JP2002268543A - Electronic information proving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for accurately restoring an original by exchanging the small amount of electronic information and to provide a method for proving the truthfulness of the electronic information without presenting the information even to an interposed trust institution. SOLUTION: Original electronic information Or is finely divided and turned to information pieces, an order is replaced, then they are divided into a plurality of information groups and multiple pieces of divided electronic information G1 and G2, etc., are formed. Also, a key file K having dividing and order replacing methods recorded therein is prepared. The key file K and one piece of the divided electronic information further when needed are stored in the storage device of a third party trust institution TTP as deposit electronic information. The pieces of the divided electronic information are distributed among interested parties A and B, etc., and kept in the respective storage devices. The pieces of the divided electronic information G1 and G2, etc., kept by the interested party and the deposit electronic information stored by the third party trust institution TTP are gathered as needed and the original electronic information Or is restored on the basis of the dividing and order replacing methods recorded in the key file K.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic information certification method for confirming whether electronic information stored by a party has the same identity as an original.

[0002]

2. Description of the Related Art In electronic commerce, a party concludes a contract through a communication network, stores the contents of the contract as electronic information, and executes a contract in accordance with the stored contract contents. Since the electronic information can be easily tampered with, and even if it is changed, it is not easy to identify the changed part, so that whether or not the contract contents stored by each person are the same as the original may cause a dispute. As a method of confirming that the stored electronic information is the same as the original, there is a method in which the parties share the original and, when necessary, integrate the two to restore the original.

However, in this method, as long as the portion where the two pieces of electronic information are joined can be maintained, even if the other parts are modified, the consistency as the electronic information is established, and the electronic information is restored to another electronic information. And there was a risk of conflict between the parties. In order to eliminate such unnecessary disputes, a system for mutually confirming the authenticity of electronic information through a fair third-party depository is conceivable. The parties may deposit the contents of the contract directly with a third-party depository and refer to it when necessary. However, such an institution must commission and record the contents of the contract each time it is signed,
The required storage capacity is enormous. In addition, it is indispensable that the amount of communication required for operation is enormous and the demand for communication lines is strict.

[0004] For this reason, it is required that the original can be restored fairly with the smallest possible amount of information. Furthermore, if the information is concentrated in a third-party depositary organization, it is easy to be attacked by a malicious third party, and the burden of guaranteeing the security of the deposited information is large. For the depositing party,
Since the depositary institution is an unrelated third party, it is not desirable to know the information content, and it is desirable to mechanically guarantee only the authenticity of the content if possible.

[0005]

An object of the present invention is to provide a method for accurately restoring an original by exchanging a small amount of electronic information. It is an object of the present invention to provide a method for proving the authenticity of electronic information without disclosing information.

[0006]

In order to solve the above-mentioned problems, the electronic information certification method of the present invention divides the original electronic information into small pieces, changes the order of the pieces into information pieces, and then divides the original electronic information into a plurality of information groups. Create a key file in which the divided electronic information is formed and record the method of dividing and changing the order, store the key file as depositary electronic information in a storage device of a third-party depository, and divide the divided electronic information between the parties. If necessary, the divided electronic information stored by the parties and the deposited electronic information stored by the third-party depository are merged, and the division and order rearranged in the key file are stored. The method is characterized in that the original electronic information is restored based on the method.

[0007] Since the original electronic information is divided into small pieces and the order is changed thereafter, the information content cannot be read as it is. Moreover, since the parties are divided and shared with each other, and only the third-party depositary institution has information describing the method of division and reordering, neither party can know the information content from the electronic information stored. Also, the electronic information cannot be altered so as not to be unnatural when restored later. Furthermore, since the contents of electronic information such as a contract cannot be read from a file deposited at a third-party depository, there is no leakage of secrets to anyone other than the parties. In addition, since the original electronic information itself is not deposited at the depositary institution, even if the number of deposits increases, the capacity of the storage device to be held by the depository is extremely small. Naturally, the amount of electronic information communication between the depositary institution and the user is also very small.

This method can also prevent fraudulent acts in which the parties collude and falsify the original, such as fraudulent insurance money due to insurance fraud. In addition, this method can be used not only to prove the identity of the original electronic information file and the original, but also to restore the original when the electronic information file is damaged in order to record it again. Nor.

In the electronic information certification method of the present invention, in addition to a key file in which a method of dividing and rearranging the original electronic information is recorded, one of the divided electronic information is used as deposited electronic information by a third party depository. You may make it memorize | store in a memory | storage device. In this case, the remaining divided electronic information was divided among the parties and stored in respective storage devices, and the divided electronic information stored by the parties and the third-party depository were stored as necessary. The divided electronic information is combined, and the original electronic information is restored based on the division and rearrangement method recorded in the key file.

[0010] The key file is also divided into information elements, the order of which is changed and distributed among the parties, and the header information recording the method of changing the order of division of the key file is deposited in a third party depository. Then, when restoring the original, the key file may be restored from the header information, and the divided electronic information may be combined and restored based on the restored key file. By dividing the key file as described above, restoring information becomes more difficult, and the security is improved.

In this way, by storing a part of the electronic information by the depositary institution and supplementing it with the electronic information from the parties at the time of restoration, the original electronic information can be divided and divided by a relatively simple method. Even in the case of changing the order, the contents cannot be read unless the electronic information stored in the depository is supplemented, so that the confidentiality can be maintained more accurately and the mutual distrust between the parties can be further alleviated.

Furthermore, the original electronic information may be divided and distributed by one of the parties. However, the depository once deposits the entire electronic information, divides it, rearranges the order, and distributes it to each party. You may make it. With such a method, the authenticity of the original can be guaranteed, and the depositing organization can discard the portion of the electronic information distributed to the parties, so that the deposited capacity can be extremely increased. It goes without saying that the third party depository may store only the key file. In the electronic information certifying method of the present invention, a third party arbitration institution can divide and restore the divided electronic information possessed by the parties and the depositary institution. Further, the divided electronic information may be encrypted and stored.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an electronic information certification method according to the present invention will be described in detail with reference to the drawings based on embodiments. FIG. 1 is a block diagram showing the configuration of one embodiment of the present invention.
Is a flowchart showing a state of electronic information distribution in the present embodiment,
FIG. 3 is a block diagram showing the configuration of the second embodiment, FIG. 4 is a block diagram showing the configuration of the third embodiment, and FIG. 5 is a block diagram showing the fourth embodiment.

[0014]

Embodiment 1 In the electronic information certifying method of this embodiment, as shown in FIGS. 1 and 2, an original Or issued by a party A is divided into an appropriate number of information fragments according to a division function dv specified at that time. p1, p2, p3, p4, ..., pn-1,
pn. Each piece of information may be of any size. Note that if you divide by bits instead of bytes,
Since the information pieces after splitting will not be displayed in a meaningful character format as it is, it will be difficult to read the contents,
Bit division is preferred for security.

Next, according to the specified order change distribution function sh, the division information D obtained by division as described above is obtained.
The arrangement order of f (pi) is changed, and this is divided at an appropriate position, and the information group G1 (u1, u2,.
um-1, um), G2 (v1,..., vp), G3
(W1,..., Wq),. The divided information group is distributed to the related parties and stored in the storage devices of the related parties. When forming the information group Gi, it goes without saying that the same result is obtained even if the arrangement order is changed after distributing the information pieces pi of the division information Df.

The generated information group Gi is distributed to the opposing parties A, B,... And the third-party depositary institution TTP so that there is no duplication. The third-party depositary institution TTP further records a key file K including the division function dv and the order change distribution function sh. In order to secure mutual trust, it is preferable that the party A distributes the information group other than the electronic information group to be stored by itself and the key file K to other places and then discards them.

For example, when the content of the contract arises at the party B, the parties A, B,... Discuss with each other, request the other party and the third-party depositary organization TTP,
Receive the information groups G1, G2, G3,... And the key file K stored by the depository. The party B determines the information groups G1, G2, and G3 according to the order change distribution function sh stored in the key file K and, if necessary, the division function dv.
By integrating G3,... And returning to the original order, the division information Df, and thus the original electronic information Or, can be restored. Even when an information group is formed by distributing the information pieces of the divided information and then changing the arrangement order, since the procedure is shown in the order change distribution function sh, the inverse function is similarly applied. Thus, the original Or can be restored.

The party B can verify whether the contract contents are correct by comparing the contract contents stored as the basis of the contract act with the restored original electronic information. In addition,
This method is not limited to contracts, and can be used for sharing the same electronic information between parties. Further, even if the electronic information stored therein is damaged for some reason, the original electronic information thus restored can restore the contents to the original form.

According to the electronic information certifying method of this embodiment, one of the parties keeps only a part of the contract contents, and therefore cannot unilaterally falsify the contract contents. In addition, it is sufficient to store a very small part of the contract contents and a small key file for the third party's deposit institution TTP, so that a large number of contracts can be made without having a large capacity. further,
Since the key file K, which is a key for restoring the electronic information, is stored by the third-party depositary institution TTP, the parties must
Otherwise, the electronic information cannot be restored, and the fairness of the proof can be ensured. For simplicity, the figure shows a case where there are two parties, but it goes without saying that the same method can be used even if there are many parties.

[0020]

[Embodiment 2] The electronic information certification method of this embodiment is different from the first embodiment in that the third-party depositary organization TTP stores only the key file K without storing the division information, as shown in FIG. It is different from the example. The party A obtains the original information Or according to the division function dv and the order change distribution function sh.
To generate divided electronic information G1 stored by itself and divided electronic information G2 stored by the other party B. The split electronic information G1 and G2 are shared by the parties A and B, and the key file K recording information on the method of split distribution is deposited with the third party depositary organization TTP.

For example, when the party B feels necessary, it obtains the divided electronic information G1 stored by the other party A and the key file K stored by the third-party depositary organization TTP, and stores it. The divided electronic information G2 and the divided electronic information G1 obtained from the other party A are combined, and the original electronic information Or is restored based on the information in the key file K. In this method, since the third-party depositary institution TTP only needs to store the key file K, the capacity of the storage device and the amount of information communication at the time of inquiry are reduced. Note that the same method can be used even when the number of parties is three or more, as in the first embodiment.

[0022]

Embodiment 3 In the electronic information certifying method of this embodiment, as shown in FIG. 4, the entirety of the original electronic information Or, which describes the contract contents agreed between the parties, is once passed to a third-party depositary institution TTP and deposited. The institution decides the division function dv and the order change distribution function sh by itself, divides the electronic information and rearranges the order, and then communicates with the parties A, B,. The depositing organization records the key file K containing the used order change distribution function sh and, if necessary, the divided electronic information, and, upon request, stores the information group stored by itself and the order change distribution. The function is sent. By distributing the information in this way by a third party, the fairness of the proof of the contract can be further enhanced, and the depository can discard the part of the electronic information distributed to the parties, so that a large amount of Can receive.

[0023]

[Embodiment 4] In the electronic information certification method of this embodiment, as shown in FIG. 5, the original is confirmed by a third-party arbitration organization ADR. In FIG. 5, the party A divides the original Or based on the division function and the order change distribution function, stores the divisional electronic information G1 as its own, and sends the second divisional electronic information G2 to the other party B, Further, the key file K in which the third divided electronic information G3, the division function and the order change distribution function are recorded is sent to the depositary institution TTP, and is stored there.

Thereafter, when any party has doubts about the contract contents to which the party or the other party complies, the party requests a confirmation from the arbitration body ADR in consultation with the other party. Then, the arbitration organization ADR allows the parties A, B and the depositary institution TTP to provide the divided electronic information G1, G2, G3 and the key file K, and restores the original electronic information Or from them. You can check the contents. Here also, it goes without saying that the depositing organization TTP may store only the key file K.
Also, even if there are three or more parties, the information content can be confirmed in the same manner.

[0025]

Embodiment 5 In the electronic information certification method of this embodiment, a key file used for restoring divided electronic information is also divided and rearranged in order, and distributed to a party or a third party depositary organization TTP. It was done. By distributing the key file in this way, even if a part of the split information is obtained, only a part of the key file can be restored at best, and even the obtained part can be converted to the original electronic information. Since the information cannot be restored to a certain form, the security of the information is further improved.

[0026]

As described in detail above, according to the electronic information certification method of the present invention, the original can be accurately restored by exchanging a small amount of electronic information, and the information content is disclosed to the intervening depository institutions. Without this, it is possible to prove the authenticity of electronic information. Also, the amount of information that the depository must store is small,
Since the amount of information exchanged between them is small, an electronic information certification system can be constructed economically.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of an electronic information certification method according to the present invention.

FIG. 2 is a flowchart showing a state of electronic information distribution in the present embodiment.

FIG. 3 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a third exemplary embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a fourth exemplary embodiment of the present invention.

[Explanation of symbols]

 A, B Parties TTP Third-party depositor ADR Third-party arbitrage organization Or Original electronic information Df Division information G1, G2, G3, ... Division electronic information K Key file dv Division function sh Order conversion distribution function

Claims (6)

[Claims] 1. A method for generating a key file in which original electronic information is finely divided and divided into a plurality of information groups to form a plurality of divided electronic information, and a method of dividing and rearranging the order is recorded. The key file is stored as deposited electronic information in a storage device of a third-party depository institution, and the divided electronic information is divided among the parties and stored in respective storage devices. The divided electronic information stored in the storage device of the party and the deposited electronic information stored in the storage device of the third-party depository are combined, and based on the division and reordering method recorded in the key file, the original electronic An electronic information certification method characterized by restoring information. 2. The electronic information certification method according to claim 1, wherein the deposited electronic information includes at least one of the divided electronic information in addition to the key file, and the remaining divided electronic information is shared between the parties. An electronic information certifying method characterized by doing so. 3. The electronic information certification method according to claim 1, wherein the key file is further divided into a plurality of information groups after the key file is finely divided into information pieces and the information is divided into a plurality of information groups. And generating header information recording the division and permutation method, storing the header information in the storage device of the third-party depository in place of the key file as electronic depository information, and storing the divided key file element The key file is restored based on the header information when the original electronic information is needed, and the key file is restored based on the restored key file when the original electronic information is required. An electronic information certifying method characterized by restoring original electronic information by using the method. 4. The electronic information certification method according to claim 1, wherein the third-party depositary institution creates the divided electronic information and the key file from the original electronic information. 5. The electronic information certification method according to claim 1, wherein a third party arbitration organization collects and restores the divided electronic information possessed by the three parties. 6. The electronic information certification method according to claim 1, wherein said divided electronic information is encrypted and stored.