incorporating a decryption module as a plug-in in a general-purpose browser.
In addition, in the above classification, the receiver (B) inputs an ID, obtains a cookie set individually for each terminal (A), picks up a different IP6 for each terminal (A) to be realized in the near future, and connects At this time, different parameters are obtained for each receiver (B), and a unique value (hard disk serial number, CPU ID, MAC address) unique to the terminal (A) is obtained.

A method of adding data for each management ID will be described with reference to FIG.
a) The management ID (R) of the connected terminal (A) has been acquired.
b) Different data for each connected management ID is added to the secret data to be received.
c1) The terminal (A) of the recipient (B) separates the added data (E) and decrypts the encrypted secret data (H2), and c2) converts the decrypted secret data (H1) into the decrypted secret data (H1). The added data (E) is added again so as not to affect the browsing and use of the secret data (H1).
Since the decrypted secret data (H1) is added with different data (E) for each receiver (B) or receiver terminal (A) requested by connecting to the server (Z), the secret data is added. When (H1) is leaked, it can be traced from which recipient or from which terminal.
For this purpose, the server (Z) must store the additional data (E) and the management ID (R) in association with each other.
When re-adding the different data (E) to the secret data (H1), a location determined in advance in the secret data (H1) is used, or when the secret data (H1) is general-purpose image data, It is added to a comment area or the like possessed by a general-purpose image data format or the like so as not to affect the browsing and use of the secret data (H1).
The above is easy to implement with the CGI of the WWW server by connecting the server (Z) of the sender of the secret data (H1) as a WWW server and connecting from the browser of the terminal (A) of the receiver (B). Here, CGI refers to all programs that are processed by a server in a broad sense. Decryption can be easily realized by using a dedicated browser in the terminal (A) or incorporating a decryption module as a plug-in in a general-purpose browser.

A method for sending and receiving confidential data via a communication line Method for sending and receiving secret data using unique ID Method for sending and receiving secret data using unique ID of terminal How to send and receive doubly encrypted secret data A method of sending and receiving secret data with double encryption using eigenvalues How to send and receive relevant confidential data using a database Distributing a recording medium and distributing a decryption key Distributing a decryption key using a restricted server How to add data by separating connections to servers Method of adding data for each management ID

Explanation of symbols

Described in the figure

Claims (10)

A secret data communication system comprising the steps of carrying out the secret data communication of e to f after the following preparatory steps a to c and d data maintenance step to be performed as needed. A step of negotiating in advance between the secret data sender and the secret data receiver to transmit / receive the secret data via the communication line;
b. A step of setting a long key for encrypting / decrypting data between the secret data sender and the secret data receiver, and exchanging the encrypted data to the sender and the decryption key to the receiver.
c. Enabling the secret data recipient to read the exchanged decryption key on the recipient's terminal;
d. The secret data sender encrypts the secret data with the exchanged encryption key, and stores the encrypted secret data on a server connectable via a communication line.
e. The receiver uses the terminal to connect to the server via a communication line and requests secret data, and the server transmits the stored secret data requested through the communication line while being encrypted. And allowing the receiver's terminal to receive the data.
f. The terminal of the receiver decrypts the received encrypted secret data using the decryption key that can be read by the terminal, and makes the receiver use the decrypted secret data.
A secret data communication system characterized in that the secret data encryption / decryption key is exchanged between the secret data sender and the secret data receiver by distributing the encryption / decryption key by the receiver A secret data communication system comprising the steps of carrying out secret data communications of g to h after the following preparatory steps a to e and f data maintenance steps to be performed as needed. A step in which a secret data sender and a secret data receiver negotiate in advance to transmit / receive secret data via a communication line, and set a management ID for each terminal of the receiver or the receiver between the two .
b. The secret data sender stores the management ID on a server connectable via a communication line.
c. A step of setting a long key for encrypting / decrypting data between the secret data sender and the secret data receiver, and exchanging the encrypted data to the sender and the decryption key to the receiver.
d. Enabling the recipient of the secret data to read the exchanged decryption key on the recipient's terminal.
e. The secret data receiver uses the terminal to connect to the server via a communication line, presents the management ID and requests registration of a unique ID of the terminal, and the server is connected to the server. Obtaining or setting a unique value of the terminal as a unique ID, and linking the unique ID and the management ID and storing them on the server.
f. The secret data sender encrypts the secret data with the exchanged encryption key, and stores the encrypted secret data on a server connectable via a communication line.
g. The receiver uses the terminal to connect to the server via a communication line to request secret data, the server acquires a unique ID of the connected terminal, and the acquired unique ID is Checking whether it is stored in the server, and if it is stored, receiving the requested secret data to the receiver's terminal via the communication line while being encrypted.
h. The terminal of the receiver decrypts the received encrypted secret data using the decryption key that can be read by the terminal, and makes the receiver use the decrypted secret data. A secret data communication system comprising the steps of carrying out the secret data communication of e to f after the following preparatory steps a to c and d data maintenance step to be performed as needed. The receiver of the secret data uses a terminal to connect to the server of the sender of the secret data via the communication line and notifies in advance that the secret data is transmitted / received via the communication line, and the server is connected to the terminal Acquiring or setting a unique value of the machine as an ID unique to the terminal and storing it on the server.
b. A step of setting a long key for encrypting / decrypting data between the secret data sender and the secret data receiver, and exchanging the encrypted data to the sender and the decryption key to the receiver.
c. Enabling the recipient of the secret data to read the exchanged decryption key on the recipient's terminal.
d. The secret data sender encrypts the secret data with the exchanged encryption key, and stores the encrypted secret data on a server connectable via a communication line.
e. The receiver uses the terminal to connect to the server via a communication line to request secret data, the server acquires a unique ID of the connected terminal, and the acquired unique ID is Checking whether it is stored in the server, and if it is stored, receiving the requested secret data to the receiver's terminal via the communication line while being encrypted.
f. The terminal of the receiver decrypts the received encrypted secret data using the decryption key that can be read by the terminal, and makes the receiver use the decrypted secret data. A secret data communication system comprising the steps of carrying out the communication of secret data of g to i after the following preparatory steps a to e and f data maintenance step to be performed as needed. A step in which a secret data sender and a secret data receiver negotiate in advance to transmit / receive secret data via a communication line, and set a management ID for each terminal of the receiver or the receiver between the two .
b. An encryption / decryption key is set for each set management ID between the secret data sender and the secret data receiver, and exchange is performed so that the sender is encrypted and the decryption key is passed to the receiver. Step to do.
c. The secret data sender associates and stores the management ID and the individual encryption key on a server connectable via a communication line.
d. A common encryption / decryption key is set between the secret data sender and the secret data receiver for all the secret data senders and receivers, and exchange is performed so that the encryption key is sent to the sender and the decryption key is passed to the receiver. Step to do.
e. The receiver of the secret data can read the exchanged common decryption key and the individual decryption key on the receiver's terminal (and the set management ID is read from the receiver's terminal). The step of making the server obtainable.
f. The secret data sender encrypts the secret data with the exchanged common encryption key, and stores the encrypted secret data on the server connectable via a communication line.
g. The secret data receiver uses the terminal to connect to the server via a communication line to request secret data, and the server obtains the management ID.
h. The server further encrypts the requested encrypted private data with the individual encryption key stored in association with the acquired management ID, and the double encrypted data is encrypted. And receiving the receiver's terminal through the communication line.
i. The recipient's terminal decrypts the received double-encrypted secret data with the two kinds of decryption keys that can be read by the terminal, and makes the receiver use the decrypted secret data. A secret data communication system comprising the steps of carrying out the communication of secret data of g to i after the following preparatory steps a to e and f data maintenance step to be performed as needed. A step in which a secret data sender and a secret data receiver negotiate in advance to transmit / receive secret data via a communication line, and set a management ID for each terminal of the receiver or the receiver between the two .
b. The secret data sender or receiver acquires a unique value of the terminal of the secret data receiver for each set management ID, and uses the acquired unique value to obtain an individual encryption / decryption key. Generating, notifying the recipient of the method of generating the decryption key, and passing the generated individual encryption key to the sender.
c. The secret data sender associates and stores the management ID and the individual encryption key on a server connectable via a communication line.
d. A common encryption / decryption key is set between the secret data sender and the secret data receiver for all the secret data sender and receiver so that the encryption key is transmitted to the sender and the decryption key is passed to the receiver. Step to replace.
e. The secret data receiver can read the exchanged common decryption key on the receiver's terminal, and can use the receiver's terminal to perform the individual decryption using the notified generation method. The step of enabling key generation.
f. The secret data sender encrypts the secret data with the exchanged common encryption key, and stores the encrypted secret data on a server connectable via a communication line.
g. The receiver uses the terminal to connect to the server via a communication line to request secret data, and the server acquires the management ID. (Obtain automatically, fill in form and get)
h. The server further encrypts the requested encrypted private data with the individual encryption key stored in association with the acquired management ID, and the double encrypted data is encrypted. And receiving the receiver's terminal through the communication line.
i. The recipient's terminal generates and decrypts the individual decryption key that allows the received double-encrypted secret data to be generated using the terminal, and further allows the reading Decrypting with the common decryption key and making the receiver use it. A secret data communication system comprising the following steps: a to c, preliminarily prepared steps, and d to e data maintenance steps to be performed as necessary, and then f to h secret data communications are performed. A step of negotiating in advance between the secret data sender and the secret data receiver to transmit / receive the secret data via the communication line; (Apply to the sender by presenting the receiver's information and contact the sender and the receiver in advance to send and receive confidential data. The sender and the receiver are not unspecified, and the transmission is predetermined. And recipients.)
b. A step of setting a long key for encrypting / decrypting data between the secret data sender and the secret data receiver, and exchanging the encrypted data to the sender and the decryption key to the receiver.
c. Enabling the secret data recipient to read the exchanged decryption key on the recipient's terminal;
d. The secret data sender encrypts the secret data with the exchanged encryption key, and binds an identifier for identifying the secret data to each encrypted secret data on a server connectable via a communication line. Step to save.
e. At the same time, the secret data sender stores a part of the secret data or / and summary data of the secret data and the identifier as the search secret data in the database, which are necessary for searching the secret data.
f. The receiver uses the terminal to connect to the server via a communication line and presents a search condition to request secret data.
g. The server makes a selection based on the search condition using the search secret data database, obtains an identifier of the corresponding secret data, and connects the communication line while encrypting the corresponding secret data associated with the identifier. And receiving the data through the recipient's terminal.
h. The terminal of the receiver decrypts the received encrypted secret data using the decryption key that can be read by the terminal, and makes the receiver use the decrypted secret data.
If the secret data is changed even after reaching the step of sending and receiving the secret data by performing communication, the secret data sender can encrypt the secret data and store it on the server to keep the secret data up-to-date. In this case, the secret data can be transmitted and received without any change in the communication method. A key for encryption / decryption of data exchanged in claim 1 b, claim 2 c, claim 3 b, claim 4 b and d, claim 5 d, or claim 6 b. The key for data encryption / decryption is stored by storing the data in an electronic recording medium and distributing the electronic recording medium in such a way that the encryption key is passed to the sender of the secret data and the decryption key is passed to the receiver of the secret data. The secret data communication system according to claim 1, claim 2, claim 3, claim 4, claim 5, or claim 6, wherein the secret data communication system is exchanged. The encryption / decryption key exchanged in claim 1b, claim 2c, claim 3b, claim 4b and d, claim 5d, or claim 6b is a communication line. Save it in advance on a server that can be connected via, and notify the other party of the storage location and the method for connecting to the storage location.
The other party uses a terminal to connect to the storage location on the server via a communication line using the connection method, and receives and stores the encryption / decryption key at the terminal. The decryption key is exchanged such that the secret data is transmitted to the sender side of the secret data and the decryption key is passed to the receiver side of the secret data. The secret data communication system according to claim 4, claim 5 or claim 6. When the receiver connects to the server of the secret data sender and requests the secret data in claim 1e or claim 6f, the server separates the connected receiver or terminal,
7. The secret data communication system according to claim 1 or 6, wherein different data is added to the classified receiver or terminal for the secret data to be received by the receiver terminal. Claim 2 is characterized in that different data for each management ID connected is added to the secret data received in g of claim 2, e of claim 3, h of claim 4 or h of claim 5. The secret data communication system according to claim 2, claim 4, claim 4 or claim 5.