JP2002507771A - Method and apparatus for data spoofing - Google Patents

Abstract

(57) [Summary] A relatively long column of secondary data can be concealed in association with primary data, and furthermore, concealment coding that minimizes primary data degradation can be performed. A method or apparatus is provided. A primary data (10) has a plurality of first data accessible by an address, and a secondary data (12) has a plurality of second data. The data encoding means (14) searches for a first data element that matches the component of the second data element, and when a match is found, a key including the address of the matching first data element. Generate element (18). The data decoding means (20) extracts secondary data (12) from the encoded data sample (16) using the encoded data sample (16) and the key element (18).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates generally to coding techniques, and in particular, to a method and apparatus for coding concealed (steganographic) data.

This encoding method is applied particularly to digital concealment of audio, still image and moving image data, and it is convenient to describe the encoding method and apparatus in connection with these application examples. However, it will be appreciated that the invention is intended for wider applications and uses. For example, the encoding method of the present invention could be used in the field of data encryption.

[0003]

[Prior art]

The rapid growth of multimedia products and services provided over the Internet has led to demands for copyright authentication and full data protection. For the past few years,
Many digital watermarking techniques have been studied to solve the problem of legitimate use of copyright information on the Internet.

In recent years, many digital watermarking techniques have been patented. For example, US Patent 5,636,29
2 [Rhoads (1997)] and US Patent 5,659,726 [Sandford and Handel (1997)] include digital watermarking technology. Rhoads is a method of attaching an identification code (ID code) to a carrier such as electronic data or a physical medium, and a method whereby the carrier can be identified by recognizing the identification code later. Is disclosed. Sandford and Handel discloses a method of embedding additional information in host data such as photos, television signals, facsimile transmissions, or ID cards.

[0005] As used herein, the term concealment ("steganography") refers to the fact that in a medium, a third party stealing the media includes a message in which the media is hidden. And is intended to mean various ways of seeking to hide existing messages so that the information contained in the message cannot be obtained. Digital watermarking is an example of a concealment method used to embed secondary data, such as characters, in primary or host data, such as a digital image.

[0006] The term cryptography ("cryptography") refers to the information contained in a message, and when a message is sent from a sender to a recipient, a third party who intercepts the message, It is intended to mean various techniques that seek to hide the information contained in the message so that the information contained in the message cannot be read or retrieved.

As used herein, the term camouflaging (“camouflaging”) refers to
By using a combination of primary or host data and key data, it is intended to mean an implicit coding method that hides secondary data.

[0008] The encoding method actually uses information elements existing in the primary data, instead of embedding information in the primary data like a digital watermark.

[0009] Many prior art techniques for digital watermarking techniques, including the technique disclosed in the above-mentioned US patents, involve a small number of logical bits ("1" and "0") and a small number of characters (eg, "A1").
2 ”) can only be hidden in the host data. However, to record detailed proprietary information for a copyrighted host work such as images, entire messages or texts in Singapore, for example, Will need to be hidden or associated with host data, such as "Digital
image of Singapore is the property of Mr John Tan, dated 16 December 199
The sentence "7" would provide more solid evidence to prove ownership of the host work than if it had to rely on simple code to prove piracy.

[0010] Therefore, a relatively long column of secondary data (for example, text) is converted into primary data (for example, text).
There is a need for a method and apparatus for concealment encoding that can be concealed in association with image, audio, or video data and that has minimal degradation of primary or host data. In some embodiments, the primary data will not change at all during the encoding process.

In addition to the above Internet applications, many potential consumer, commercial or service applications benefit from the use of digital concealment / watermarking techniques for both copy protection purposes and secure information transmission. Can be obtained. These applications include text encoding, digital still or video cameras, copyright protection, text encoding including proprietary and attribute information associated with tracking sound recordings in the music industry. The commercial and service sectors could benefit from secure transmission and the acceptance of sensitive information that can be concealed in the general stream of data transmitted over the public network.

[0012]

[Problems to be solved by the invention]

The present invention has been made in view of the above background, and it is possible to conceal a relatively long column of secondary data in association with the primary data, and furthermore, to conceal the primary data with minimum degradation. It is an object of the present invention to provide a method and apparatus for efficient coding.

[0013]

[Means for Solving the Problems]

In one aspect, the present invention provides an implicit coding method that includes the following steps.

(A) supplying primary data including a first data element to which a plurality of addresses can be added; (B) supplying secondary data including a plurality of second data elements; and (C) ) For the second data element, (C1) search for the first data element that matches the component of the second data element, and (C2) find the one that matches the component of the second data element. When found, generate a key element that includes the address of the matched first data element.

When a match with a component of the second data element is found, the address of the matched first data element is stored as a key element associated with the second data element. A sequence of key elements (including addresses) is associated with a corresponding sequence of second data elements. The sequence of key elements specifies where each second data element of the secondary data can be found in the primary data. In this state, the secondary data is considered to be hidden in the primary data and key data. The unique key data generated for the given primary data and secondary data is stored for use in a complementary decoding method described later.

The primary data and the secondary data are represented digitally. However, in some situations, the present invention can be applied to data in any form of document or depiction using any convenient set of symbols. Primary data may represent still images, moving images, audio, text, or other forms of information. Similarly, the secondary data may represent a still image, a moving image, audio, text, or other information. In a preferred embodiment of the invention, the secondary data comprises a text message and each second data element comprises an alphabetic or numeric character. Alphabetic or numeric characters are used to compose the message text.

In a typical application of the invention, the message text will include copyright information related to images, video, audio, etc. In one example, the message may include one or more of the title of the work, the author, the copyright owner, the work to be paid for, and general information about the distribution of the publisher.

[0018] The primary data may include a still image. The first data elements are arranged in a two-dimensional array, with each first data element defining a characteristic associated with a still image. Generally, the first data element is obtained from a data sequence depicting a digitized still image. The still images can be obtained from digital still cameras, computer games and other software, or other sources. The still image is, for example, a grayscale or color image, and has any known format (BMP, GMP).
IF, TIFF, JPEG, etc.).

The primary data may optionally or additionally include a moving image. The first data elements are arranged in a three-dimensional array, wherein each first data element defines a characteristic associated with a moving image element. Generally, the first data element is obtained from a data sequence describing a digitized moving image. The digitized video can be obtained from a video compact disc (VCD) player, a laser disc (LD) player, a computer game or other software. The moving image may be recorded in any known format (such as MPEG).

The primary data may optionally or additionally include audio information.
The first data elements are arranged in a one-dimensional array, each first data element defining a property associated with a digital audio sample. Generally, a digital audio sample is obtained from a sequence of data representing digitized speech or music. Digitized audio can be obtained from a compact disc (CD) player, digital audio tape (DAT) player, laser disc (LD) player, video compact disc (VCD) player, or other source. Further, the digitized audio may be recorded in any known format (WAV, AIFF, etc.). In one example, digitized audio is obtained from two data streams representing two channels digitized for stereo reproduction.

In the above-described encoding method, the elements of the first data and the second data are represented by integer values, and the step (C) further includes the following.

If no match is found for the content of the second data element, (C3) generate second data corrected by increasing or decreasing the integer value of the second data element; ) Finding a first data element that matches the integer value of the corrected second data element; and (C5) finding a match with the corrected second data element. One key data including an address of the data element is generated, and the matched component of the first data element is converted to the second data based on the corrected second data element. Replace with the integer value of the element.

When the compatibility with the corrected second data element is not recognized, the method may further include the following processing.

(C6) A newly corrected second data element is generated by increasing or decreasing the corrected second data element, and the step (A) is performed on the newly corrected second data element. C4) and (C5) are repeatedly executed.

For example, if the required integer value 105 is not found in the primary data, a search is performed on the value 104 or 106. When any of these values is found, the address of the first data element having that value is stored in a key element. Then, the component of the first data element (104
Or 106) is replaced with 105. On the other hand, if the value 104 or 106 is not found, a search is performed for the value 103 or 107. Such a change in the primary data can be considered as one of the forms of embedding the secondary data in the primary data in the digital watermark effect. However, it is relatively rare that a required value does not exist in the primary data. It has been found that the changes that occur in the primary data, such as the modified moving image and audio data, are small.

[0026] The modified version of the primary data will then be stored for distribution by the Internet or other means. The modified primary data includes secondary data that can be retrieved at any time by using key data generated during the encoding process.

In the encoding method, the data shift (“data shiftin”) is performed in the step (C).
g ") step. This data shifting step is required whenever the range of the secondary data is not within the range of the primary data.
This will occur if the next data is a digitized audio signal and the secondary data is a text message. Similar data shifting steps would apply to other types of data. The data shifting step determines a range of components of the first data element, determines a range of components of the second data element, and compares the range of the first data element with the range of the second data element. If the range of the second data element is outside the range of the first data element,
Shifting the components of the second data element so that the range of the data element of the second data element substantially falls within the range of the first data element, and converting the shifted second data element to the first data element in step (C). 2 may be used as the second data element.

Preferably, the step of determining a range of components of the first data element includes calculating an intermediate value and a standard deviation of the first data element, and determining the first value based on the intermediate value and the standard deviation. Of determining the lower limit of the data element of. The step of determining the range of the component of the second data element may include setting a minimum value based on the range of the valid second data element as the reference value. The step of performing the comparison includes a process of calculating an offset value by subtracting the reference value from the lower limit value,
Then, the step of performing the shift may include a process of adding the offset value to a component of each second data element. Preferably, the offset value is stored together with the key element in the key data.

When the data shifting offset processing is applied to the secondary data by the encoding method, the complementary decoding method needs to have a step for removing the offset due to the data shift.

As compared with the existing concealment techniques and digital watermarking techniques, the present invention has a completely different advantage that long sentences can be concealed. In many cases, even a long sentence does not affect or impair the integrity of the primary data. Since the method of the present invention utilizes data already present in the primary data, the primary data remains unchanged even after the encoding process. Even if a special value included in the secondary data is not found in the primary data and the primary data is changed to embed the value, the primary data is not substantially changed. To remain.

In another aspect, the present invention provides a method for implicitly decoding secondary data comprising a plurality of second data elements, wherein the secondary data is a key element associated with the primary data. Embedded in the method, the method includes the following steps.

(A) The above-mentioned 1 including a plurality of first data elements that can be assigned addresses.
Providing the following data: (B) each key element providing a key element containing the address of the first data element; and (C) for each key element, a component of the addressed first data element. To generate the second data element.

In a further aspect, the present invention is an apparatus for concealed encoding, comprising: (A) providing primary data having a plurality of first data elements accessible by address; (B) means for providing secondary data including a second data element; and (C) for each second data element, a first data element that matches a component of the second data element.
And (D) generating a key element including the address of the first data element that matches when the one that matches the component of the second data element is found. Provide equipment.

In a further aspect, the present invention provides an apparatus for implicit decoding of secondary data comprising a plurality of second data elements, wherein the secondary data is included in a key element together with the primary data. The apparatus comprising: (A) means for providing the primary data comprising a plurality of first data elements accessible by address; and (B) an address of each of the first data elements. Means for providing the key elements comprising: (C) means for generating one second data element for each key element by retrieving the components of the addressed first data element. .

In a further aspect of the present invention, the above-described encoding method is a cryptography
). In an application, a message concealed by a complex cryptographic encoding is sent from a sender to a recipient. The data is encoded in key elements generated by the method in association with the primary data. The concealed message will be decrypted by the recipient from the key element using the primary data by a complementary decryption method.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the present invention will be described with reference to FIGS. The accompanying drawings are incorporated in and constitute a part of the specification of the present invention, and are submitted for explaining embodiments of the present invention and explaining the principle of the present invention. However, the drawings and the following detailed description are provided for illustrative purposes only, and are not intended to define the scope of the invention.

FIG. 1A shows one one-dimensional data array including integer values representing digital audio signals, FIG. 1B shows one two-dimensional data array including integer values representing digital still images, and FIG. 3 shows an example of an audio signal, FIG. 3 shows an example of a still image, FIG. 4 shows a set of ASCII characters, FIG. 5 shows a typical gray scale distribution in a digital image, and FIG. And 6B show a 4 × 8 two-dimensional data array of data elements representing pixels of a grayscale image, FIG. 7 shows a schematic block diagram of a digital camouflage device according to the present invention, and FIG. 9 is a pseudo code of a text encoding process by digital spoofing, FIG. 9 is a pseudo code of a text decoding process by digital spoofing, and FIG. 10 is a pseudo code of the text decoding process shown in FIG. Sky Shows the placement program, FIG. 11 shows an example of a digital impersonation process text message combined alphabet character in the image, Figure 12,
FIG. 12 shows the entire paragraph of the disguised sentence in the image of FIG. 11.

In a preferred embodiment of the present invention relating to digital spoofing, the present invention converts the value of data existing in various digital formats such as audio, still images, moving images, etc. into a string of letters or a combination of letters or numbers. Used for encoding and decoding.

FIG. 1A shows a one-dimensional data array including, for example, integer values representing digital audio data (conversation or music) based on a conventional digital audio format.

FIG. 1B shows a digital still image in GIF or JPEG format, for example.
Alternatively, a two-dimensional data array including integer values representing one moving image frame in the MPEG format is shown.

FIG. 2 shows typical digital samples of an audio waveform (music) in WAV format, plotting amplitude (vertical axis) against time (horizontal axis).

FIG. 3 shows a typical 8-bit grayscale image of 512 × 512 pixels.

Digital impersonation is a method in which objects to be impersonated (eg, leaves, insects, reptiles, etc.)
It can be described in analogy with the impersonation of nature, which completely hides itself in the surrounding environment. In the present invention, digital spoofing is performed by finding secondary data such as an integer-type character string of a combination of alphabets or numbers by searching for a spatial position of an integer value that matches the value of the character string, thereby obtaining a primary image such as an image. Hide in data.

FIG. 4 shows a table of ASCII codes. The number on the left of the table is the character code 10
The numbers on the left side of the hexadecimal number (0-127) are shown, and the numbers above the table show the numbers on the right side of the character code. For example, the character code for "F" is 70, and "&"
The character code for "" is 38. Alphabetic and numeric codes commonly used for a sentence sequence are as follows.

48 to 57 represent the numbers “0 to 9”, 65 to 90 represent the uppercase letters “A to Z”, and 97 to 122 represent the lowercase letters “a to z”.

The present invention can be applied to many different formats for audio, image, or video data. In the case of digital image and video spoofing, the distribution of histograms for many natural images, such as human faces and landscapes, will cover a wide range of grayscale levels. For example, an 8-bit or 256-level gray level image includes an image whose pixel value is between 0 and 255. FIG. 5 shows a histogram of a typical image. It is desirable that there be a wide range of pixel values in the image in order to accurately match the character code of the combination of alphabets and numbers to be disguised. It is also desirable that many pixels have the same integer value at different spatial locations in the image. For example, in FIG. 5, there are 2500 pixels having a value of 105 in the image.

For each alphabetic or numeric character in a sentence encoded in the image, a process is first performed to find one pixel in the image that exactly matches the character. When a matching pixel is found, the address of that pixel's spatial location is stored in the key element. However, there may be one or more pixels having the same value as the value of the letter of the alphabet or number. When such a case occurs, the present encoding method selects the first found pixel. The address of the pixel will constitute a significant part of the key element that is later used to compound the hidden alphanumeric string. Table 1 is an example of a character string of alphabets and numbers, "Th
is is an Exmple ”and an integer value corresponding to the character string.

[0048]

[Table 1]

As described above, “This is an Example” is a data string [84 104 105 115 32 105
115 32 97 110 32 69 120 97 109 112 10 8 101].

FIGS. 6A and 6B show an example of a two-dimensional data array representing the pixel values of a 4 × 8 pixel image. Elements (1,1), (1,2),..., (4,8) are addresses of spatial positions of pixels in the image. These addresses are stored as key elements when the value of an alphabetic or numeric character matches the value of a pixel during a search. For example, in the encoding process, the first letter of the alphabet or the number, and its integer value is 84 (
“T” (see bold characters in FIG. 6A) matches the values of the pixels located at (3, 1) and (2, 8). The address of the first position (3,1) is stored in a key element that will be used later in the complementary decryption process.

However, even when searching for the values of all the pixels in the image, the values of certain alphabetic or numeric characters may not eventually match exactly. In such a case, the present invention executes a new search for the corrected value by increasing or decreasing the value of the character by one. Then, the address of the pixel including the corrected value is stored as a key element. For example, if the first alphabetic or numeric character in the document string is an integer value of 84
If the value of “T” is not found and the value of 84 is not found by the pixel value search process, a new search process for searching for the value of 83 or 85 starts. These values correspond to “S” and “U”, respectively, of the letters of the alphabet or the numbers.

In one example, when a new search finds a pixel with a value of 83 or 85, the search first checks whether the pixel is already in use. If used, and the same pixel value is provided at another address, the method of encoding selects another pixel having a value of 83 or 85. If such a pixel is found, the value of that pixel is rewritten to the character value of 84.

If the corrected value is not found by removing the value of the character by 1, the value of the character is increased or decreased by 2 to find the corrected value (82 or 86 in this embodiment). Is started. Then, the step of rewriting with matching is repeated as described above.

Referring to FIG. 6B, when using the same example of alphabetic or numeric characters and image pixel values as in FIG. 6A, the third and sixth alphabetic or numeric characters correspond to a value of 105. Since the image corresponding to “i” does not exist in the (4 × 8) image, an exact match is not found after the image search. In this case, the present encoding method searches for a value obtained by increasing or decreasing the value.

The method, including the steps of “off-pixel” searching and overwriting, is performed as follows.

1. The value of the character 105 (“i”) in the image is searched.

[0057] 2. Could not be found.

[0058] 3. The value is increased or decreased to 104 or 106.

4.106 was not found.

Two pixels with a value of 5.104 were found (shown in bold in FIG. 6B).

[0061] 6. Check if the pixel has been used before.

[0062] 7. If the pixel is used, the coordinates of the spatial position of the second pixel are stored, and the pixel value in the image is overwritten with the character value 105.

[0063] 8. If the pixel is not used, the coordinates of the spatial position of the first pixel are stored, and the pixel value in the image is overwritten with the character value 105.

Since many natural images include a wide range of pixel values, almost all alphabetic or numeric symbol values can be matched exactly. Due to many tests with different natural images, the maximum required for off-pixel search is generally
+/− 3 pixel values. Analysis of the pre-formed correlation of the same image before and after data spoofing using the present invention shows that the two images are often completely identical. Even if no pixel exactly matches the value of an alphabetic or numeric character, overwriting with a slightly different pixel value in the image has only a small effect on the image quality degradation. In such a situation, the correlation coefficient between the two images will be substantially 1 for all practical cases.

The complementary compounding process using the unique key data generated from the address of the spatial position of the pixel corresponding to the alphabet or numeric character constituting the document sequence is relatively simple. . The unique key data provides an address of a spatial location that will be retrieved from the document sequence image concealed by the address.

The key data is unique to a specific image and a specific document sequence. If the key data were applied to another image, the retrieved document sequence would simply be a sequence of disordered characters.

In digital audio camouflage, the dynamic range of audio samples associated with music and speech is not as wide as digital still images or video images. Audio integer values will be in a range slightly different from the range of alphabetic or numeric character values. Therefore, a slightly different response is required for the process of disguising the alphabet or numeric document sequence in the digital audio signal.

The present invention may include a statistical measure that can be applied accordingly to the determination of the dynamic range of the first audio sample. Intermediate value of audio sample (μ
) And standard deviation (σ) are determined and used to determine the lower limit of the audio sample. For example, if the integer value 65 uses the alphabetic or numeric character code for the corresponding "A" as a reference value, the alphabet and number set is adaptively shifted to match the dynamic range of the audio sample. Will. Statistical applications adapted in this way have proven to be very robust for the embedding of alphabetic or numeric document sequences into digital audio samples of music or speech. The steps of the method, including the adapted statistical range shift process, are preferably as follows.

Encoding Process An integer value of an alphabetical or numeric reference character (65 corresponding to “A”) is stored. 2. Determine the median and standard deviation of the audio sample. 3. The lower limit of the range of the audio sample is determined, for example, by subtracting the standard deviation three times from the intermediate value (= μ−3σ). 4. Subtracting the referenced character from the lower end of the audio sample range yields a data shifting offset. 5. Add the offset value of the data shift to the alphabetic or numeric characters to be written. 6. The search, key element generation, and rewrite steps are performed as described above in relation to the image specimen. 7. Generate unique key data from key elements.

Combination processing The value of the audio sample located at the addressed position in the key element of the unique key data is extracted. 9. The data shift procedure is reversed by subtracting the data shift offset value from the extracted value to obtain an alphabetic or numeric character value.

FIG. 7 is a schematic block diagram showing a digital encoding / decoding process according to an embodiment of the present invention. The sampled data (10) is supplied to data encoding means (1
4), is encoded with a character string (12) of alphabets or numbers. The unique key data (1) including the encoded data sample (16) and the address of the spatial position
8) are obtained by the data encoding means (14). These two outputs (
16, 17) are used in the decoding means (20). The original alphanumeric string (12) is extracted as (12A) from the encoded data sample (16) by using the position address contained in the unique key data (18). The encoded data sample (16) is transformed by the decoding means (20).
Remains unchanged or with minimal changes.

FIG. 8 shows a pseudo code of a sentence encoder by digital spoofing, and FIG. 9 shows a pseudo code of a sentence decoder by digital spoofing. The pseudo code of the spatial position program used in the encoding process is shown in FIG. In these figures,
The term "unlabelled" is used to refer to the raw data, and the term "labelled" is used to refer to the encoded data. used.

An example of using the present invention to disguise a character label on a digital image is shown in FIG. A document string containing 83 characters "This example shows an alphanume ri
c text message camouflaging into the image of Lena. "is disguised in Lena's image. The correlation coefficient is exactly 1, which means that the labeled and unlabeled images Further, FIG. 12 shows an example in which an entire paragraph of an English sentence including 126 words and 784 characters is hidden in the same Lena image. Therefore, also in this example, the correlation coefficient is exactly 1.

The present invention, which conceals strings of letters of the alphabet or numbers in digital data, has many solutions to the problem of copyright protection in the consumer sector and the problem of secure message transmission in the commercial or service sector. Has useful compatibility. For example, data spoofing has been used in digital still cameras and camcorders, and more recently in consumer electronics such as VCDs and DVD players, to certify the ownership of intellectual property genuine proprietary products. Will be incorporated. Another main application of data hiding is to prevent unauthorized copying or downloading of satellite images or music CDs or tapes.

In the commercial sector, strict monitoring is required for copyright protection of multimedia data on the Internet. This is because a great deal of original data, in the form of music, images and videos, has been illegally downloaded and redistributed without the consent of the true owner. The present invention is used to address this issue, as well as providing secure transmission of messages in advertisements and other operations. Similarly, service departments such as security and banks can spoof secret document messages into original images or voices for secure transmission.

It will be appreciated that such superior techniques may constitute various applications and modifications of the above-described embodiments without departing from the spirit and scope of the invention. Therefore, it is to be understood that within the scope of the appended claims, the invention may be practiced other than as specifically described herein.

[Brief description of the drawings]

FIG. 1 is a one-dimensional data array including integer values representing digital audio signals.

FIG. 2 is an example of an audio signal.

FIG. 3 is an example of a still image.

FIG. 4 is a set of ASCII characters.

FIG. 5 shows a typical gray scale distribution in a digital image.

FIG. 6 shows a 4 × 8 two-dimensional data array of data elements representing pixels of a grayscale image.

FIG. 7 is a schematic block diagram of a digital impersonation device.

FIG. 8 is a pseudo code of a text encoding process by digital spoofing.

FIG. 9 is a pseudo code of a text compounding process by digital impersonation.

FIG. 10 is a space layout program used in the process of compounding shown in FIG.

FIG. 11 is an example of digital disguise processing of a character message obtained by combining an alphabet and a character in an image.

FIG. 12 shows an example of digital concealment processing of a character message in which an alphabet and a character are combined in an image.

[Explanation of symbols]

10: Sampling data, 12: Alphabet or numeric character string, 12A: Alphabet or numeric character string, 14: Data encoding means, 16: Encoded data sample, 16A: Encoded data sample, 18 unique key data, 20
... Data decryption means

────────────────────────────────────────────────── ─── Continuing on the front page (71) Applicant Suite 106, Innovation Center, Block 1, 16 N anyang Drive, Singapore 637722 (72) Inventor Ethiopian Anthony Tan Shen Singapore 639 798 Nanyang Avenue Block S2 School and Electronic Electric engineering Nanyang Technological University F-term (reference) 5B017 AA03 CA00 CA06 CA09 5C077 LL14 PP19 PP23 PQ12 5J104 AA14 PA07

Claims (45)

[Claims] 1. An concealed encoding method comprising the following steps. (A) providing primary data including a plurality of first data elements accessible by an address; (B) supplying secondary data including a plurality of second data elements; and For the second data element: (C1) search for a first data element that matches the second data element; and (C2) find a match that matches the component of the second data element: Generate a key element that contains the address of the matching first data element. 2. The concealment encoding method according to claim 1, wherein the first data element and the second data element are represented by integer values, and the step (C) further includes the following processing. Features. If no match is found with the component of the second data element, (C3) generate a corrected second data element by increasing or decreasing the integer value of the second data element; Searching for a first data element that matches the integer value of the corrected second data element; and (C5) when a match with the corrected second data element is found, the first data element that matches A key element including the element address is generated, and the corresponding component of the first data element is replaced with the integer value of the second data element that is the basis of the corrected second data element. 3. The concealment encoding method according to claim 2, wherein the step (C) further includes the following processing. (C6) generating a new corrected second data element by increasing / decreasing the corrected second data element when no match is found with a component of the corrected second data element Steps (C4) and (C5) are repeated for the new corrected second data element. 4. The concealed encoding method according to claim 1, further comprising the following processing prior to step (C). Determining a range of components of the first data element; determining a range of components of the second data element; comparing the range of the first data element with the range of the second data element; If the range of the element exceeds the range of the first data element, the second
The components of the second data element are shifted such that the range of the data element of the second data element is substantially within the range of the first data element, and in step (C), the shifted second data element is Used as the second data element. 5. The concealment encoding method according to claim 4, wherein the step of determining the range of the first data element includes the following processing. An intermediate value and a standard deviation of the first data element are calculated, and a lower limit of the first data element is determined based on the intermediate value and the standard deviation. 6. The concealment encoding method according to claim 4, wherein the step of determining the range of the second data element includes the following processing. As the reference value, the minimum value belonging to the range of the valid second data element is set. 7. The concealment coding method according to claim 6, wherein the step of performing the comparison includes a process of calculating an offset value by subtracting the reference value from the lower limit. 8. The concealment encoding method according to claim 7, wherein the step of performing a shift includes a process of adding the offset value to a component of each second data element. 9. The concealed encoding method according to claim 1, further comprising a process of storing a key element. 10. The concealed encoding method according to claim 7, further comprising a step of storing the offset value together with the key element. 11. The concealed encoding method according to claim 1, wherein the following is included. Step (A) includes providing a digital representation of a component of each first data element; Step (B) includes providing a digital representation of a component of each second data element; C1) includes a process of comparing the digital representation values of the first data element and the second data element. 12. The concealment encoding method according to claim 1, wherein the secondary data includes a document sequence, and each second data element includes an alphabet or a numeric character. 13. The concealment encoding method according to claim 12, wherein said document sequence includes at least one of the following. A general term for the title, author, copyright owner, payable group, or publisher distribution. 14. The concealed encoding method according to claim 2, further comprising a process of storing the primary data or the changed primary data generated in the step (C5). 15. The concealed encoding method according to claim 1, wherein the primary data includes first data elements arranged in a two-dimensional array, and each first data element is associated with a still image element. The characteristic is defined. 16. The method of claim 15, wherein the first data element is obtained from a data sequence representing a digitized still image. 17. The concealment encoding method according to claim 16, wherein the digitized still image is obtained from a digital still camera. 18. The concealment encoding method according to claim 16, wherein the digitized still image is obtained from a computer game or other software. 19. The method of claim 1, wherein the primary data includes first data elements arranged in a three-dimensional array, each first data element being associated with a moving picture video element. The characteristic is defined. 20. The concealment encoding method according to claim 19, wherein the first data element is obtained from a data sequence representing digitized moving picture video. 21. The concealment encoding method according to claim 20, wherein the digitized moving picture video is obtained from a Video Compact Disc player. 22. The concealment encoding method according to claim 20, wherein the digitized moving image video is obtained from a laser disk (Laser Disk) player. 23. The concealment encoding method according to claim 20, wherein the digitized moving image video is obtained from a digitized moving image included in a computer game or other software. 24. The concealment encoding method according to claim 20, wherein the digitized moving image video is obtained from a Digital Versatile Disk player. 25. The method of claim 1, wherein the primary data comprises first data elements arranged in a one-dimensional array, each first data element being associated with a digital audio sample. The characteristic is defined. 26. The concealment encoding method according to claim 25, wherein the digital audio sample is obtained from a data sequence representing digitized voice or music. 27. The concealment encoding method according to claim 25, wherein the digital audio sample is obtained from two data strings representing digitized two-channel audio data for stereo reproduction. I do. 28. The concealment encoding method according to claim 25, wherein the digitized voice or music is obtained from a Compact Disc player. 29. The concealment encoding method according to claim 25, wherein the digitized voice or music is obtained from a digital audio tape (Digital Audio Tape) player. 30. The concealment encoding method according to claim 25, wherein the digitized voice or music is obtained from a laser disc (Laser Disc) player. 31. The method of claim 25, wherein the digitized audio or music is obtained from a Video Compact Disk player. 32. The concealment encoding method according to claim 1, wherein the number of the first data elements is equal to the second data element.
The number of data elements is larger than the number of data elements. 33. The concealment encoding method according to claim 1, wherein a plurality of second data elements having equal components are made to match a plurality of first data elements having different addresses, so that each of the first data elements has a different address. The address of the data element is used only once to generate the key element. 34. A method for concealed decoding of secondary data including a plurality of second data elements, the secondary data being encoded by a key element associated with the primary data, the following steps: It is characterized by including. (A) providing the primary data including a plurality of first data elements accessible by an address; (B) providing the key elements each including an address of the first data element; (C) For each key element, the second data element is generated by extracting the component of the first data element to which an address is assigned. 35. The concealment decoding method according to claim 34, wherein a component of the second data element is shifted by an offset value, and further comprising: (D) providing the offset value; and (E) subtracting the offset value from the second data element. 36. The method of claim 34, wherein each second data element comprises an alphabetic or numeric character. 37. An apparatus for concealment encoding, comprising: (A) 1 including a plurality of first data elements accessible by an address
Means for supplying next data; (B) means for supplying secondary data including a plurality of second data elements; and (C) for each second data element, the component of the second data element is matched. (D) means for generating a key element including the address of the matched first data element when a match with the component of the second data element is found. 38. The apparatus for concealment coding according to claim 37, wherein the first data element and the second data element are represented by integer values, the apparatus comprising: I do. (E) means for generating a corrected second data element by increasing or decreasing the integer value of the second data element when no match is found with the component of the second data element; (F) Means for searching for a first data element that matches the integer value of the corrected second data element; (G) when a match with the corrected second data element is found, Means for generating a key element including the address of the first data element; (H) an integer value of the second data element that is the basis of the corrected second data element, Means to replace components. 39. The apparatus for concealment encoding according to claim 37, further comprising the step of: when no one matches the corrected second data element. Means for generating a new corrected second data element by increasing or decreasing the number of elements. 40. The apparatus for concealment encoding according to claim 37, further comprising: Means for determining the range of the component of the first data element; means for determining the range of the component of the second data element; means for comparing the range of the first data element with the range of the second data element; When the range of the second data element exceeds the range of the first data element,
Means for shifting the components of the second data element so that the range of the second data element falls substantially within the range of the first data element; and Means to use as data elements. 41. An apparatus for concealed decoding of secondary data including a plurality of second data elements, wherein the secondary data is encoded by a key element associated with the primary data. It is characterized by including the following. (A) means for supplying the primary data including a plurality of first data elements accessible by an address; (B) means for supplying the key elements each including the address of the first data element. (C) means for generating a second data element corresponding to each key element by extracting a component of the first data element to which an address is assigned. 42. A cryptographic encoding method comprising the following steps. (A) 1 including a plurality of first data elements accessible by an address
(B) providing secondary data comprising a plurality of second data elements, and (C) for each second data element: (C1) a component of the second data element Searches for a first data element that matches the element, and (C2) generates a key element that includes the address of the first data element that matches when the element that matches the element of the second data element is found. I do. 43. A method for cryptographically decrypting secondary data including a plurality of second data, comprising:
Are encoded with key elements associated with the primary data, and the method comprises the following steps. (A) supplying the first data including a plurality of first data elements accessible by an address; (B) supplying the key elements each including an address of the first data element;
(C) For each key element, one second data element is generated by extracting a component of the first data element to which an address is assigned. 44. An apparatus for cryptographic encoding, comprising: (A) 1 including a plurality of first data elements accessible by an address
Means for supplying next data; (B) means for supplying secondary data including a plurality of second data elements; and (C) for each second data element, the component of the second data element coincides Means for searching for a single first data element, (D) generating a key element including the address of the matched first data element when a match is found with a component of the second data element means. 45. An apparatus for cryptographically decrypting secondary data including a plurality of second data elements, wherein the secondary data is encoded by a key element associated with the primary data, The apparatus is characterized by comprising: (A) means for supplying the primary data including a plurality of first data elements accessible by an address; (B) supplying the key elements each including an address of one first data element. (C) means for generating one second data element corresponding to each key element by extracting a component of the first data element with an address.