KR20170109948A - Data transmission method with enhanced data transmission security and wireless device for the method - Google Patents

Abstract

A shot segmentation technique of a video content to which a content adaptive threshold is applied is disclosed. The shot segmentation technique according to the present invention includes a process of adaptively obtaining a threshold value serving as a criterion of shot segmentation after content is adaptively obtained when dividing a shot into image content. For example, the target image content is divided into a plurality of shots by applying a preset threshold value to the analysis and processing results of the image information on the image content. Then, the variation threshold is obtained through analysis and processing of the image information for each of the plurality of shots obtained as a result of the segmentation, and then the variation threshold is divided and a part of the plurality of shots is divided again into a plurality of shots.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission method and data transmission method,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wireless communication technology, and more particularly, to a data transmission technology with enhanced data transmission security.

Many encryption technologies are used in wireless communication systems. This means that the security of the existing wireless communication channel is based on encryption. More specifically, the transmitting terminal encrypts and transmits data based on a previously shared key, and the receiving terminal decrypts the received encrypted data using the shared key.

However, according to this conventional method, communication security is no longer ensured in a situation where a shared encryption / decryption key is exposed. This is because the existing technologies do not rely on the fact that the eavesdropper relies on facts such as difficult or not easy to obtain the encryption / decryption keys used by legitimate users, and is not mathematically or practically impossible . For example, as the computing capacity available to the eavesdropper increases, the security effect of the existing method will be reduced, and the probability that the eavesdropper will steal or decrypt the encryption / decryption key increases.

Various methods have been proposed to overcome the limitation of the conventional encryption method. For example, Korean Patent Publication No. 2011-0073563, entitled " Generation of a Perfect Secret Key in a Wireless Communication Network ", discloses a technique for generating a perfect random secret key between two or more transceivers, A random secret key is generated utilizing the channel impulse response (CIR) estimated based on the signal. As another example, Korean Patent Publication No. 2007-0055557, entitled " Method and Apparatus for Encrypting OTA Communication in a Wireless Communication System ", discloses a technique for encrypting symbols in the physical layer, And amplitude adjustment to transmit and transmit the symbols. As another example, Korean Patent No. 1446629, entitled " Device and method for transmitting secure data in a wireless communication system ", discloses a technique for generating a physical layer cryptographic key stream from a radio channel state and encrypting plaintext data and transmitting encrypted data. , Which utilizes the radio channel state information obtained from the received pilot signal.

However, Korean Patent Laid-Open Publication No. 2011-0073563 and Korean Patent No. 1446629 described above have basically the same limitations as those of the conventional method in terms of enhancing the security of a wireless communication channel based on encryption. Korean Unexamined Patent Publication No. 2007-0055557 also imposes phase and / or amplitude modulation on the divided symbols by further dividing the bit stream into symbols for encryption, and thus there is a limit to the applicable wireless communication systems and the like.

Korea Patent Publication No. 2011-0073563 Korea Patent Publication No. 2007-0055557 Korea Patent No. 1446629

One of the problems to be solved by the present invention is to provide a data transmission method in which data transmission security is enhanced compared to a conventional encryption-based method, and a wireless device therefor.

Another object of the present invention is to provide a data transmission method that can be used in parallel with an existing encryption-based method and a wireless device for the same.

According to an aspect of the present invention, there is provided a method for transmitting secure data in a wireless communication system, the method including: a parameter determination step of determining a plurality of parameters to be applied to division of the secure data; Dividing the secure data into T pieces of fragmented data, modulating the fragmented T pieces of fragmented data, and transmitting the fragmented T pieces of fragmented data in a beamforming manner, wherein the plurality of parameters include a prime factor p for size adjustment, (T) of pieces of fragmented data, the number (K) of pieces of necessary pieces of data, and (K-1) random variables used in the data segmentation process.

According to the embodiment of the present invention, the transmitter divides and transmits data using radio channel information between radio transceivers, and the receiver assembles and decodes the received divided data. Thus, even if the eavesdropper knows the encryption key, it is difficult to obtain information about the transmitted data, thereby enhancing security of the wireless channel such as eavesdropping.

1 is a diagram illustrating a configuration of a wireless communication system to which a wireless data transmission method according to an embodiment of the present invention can be applied.
FIG. 2A is a block diagram illustrating a configuration of a wireless terminal including both a transmission / reception module as a configuration of a wireless terminal according to an embodiment of the present invention.
FIG. 2B illustrates the configuration of the wireless terminal shown in FIG. 2A as a transmitting terminal and a receiving terminal.
3 is an example of a result of a simulation using a data transmission method according to an embodiment of the present invention in the same wireless communication environment and an error-probability comparison using an existing data transmission method.
FIG. 4 is another example of a simulation result of comparing the error-probability between the case of using the data transmission method according to the embodiment of the present invention and the case of using the existing data transmission method in the same wireless communication environment.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. However, these drawings are only an example for easily describing the content and scope of technical ideas, and thus the technical scope thereof is not limited or changed. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea based on these examples. Also, terms and words used in the present specification are terms selected in consideration of the functions in the embodiments, and the meaning of the terms may vary depending on the user, the intention or custom of the operator, and the like. Therefore, the terms used in the following embodiments are defined according to their definitions when they are specifically defined in this specification, and in the absence of a specific definition, they should be construed in a sense generally recognized by ordinary artisans.

1 is a diagram illustrating a configuration of a wireless communication system to which a wireless data transmission method according to an embodiment of the present invention can be applied. In the wireless communication system shown in FIG. 1, there is also an eavesdropper in addition to a transmitter and a receiver. The transmitting terminal, the receiving terminal, and the tapping terminal are all multi-antenna apparatuses each including a plurality of antennas. More specifically, in FIG. 1, it is assumed that the transmitting terminal has N _t antennas, the receiving terminal has N _r , and the eavesdropping terminal has N _e antennas. In this case, the radio channel information between the transmitting terminal and the receiving terminal, which is denoted by H, is composed of matrix information of the size of N _r ㅧ N _t , and radio channel information between the transmitting terminal indicated by G and the tapping terminal is N _r ㅧ N _{e is the} size of matrix information. In this wireless communication system, when the transmitting terminal transmits encrypted data to the receiving terminal through the H channel, the encrypted data may be transmitted to the wiretap terminal through the G channel due to the characteristics of the wireless channel.

2A and 2B are block diagrams illustrating a configuration of a wireless terminal according to an exemplary embodiment of the present invention. FIG. 2A illustrates a wireless terminal including both transmission and reception modules. FIG. (I.e., a wireless terminal having a transmitting module) and a receiving terminal (i.e., a wireless terminal having a receiving module). Referring to FIGS. 2A and 2B, the wireless terminal 100 includes a transmission module 110 and a reception module 120. The transmitting module 110 includes a parameter determining unit 112, a data dividing unit 114, a data mapping unit 116, and a data transmitting unit 118, And the reception module 120 includes a data receiving unit 122 and a data integrating unit 124. [

The parameter determination unit 112 performs a function of setting or determining a variable value used for dividing data to be transmitted through the transmission module 110. More specifically, the parameter determination unit 112 determines the number of pieces of data to be transmitted, that is, the fractional value (p) for size adjustment, which is an arbitrary decimal value necessary for adjusting the size of the divided data, (K) pieces of pieces of fragment data necessary for the receiving terminal to succeed in decoding among T pieces of piece data, and (K-1) arbitrary random variables used in the data dividing process are determined .

The parameter determination unit 112 may determine the variables to be used in the partitioning based on the values specified by the system or the user and / Or a random variable. However, among the above parameters, the decimal value p for size adjustment should be shared by the promising pattern between the transmitting terminal and the receiving terminal.

First, the total number T of pieces of piece data and the number K of pieces of pieces of necessary pieces of data are variables influenced by the radio channel environment. More specifically, T and K may be influenced by the number of antennas of each of the transmission / reception terminals, the number of independent frequencies that can be used in transmission, the correlation of wireless channels by antennas, Value or any value. For example, the maximum value of the number (T) of all fragment data should be equal to or smaller than the rank value in the multi-antenna environment. In one example, if the correlation is zero, the rank value may be determined as min (N _t , N _r ). The total number of pieces of piece data T is a variable determined according to channel information that can be used independently between a transmitting terminal and a receiving terminal of the wireless communication system and can be used independently between a transmitting terminal and a receiving terminal in a wireless communication system. Is less than or equal to the number of frequencies (P). It is also clear that the value of the number of pieces of necessary piece data K is also smaller than or equal to the total number of pieces of piece data T.

The data division unit 114 divides the data to be transmitted into T data by using the variable values determined by the parameter determination unit 112. In the present specification, one pieces of piece data constituting T pieces will also be referred to as a share. The i (i? T) th share (S _i ) can be obtained through a formula of a polynomial function as shown in the following Equation (1).

Here, variables a ₁ to a _K-1 correspond to (T-1) random variables arbitrarily generated by the parameter determination unit 112, a ₀ denotes data to be transmitted, i.e., secret data do. The variable p is also an arbitrary decimal value determined by the parameter determination unit 112 and is a value previously shared with the receiving terminal as described above. In Equation (1), 'mod' denotes a modulo operation.

The polynomial operation as expressed by Equation (1) can be variously defined according to the variable value determined by the parameter determination unit 112, for example, as illustrated in the following Equation (2).

The data mapping unit 116 performs a modulation process on the shares S _i to S _T generated by the data division unit 114. The data transmission unit 118 transmits the modulated data to the receiving terminal through beamforming previously set between the transmitting and receiving terminals. The process of transmitting data between the transmitting terminal and the receiving terminal through the above process is expressed by Equation (3).

Where H is a vector representing a radio channel between a transmitting terminal and a receiving terminal, V is a beamforming vector, x is a modulated shareer Information, and n denotes a noise vector. If multiple non-multi-antenna frequencies are used, then the modulated share information for each frequency is mapped to 1: 1.

Referring to FIGS. 2A and 2B, the data receiver 122 estimates shared beam information modulated through reception beamforming and filtering using the received y value. The data combining unit 124 reconstructs data transmitted from the transmitting terminal, for example, secret data using the estimated share information. For example, the data combining unit 124 may calculate the Lagrangian interpolating polynomial as shown in Equation (4) to recover the security data. It is obvious that Equation (4) can be changed according to the polynomial function represented by Equation (1).

For example, suppose that the value of shareer estimated by the data receiving unit 122 is S ₂ = 1942, S ₄ = 3402, and S ₅ = 4144. In this case, the data combining unit 124 obtains 1234 + 16i + 94i ² by applying the estimated S ₂ , S _4, and S ₅ to the equation (5) to develop the polynomial equation.

As described above, according to the embodiment of the present invention, the transmitting terminal divides data (for example, security data) to be transmitted into T pieces and transmits the divided data. Even if only K pieces of T pieces of piece data transmitted from the receiving terminal are received It is possible to restore the data.

3 is an example of a result of a simulation using a data transmission method according to an embodiment of the present invention in the same wireless communication environment and an error-probability comparison using an existing data transmission method. If the error probability is low in this simulation, it indicates that the reception ratio at the reception terminal or the wiretap terminal is good, and if the error probability is high, the reception rate at the reception terminal or the wiretap terminal is poor. Therefore, for superior transmission security, it is desirable that the error-probability is low in the receiving terminal and the error-probability is high in the wiretap terminal. The wireless communication environment used in this simulation is as follows.

- Channel environment: Rayleigh flat fading channel

(N _t ) = 8, the number of antennas of the receiving terminal (N _r ) = 8, the number of antennas of the wiretap terminal (N _e ) = 8

- Modulation method: Quadrature Amplitude Modulation (QAM)

- Parameter for data partitioning: One piece of security data is divided into 8 partitions and transmitted (total number of piece data (T) = 8, number of necessary piece data (K) = 4)

- Existing data transmission method to be compared: Spatial Multiplexing (SM) method generates 8 security data and transmits it at the same time and transmits one security data by diversity method

Referring to FIG. 3, among the existing methods to be compared, when the security data is transmitted using the SM technique, the error probability of the eavesdropping terminal (SM-8-QAM (eavesdropper) -8-QAM (receiver)) error-probability is also high. This means that not only the receiving terminal but also the eavesdropping terminal are in an unreceivable state in which they can not receive security data. When the security data is transmitted using the diversity technique, it is known that the error probability of both the receiving terminal (Diversity-8-QAM (receiver) and the diversity-8-QAM (eavesdropper) This means that the security data is well received by the receiving terminal as well as the wiretap terminal, which means that eavesdropping can be performed easily. Therefore, it can be seen that the conventional data transmission method has a certain limit.

On the other hand, in the case of transmitting the security data using the method according to the embodiment of the present invention, the error probability of the receiving terminal (Sharing-8, 4 QAM (receiver) QAM (eavesdropper)) error-probability is high. This means that in the case of the receiving terminal, the reception rate for the security data is high and the data reception is smooth, whereas in the case of the wiretap terminal, the wiretapping is not performed well because the security data is not received well. Therefore, when using the data transmission method according to the embodiment of the present invention, it can be seen that the wireless data transmission efficiency is excellent as well as the data transmission security as compared with the existing data transmission method.

FIG. 4 is another example of a simulation result of comparing the error-probability between the case of using the data transmission method according to the embodiment of the present invention and the case of using the existing data transmission method in the same wireless communication environment. 4 differs from the simulation result (K = 4) shown in FIG. 3 in that the number of required pieces of data (K) = 5 and the remaining wireless communication environment is completely the same as that in FIG. 3 Do.

Referring to FIG. 4, in the case of transmitting security data using existing methods (SM-8-QAM (receiver) and SM-8-QAM (eavesdropper)) and diversity technique (Diversity-8-QAM (receiver) and diversity-8-QAM (eavesdropper)) have the same limitations as those described with reference to FIG. 3, while the method of transmitting data according to the present invention (Sharing-8, 4-QAM (receiver) and Sharing-8, 4-QAM (eavesdropper)) are superior in wireless data transmission efficiency and data transmission security. In contrast to FIG. 3, it can be seen that the error probability of the receiving terminal increases as the number K of required pieces of data increases, but the error probability of the terminal also increases.

3 and FIG. 4, it can be seen that the important parameter for determining the eavesdropping prevention rate and the reception ratio by the receiving terminal is the number (K) of necessary piece data in the embodiment of the present invention . Therefore, when the data transmission method according to the embodiment of the present invention is used, the desired reception ratio and the eavesdropping prevention ratio can be obtained by appropriately setting or adjusting the number K of pieces of necessary pieces of data.

As described above, according to the embodiment of the present invention, the transmitting terminal divides the security data into a predetermined number by applying a pre-shared prime number (p) between the transmitting and receiving terminals, And restores the secret data by assembling. Therefore, according to the embodiment of the present invention, even if the encryption key is leaked, the data can be protected in the physical layer through the process of dividing and assembling the data. Also, compared with the conventional transmission method, the receiving terminal can receive the security data with a high reception ratio, and the eavesdropping rate of the eavesdropping terminal can be lowered, as well as the user can select the desired reception ratio and the eavesdropping rate by adjusting the parameter value . In addition, if fragments data (share) is not eavesdropped more than the number K of pieces of fragment data set, the eavesdropper terminal can not receive and decrypt the secure data, so that security is enhanced.

The above description is only an example and should not be construed as being limited thereto. It is to be understood that the technical spirit of the present invention should be defined only by the invention disclosed in the claims, and all technical ideas within the scope of equivalents thereof should be construed as being included in the scope of the present invention. Therefore, it is apparent to those skilled in the art that the above-described embodiments can be modified and implemented in various forms.

110: Transmission module
112:
114:
116: Data mapping unit
118: Data transfer unit
120: receiving module
122:
124:

Claims (1)

A method for transmitting secure data in a wireless communication system,
A parameter determination step of determining a plurality of parameters to be applied to the division of the secure data;
Dividing the secure data into T pieces of piece data based on the determined parameters; And
Modulating the fragmented T pieces of fragmented data and transmitting the fragmented T pieces of fragmented data in a beamforming manner,
The plurality of parameters includes a prime factor p for scaling, a number T of pieces of fragment data, a number K of pieces of necessary pieces of data, and (K-1) random variables used in the data segmentation process .

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