JP2008096644A - Information transmission system, information dispersion apparatus, information recovery device, information transmission method, information dispersion program and information recovery program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information dispersion system capable of dispersing one-bit audio data in secret without increasing a transmission band. <P>SOLUTION: One-bit random numbers Rj are generated from random number generators 13-0 to 13-(j-2), respectively. In a secret dispersion unit 12, one-bit audio bit stream k is dispersed into n groups of dispersed signals s<SB>i</SB>. The dispersed signal s<SB>i</SB>are transmitted from a transmitter 14, being dispersed through the respective channels. The transmitted dispersed signals s<SB>i</SB>are received by a receiver part 21 and are recovered into the original one-bit audio signal by a recovery unit 22 by simultaneously processing every one bit of all the dispersed signals s<SB>i</SB>by XOR operation. Since each dispersed signal becomes the same as the original signal in size even if one-bit audio bit stream is dispersed into n pieces of dispersed signals, an excessive communication band and listening capacity are not suppressed in the case of network distribution. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an information transmission system, an information distribution apparatus, an information restoration apparatus, an information transmission method, an information distribution program, and an information restoration program that secretly distribute and transmit data represented by a 1-bit sequence.

  A 1-bit audio system, which can be one of the next generation of major audio technologies, can transmit audio data in a narrower transmission band than multi-bit audio data, and can be used for music / audio data distribution over a network. Expectation is put. On the other hand, when such audio data is distributed using a network, it is necessary to prevent data eavesdropping during transmission and protect copyright.

  Corresponding to these problems, the security for copyright protection in the conventional method includes a method of encrypting transmission data and a method of transmitting the transmission data by decomposing it into a plurality of series. The former performs encryption / decryption using the same secret key on both the transmission side and the reception side. However, with this method, there is a risk that transmission data may be wiretapped due to leakage of a secret key or decryption of encryption by a computer.

  In the latter case, the data cannot be restored unless all of the transmission data divided into a plurality of pieces is prepared. For this reason, more secure data transmission is possible. However, in the conventional dispersion of transmission data, a sound close to the original signal is gradually heard as the separated transmission data are added. For this reason, there is a possibility that the contents may leak even if the decomposed data is not prepared a little.

Therefore, Patent Document 1 proposes a 1-bit audio (n out-of n) secret sharing system (Binary Audio Secret Sharing: BASS) based on a visual secret sharing method for binary images. In the system shown in Patent Document 1, each bit of 1-bit audio is distributed into n signals of d (= 3) bit frame representation, and if all n distributed signals are not complete, the original audio information is obtained. Is a highly confidential method that makes it impossible to restore.
JP 2005-165062 A

  However, in the system of Patent Document 1, since the original 1-bit audio data is represented by d bits, the size of each distributed signal is d times that of the original signal. For this reason, there arises a problem that the transmission band necessary for sending the audio data becomes nd times.

  That is, the 1-bit audio system can transmit audio data in a narrow transmission band as described above. On the other hand, in the system of Patent Document 1, by secretly sharing audio data, the transmission band necessary for sending the audio data becomes nd times, and the advantage of 1-bit audio cannot be utilized. There is a problem. Similarly, when the data is stored in a fixed medium, there is a problem in that the storage capacity is greatly reduced.

  Therefore, the present invention has been made in view of the above-described problems, and an information distribution system, an information distribution apparatus, an information restoration apparatus, an information transmission method, and the like that can secretly distribute 1-bit audio data without increasing a transmission band, An object is to provide an information distribution program and an information restoration program.

The present invention proposes the following items in order to solve the above-described problems.
(1) The present invention uses a secret sharing method using XOR to generate n distributed signals from a 1-bit audio signal, and transmits the n distributed signals to respective transmission paths; A receiver that receives n distributed signals respectively transmitted through the transmission path and restores the original 1-bit audio signal from the received n distributed signals by a secret sharing method using XOR; An information transmission system characterized by comprising:

  According to the present invention, the transmitter generates n distributed signals having the same size as the 1-bit audio data from the 1-bit audio signal using the secret sharing method using XOR, and the n distributed signals Are transmitted to the respective transmission lines. Then, the receiver receives n distributed signals respectively sent via the transmission line, and the original 1-bit audio signal is received from the received n distributed signals by the secret sharing method using XOR. Restore. Therefore, the transmission band necessary for sending audio data is 1 / d of the system described in Patent Document 1, and 1-bit audio data can be secretly distributed without squeezing the transmission band.

  (2) In the information transmission system according to (1), the present invention is configured such that the generation of the distributed signal is performed using n-out− using XOR from the 1-bit audio signal and (n−1) random number sequences. An information transmission system characterized by secret sharing of of-n is proposed.

  (3) In the information transmission system of (1), the present invention is characterized in that the restoration of the dispersed signal restores the original 1-bit audio signal by XOR of the received n dispersed signals. A transmission system is proposed.

  (4) The present invention performs n-out-of-n secret sharing using XOR from a 1-bit audio signal and (n-1) random number sequences to generate n distributed signals. An information dispersal device characterized by the above is proposed.

  (5) The present invention proposes an information restoration apparatus that restores an original 1-bit audio signal by XOR of n received received distributed signals.

  (6) The present invention includes a step of generating n distributed signals from a 1-bit audio signal using a secret sharing method using XOR, and a step of transmitting the n distributed signals to the respective transmission lines. , Receiving n distributed signals respectively sent through the transmission path, and restoring the original 1-bit audio signal from the received n distributed signals by a secret sharing method using XOR. And an information transmission method characterized by comprising the steps.

  According to the present invention, n distributed signals are generated from a 1-bit audio signal using a secret sharing method using XOR, and the n distributed signals are transmitted to the respective transmission lines. Then, n distributed signals respectively transmitted through the transmission path are received, and the original 1-bit audio signal is restored from the received n distributed signals by a secret sharing method using XOR. Therefore, 1-bit audio data can be secretly distributed without increasing the transmission band.

  (7) In the information transmission method according to (6), the distributed signal is generated from the 1-bit audio signal and (n−1) random number sequences using n-out− using XOR. An information transmission method characterized by performing secret sharing of of-n is proposed.

  (8) In the information transmission method of (6), the present invention is characterized in that the restoration of the distributed signal restores the original 1-bit audio signal by XOR of the received n number of distributed signals. A transmission method is proposed.

  (9) The present invention includes a step of outputting a 1-bit audio sequence from a 1-bit audio sound source, a step of outputting a random number sequence from (n−1) random numbers, and an n-out-of-n secret. Proposing an information distribution program for causing a computer to execute the steps of generating n distributed signals from the 1-bit audio signal and the random number sequence and outputting the n distributed signals by distribution. ing.

  (10) The present invention includes a step of receiving n distributed signals, a step of performing an XOR operation on the n distributed signals to restore the original 1-bit audio signal, and outputting the restored 1-bit audio signal And an information restoring program for causing a computer to execute the step.

  According to the present invention, the (n-out-of-n) secret sharing method using XOR is used to distribute a 1-bit audio bitstream into n distributed signals for transmission. Therefore, even if a 1-bit audio bit stream is distributed to n distributed signals, the size of each distributed signal is the same as the original signal, and therefore compression of extra communication bandwidth and recording capacity is required during network distribution. There is an effect that there is nothing. In addition, since the original signal is restored at a high speed bit by bit using only the XOR operation, there is an effect that the restoration is possible at a high speed and is suitable for streaming distribution.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Note that the constituent elements in the present embodiment can be appropriately replaced with existing constituent elements and the like, and various variations including combinations with other existing constituent elements are possible. Therefore, the description of the present embodiment does not limit the contents of the invention described in the claims.

<(N-out-of-n) Secret Sharing Method Using XOR>
In the present embodiment, 1-bit audio data is secretly distributed in n series and transmitted using the (n-out-of-n) secret sharing method using XOR (exclusive OR). . In the (n-out-of-n) secret sharing method, information cannot be recovered unless the information is divided into n pieces and these n pieces of information are collected. First, the (n-out-of-n) secret sharing method using the XOR used in this embodiment having such characteristics will be described.

In the present embodiment, the original information signal k is converted to n distributed signals s _i (0 ≦ i ≦ n−) by the (n-out-of-n) secret sharing method using XOR based on the following equation. 1).

In the above equation, n is the number of variances, k is the original information signal, and s _i is the variance signal. R _i (0 ≦ i ≦ n−2) is an independent random number. Here, the bit number b of k, s _i , and R _i is (b ≧ 1).

The dispersion according to the above equation is to disperse the original information signal k of 1 bit into n distributed signals s _i (0 ≦ i ≦ n−1). In the distributed signals s ₀ to s _n−2 , The random number R _i (0 ≦ i ≦ n−2) is transmitted, and in the distributed signal s _n−1 , the XOR of the random number R _i transmitted in the sequence from the distributed signal s ₀ to the s _n−2 and the original information signal k XOR is transmitted. When such a secret sharing method is used, data is distributed as shown below.

In this data distribution, in order to restore the original signal k, XOR of all the distributed signals from s ₀ to s _n−1 may be calculated as shown in the following equation.

As described above, in the (n-out-of-n) secret sharing method using the XOR used in the present embodiment, the random number R is used for the distributed signals s ₀ to s _n-2 as shown in the equation (1). _i (0 ≦ i ≦ n−2) is transmitted, and in the distributed signal s _n−1 , the XOR of the random number R _i transmitted from the distributed signal s ₀ to the s _n−2 sequence and the original information signal k , The original 1-bit information signal can be dispersed into n distributed signals. When such a secret sharing method is used, it cannot be restored at all unless all n distributed signals s _i (0 ≦ i ≦ n−1) are collected.

<Configuration of transmitter and receiver of information distribution system for 1-bit audio>
FIG. 1 shows the configuration of the transmitter of the information distribution system for 1-bit audio of this embodiment, and FIG. 2 shows the configuration of the receiver.

In the transmitter 1 of FIG. 1, the 1-bit audio bitstream k (information signal k) output from the 1-bit audio source 11 is sent to the secret distributor 12. Also, 1-bit random numbers R _i (0 ≦ i ≦ n−2) are generated from the random number generators 13-0 to 13- (j−2), respectively. This random number R _i (0 ≦ i ≦ n−2) is sent to the secret distributor 12. The random number generators 13-0 to 13- (j-2) may be true random numbers or pseudo random numbers.

In the secret sharing unit 12, as shown in the above equation (1), the 1-bit audio bit stream k is distributed into n series of distributed signals s _i (0 ≦ i ≦ n−1). In this way, the n distributed signals s _i (0 ≦ i ≦ n−1) are sent from the secret sharing device 12 to the transmission unit 14. The stream of the distributed signal s _i (0 ≦ i ≦ n−1) is distributed and transmitted from the transmission unit 14 via each channel of the transmission path 15 such as the Internet.

In the receiver 2 of FIG. 2, the stream of the distributed signal s _i (0 ≦ i ≦ n−1) transmitted through the transmission path 15 is received by the receiving unit 21 and sent to the restoring unit 22. The restorer 22 synchronizes all n distributed signals s _i (0 ≦ i ≦ n−1), and all these distributed signals s _i (0 ≦ i ≦ n−1) are simultaneously bit by bit. XORed. Thereby, as shown in the equations (2) and (3), the original 1-bit audio signal k is restored, and the restored 1-bit audio bit stream is output from the restorer 22.

  As described above, in the present embodiment, the (n-out-of-n) secret sharing method using XOR is used to distribute and transmit a 1-bit audio bitstream into n distributed signals. I have to. Therefore, even if a 1-bit audio bit stream is distributed to n distributed signals, the size of each distributed signal is the same as the original signal. There is no pressure on the recording capacity. In addition, since the original signal can be restored at a high speed bit by bit using only the XOR operation, it is also suitable for streaming distribution.

  Note that the above-described distributed processing for distributing the 1-bit audio bitstream during transmission into n distributed signals and the processing for restoring the original 1-bit audio bitstream from the distributed signals during reception can be performed by software. .

<Distribution procedure during transmission>
FIG. 3 is a flowchart showing a distribution procedure at the time of transmission. In FIG. 3, at the time of transmission, first, a 1-bit audio bit stream k is output from a 1-bit audio sound source (step S1).

Next, (n−1) random number sequences R _i (0 ≦ i ≦ n−2) are generated, and the random number sequences R _i are output (step S2).

  By using the n-out-of-n secret sharing method using XOR, n distributed signals are generated from the 1-bit audio bitstream and (n−1) random number sequences (step S3). The dispersed signal is output to each channel of the transmission path (step S4).

<Restoring procedure when receiving>
FIG. 4 is a flowchart showing a restoration procedure at the time of reception. In FIG. 4, at the time of reception, n distributed signals s _i (0 ≦ i ≦ n−1) from each channel of the transmission path are received (step S11).

Then, all of these distributed signals s _i (0 ≦ i ≦ n−1) are simultaneously XORed bit by bit to restore the original 1-bit audio bit stream (step S12), and the restored 1-bit audio bits A stream is output (step S13).

Here, in the above example, the _{s n-2} from the variance signal _{s 0,} and transmits the random number _{R i (0 ≦ i ≦ n} -2), distributed signal _s in _{n-1, s} from the distributed signal _{s 0 n -XOR} of all the random numbers R _i (0 ≦ i ≦ n−2) transmitted in ₋₂ and the original information signal k. In this case, the distributed signals s ₀ to s _n−2 are all equal to the random number R _i (0 ≦ i ≦ n−2) output from the random number generator. Thus, some _{s n-2} from the variance signal _{s 0,} or, instead of transmitting all the variance signal _{s 0} to _{s n-2,} the species used to generate the random number _{R i} a (Seed) You may make it transmit securely. However, in this case, a pseudo-random number generator is used instead of a natural random number generator to generate the random number R _i .

  Each process of the information transmission system, the information distribution device, and the information restoration device is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the information transmission system, the information distribution device, and the information restoration device. The information transmission system, the information distribution apparatus, and the information restoration apparatus of the present invention can be realized by executing. The computer system here includes an OS and hardware such as peripheral devices.

  Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW (World Wide Web) system is used. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

  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, and what is called a difference file (difference program) may be sufficient.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes a design and the like within a scope not departing from the gist of the present invention.

It is a block diagram which shows the structure by the side of the transmitter of the transmission system of 1 bit audio bit stream of this embodiment. It is a block diagram which shows the structure by the side of the receiver of the transmission system of 1 bit audio bit stream of this embodiment. It is a flowchart used for description of the information dispersion | distribution process in the transmission system of 1 bit audio bit stream of this embodiment. It is a flowchart used for description of the information decompression | restoration process in the transmission system of 1 bit audio bit stream of this embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Bit audio sound source, 12 ... Secret sharing machine, 13 ... Random number generator, 14 ... Transmission part, 15 ... Transmission path, 21 ... Reception part, 22 ... Restoration vessel

Claims (10)

A transmitter for generating n distributed signals from a 1-bit audio signal using a secret sharing method using XOR, and transmitting the n distributed signals to the respective transmission lines;
A receiver that receives n distributed signals respectively transmitted through the transmission path and restores the original 1-bit audio signal from the received n distributed signals by a secret sharing method using XOR; ,
An information transmission system comprising:   2. The distributed signal is generated by performing n-out-of-n secret sharing using XOR from the 1-bit audio signal and (n−1) random number sequences. Information transmission system described in 1.   2. The information transmission system according to claim 1, wherein the restoration of the distributed signal restores the original 1-bit audio signal by XOR of the received n number of distributed signals.   Information characterized by generating n distributed signals by performing n-out-of-n secret sharing using XOR from a 1-bit audio signal and (n-1) random number sequences. Distributed device.   An information restoration apparatus which restores an original 1-bit audio signal by XOR of received n distributed signals. Generating n distributed signals from a 1-bit audio signal using a secret sharing method using XOR;
Transmitting the n distributed signals to respective transmission lines;
Receiving n distributed signals respectively sent through the transmission path;
Restoring the original 1-bit audio signal from the received n distributed signals by a secret sharing method using XOR;
An information transmission method comprising:   7. The shared signal is generated by performing n-out-of-n secret sharing using XOR from the 1-bit audio signal and (n-1) random number sequences. Information transmission method described in 1.   The information transmission method according to claim 6, wherein the restoration of the distributed signal is to restore the original 1-bit audio signal by XOR of the received n number of distributed signals. Outputting a 1-bit audio sequence from a 1-bit audio source;
Outputting a random number sequence from (n-1) random numbers;
generating n distributed signals from the 1-bit audio signal and the random number sequence by n-out-of-n secret sharing;
Outputting the n distributed signals;
Information distribution program for causing a computer to execute receiving n distributed signals;
Performing an XOR operation of the n distributed signals to restore the original 1-bit audio signal;
Outputting the restored 1-bit audio signal;
Information restoration program to make computer execute.

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