JP2000338870A - Text electronic authentication device, method, and recording medium recording text electronic authentication program - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide an appropriate authentication for an electronic document in which a text typified by an HTML document is described, and to ignore an illegal copyright. An object of the present invention is to provide a text electronic authentication apparatus capable of extracting authentication information embedded in an electronic document in order to eliminate copying and the like. A text electronic authentication device according to the present invention reads a text from an electronic document in which the text is described, extracts a feature of the read text, and obtains information representing the text feature, information of a publisher, and authentication of the text. A function for embedding the encrypted electronic authentication information in the text, making the encrypted electronic authentication information invisible and indecipherable by the existing electronic document display using the information for It has a function of extracting information of the publisher and information for authenticating the text and the original text from the electronic document in which the authentication information is embedded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an electronic authentication apparatus that inserts watermark information into text for the purpose of electronic authentication of an electronic document (file) in which text is described.

[0002]

2. Description of the Related Art Conventionally, in the Internet, HTML
(Hyper Text Markup Language) document files are used as standard documents. The authentication of the text described in the HTML document file is performed by a secure method that can be authenticated from an appropriate site, for example, SSL (secure).
Appropriate authentication is performed by using a socket layer).

[0003]

However, these documents are stored in a browser or in a mechanical form such as a crawler.
Since the software for extracting the HTML document from the web server can be extracted from the server side to the client side, the document extracted on the client side can be used illegally. Further, the method such as SSL is appropriate when text information including only specific information is exchanged, but it is difficult to perform appropriate authentication for any document. HTML
It was difficult to give proper certification to documents.

[0004] The present invention has been made in view of the above points, and has been developed in accordance with the HT standard used in the Internet and the like.
Appropriate authentication can be given to an electronic document represented by an ML document, and authentication information (watermark) embedded in an electronic document such as an HTML document is used in order to eliminate illegal copying ignoring copyright. The present invention provides a text electronic authentication device, a method, and a recording medium on which a text electronic authentication program can be extracted.

[0005]

SUMMARY OF THE INVENTION A text electronic authentication apparatus according to the present invention enables a digital electronic document in which text is described to authenticate an electronic document by embedding authentication information in the electronic document. An apparatus, comprising: a text reading unit that reads text from an electronic document in which the text is described; a text feature extraction unit that extracts features of the text read by the text reading unit; A text publisher information input unit for inputting publisher information, a text authentication information input unit for inputting text authentication information described in the electronic document, and text features extracted by the text feature extraction unit , Information on the publisher input to the text publisher information input unit, and information input to the text authentication information input unit. And information for the text of authentication was,
And is invisible on existing electronic document displays,
And, a text authentication information generating unit to be unencrypted encrypted electronic authentication information, and the encrypted electronic authentication information generated by the text authentication information generating unit is embedded in the text read by the text reading unit, and A text authentication information embedding unit for embedding the encrypted electronic authentication information so that the encrypted electronic authentication information is not lost even if the text in which the encrypted electronic authentication information is embedded is edited.

[0006] With the above configuration, authentication information including information representing the characteristics of the text, information on the publisher of the text, and information for authenticating the text is encrypted and embedded in the electronic document. The presence or absence of falsification can be detected based on the characteristics of the text, and the electronic document can be authenticated based on the publisher based on the information of the publisher of the text and the information for authenticating the text.
In addition, the information of the publisher of the text is information indicating that the user has issued the text (for example, a company organization having copyright of the text, an address of an individual who wrote the text,
Name etc.). The information for text authentication is an ID issued by a public organization or a certain authentication company. An electronic document display is a dedicated display device or a Web executed on a computer such as a personal computer.
It uses browsing application software such as a browser.

Further, in the text electronic authentication device of the present invention, the text feature extraction unit can execute a plurality of extraction methods according to the size of the feature of the text to be extracted, and the size of the feature of the text to be extracted is provided. In accordance with the designation of the length, the feature of the text is extracted and output, and an identifier indicating the extraction method used is further output. According to the invention, when authenticating the entire text,
Appropriate authentication can be performed by selecting and executing an extraction method corresponding to the size of the feature of the text to be extracted in accordance with the situation where the contents of the text are also to be authenticated.

Further, in the text electronic authentication apparatus of the present invention, the text authentication information generating section receives information representing the characteristics of the text, and outputs a characteristic amount inputting information representing the characteristics of the text. An identifier indicating an extraction method used for extracting a feature of a text is input, a feature identifier input unit for outputting the identifier, and information of a publisher of the text are input, and information of a publisher of the text is input. An information input unit that outputs information for authentication of the text, and an authentication information input unit that outputs information for authentication of the text, and information indicating characteristics of the text. An encryptor that encrypts authentication information including an identifier, information of a text issuer, and information for text authentication, and outputs encrypted authentication information;
The encrypted authentication information, the display device as an invisible byte sequence converted to a code not used for displaying text, a code conversion unit that outputs the invisible byte sequence, the invisible byte sequence is input, the invisible byte sequence And an encrypted authentication information output unit that outputs

Further, in the text electronic authentication device of the present invention, the text authentication information embedding section receives the identifier, and inputs a feature quantity identifier input section for outputting the identifier; An encrypted authentication information input unit that outputs a byte string, a text input unit into which a text described in the electronic document is input, and a determination unit that determines whether all of the invisible byte strings have been inserted into the electronic document. An embedded encryption authentication information output unit that captures and outputs the encrypted authentication information according to the identifier; an embedded text output unit that captures and outputs text described in the electronic document according to the identifier; If it is determined by the section that all of the invisible byte strings are embedded in the electronic document, all of the remaining text described in the electronic document A text output unit that outputs the embedded encrypted authentication information output unit and the embedded text output unit when the determination unit determines that all of the invisible byte strings have not been inserted into the electronic document. It is characterized in that output is performed alternately.

Further, the present invention is an apparatus for extracting authentication information from an electronic document in which authentication information is embedded by the text electronic authentication apparatus according to claim 1, wherein the text authentication information embedding section performs the encryption. A text authentication information extracting unit that reads a text in which electronic authentication information is embedded, separates and extracts the text described in the electronic document and the encrypted electronic authentication information, and the electronic device that is extracted by the text authentication information extracting unit. A text feature extracting unit that extracts text features based on the text described in the document; encrypted electronic authentication information separated and extracted by the text authentication information extracting unit; and a text extracted by the text feature extracting unit. Decrypts the encrypted authentication information embedded in the text based on the characteristics of A text authentication reading unit, a text publisher information extracting unit that reads information of a text publisher from the electronic authentication information decrypted by the text authentication information reader, and an electronic authentication information decrypted by the text authentication information reader. And a text authentication information extraction unit for reading information for text authentication.

Further, the text electronic authentication method of the present invention comprises:
A text electronic authentication method for embedding authentication information in an electronic document in which the text is described, whereby the electronic document can be authenticated, wherein the text is a text that reads a text from the electronic document in which the text is described A reading procedure, a text feature extraction procedure for extracting a feature of the text read by the text reading procedure, a text publisher information input procedure for inputting information on a publisher of the text described in the electronic document, and the electronic document A text authentication information inputting step of inputting information for text authentication described in the text information, information representing characteristics of the text extracted by the text feature extracting step, and a publisher input by the text publisher information inputting step. Information for authenticating the text input by the text authentication information input procedure. And a text authentication generation procedure that is invisible to an existing electronic document display device and is indecipherable and that cannot be decrypted; and the encrypted electronic authentication information generated by the text authentication generation procedure. Embedded in the text read by the text reading procedure, and also embeds the encrypted electronic authentication information so that the encrypted electronic authentication information is not lost even if the text in which the encrypted electronic authentication information is embedded is edited. And a procedure.

Further, the present invention is a method for extracting authentication information from an electronic document in which authentication information is embedded by the text electronic authentication method according to claim 6, wherein said encrypted electronic information is included in said text authentication embedding procedure. The text embedded with the authentication information is read, the text described in the electronic document is separated from the encrypted electronic authentication information, the text authentication information extracting procedure to be extracted, and the electronic document extracted by the text authentication information extracting procedure A text feature extraction procedure for extracting a text feature based on the text described in, an encrypted electronic authentication information separated and extracted by the text authentication information extraction procedure, and a text extracted by the text feature extraction unit procedure. Based on the features of A text authentication reading procedure for decoding information, a text issuer information extraction procedure for reading information on a text issuer from the electronic authentication information decoded by the text authentication reading procedure, and an electronic decryption procedure performed by the text authentication reading procedure. A text authentication information extracting step of reading information for authenticating the text from the authentication information.

Further, the present invention is a recording medium which records a text electronic authentication program which enables authentication of an electronic document in which text is described by embedding authentication information in the electronic document. A text reading procedure for reading a text from an electronic document in which the text is described, a text feature extracting procedure for extracting features of the text read by the text reading procedure, and information on a publisher of the text described in the electronic document A text publisher information input procedure for inputting, a text authentication information input procedure for inputting information for text authentication described in the electronic document, and information representing the text features extracted by the text feature extraction procedure. , The publisher information input by the text publisher information input procedure,
Using the information for text authentication input by the text authentication information input procedure, the text authentication generation is performed as encrypted electronic authentication information that is invisible and indecipherable on existing electronic document displays. And encrypting the encrypted electronic authentication information generated by the text authentication generating procedure into the text read by the text reading procedure, and editing the text in which the encrypted electronic authentication information is embedded. By providing a computer-readable recording medium recording a text electronic authentication program for causing a computer to execute a text authentication embedding procedure for embedding encrypted electronic authentication information so that the authentication information is not lost, the text can be easily read using a computer. An electronic authentication device can be realized.

The present invention also provides a recording medium storing a program for extracting authentication information from an electronic document in which the authentication information is embedded by a computer having the text electronic authentication program according to claim 8 mounted thereon. In the text authentication embedding procedure, read the text in which the encrypted electronic authentication information is embedded, to separate the text described in the electronic document and the encrypted electronic authentication information,
A text authentication information extraction procedure to be extracted, a text feature extraction procedure to extract text features based on the text described in the electronic document extracted by the text authentication information extraction procedure, A text authentication reading step for decrypting the encrypted authentication information embedded in the text based on the extracted encrypted electronic authentication information and the text feature extracted by the text feature extraction unit procedure; and From the electronic authentication information decrypted by the authentication reading procedure, a text publisher information extraction procedure for reading the information of the text publisher, and from the electronic authentication information decrypted by the text authentication reading procedure, information for authenticating the text is obtained. Read text authentication information extraction procedure To provide a computer readable recording medium recording a text electronic authentication program to be executed by the computer, it can be easily realized text electronic authentication system using a computer.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a text electronic authentication device according to an embodiment of the present invention.

T-1 is a text reading unit which opens a file in which text is described and reads it on a device or a storage medium. T-2 is a text feature extraction unit for extracting data (text feature information) representing the features of the text read by the text reading unit of T-1. Here, various types of text feature information can be considered. For example, all text data may be captured as text feature information. In this case, assuming that the data amount for authenticating the text is fixed, the larger the text feature information is, the smaller the ratio of the text feature information described in the text authentication information is. In other words, if all text data is text feature information,
Although authentication is possible for all text data, it is highly likely that authentication of individual text contents described in the text will not be possible.

As a method of using the present apparatus, when authenticating the entire text, the entire text should be extracted as text feature information. However, when the content of the text is to be authenticated, for example, a part of the text written by oneself is used. In order to authenticate whether or not the word is not the whole text, it is necessary to extract independent words or important words included in the text and use them as text feature information.
In consideration of these characteristics, the user sets the following optimal text feature amount (the size of the text feature information) or a flag (identifier, text feature amount parameter) corresponding to the text feature amount as shown below as an example. 2 is set in the text feature extraction unit. Text features Text extraction part Text extraction method Large whole text-Medium Independent words contained in text Morphological analysis Small words Important words contained in text Summary analysis The text feature extraction part of T-2 is the text feature amount set by the user A flag specifying the used text extraction method as a text feature parameter based on T-5
Is notified to the text authentication information generation unit of.

T-3 is a text issuer information input unit. This describes information (text issuer information) indicating that the user has issued the text. For example, information indicating a company organization having a copyright of the text or an address, a name, a URL or the like of an individual who wrote the text is described. T-4 is a text authentication information input unit. This is a part for inputting an issuer ID (text issuer ID) issued by a public organization or a certain certification company. The publisher can be specified based on the text publisher ID. However, in order to uniquely indicate the ID of the publisher, the text publisher ID needs to be unique in the world.

T-5 is a text authentication information generator. In the text authentication information generating unit, the text feature information and the text feature amount parameter extracted by the text feature extracting unit of T-2, and the text indicating the information of the publisher input by the text publisher information input unit of T-3 This is a section for generating text authentication information of the corresponding text by inputting the publisher information and the text publisher ID input in the text authentication information input section of T-4.

More specifically, as shown in FIG. 2, a text feature information input unit T-5a for inputting text feature information extracted by the text feature extraction unit T-2, and a notification from the text feature extraction unit T-2. Parameter input unit T-5b for inputting a text feature parameter to be input, and T-3
Issuer information input unit T-5c for inputting the text issuer information input in the text issuer information input unit of T-4;
Text publisher I entered in the text authentication information input section of
An issuer ID input unit T-5d for inputting D, an encryptor T-5e for encrypting text authentication information including text feature information, text issuer information, text issuer ID, and text feature amount parameter; A code conversion unit T-5f for further converting the encrypted text authentication information into a code (invisible byte sequence) invisible to the browser, and an encryption authentication for outputting the invisible byte sequence code-converted by the code conversion unit T-5f. And an information output unit T-5g. The details of the encryption and the code conversion will be described later.

T-6 is a text authentication information embedding section. The text authentication information embedding unit embeds the text authentication information (invisible byte string) generated in the text authentication information generation unit of T-5 into the input text. However, since the text authentication information is text information, the embedding into text may be leaked to another person and the text authentication information may be deleted.
In addition, when embedding in a text, it can be considered that the embedding is hindered when browsing a normal text. Therefore, in this apparatus, the text authentication information generated by the T-5 text authentication information generation unit is scattered in the text so as not to be easily leaked to others, and the text authentication information is not hindered from browsing the text. And is embedded in the text. In other words, embed the text authentication information in the same way as when browsing normal text, and distribute the text authentication information in the text so that it is durable to changes such as cutting or deleting text. Embed.

More specifically, as shown in FIG. 3, a feature parameter input section T-6a for reading a text feature parameter (F value) from the text authentication information generating section of T-5.
An encrypted authentication information input unit T-6b for inputting an invisible byte string from the text authentication information generation unit of T-5;
A text input unit T-6c for inputting a text input from a text reading unit, and a determination unit T-6 for determining whether all invisible byte strings have been output and controlling each output unit.
d and the text feature parameter (F value),
An embedded text output unit T-6e that reads an input text, outputs a byte sequence of the read text, reads an invisible byte sequence based on a text feature parameter (F value), and outputs the read invisible byte sequence. It comprises an embedded encrypted authentication information output section T-6f and a text output section T-6g for outputting the remaining input text when all invisible byte strings are output.

T-7 is a text authentication information extracting section. A processing unit for extracting the text authentication information embedded by the text authentication information embedding unit of T-6 from the text in which the text authentication information is embedded for authentication or the like. The processing unit also performs a process of separating the text authentication information and the original text from the text in which the text authentication information is embedded. T-8 is a text feature extracting unit. This is a part for extracting the text feature information used when generating the text authentication information from the text (original text) obtained by separating the text authentication information. Since the text authentication information and the original text are separated by the text authentication information extracting unit of T-7, the feature of the text (text feature information) is recalculated from the separated text.

T-9 is a text authentication reading section. For the text authentication information separated by the text authentication information extracting unit of T-7, the text publisher ID and the text publisher information are separated and extracted using the text feature information extracted by T-8. T-10 is a text publisher information extraction unit that extracts and outputs the text publisher information extracted in T-9. T-11 is a text authentication information extraction unit, and the text issuer ID extracted in T-9
And output it to the output device. The text electronic authentication device may be configured as a dedicated device, or may be realized by causing a computer to read and execute a program that realizes the functions of the above-described units. Further, it is assumed that the text electronic authentication device is connected to an input device, a display device, and the like (neither is shown) as peripheral devices. Here, the input device refers to an input device such as a keyboard and a mouse. What is a display device CRT
(Cathode Ray Tube) or a liquid crystal display device.

Next, the operation of the thus configured text electronic authentication apparatus of the present embodiment will be described with reference to the drawings. The following description is an operation example for an HTML document (HTML text).

The mainstream HTML text on the Internet is a document in which text is structured based on text attributes described by tags “<” and “>”. This tag is generally authenticated and specified by W3C (World Wide Web Consortium) or the like. Authoring software and the like exist for describing the HTML text. on the other hand,
As a device for viewing (browsing) a document described in the HTML text format, there is generally a browser. This is an apparatus that presents information by structuring text information based on the information of the tag and rearranging it on a display device. In these browsers, the normal HT
It has a mechanism to interpret and display ML text.

For example, the following example is considered as an example of an HTML text. <HTML><TITLE> This is a test </ TITLE><BODY><H1> The weather is fine today. </ BODY></HTML> As described above, the HTML text has a plain text structure. When this is displayed by a browser capable of viewing the HTML text, for example, the result is as shown in FIG. The <TITLE> section is displayed at the top of the display (browser). On the other hand, the portion indicated by the <H1> tag is displayed on the display.

The T-1 text reading section reads such HTML text (FIG. 8A: step S1). If data is read in units of 8 bits,
The following groups of bytes are read into the device.

Next, the text feature extraction unit of T-2
The text characteristic information which is data representing the characteristics of the text read by the text reading unit -1 is extracted (FIG. 8).
(A): Step S2).

For example, the relationship between a text feature, a text extraction part, a text extraction method, and a text feature parameter (F value) is defined as follows. Text feature Text extraction part Text extraction method F unit Large Large whole text-1 Whole tagless text Tag analysis 2 Tag Independent words included in text Morphological analysis 3 Words Important sentence included in text Summary analysis 4 Important sentence Small text included Important words summary analysis + morphological analysis 5 important words

To extract the text of the entire text,
All of the text read by the text reading unit of T-1 is passed as it is to the text authentication information generating unit of T-5 as text feature information. The flag (F) indicating the text extraction method is initially set.

When the text feature information composed of the entire text is passed, the following byte string is passed to the text authentication information generating section of T-5. In this case, 167 bytes are required.

Although the HTML text structures a document by tag information, the tag itself does not include the meaning of the document. Therefore, it is conceivable to use text in which the tag information of the HTML text is deleted as text feature information. For example, this is a test today is fine. Is represented by a byte example. And can be represented by 38 bytes.

Further, the independent word included in the text is often used as a keyword of the text, and is often used to represent the content of the text. For example, morphological analysis is usually used as a method for extracting independent words contained in these texts. With morphological analysis, the input character string is searched against a word dictionary, and part-of-speech information (part-of-speech), head-of-sentence information (head-of-sentence possible), forward connection information (antecedent), backward connection information (adjoint) Get information such as. In an ordinary word dictionary, a high-speed search can be performed by performing a special dictionary structure called a TREΙ dictionary structure.

When the dictionary items include "Ah", "Greetings", "Ai", etc., each of the first characters (in this case, different from the alphabet because it is Japanese, indicates 2 bytes of Japanese characters) Are the same, and the second character is the same. If the last character matches, the part-of-speech information (part-of-speech), head-of-sentence availability information (head-of-sentence possible), forward connection information (prefix), back connection information
Information such as (subsequent) is described.

The head-of-sentence information is a flag indicating whether or not it can be at the head of the sentence. If the beginning of the sentence is acceptable, the word may be present at the beginning of the sentence, but if the sentence is not the beginning of the sentence, the word is not permitted to be at the beginning of the sentence. The forward connection information is permitted to be connected only when the part of speech or attribute of the preceding word is appropriate, and is deleted as a candidate when the preceding word is not permitted to be connected. Similarly, the backward connection information is permitted to be connected only when the part of speech or attribute of the subsequent word is appropriate, and is deleted as a candidate when the word is not permitted to be connected later.

A candidate is selected by such a part-of-speech connection. The maximum likelihood candidate is selected by a method called a minimum cost method. The minimum cost method is a processing method in which a morpheme candidate having the lowest cost is set as a maximum likelihood candidate. The costs used in the morphological analysis include the following two types of costs. 1. Connection costs 2. Word cost The connection cost is the cost required to connect a word to a word. Since the words are words, the connection cost for the word + the use of the word is zero. The word cost is a cost related to the word. For example, a frequently used word has a low cost. Also, since utilization is not a word, the cost is zero. By the morphological analysis, the text part is decomposed into words, and at the same time, parts of speech that are considered to be correct are given to each word. In this embodiment, the candidate with the smallest sum of the connection cost and the word cost is set as the maximum likelihood candidate. Note that the numerical definitions of the connection cost and the word cost are made separately.

Here, it is assumed that the previous example sentence has been input. This is a test Today is fine. The morphological analysis in this example is as follows.

This is a test. −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− This noun is a particle test verb. Period cost = 33

The weather is fine today. −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Period cost = 49

When only independent words are extracted from such example sentences, the test, today, and weather are extracted. This is represented by a byte string as follows. In this example, text features can be represented by a total of 19 bytes.

In addition, a text summary is used. For example,
Text summarization method invented by Inagaki et al.
If the 180181 published document summarizing apparatus and a recording medium for recording a program for the same are used, an important point can be extracted from the text. For example,
As a gist of the above example, the weather is fine today. Is chosen. Then, the byte sequence for this is as follows.

Further, when the sentence is subjected to morphological analysis and an independent word is extracted from the sentence, the weather is extracted today. This is represented by a byte string as follows. 0000000 baa3 c6fc c5b7

In this way, appropriate text feature information is extracted according to the application. For example, when authenticating the entire text, the entire text should be extracted, but if you want to authenticate the contents of the text, for example, to authenticate whether it is part of the text you wrote, , Instead of extracting the entire text, it extracts text that is independent or important from the text,
Must be text feature information. The user sets an optimal text feature amount in consideration of these characteristics. The text feature extraction unit of T-2 notifies the text authentication information generation unit of T-5 of the text extraction method (F value) used for extracting the text feature information based on the text feature amount set by the user. I do.

Next, the text publisher information input section of T-3 receives information (text publisher information) indicating the identity of the person who issued the text and describes it in a predetermined format (FIG. 8 (a)). ): Step S3). For example, information indicating a company organization having a copyright of the text or an address, a name, a URL or the like of the individual who wrote the text is input and described in a predetermined format.

As an example, the following text publisher information is described. <Name> Tarou Aiue </ Name><Affiliation> Taro Co., Ltd. </ Affiliation><Where> Taro-ku, Kyoto 1 </ Address><URL> http://aaaaaa.ne.jp/aaa.htm1 </ URL ><Date of creation> March 1, 1999 </ Date of creation><Date of issue> March 2, 1999 </ Issuance date><Date of holding rights> March 2, 2000 </ Date of holding rights>

Next, the text publisher information input unit of T-3 sends the text publisher information to the text authentication information generator of T-5. When the text publisher information is sent to the text authentication information generator of T-5, SGML (Standard) is used to clarify the attributes of the text publisher information (that is, whether the address is an address or a name). general
(like Marked Language), it is surrounded by its attributes with tags. For example, the value of the attribute, that is, the name here is described between the tags of <name></name>. At the end of an attribute such as a name, a tag (here, a </ name> part) described by “/” becomes a marker indicating this.

These are represented by byte strings as follows.

The text authentication information input section of T-4 receives the ID of the issuer issued by a public organization or a certain certification company and describes it in a predetermined format (FIG. 8B: step S4). The publisher can be specified based on the text publisher ID. However, in order to uniquely indicate the ID of the publisher, the text publisher ID needs to be unique in the world. For example, an issuer organization ID shown below and a text issuer ID uniquely issued by the issuer organization are described as a text issuer ID. <Issuing organization ID> AAA </ Issuing organization ID><IssuingID> 123456789 </ Issuing ID>

Next, the text authentication information generating section of T-5 generates text authentication information (FIG. 8A: step S5). Specifically, the text feature information extracted by the text feature extraction unit of T-2 is input to the text feature information input unit T-
5a (FIG. 9: step S51), and a text feature parameter notified from the text feature extraction unit of T-2 is received by the feature parameter input unit T-5b (FIG. 9: step S52). The text publisher information indicating the publisher information input in the text publisher information input unit 3 is received in the publisher information input unit T-5c (FIG. 9: step S53), and the text authentication information input unit in T-4 is received. Is received by the issuer ID input unit T-5d (FIG. 9: step S54), and when all the information is obtained, the text authentication information is generated as follows. Text credentials are themselves embedded in the text,
If the text authentication information is simply embedded in the text, the text authentication information is displayed on the browser and may be falsified by a special editor. Therefore, the present apparatus performs encryption so that the text authentication information becomes invisible on a browser or the like and the text authentication information is not known.

That is, first, the encryptor T-5e encrypts the text authentication information so that it cannot be decrypted by a normal user (FIG. 9: step S55). For encryption, for example,
FEAL-8, NX invented by Shimizu et al.
252650, a "data spreading device"). An encryption device is basically a device that, when given a byte sequence and an encryption key, encrypts the byte sequence based on the byte sequence and returns an encrypted byte sequence. Normal,
These encryption devices encrypt a byte sequence and convert it to an appropriate byte sequence. However, with these encryption devices,
The encryption is not performed so as to be invisible to the browser, but may be visible to the browser or become a control code.

For example, 0x20 is a half-width space,
0x0a is recognized by ordinary browsers as a line feed code. Therefore, if the text authentication information is simply generated by the encryptor T-5e, the text authentication information becomes visible to the browser. Therefore, in order to make the invisible in the browser, the byte string generated by the encryptor T-5e is converted into a special code string to generate a byte string invisible in the browser. For example, in the SJIS kanji code system, the first byte is defined as follows. Control code group from 0x00 to 0x1f ASCII code group from 0x20 to 0x7F SJIS code group from 0x81 to 0x9F Half-width katakana code group from 0xa1 to 0xCF SJIS code from 0xE0 to 0xf9 Use as Kanji code Is done. Other codes are conversely hidden code groups in the browser. That is,
FIG. 5 shows the relationship of the kanji code to the first byte and the second byte.

That is, the shaded portion is a code group used in the kanji code, and the white portion is a code group not used in the kanji code and a code group that may be invisible to the browser. . By mapping the encrypted byte strings to the unused area represented by these 2 bytes, any encrypted 8 bytes are represented. For example, by writing a mapping table such as encrypted byte representation byte 0x00 0f8080 0x01 0x8081 Ox02 0x8082 0x03 0x8083… 0xff 0xffff as shown below, it is possible to convert the encrypted byte sequence into an invisible byte sequence invisible to the browser. it can.

In the text authentication information generating section of T-5, the code converting section T-5f finally converts the encrypted byte sequence into an invisible byte sequence (FIG. 9: step S56), and outputs the encrypted authentication information. T-5g outputs the invisible byte sequence (FIG. 9: step S57). The data string to be encrypted includes text publisher information output from the text publisher information input unit of T-3, text publisher ID output from the text authentication information input unit of T-4, 2 is the text feature information and the text parameter feature parameter (F value) output from the text feature extraction unit 2. The text feature information is used to clarify the features of the input text, so if a difference between the restored data and the current data is found when Indicates that data has been tampered with.

Next, the details of the encryption in the text authentication information generating section of T-5 will be described. The text issuer information, the text issuer ID, and the text feature parameter are encrypted, and the text feature information is encrypted according to the number of bytes to be embedded. Since the text publisher information and the text publisher ID are always embedded, the number of embedded bytes must be larger than the sum of the bytes of these pieces of information. That is, (text publisher information byte count) + (text publisher I
D number of bytes) + n <number of embedded bytes where n is the number of bytes of the text feature parameter (F value).

The T-5 text authentication information generation section divides the data to be encrypted in units of embedded bytes.
(Padding 0x00 for the last remainder.)
As shown in FIG. 6, encryption is performed on each of the divided byte strings, and an exclusive OR of the next divided text feature information is further calculated on the encrypted result. Encrypt the result with the private key. This is done by the amount of text feature information divided by the number of bytes that can be embedded, and finally the encrypted result is embedded.

This is similar to an operation mode used in a block cipher type encryption device such as FEAL or the like, which is used as a method for increasing the strength of encryption for undesired and unbalanced input data (eg, text). By using this operation mode, the text features are not only simply encrypted text features, but also encrypted by exclusive OR with the encrypted text features, so that the input to the encryptor is It is dispersed, and the encryption strength is significantly increased.

For example, if the number of bytes that can be embedded is 8 bytes, the text must be encrypted within 8 bytes. The byte sequence of the information to be encrypted is as follows.

These are divided by the number of bytes that can be embedded (8 bytes). The last (24) -th divided data is padded with 0x00 at the end. Then, the output of the encryptor in (1) is exclusive-ORed with (2), the result is applied to the encryptor, and the exclusive-OR is performed with (3). The result applied to the encryptor up to the last (24) is defined as the final encryption result. The details of the encryption in the text authentication information generation unit of T-5 have been described above.

Also, the possibility of editing a part of the text may cause the entire text to be fragmented.
In this apparatus, text feature information is extracted based on the unit to be analyzed based on the F value, and the text feature information encrypted for each analysis unit, the text publisher information of the entire text, the text publisher The ID and the text feature parameter (F value) are embedded in the text authentication information embedding unit of T-6 (FIG. 8B: step S7).

Here, the operation of the text authentication information embedding section of T-6 will be described in detail. First, a text feature parameter (F value) from the text authentication information generation unit of T-5
Is input to the text feature parameter input unit T-6a (FIG. 10: step S61). Then, the invisible byte sequence generated by the text authentication information generation unit at T-5 is input to the encrypted authentication information input unit T-6b (FIG. 10: step S62). Further, the text in which the text authentication information is embedded is input from the text reading unit T-1 to the text input unit T-6c (FIG. 10: step S63). When the information input to each input unit is completed, the determination unit T-
6d determines whether all invisible byte strings have been output (FIG. 10: step S64).

If the determining unit T-6d determines that all the invisible byte strings have not been output, the embedded text output unit T-6f converts the input text into a byte string of a size separately determined based on the F value. Read and output each time (Fig. 1
0: Step S65). Further, the embedded encryption authentication information output unit T-6e reads and outputs the invisible byte sequence for each byte sequence of a size separately determined based on the F value (FIG. 10: step S66). Until all invisible byte strings are output, steps S64 to S64 in FIG.
S66 is repeated. When the determining unit T-6d determines that all the invisible byte strings have been output, all the remaining input texts are output (FIG. 10: step S67). The operation of the text authentication information embedding unit at T-6 has been described in detail above.

Next, the operation of the text authentication information embedding section of T-6 will be described with a specific example. F shown in the above example
When the value is 1, that is, when the entire text is used as a text feature, the text is inserted at an arbitrary position (a range that does not obstruct the boundary of 2 bytes such as SJIS). For example, if the following text is entered,

Assuming that the final encrypted data is 8081 8283 8485 8687, the encrypted data is embedded in the underlined portion.

When the F value is 2, the processing is performed on a tag basis, and is therefore embedded for each tag. When the final encrypted data of the first tag is 8081 8283 8485 8687, the final encrypted data of the second tag is 8889 9091 9293 9495, it is embedded in the data as follows. The above is the operation up to embedding the text authentication information in the HTML text.

Next, H in which the text authentication information is embedded
The operation at the time of performing TML text authentication will be described.

First, the text authentication information extracting section at T-7 extracts the text authentication information embedded by the text authentication information embedding section at T-6 from the text for authentication. Further, the T-7 text authentication information extracting unit also performs a process of separating the text authentication information and the original text from the text in which the text authentication information is embedded. That is, for example, in the code area shown in FIG.
The byte string of the area used in JIS is determined to be text (text byte string), and the other byte strings are determined to be text authentication information. The text byte sequence is
The text feature information is passed to the text feature extraction unit of T-8 to extract the text feature information. On the other hand, the encrypted text authentication information is passed to the T-9 text authentication information reading unit in order to restore it.

Next, the text feature extracting section of T-8 extracts the text feature information used for generating the text authentication information from the text from which the text authentication information is separated (ie, the original text). is there. T-
7, the text authentication information extraction unit separates the text authentication information from the original text, and recalculates the text features from the separated original text in the same processing method as the T-2 text feature extraction unit. I do. Since the text feature parameter (F value) is initially set, corresponding processing is performed based on the value to extract text feature information and an analysis unit for extracting the text feature information.

Next, the text authentication reading section of T-9 applies the text feature information extracted by the text feature extracting section of T-8 to the text authentication information separated by the text authentication information extracting section of T-7. Then, the text issuer ID and the text issuer information are separated and extracted using the analysis unit. Since the number of embedded bytes is specified based on the analysis unit extracted by the T-8 text feature extraction unit, the text feature information extracted by the T-8 text feature extraction unit is separated into n columns based on the number of embedded bytes. This n
The column is decrypted by a method as shown in FIG. 7, and text publisher information and a text publisher ID are extracted.

In the above example, consider the following example in which encrypted information and original text information are separated from text in which information such as text authentication information is embedded as watermark information.

The part with the underline and the part other than the underline are separated. The separation is performed by using an SJIS code system as shown in FIG. 5 and separating the data into SJIS codes and other data. result,
It is separated as follows.

Further, the encryption unit is restored, and text publisher information and text publisher ID are calculated. For example, <name> Taro </ name><issuerID> 123 </ issuer ID> is extracted from the above data.

Next, the text publisher information extraction unit of T-10 extracts and outputs the text publisher information extracted by the text authentication reading unit of T-9. In the above example, T
Since the text issuer information extracted by the text authentication reading unit -9 is “<name> Taro </ name>”, this information is output to the output device. Next, the text authentication information extracting unit at T-11 extracts the text publisher ID extracted by the text authentication reading unit at T-9 and outputs the text publisher ID to the output device. In the above example, the text issuer ID extracted by the text authentication reading unit of T-9 is “<issuer ID>
123 </ issuer ID> ”, this information is output to the output device. The above description has been given of the operation when performing the authentication of the HTML text in which the text authentication information is embedded.

The present invention is not limited to the Internet,
A network using an AN or dial-up may be used. Further, it may be realized as a stand-alone device. The function of embedding authentication information and the function of extracting authentication information may be realized as separate devices, or may be realized as the same device. Further, a program (text electronic authentication program) for realizing the text electronic authentication device of the present invention is recorded on a computer-readable recording medium, and the program recorded on this recording medium is read and executed by a computer system. Thus, electronic authentication of the text may be performed. That is,
One of the text electronic authentication programs includes a function of the text reading unit, a function of the text feature extracting unit,
The computer realizes the function of the text issuer information input unit, the function of the text authentication information input unit, the function of the text authentication information generation unit, and the function of the text authentication information embedding unit. The other part of the text electronic authentication program includes a function of a text authentication information extracting unit, a function of a text feature extracting unit, a function of a text authentication information reading unit, a function of a text publisher information extracting unit, and a function of a text authentication information extracting unit. The function of the extracting unit is realized by a computer.

It is to be noted that the "computer system" here includes an OS and hardware such as peripheral devices. The “computer system” also includes a homepage providing environment (or a display environment) if a WWW system is used. Also,
"Computer readable recording medium" means a floppy disk, a magneto-optical disk, a ROM, a CD-ROM.
And a storage device such as a hard disk built in a computer system. Further, "computer-readable recording medium" refers to a communication line for transmitting a program through a network such as the Internet or a communication line such as a telephone line for a short time, such as a communication line.
It also includes those that dynamically store programs (transmission media or transmission waves) and those that store programs for a certain period of time, such as volatile memories in computer systems serving as servers and clients in that case. Further, the program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to the embodiments, and includes a design and the like within a range not departing from the gist of the present invention. It is.

[0077]

As described above in detail, according to the present invention, it is possible to extract the characteristics of a text from an electronic document in which the text is described, and obtain information of the text issuing source and authentication. Information is entered, and these information are invisible and indecipherable encrypted electronic authentication information on an existing electronic document display, and are embedded in the electronic document. Appropriate authentication for can be given.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a text electronic authentication device according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a text authentication information generation unit according to an embodiment.

FIG. 3 is a diagram illustrating a configuration of a text authentication information embedding unit according to an embodiment;

FIG. 4 is a display example of an example of an HTML text.

FIG. 5 is a diagram showing kanji codes and other codes in the SJIS kanji code system.

FIG. 6 is a diagram illustrating an encryption procedure in a text authentication information generation unit.

FIG. 7 is a diagram illustrating a decryption procedure in a text authentication reading unit.

FIG. 8 is a diagram illustrating an operation procedure of the text electronic authentication device according to the embodiment;

FIG. 9 is a diagram showing an operation procedure of a text authentication information generation unit according to one embodiment.

FIG. 10 is a diagram illustrating an operation procedure of a text authentication information embedding unit according to an embodiment.

[Explanation of symbols]

T-1: Text reading unit T-2: Text feature extracting unit T-3: Text issuing information input unit T-4: Text authentication information input unit T-5: Text authentication information generating unit T-6: Text authentication information Embedding unit T-7: Text authentication information extraction unit T-8: Text feature extraction unit T-9: Text authentication information reading unit T-10: Text issuer information extraction unit T-11: Text authentication information extraction unit T-5a ... Text feature information input section T-5b ... Feature parameter input section (Feature identifier input section) T-5c ... Publisher information input section T-5d ... Publisher ID input section (Publisher authentication information input section) T- 5e: encryptor T-5f: code conversion unit T-5g: encrypted authentication information output unit T-6a: feature amount parameter input unit (feature amount identifier input unit) T-6b: encrypted authentication information input Power section T-6c: text input section T-6d: determination section T-6e: embedded encrypted authentication information output section T-6f: embedded text output section T-6g: text output section

Continuing from the front page (72) Inventor Daijiro Mori 3-19-2 Nishi Shinjuku, Shinjuku-ku, Tokyo Japan Telegraph and Telephone Corporation (72) Inventor Kazuo Tanaka 3-192-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd. F term (reference) 5J104 AA08 AA14 NA27 NA36 NA38 PA07 PA09

Claims (9)

[Claims] 1. A text electronic authentication device which authenticates an electronic document in which text is described by embedding authentication information in the electronic document, wherein the electronic document in which the text is described is provided. A text reading unit that reads text from the text reading unit; a text feature extracting unit that extracts features of the text read by the text reading unit; and a text publisher information input unit that inputs information about the publisher of the text described in the electronic document. A text authentication information input unit for inputting information for authentication of a text described in the electronic document; information representing a feature of the text extracted by the text feature extraction unit; and the text publisher information input unit. Using the information of the input publisher and the information for text authentication input to the text authentication information input unit, A text authentication information generating unit that is invisible to an existing electronic document display device and is invisible and cannot be decrypted; and reads the encrypted electronic authentication information generated by the text authentication information generating unit into the text. A text authentication information embedding section that embeds the encrypted electronic authentication information so that the encrypted electronic authentication information is not lost even if the text embedded with the encrypted electronic authentication information is edited, embedded in the text read by the section; A text electronic authentication device comprising: 2. The text feature extraction unit is capable of executing a plurality of extraction methods according to the size of the feature of the text to be extracted, and according to the designation of the feature size of the text to be extracted, 2. The text electronic authentication apparatus according to claim 1, wherein the feature is extracted and output, and an identifier indicating the extraction method used is further output. 3. The text authentication information generating unit, wherein information representing characteristics of the text is input, and a feature amount input unit for outputting information representing the characteristics of the text; An identifier indicating the extracted extraction method is input, a feature amount identifier input unit that outputs the identifier, and an issuer information input unit that receives information of the publisher of the text and outputs information of the publisher of the text. An authentication information input unit for inputting information for authenticating the text and outputting information for authenticating the text; information indicating characteristics of the text; an identifier; and information on an issuer of the text An encryptor that encrypts authentication information including information for text authentication and outputs encrypted authentication information; and that the display device does not use the encrypted authentication information for displaying text. And a code conversion unit that outputs the invisible byte sequence, and an encrypted authentication information output unit that receives the invisible byte sequence and outputs the invisible byte sequence. 3. The text electronic authentication device according to claim 2, wherein 4. The text authentication information embedding section, wherein the identifier is input, a feature quantity identifier input section that outputs the identifier, and encrypted authentication information that receives the invisible byte sequence and outputs the invisible byte sequence. An input unit, a text input unit into which a text described in the electronic document is input, a determination unit that determines whether all of the invisible byte strings have been inserted into the electronic document, and the encryption authentication according to the identifier. An embedded encryption authentication information output unit that captures and outputs information; an embedded text output unit that captures and outputs text described in the electronic document according to the identifier; and the determination unit converts all of the invisible byte strings. A text output unit that outputs all the rest of the text described in the electronic document when it is determined that the text is embedded in the electronic document; When the determining unit determines that all of the invisible byte strings have not been inserted into the electronic document, the embedded encrypted authentication information output unit and the embedded text output unit output alternately. The text electronic authentication device according to claim 3. 5. An apparatus for extracting authentication information from an electronic document in which authentication information is embedded by the text electronic authentication apparatus according to claim 1, wherein the encrypted electronic authentication information is embedded by the text authentication information embedding unit. A text authentication information extracting unit that reads an embedded text and separates and extracts the text described in the electronic document and the encrypted electronic authentication information; anda text authentication information extracting unit that is described in the electronic document extracted by the text authentication information extracting unit. A text feature extracting unit that extracts text features based on the extracted text; an encrypted electronic authentication information separated and extracted by the text authentication information extracting unit; and a text feature extracted by the text feature extracting unit. And a text for decrypting the encrypted authentication information embedded in the text. An authentication reading unit, from the electronic authentication information decrypted by the text authentication information reading unit, a text publisher information extracting unit that reads information of a text publisher, and from the electronic authentication information decrypted by the text authentication information reading unit, A text authentication information extracting unit that reads information for text authentication. 6. A text electronic authentication method for embedding authentication information in an electronic document in which a text is described, whereby the electronic document can be authenticated, wherein the electronic document in which the text is described A text reading procedure for reading a text from the text, a text feature extraction procedure for extracting a feature of the text read by the text reading procedure, and a text publisher information input procedure for inputting information about a publisher of the text described in the electronic document. A text authentication information inputting step of inputting information for text authentication described in the electronic document; information representing a text feature extracted by the text feature extracting procedure; and the text publisher information inputting procedure. The input publisher information and the text input by the text authentication information input procedure Using information for authentication, a text authentication generation procedure that is invisible to existing electronic document displays and that is encrypted electronic authentication information that cannot be decrypted, and a text authentication generation procedure generated by the text authentication generation procedure The encrypted electronic authentication information is embedded so that the encrypted electronic authentication information is embedded in the text read by the text reading procedure, and the encrypted electronic authentication information is not lost even if the text in which the encrypted electronic authentication information is embedded is edited. And a text authentication embedding procedure. 7. A method for extracting authentication information from an electronic document in which authentication information is embedded by the text electronic authentication method according to claim 6, wherein the encrypted electronic authentication information is embedded in the text authentication embedding procedure. A text authentication information reading procedure, separating the text described in the electronic document from the encrypted electronic authentication information and extracting the text authentication information, and a text authentication information extracting procedure described in the text authentication information extracting procedure. A text feature extraction procedure for extracting text features based on text, encrypted electronic authentication information separated and extracted by the text authentication information extraction procedure, and a text feature extracted by the text feature extraction unit procedure are also included. And decrypt the encrypted authentication information embedded in the text From the text authentication reading procedure to perform, from the electronic authentication information decrypted by the text authentication reading procedure, a text publisher information extraction procedure to read the text publisher information, and from the electronic authentication information decrypted by the text authentication reading procedure, A text authentication information extraction procedure for reading the information for text authentication. 8. A recording medium recording a text electronic authentication program for embedding authentication information in an electronic document in which the text is described, whereby the electronic document can be authenticated, wherein the text is A text reading procedure for reading a text from the described electronic document, a text feature extracting procedure for extracting a feature of the text read by the text reading procedure, and a text for inputting information of a publisher of the text described in the electronic document Issuer information input procedure; text authentication information input procedure for inputting information for text authentication described in the electronic document; information representing text features extracted by the text feature extraction procedure; Source information input in the source information input procedure and the text authentication information input procedure A text authentication generating procedure that uses the input information for text authentication to make encrypted electronic authentication information that is invisible and indecipherable with an existing electronic document display, and the text authentication The encrypted electronic authentication information generated by the generating procedure is embedded in the text read by the text reading procedure, and the encrypted electronic authentication information is not lost even if the text in which the encrypted electronic authentication information is embedded is edited. A computer-readable recording medium recording a text electronic authentication program for causing a computer to execute a text authentication embedding procedure for embedding encrypted electronic authentication information in a computer. 9. A recording medium storing a program for extracting authentication information from an electronic document in which authentication information is embedded by a computer having the text electronic authentication program according to claim 8, wherein the text authentication embedding procedure is performed. Reading the text in which the encrypted electronic authentication information is embedded, separating the text described in the electronic document from the encrypted electronic authentication information, extracting the extracted text authentication information, and extracting the text by the text authentication information extracting procedure. A text feature extraction procedure for extracting a text feature based on the text described in the electronic document obtained, an encrypted electronic authentication information separated and extracted by the text authentication information extraction procedure, and a text feature extraction unit procedure Of the text extracted by A text authentication reading procedure for decrypting the encrypted authentication information embedded in the text; and a text publisher information extracting procedure for reading text publisher information from the electronic authentication information decrypted by the text authentication reading procedure. And a computer-readable recording medium storing a text electronic authentication program for causing a computer to execute a text authentication information extracting procedure for reading information for text authentication from the electronic authentication information decrypted by the text authentication reading procedure. .