JPH01163871A - Hierarchization system for slip compressed sentence - Google Patents

Abstract

PURPOSE:To smooth an electronic transaction through an information network by enabling a slip confirmation by a segment-wise compressed sentence by the completion stage of a transaction, enabling to detect the falsification of a slip and enabling a unique digital signature reflecting a slip content. CONSTITUTION:An electronic transaction is executed between computers 101 and 102 connected by a network 103. A slip prepared here is divided into some segments, data to be the point of a transaction are included in each divided segment, a compressed sentence is prepared for each segment, a compressed sentence including the content of the compressed sentence for each segment is prepared and it turns to be a representative compressed sentence in a transaction slip. The representative compressed sentence is used for a digital signature in the electronic transaction and the compressed sentences of each segment are preserved for the false detection of a slip falsification and the like. Thus, such electronic transaction such as the signing and sealing of contracts with the use of a computer can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to electronic transactions via information networks.

[Conventional technology]

An era of business communications is about to begin, in which meetings and various transactions can be conducted electronically via communication networks. It is expected that electronic transactions, such as signing and stamping contracts using computers, will become a reality in the near future.

Digital signatures created by applying public key cryptography are attracting attention as they bring the following functions to electronic transactions.

(1) The sender cannot deny the fact of the communication or the contents of the communication.

(2) The recipient cannot deny the fact of the communication or the contents of the communication.

As a result, it is expected that digital signatures will be able to realize functions equivalent to conventional seals in data communications.

[Problem that the invention seeks to solve]

By the way, a digital signature in an electronic transaction consists of a compressed text of the transaction slip and content indicating the transaction status. It's expensive.

Therefore, if a transaction slip is illegally tampered with, the compressed text of the tampered slip will be different from the compressed text that should have been created, proving that the slip has been tampered with.

However, although it is possible to prove that the slip was tampered with, it is impossible to prove which part of the slip was tampered with.

[Means for solving problems]

In order to solve the above problems, the present invention uses the following means.

(1) Divide the slip to be created into several parts. Each divided part contains data that becomes the key point of the transaction.

(2) Create a compressed sentence for each part, create a compressed sentence containing the contents of the compressed sentence for each part, and use this as a representative compressed sentence in the transaction slip.

(3) A representative compressed text is used for the digital signature in electronic transactions, and the compressed text for each part is saved for use in detecting fraud such as falsification of documents.

[Effect]

The technical measures described above result in the following effects.

1. Reduce unnecessary transactions due to careless mistakes Detect unavoidable human errors in transactions by creating compressed statements for each part and checking compressed statements at the transaction stage. This makes it easier to avoid unnecessary transactions.

2. Detection of unauthorized tampering parts of transaction slips By including data that is the key point of the transaction in each part of the split slip (for example, in the case of stock trading, limit price 2 shares, brand, trade, etc.), each part can be detected. Since each part compressed sentence in is considered to reflect each point data, it becomes easy to estimate the tampered part.

3. Digital signature part that reflects the contents of the slip By using the representative compressed sentence created by using all the compressed sentences as input data as the original text of the digital signature, the digital signature can be realized as a unique one that reflects the contents of the slip. It is possible. [Example] An example of the present invention will be described below with reference to FIGS. 1 and 2. Electronic transactions are carried out between two parties connected by the network shown in FIG.

5tepl: In the computer 101 or 102,
The transaction slip 201 is based on predetermined rules.

Ml (202), M2 (203), M3 (204)
.

M4 (205) is divided into 4 parts (here, 4 parts).

The part data of Ml includes brand data, and the part data of M2 includes trading data.

The part data of M3 includes data on the number of stocks, and the part data of M4 includes limit price data.

5step2: Regarding the divided part data M1 to M4,
Calculate body part compression sentences MACI to MAC4 from each data! ! ! 101 (or 102).

The compressed sentence creation method will be described later.

5tep3: Based on the part compressed sentences MACI to MAC4, calculate the representative compressed sentence MAC of the transaction slip 201 on the computer 101 (
Or in step 102), create, MAC and MA
Let CI to MAC4 be the compressed text data of the slip 201.

5tep4: The computer 101 (computer 102) creates and sends the compressed text and slip data to the communication network 10.
3 to the computer 102 (computer 101),
The following electronic transactions (electronic seal exchange) will be conducted.

5tep5: The computer 102 (computer 101) similarly creates a part compressed sentence and a representative compressed sentence, and checks the transaction slip. Here, careless slip creation mistakes are detected.

5tep6: When exchanging electronic signatures, the computer 102 (or 101) performs a digital signature using the representative compressed text and performs electronic transactions.

5step 7: If a discrepancy occurs between the computers 101 and 102 after the check, the part compression statement of the slip to be claimed,
By creating and comparing one representative compressed sentence, unauthorized tampering of the slip data is detected and the tampered part is estimated.

To create a compressed statement, the transaction slip M is divided into 56-bit blocks, and each block is divided into M1, M2, . ...Let it be Mn.

If the last Mn is less than 56 bits long, 0'' is added to correct it.

A parity bit of 1 bit is added to the block in units of 7 bits, the block length is expanded to 64 bits, and this is set to Kl, 2...Kn.

r is the exclusive OR of input data I(i-1) encrypted (E) with key Ki and I(i-1).
(i).

I(i)=I (i-1) ■EKi(I (i
-1)) The above processing is performed for i=1*2... Further, it is assumed that the initial value ■(0) is a predetermined value. However, ■ represents the exclusive OR of bit correspondence, and the finally obtained value I (n) becomes the compressed sentence.

The part compression sentence is created from a part of the transaction slip M.

Modification 1 of the Embodiment The method of dividing the slip may be equal division, division by level, or even division, depending on necessity and requirements. Furthermore, division can be performed on the entire document or a portion thereof.

Modified example 2 of the embodiment The region compression sentence may be independent for each region, or the region M2 may include the compression result of the region M1, and the region M2 may include the compression result of the region M1.
3 may include the compression results of the region M2.

〔Effect of the invention〕

1. Reduce unnecessary transactions due to careless mistakes.

In dealing with unavoidable human error,
By creating a compressed statement for each part and checking the part compressed statement at the transaction stage, human errors can be detected and unnecessary transactions can be avoided.

2. Detection of document tampering parts By including gators that are the key points of a transaction in each part of the split slip (for example, in stock trading, limit price 9 shares, brand, trade, etc.), the part is compressed for each part. Since the sentence is considered to reflect each point data, the tampered part can be easily estimated.

3. Digital signature that reflects the contents of the slip By using the representative compressed text created by inputting the compressed text of each part as the original text of the digital signature, it is possible to create a unique digital signature that reflects the contents of the slip. It is possible.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a configuration example of an electronic trading system implementing the present invention, and Fig. 2 is an example of dividing a slip assuming stock buying and selling for creating a hierarchically compressed slip statement in electronic trading of the present invention. FIG.

Claims (1)

[Claims] 1. In electronic transactions, when creating a compressed document for a document that is required between transactors to authenticate the other party and confirm transaction details (slips), all or part of the document is divided into several parts. , and each divided part includes data that is a key point in the transaction slip, a compressed sentence is created for each divided part, and a unique representative compression that reflects the contents of the slip is created from the compressed sentence for each part. By creating a sentence and applying a digital signature using the representative compressed sentence, it is possible to confirm the document using the compressed sentence for each part before the end of the transaction, and also to detect unauthorized tampering of the document. A document compression text layering method that is characterized by making it possible to create a unique digital signature that reflects the contents.