KR100638583B1 - Method for preventing and tracking illegal duplicate of copyright in power line communication home networking environment - Google Patents

Abstract

A method for preventing and tracking illegal copy is provided to quickly stop a copy operation and track the illegal copy by a location information signal through a power line if the illegal copy is revealed by extracting watermark information during the illegal copy, and comparing an extracted watermark with the original watermark simultaneously with discriminating a relation level. The watermark information is extracted when the writing is copied(A). If the relation level over a threshold is represented by comparing the watermark information with the original watermark, an encoded alarm signal and the location information signal are transmitted through the power line while stopping the copy operation(B). The copy operation is tracked by interpreting/tracking the alarm signal and the location information signal transmitted through the power line(C).

Description

METHODS FOR PREVENTING AND TRACKING ILLEGAL DUPLICATE OF COPYRIGHT IN POWER LINE COMMUNICATION HOME NETWORKING ENVIRONMENT}

1 is a conceptual diagram showing a piracy prevention and tracking system according to the present invention.

Figure 2 is a block diagram showing a piracy prevention and tracking system according to the present invention.

3 is a conceptual diagram illustrating a process of inserting watermark information into a work applied to the anti-piracy and tracking system according to the present invention.

Figure 4 is a flow chart for explaining the piracy prevention and tracking method according to the present invention.

5 is a conceptual diagram illustrating a process of extracting watermark information from a work applied to the anti-piracy and tracking system according to the present invention.

         Explanation of symbols on the main parts of the drawings

10: replicator 20: copyrighted work

30: Piracy Determination 31: Memory

32: Extractor 33: Comparator

34 Turbo Encoder 35 Modulator

36: Ampener 37: Transmission Bandpass Filter

38: shock sensor 39: controller

40: PLC transmission modem 50: wireless transmitter

60: supervisory authority reading unit 61: PLC receiving modem

62: receive bandpass filter 63: decoder

64: demodulator 65: turbo decoder

66: Internet Backbone 67: Wireless Receiver

The present invention relates to a method for preventing and tracking illegal copying, and more particularly, to illegally copy a copyrighted work using a copying machine, extracts watermark information, compares it with the original watermark, and determines the magnitude of the correlation. The present invention relates to an anti-piracy prevention and tracking method that allows the location information signal to be transmitted and traced while stopping the duplication process if the duplication is revealed.

Recently, due to the rapid development of networks such as computer communication and the Internet and the increase of digital data, the issue of intellectual property rights from illegal copying has been highlighted, and thus, copyrights to prevent unauthorized copying and protect the ownership of the owners without permission. The technology of protection techniques is urgently required.

With this trend, watermarking techniques have been proposed for various purposes, in particular for copyright protection of multimedia data.

Watermarks must be embedded in audio, video or image signals and must not be recognized by non- copyright holders and must be legally detectable by the copyright owner.

In this case, the watermark is an invisible mark displayed on voice, video, or image data for copyright protection, and refers to a specific code or pattern inserted in a work such as voice, video, or image.

By measuring whether or not the watermark is inserted and tampered with, it is possible to check whether the work is forged or stolen.

However, only by inserting a watermark in specific data, many problems appear to be limited to prevent illegal copying and prevent mass distribution.

Therefore, in the following, we propose a method for preventing illegal duplication by simply responding to watermark detection as well as inserting a simple watermark, and using a DS-CDMA / BPSK system in a PLC (Power Line Communication) environment considering AWGN and impulse noise. It aims to be able to operate with proposed piracy prevention and tracking method.

The present invention has been made through the above proposal, and its purpose is to extract the watermark information during illegal copying of a work, compare it with the original watermark, and determine the magnitude of the correlation to promptly identify the illegal copying. It provides an illegal copy prevention and tracking method that can send location information signal to power line and stop it while stopping the copying process.

The present invention for achieving the above object,

(A) extracting watermark information when the copyrighted work is reproduced;

(B) transmitting the encrypted alarm signal and the location information signal to the power line while stopping the copying operation if the watermark information is compared with the original watermark and the correlation is higher than the threshold value;

And (C) decoding and tracking the alarm signal and the location information signal sent out to the power line.

Hereinafter, a preferred embodiment of the anti-piracy and tracking system according to the present invention will be described with reference to the drawings, and a plurality of embodiments may exist, and through these embodiments, the objects, features, and advantages of the present invention may be further improved. I can understand well.

The present invention uses the watermark information to protect the copyrighted work 20 of certain contents (for example, currency, social security card, driver's license, passport, etc.) and to prevent mass distribution due to illegal copying. We suggest a system that can detect and prevent duplication and track the location of piracy.

1 is a conceptual diagram showing a piracy prevention and tracking system according to the present invention, Figure 2 is a block diagram showing a piracy prevention and tracking system according to the present invention.

Piracy prevention and tracking system according to the present invention can be used in the replicator 10, that is, built-in or separately installed in the replicator 10, which can be called input and output devices such as copiers, scanners, printers, to prevent illegal copying By inserting watermark information into the work 20, for example, the work 20, such as money, resident registration card, driver's license or passport, it is designed to prevent piracy and to track the piracy location.

More specifically, the piracy prevention and tracking system according to the present invention is prepared by inserting the watermark information in advance in the copyrighted work 20 to prevent piracy while the replicator 10 is based.

3 is a conceptual diagram illustrating a process of inserting watermark information into the copyrighted work 20 applied to the anti-piracy and tracking system according to the present invention.

As shown in FIG. 3, the process of inserting watermark information into the work 20 (see patent application No. 2004-98292 filed by the applicant as of November 26, 2004) is an original image (for example, a currency image). Frequency transform [Discret Cosine Transform (DCT), Discrete Fourier Transform (DFT), or Discrete Wavelet Transform (DWT)] to determine the intermediate frequency region to insert watermark information (S11), and to insert or extract watermark information. A random sequence is generated using a secret key value to be used at step S12. The pixel value of the watermark information (watermark image) is padded with 0 and 1, and the pixel value 0 is inserted into the intermediate frequency region. In step S13, the original image into which the watermark information is inserted is inversely transformed to provide a watermarked work 20 (for example, currency) (S14).

More specifically, the anti-piracy and tracking system according to the present invention extracts watermark information and compares it with the original watermark when the copyrighted work 20 is copied using a copying machine 10 such as a copy machine, scanner or printer. In order to show the degree of correlation above the threshold, the piracy determiner 30 sending the encrypted alarm signal is a key component, and the PLC transmission modem 40 sending the alert signal of the piracy determiner 30 to the power line. It consists of a configuration including a supervisory authority reading unit 60 to decode and track the encrypted alarm signal transmitted by the PLC transmission modem 40 at the same time as the essential configuration.

Duplicator 10 such as a copier, scanner or print is basically forced to use the power, according to the present invention, when the illegal copying of the copyrighted work 20 according to the present invention PLC transmission of the alarm signal encrypted in the piracy determination unit 30 The modem 40 may be transmitted to the power line, and the supervisory authority reading unit 60 may decrypt and track the encrypted alarm signal input through the power line.

More specifically, the illegal copy judging device 30 includes a memory 31 in which the original watermark is stored in advance, and an extractor 32 extracting watermark information when the copyrighted work 20 is copied through the copying machine 10. And a comparator 33 for generating an alarm signal when the watermark information of the copyrighted work 20 and the original watermark of the memory 31 are compared to show a correlation degree equal to or greater than a threshold value.

And a turbo encoder 34 for converting the alarm signal of the comparator 33 into digital data, and modulating the digital data of the turbo encoder 34 (more specifically, a BPSK modulator, a QPSK Modulator, or a QAM). Modulator), and a passivator 36 for inserting and encrypting a PN code into a modulated signal of the modulator 35, and a transmission bandpass filter 37 for removing a noise signal contained in an encrypted signal of the passivator 36. It consists of a configuration that includes.

More preferably, the illegal copy judging device 30 has a shock sensor 38 for detecting a shock, and erases the original watermark of the memory 31 when a shock is detected by the shock sensor 38. At the same time, a controller 39 for temporarily stopping the operation of the replicator 10 is added to prevent the leakage of the original watermark in advance.

At this time, the alarm signal of the illegal copy determiner 30 via the PLC transmission modem 40 may include a location information signal, and the location of the illegal copy can be tracked by the location information signal.

On the other hand, the supervisory authority reading unit 60 includes a PLC receiving modem 61 which is located in a public institution, for example, a police agency or a government agency, and receives an encrypted signal transmitted by the PLC transmitting modem 40, and receives the PLC. A decoder for removing a noise signal contained in an encryption signal of the modem 61, and a decoder for extracting a modulation signal by inserting a PN code into an encryption signal passed through the reception bandpass filter 62; 63, and a demodulator 64 for demodulating the modulated signal of the decoder 63 into digital data; It may have a decoder 65.

At this time, the warning signal output from the turbo decoder 65 includes the location information signal to be able to identify the site of the illegal copy.

On the other hand, the supervisory authority reading unit 60 may be provided with an Internet backbone 66 for receiving an encryption signal transmitted by the PLC transmission modem 40, which encrypts the Internet backbone 66. A reception bandpass filter 62 for removing a noise signal contained in the signal, and a decoder 63 for inserting a PN code into an encryption signal passed through the reception bandpass filter 62 to extract a modulated signal. The demodulator 64 may demodulate the modulated signal of the decoder 63 into digital data, and the turbo decoder 65 may output digital data of the demodulator 64 as an alarm signal.

At this time, it is assumed that the warning signal output from the turbo decoder 65 includes a location information signal together.

In another embodiment, the piracy prevention and tracking system according to the present invention is based on the replicator 10 and the copyrighted work 20 into which the watermark information is inserted, and copies the copyrighted work 20 by using the replicator 10. In this case, the watermark information may be extracted and at the same time it may include an illegal copy determiner 30 that sends an encrypted alarm signal if the correlation is greater than or equal to the original watermark, and the illegal copy determiner 30 Radio transmitter 50 for radio wave propagation of the alarm signal and supervisory authority reading unit 60 for receiving and decrypting and tracking the encrypted signal propagated by the radio transmitter 50 to the radio receiver 67. Can be.

Figure 4 is a flow chart for explaining the illegal copy prevention and tracking method according to the present invention.

The piracy prevention and tracking method according to the present invention first shows (A) extracting the watermark information when the copyrighted work 20 is duplicated, and (B) comparing the watermark information with the original watermark to show a correlation higher than a threshold value. After stopping the copy operation, the encrypted alarm signal and the location information signal are sent to the power line, and (C) the alarm signal and the location information signal sent to the power line are decoded and tracked.

More specifically, step (B) generates an alarm signal and a location information signal when comparing the watermark information extracted from the asset 20 with the original watermark and outputting a correlation higher than or equal to the threshold value (b1). Converts the signal and the location information signal into digital data (b2), modulates the digital data (b3), inserts the PN code into the modulated signal and encrypts it (b4), and removes the noise signal contained in the encrypted signal It can be realized by sending out (b5).

Step (C) receives the encrypted signal transmitted to the power line (c1), removes the noise signal contained in the encrypted signal (c2), extracts the modulated signal by inserting a PN code into the encrypted signal (c3) In addition, it is designed to demodulate the modulated signal into digital data (c4) and to read and track the digital data as an alarm signal and a location information signal (c5).

5 is a conceptual diagram illustrating a process of extracting watermark information from the copyrighted work 20 applied to the anti-piracy and tracking system according to the present invention.

As shown in FIG. 5, the process of extracting watermark information into the work 20 (see Patent Application No. 2004-98292 filed by the applicant as of November 26, 2004) may include an original image in which watermark information is inserted. For example, select a coefficient value in the intermediate frequency region defined when inserting watermark information by frequency transforming (Discret Cosine Transform (DCT), Discrete Fourier Transform (DFT), or Discrete Wavelet Transform (DWT)]. (S21), after generating a random sequence with the same secret key value as the secret key value used when inserting the watermark information, calculate the correlation with the intermediate frequency coefficient value (S22), the correlation value is greater than the threshold value In this case, the alarm signal and the location information signal are transmitted in order (S23).

On the other hand, the modulator 35 applied to the anti-piracy and tracking system according to the present invention in more detail, it can be referred to as DS-CDMA / BPSK and this direct spreading method is a pseudo random noise code again for the first modulated carrier As a method of secondary modulation with (PN code), the present invention can be usefully applied to the present invention in terms of a simple system configuration and easy modulation, and in a spread spectrum communication method, processing gain in the process of spreading a band This process gain is represented by the ratio between the spread signal bandwidth and the original narrow signal bandwidth and can be expressed as Equation 1 below.

[Equation 1]

At this time, B _SS Is the bandwidth of the certain signal, and B is the bandwidth of the information signal.

In addition, the PLC transmission modem 40 or the PLC reception modem 61 is a PLC installed in a telephone pole to connect with a PLC coupler, which is a device that distributes communication signals by bypassing an indoor distribution panel power meter and an Internet backbone 66 network. It can be done with a router.

Next, a description will be given of the PLC (Power Line Communication) provided as the core of the present invention.

PLC is a high-speed communication signal of several tens to hundreds of kilowatts is sent together to a copper electric line flowing AC electricity flowing into the home by a power line, and at this time, using a PLC transmission modem 40 and a PLC receiving modem 61, etc. Only the communication signal from the electric line can be selected and utilized, and also the Internet communication by the coupling with the Internet backbone (66).

Services using PLC include home automation, automatic meter reading (AMR), and broadband communication.

It is known that home automation and remote meter reading have little difficulty in practical use because the amount of data to be transmitted is not large, and remote meter reading is actually commercialized. In the case of broadband communication, major countries are making efforts to commercialize it.

PLC can supply terminal cheaper than wireless communication method, and it doesn't cost investment by using existing power line and it saves the high installation cost which is disadvantage of current high speed communication network by using existing transformer as it does not need space occupancy cost. It becomes possible.

On the other hand, the power line for such a PLC should be able to minimize the impulse noise.

In the present invention, impulse noise is considered as a channel environment of power line communication. Among the statistical models of impulse noise, Middleton's Class A impulse noise is a quantified method used to represent almost all kinds of real impulse noise.

In general, when the narrowband noise n ( t ) is represented by an in-phase component and an orthogonal component, it can be expressed as Equation 2 below.

[Equation 2]

Where w _c is the center angular frequency of the narrowband noise.

Assuming that noise n ( t ) is A-class impulse noise, the combined probability density function (pdf) is given by Equation 3 below.

[Equation 3]

In this case, using the Jacobian theorem and represented by the orthogonal component and in-phase component, respectively,

[Equation 4]

,

는 가우스 잡음 전력 대 임펄스 잡음 전력비, A는 임펄스 지수(단위 시간당 임펄스 성분이 차지하는 비율), W= o² _G + o² _I 는 전체 잡음 전력을 나타낸다.here,

,

Is the Gaussian noise power to impulse noise power ratio, A is the impulse exponent (the ratio of impulse components per unit time), W = o ² _G + o ² _I Denotes the total noise power.

=0,2,

=0.22인 전력선에서 방출되는 A급 임펄스 잡음의 실제 파라미터를 고려하였다.In the present invention, the impulse noise parameter calculated through the measurement of the actual power line communication channel

= 0,2,

The actual parameters of class A impulse noise emitted from a power line with = 0.22 are considered.

Next, the results of simulation and examination of the anti-piracy and tracking system according to the present invention are as follows.

The image quality of the decoded image must be finally judged by a human, but is evaluated with the correlation between the original image and the extracted image.

Equation 5 is a correlation coefficient expression, and compares and processes correlation coefficients between two images in a matrix (or vector) in which A and B are the same.

[Equation 5]

A = original image, B = decoded image

= the mean of the element of a matrix(A)

= the mean of the element of a matrix (A)

= the mean of the element of a matrix(B)

= the mean of the element of a matrix (B)

Table 1 below shows the correlation between the extracted watermark and the original watermark by inserting and extracting the watermark using key values.

TABLE 1

Correlation with Changes in Thresholds

The results of Table 1 show that the correlation is the greatest when the threshold is 0.4. Therefore, in the present invention, the watermark detection judgment is simulated based on the threshold value 0.4.

TABLE 2

Image with Threshold value of 0.4

Table 2 shows extracted watermark information when the threshold value is 0.4.

When the correlation between the extracted watermark information and the original watermark matches more than a certain ratio, the illegal copy prevention and tracking system proposed by the present invention modulates the alarm signal and the location information signal through the DS-CDMA / BPSK system and then power line. It can be transmitted through.

On the other hand, Table 3 shows a comparison of the performance of the watermark image with or without the application of convolutional coding after powerline transmission.

TABLE 3

Image comparison according to whether convolution is applied after power line transmission

According to the results of Table 3, when the convolution is not applied, impulse interference after powerline transmission causes the image to be noticeably damaged, resulting in low performance with a correlation of 0.3990 at SNR of 4dB.

On the other hand, when the convolution is applied, the correlation is 0.8617 at SNR of 4dB, which shows that the correlation performance is about 2 times higher than before the convolution.

As a result, it can be seen that the present invention relates to a piracy prevention and tracking system for preventing illegal duplication by not only inserting simple watermark information but also quick response when detecting watermark information, and additionally, AWGN and impulse noise. DS-CDMA / BPSK system simulated in the power line communication (PLC) environment considering the difference, and the correlation is approximately 0.4 due to the influence of impulse noise when restoring the image in the same SNR depending on whether convolution is applied or not. It is shown that the channel coding technique is required in the communication environment using PLC. When convolution is applied, the reconstructed image can be visually confirmed even at the low SNR of SNR of 4dB and the correlation with the original watermark is 0.8617. Good performance was found.

Therefore, the present invention can be designed to prevent piracy by determining the magnitude of the degree of correlation by extracting watermark information and comparing it to the original watermark, and at the same time, utilizing the power line to track the piracy location. More quickly and precisely, illegal copying of the work 20, that is, unauthorized copying of various identification cards, passports, or currency, can be prevented in advance.

As described above, in the present invention, when watermark information is inserted into the work 20 and the work 20 is reproduced through the copying machine 10, the watermark information is extracted to be compared with the original watermark and the degree of correlation It is possible to determine the size of the illegal copying and to quickly stop and send the location information signal to the power line to track the illegal copying of the copyrighted work 20, that is, unauthorized identification of various identification cards, passports or money, etc. There is an excellent effect that can be prevented in advance.

More specifically, when duplicating the work 20 with the watermark information inserted using the copying machine 10 such as a copy machine, a printer, a scanner, etc., the watermark information is extracted and compared with the original watermark stored in the memory 31. When detected as a correlation value of more than the threshold value is regarded as an illegal copying situation, the operation of the replicator 10 can be stopped quickly, and at the same time, the location information signal can be transmitted and tracked through the power line.

Claims (3)

(A) extracting the watermark information when the copyrighted work 20 is reproduced; (B) transmitting the encrypted alarm signal and the location information signal to the power line while stopping the copying operation if the watermark information is compared with the original watermark and the correlation is higher than the threshold value; And (C) decoding and tracking the alarm signal and the location information signal transmitted to the power line. The method of claim 1, Step (B) is (B1) generating an alarm signal and a location information signal when comparing the watermark information extracted from the asset 20 with the original watermark and outputting a correlation greater than or equal to a threshold value; Converting the alarm signal and the location information signal into digital data (b2), Modulating the digital data (b3), Inserting the PN code into the modulated signal and encrypting it (b4), And (b5) removing the noise signal contained in the encrypted signal and transmitting the noise signal to the power line. The method of claim 2, Step (C) above Accepting an encrypted signal sent to the power line (c1), Removing the noise signal contained in the encrypted signal (c2), Extracting a modulated signal by inserting a PN code into the encrypted signal (c3); Demodulating the modulated signal into digital data (c4), And (c5) reading and tracking the digital data as an alarm signal and a location information signal.

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