WO2017034112A1

WO2017034112A1 - High-speed communication system and method with enhanced security

Info

Publication number: WO2017034112A1
Application number: PCT/KR2016/001658
Authority: WO
Inventors: 이창희; 황일평; 유상화; 계명균; 안승현; 정용준; 조승래; 김종완
Original assignee: 한국과학기술원
Priority date: 2015-08-24
Filing date: 2016-02-18
Publication date: 2017-03-02

Abstract

Disclosed is a scheme of transmitting at least two or more transmission signals, in which at least two or more pure random noise signals are contained, through multiple paths, according to one embodiment of the present invention. To implement such a scheme, a complementary noise generator may be used in a high-speed communication method and system with enhanced security according to the present invention. Here, the complementary noise generator refers to an apparatus in which a total sum of summing altogether at least two or more generated noises becomes 0. Namely, the complementary noise generator can generate m noises, and the sum of the m noises becomes 0. By injecting a plurality of noises having such feature into different paths, a channel capacity of each channel is reduced, thereby making a single wiretapping difficult. In comparison, because a receiver receiving a plurality of transmission signals with injected noises receives all noise signals and then sums up the noise signals, the noises are offset, and it is possible to effectively receive the original signal (random key K) intended for transmitting by a transmitter.

Description

Security-enhanced high-speed communication system and method

The present invention relates to a high speed communication system and method with improved security.

The fundamental problem in the theory of communication is that of transmitting information between both parties without the possibility of obtaining information by a third party. For example, in the field of electronic financial transactions, it is very important to keep confidential in the communication between the parties.

In general, both parties attempting to exchange messages are known as alice and bob, while eavesdroppers who attempt to gain unauthorized access to the message are known as eves. .

Many communication techniques have been developed to solve this problem. One class of techniques relies on Eve's computational limitations that prevent Eve from performing certain mathematical operations within a reasonable time. For example, the security of RSA public key cryptography relies heavily on the computational difficulty that it is difficult to factor in very large integers. Techniques of this type are known to be "conditionally secure" or "computational secure" techniques.

One problem with conditionally secure techniques is that the reliability of the security depends on the mathematical results of the complexity theory that still remain unproven. Thus, if appropriate mathematical tools can be developed, it is not at present certain that there will be no future breakdown of such techniques using the resources of a traditional computer.

As a solution to this, there is an encryption method according to quantum key distribution. The encryption method based on the two key distribution uses the basic principle of quantum mechanics to completely secure the security regardless of the eavesdropping ability of the eavesdropper, but based on the single photon light source, the key generation rate (effective key bit / total transmission bit) is about 10 Lower than -4 and vulnerable to side channel attacks that physically attack and compromise security of communications systems.

The key generation rate can be confirmed by wyner's information theory approach. The key generation rate can be the channel capacity of the sender (alice) and the receiver (bob) minus the channel capacity of the sender (alice) and the eavesman (eve). Here, the channel capacity of the sender (alice) and the eavesdropper (eve) can be changed according to the construction method of the communication channel environment.

Therefore, in order to maximize the key generation rate to ensure perfect security, it is necessary to minimize the channel capacity of the sender (alice) and the eavesdropper (eve), the present invention is based on this.

An object of the present invention is to provide a high-speed communication system and method with improved security to build an absolute security system to block the possibility of eavesdropping by utilizing the physical characteristics inherent in the channel, unlike a security system depending on the complexity of the calculation .

The present invention is not based on a single photon light source provides a communication system and method that can increase the encryption key generation rate to the transmission rate of the existing information.

Another object of the present invention is to provide a high-speed communication system and method with improved security that can be applied or used in a variety of communication channels, including various technologies of the existing optical communication, economical and compatibility is increased.

The object of the present invention is to optimize the channel capacity between the transmitter and the receiver by utilizing the physical characteristics inherent in the channel, unlike the security system depending on the computational complexity, but to minimize the eavesdropping channel based on the information theory by minimizing the channel capacity of the eavesdropper. The present invention provides a high-speed communication system and method with improved security for establishing an absolute security system for blocking.

In order to solve the above technical problem, an optical time domain reflectometer (OTDR) with increased sensitivity provided in a security-enhanced high-speed communication system according to an embodiment of the present invention applies a first optical pulse to an optical communication line. A first light source to be applied, a coupler for dividing and outputting the first light pulse into at least two paths, an optical detector for determining a time point at which the first light pulse is applied to the optical communication line, and the first light pulse to the optical communication line A second light source for applying a second light pulse, the intensity of which is weaker than the first light pulse, to the optical communication line in response to the time point at which the first light pulse is applied; The controller may include a controller that analyzes or predicts a signal leak of the optical communication line based on the result detected by the optical receiver.

In an embodiment, the first circulator transfers the first optical pulse output from the coupler to the optical communication line, and transmits the optical signal reflected from the optical communication line to the optical receiver to the optical receiver. And a second circulator for transmitting a second light pulse output from the second light source to the optical communication line, and for transmitting an optical signal from which the second light pulse is reflected from the optical communication line to the optical receiver. It may include.

In example embodiments, the second light source and the signal are configured to control operations of the second light source and the light receiver based on a time point at which the first light pulse is applied to the optical communication line. It may further include a delay line for transmitting to the optical receiver.

In an embodiment, the first circulator and the second circulator and the optical communication line is provided between, and receives the optical pulses of different wavelengths from the first circulator and the second circulator to transmit to the optical communication line The apparatus may further include a wavelength division multiplexing filter (WDM) that separates each of the optical signals having different wavelengths reflected from the optical communication line and returns them to the first circulator and the second circulator.

The optical signal in which the second light pulse is reflected and returned from the optical communication line may be configured according to a refractive index corresponding to a point at which the second light pulse catches up with the first light pulse. The light pulse may include the reflected light signal.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention comprises the steps of generating a first key (K1) by the first communication user and transmits it to the second communication user, A second communication user generating a second key K2 and transmitting it to the first communication user, wherein the first communication user or the second communication user is based on the first key and the second key; It may include the step of obtaining.

In an embodiment, the first communication user and the second communication user are connected to each other through at least one or more communication paths, and the channel capacity between the first communication user and the second communication user is the first communication user or It may be larger than the channel capacity between the second communication user and the eavesdropper.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention, the first communication user m m transmission signal injected with each of n noises (n is a natural number of 1 or more) Transmitting to the second communication user through a communication path (m is one or more natural numbers), and acquiring the transmission signal based on a transmission signal injected with each of the n noises received by the second communication user. It may include.

In example embodiments, the sum of the n noises becomes 0, and the second communication user may obtain the transmission signal by canceling the n noises.

In example embodiments, the n noises may be generated through a complementary noise generator, and the first communication user may transmit a transmission signal injected with each of n noises (n is a natural number of 1 or more) and m communication paths (m of 1 or more). Transmitting to the second communication user through a natural number) may include modulating and distributing the signal to the m communication paths based on any one of the n noises and the transmission signal. have.

The method may further include generating the n noises, wherein generating the n noises comprises: outputting a BLS (broaden light source) having a wide wavelength band to a first arrayed waveguide grating (AWG); Distributing an optical source to the p channels (p is a natural number of n or more), and combining the n optical sources among the light sources distributed in the p channels with a beam splitter (BS) to form a reflective semiconductor an optical amplifier), and passing the output of the RSOA through a second AWG to divide the n noise.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention, the step of outputting a light source corresponding to at least two modes based on the security data and the multi-mode laser, Distributing the optical source into at least two paths based on a first WDM filter; modulating a signal transmitted from the first WDM filter based on a signal modulator; based on a signal demodulator, transmitting through an optical communication line Demodulating the decoded signal, canceling noises included in the individual modes of the demodulated signals based on the second WDM filter, and acquiring the security data.

In an embodiment, outputting a light source corresponding to at least two modes based on secure data and a multimode laser may inject an output of an amplified spontaneous emission (ASE) into the multimode laser, Suppressing the noise present in the mode.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention is the step of the security data is divided into at least two or more transmission signals, at least two or more noise each of the at least two or more transmission Injecting a signal, each of the at least two or more transmission signals in which the at least two or more noises are injected, to a receiver through a plurality of different paths, and at least two in which the at least two or more noises are received by the receiver Based on the above transmission signal, it may include the step of obtaining the security data.

In example embodiments, the sum of the at least two noises may be zero, and the receiver may cancel the at least two noises to obtain the security data.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention provides a first communication user through a single path through a signal in which the noise of some of the plurality of complementary noise is injected Transmitting to the second communication user, storing the remainder of the plurality of noises through another path, the second communication user modulating the received signal to generate a transmission signal, and transmitting the transmission signal through the single path. Transmitting to the first communication user, and acquiring the transmission signal based on the modulated signal received by the first communication user from the second communication user and the stored residual noise.

The acquiring of the transmission signal by the first communication user based on the modulated signal returned from the second communication user and the stored residual noise may be performed by the first communication user by the second communication user. Summing the modulated signal returned from the stored signal with the remaining noise to cancel the plurality of complementary noises, and obtaining the transmission signal.

In an embodiment, the first communication user and the second communication user may secretly share an encryption key used for modulation and demodulation of a signal.

In an embodiment, the length of the other path may be twice the length of the single path.

In order to solve the above technical problem, a security-enhanced high-speed communication method according to another embodiment of the present invention is based on at least two signal transmitter and source noise of each of the first communication user or the second communication user, the noise Modulating a signal at a source, each of the first or second communication user transmitting the modulated signal to another user through at least one or more paths, and each of the first or second communication user Suppressing noise included in the received signal and compensating for distortion of the signal, wherein the at least one path includes at least one of an optical communication line, a wireless communication channel, and a wired communication channel in which bidirectional communication is implemented. It may include.

The effects of the improved high speed communication method and system according to the present invention will be described.

According to an embodiment of the present invention, unlike a security system that depends on computational complexity, an absolute security system that blocks the possibility of eavesdropping by using physical characteristics inherent in the channel may be constructed.

In addition, according to at least one of the embodiments of the present invention, since it is not based on a single photon light source, it is possible to increase the encryption key generation rate to the transmission rate of information.

In addition, according to at least one of the embodiments of the present invention, it can be applied to or used in various communication channels including various technologies of the existing optical communication, it is possible to increase the economics and compatibility.

1 is a diagram illustrating a system capable of detecting the presence of an eavesdropper with high sensitivity.

FIG. 2 is a diagram illustrating a known optical time domain reflectometer (OTDR).

3 is a diagram illustrating a high sensitivity OTDR included in an embodiment of the present invention.

4 is a diagram illustrating an operation method of a high sensitivity OTDR included in an embodiment of the present invention in detail.

5 is a diagram illustrating in detail the high-sensitivity OTDR included in an embodiment of the present invention.

6 is a diagram illustrating a method of making eavesdropping difficult using a communication algorithm included in an embodiment of the present invention.

FIG. 7 is a diagram illustrating a method of physically making eavesdropping using source noise included in an embodiment of the present invention.

8 is a diagram illustrating an example of generating complementary noise included in an embodiment of the present invention.

9 is a diagram illustrating an example of generating the complementary noise of FIG. 8 by actual experiment.

10 and 11 are diagrams showing states before and after applying to the RSOA described with reference to FIG. 9.

FIG. 12 is a diagram illustrating a result of calculating a maximum channel capacity of a target receiver and an eavesdropper based on noise according to an embodiment of the present invention.

FIG. 13 is a diagram illustrating an example in which a multipath security system according to an embodiment of the present invention is applied in optical communication.

14 is a diagram illustrating an example of applying a multipath security system using noise according to an embodiment of the present invention.

15 is a diagram illustrating an example in which a single-path security system using noise is applied according to an embodiment of the present invention.

16 is a diagram illustrating an example of a bidirectional multipath security system according to an embodiment of the present invention.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, and the same or similar components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other. In addition, in describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted. In addition, the accompanying drawings are intended to facilitate understanding of the embodiments disclosed herein, but are not limited to the technical spirit disclosed herein by the accompanying drawings, all changes included in the spirit and scope of the present invention. It should be understood to include equivalents and substitutes.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this application, the terms "comprises" or "having" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It is apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention.

According to an embodiment of the present invention, there is provided a system for limiting the amount of information obtained by the eavesdropper by sensitively detecting a leak of a signal, a system for limiting the eavesdropping location and the amount of information obtained by a single eavesdropper through bidirectional communication on a single communication line, and Minimizes the possibility of eavesdropping by combining at least one or two or more of the three concepts according to a multiple-input multiple-output (MIMO) system using path complexity and source noise of the signal source Can enhance security.

Referring to FIG. 1, after injecting a pulse of light into an optical communication line, a part of the light injected by the pulse may be reflected by interaction with particles of the line in the optical communication line. The reflected light can be returned to the transmitter (rayleigh scattering), and when the amount of light returned is observed over time, the leakage of the optical signal at a specific point can be confirmed. More details will be described with reference to FIG. 2.

Referring to FIG. 2, the OTDR includes a light source 201, a coupler 202, a photo detector 203, a delay line 204, a circulator 205, an optical communication line 206, an optical receiver 208, and a controller ( 209) and the like.

First, the light source 201 may inject light into the optical communication line 206 in the form of a pulse.

The coupler 202 divides the light pulse output from the light source 201 into at least two paths, transfers one light pulse of the divided light pulses to the optical communication line 206, and transmits the remaining light pulses to the light. May be delivered to the detector 203.

The photodetector (PD) 203 receives the light pulses transmitted from the coupler 202 to confirm when the light pulses are injected into the optical communication line 206.

The delay line 204 checks the time point at which the optical pulse is injected into the optical communication line 206 through the optical detector 203 and effectively detects the signal reflected back from the optical communication line 206. 208 serves to control.

The circulator 205 is a device for controlling the path of the optical pulse. The circulator 205 transmits the optical pulse transmitted from the coupler 202 to the optical communication line 206 and returns the optical signal reflected from the optical communication line 206 and returned. May be delivered to the photo detector 208.

The optical fiber 206 is a path for transmitting an optical signal, and becomes an object to be monitored by the OTDR system. Here, the optical communication line 206 may include impurities or impurity 207 in the optical communication fiber (communication line).

The photo detector 208 (Avalanche photo-diode (APD)) performs a function of detecting an optical signal reflected from the optical communication line 206 and returned to the controller 209.

The processor 209 may analyze a state of the optical communication line 206, that is, a leak of a signal, based on the result detected by the photo detector 208.

3 is a diagram illustrating a high sensitivity OTDR included in an embodiment of the present invention. Where n represents the refractive index, which is a factor determining the speed of light movement in the medium. N0 represents an initial refractive index corresponding to no action, n2 represents a change rate of the refractive index of the optical fiber which is nonlinearly changed in proportion to the light intensity, and I represents the light passing through the optical fiber (optical communication line). Indicates the intensity of the pulse.

When a very strong light pulse of several mW or more passes through the optical fiber 301 (optical communication line), at the point where the optical pulse 302 is present, the refractive index of the optical fiber 301 is temporarily changed according to the equation shown below in FIG. Will change. Specifically, when a strong light pulse 302 of several mW or more passes through the optical fiber 301, the refractive index is increased. When the light passes through the medium, the reflection of the light increases at a point where the value of the refractive index changes momentarily greatly.

Referring to FIG. 4, the optical fiber core 401 is a path through which the

optical pulses

402, 403, 404, 405 pass, and the strong optical pulse 402 is the optical fiber 401 at the point where it is present. The light intensity is strong enough to increase the refractive index of the signal. The weak light pulse 403 is a light pulse whose light intensity is weaker than the strong light pulse 402, and is faster than the strong light pulse 402.

The reflected wave 404 of the strong light pulse represents an optical signal in which a portion of the strong light pulse 402 interacts with the optical fiber 401 (rayleigh scattering), and then returns to the transmitting end after being reflected. The reflected wave 405 represents an optical signal in which a part of the weak light pulse 403 is reflected and returned to the transmitting end.

In more detail, OTDR included in the present invention, an optical pulse 402 that is strong enough to affect the refractive index of the optical fiber is transmitted before the weaker optical pulse 403, and then the strong optical pulse 402 is transmitted. Transmit the following weak light pulse 403. In this case, since the strong light pulse 402 is slower than the weak light pulse 403, the weak light pulse 403 catches up with the strong light pulse, and the optical fiber 401 at the point where the strong light pulse 402 is present. Since the refractive index increases as described above, the reflection of the weak light pulse 403 reaching the point, that is, the weak light pulse 403 at the moment of catching up with the strong light pulse 402, easily occurs. Since the optical signal generated and returned to the transmitter is generally larger than the size of the optical signal reflected and returned to the transmitter, an embodiment of the present invention can detect a physical change of a corresponding channel more sensitively.

In the known OTDR, only one strong light pulse is injected into an optical fiber to identify a communication line once. Part of the light pulse is reflected by interaction with the optical fiber and is returned to the transmitting end injecting the light pulse. The pulse power of the reflected light signal is only about 0.001%.

However, in the case of the OTDR included in the embodiment of the present invention, a point at which the refractive index is increased due to the strong light pulse 402 occurs, and the weak light pulse 403 following the strong light pulse 402 at the point is generated. It can be greatly reflected. Since the reflectance at this time is increased than the known OTDR, the amount of the returned optical signal is also increased. Through the returned optical signal, the OTDR included in the embodiment of the present invention is used for the signal leakage in the communication line. The state can be detected sensitively.

Referring to FIG. 5, the high sensitivity OTDR includes a first light source 501, a coupler 502, a photo detector 503,

delay lines

504a, 504b, 504c, a first circulator 505, and a second light source 506. ), A second circulator 507, a wavelength division multiplexing filter 508, an optical communication line 512,

optical receivers

514a and 514b, a controller 515, and the like.

First, the first light source 501 may inject light into the optical communication line 512 in the form of a pulse. The first light source 501 may output a light pulse 509 stronger than the second light source 506.

The coupler 502 divides the light pulse output from the first light source 501 into at least two paths, and divides one light pulse among the divided light pulses through the first circulator 505. And the remaining light pulses to the photo detector 503.

The photo detector 503 receives the optical pulse transmitted from the coupler 502 to confirm the time point at which the optical pulse is injected into the optical communication line 512.

The delay line 504 confirms the time point at which the optical pulse is injected into the optical communication line 512 through the photo detector 503, and provides a control signal at a time point suitable for the second light source 506 and the

optical receivers

514a and 514b. It serves to convey.

The first circulator 505 is a device for controlling the path of the optical pulse. The first circulator 505 transfers the optical pulse divided by the coupler 502 to the optical communication line 512 through the WDM filter 508, and the WDM filter 508. The optical signal transmitted from may be delivered to the optical receiver 514a.

The second light source 506 may output the weak light pulse 510 in response to the control signal transmitted from the delay line 504b, and the weak light pulse 510 output from the second light source 506 may be the first light source. It is a pulse following the strong light pulse 509 output from the light source 501, and is moving faster than the strong light pulse 509. FIG.

The second circulator 507 transmits the weak optical pulse 510 output from the second light source 506 to the optical communication line 512 through the WDM filter 508, and the optical signal transmitted from the WDM filter 508. May be delivered to the optical receiver 514b.

The WDM filter 508 may divide the light into different paths or combine light of various wavelengths into one path according to the light wavelength. Here, the WDM filter 508 receives optical pulses having different wavelengths from the first circulator 505 and the second circulator 507 and transmits them to the optical communication line 512. In addition, each of the optical signals having different wavelengths reflected from the optical communication line 512 may be transmitted to the first circulator 505 and the second circulator 507.

The strong light pulse 509 is a light pulse output by the first light source 501. The strong light pulse 509 temporarily changes the refractive index of the optical communication line 512 in the region in which it is present because of the intensity of the pulse. As a result, the refractive index of the point where the weak light pulse 510 catches up with the strong light pulse 509 is increased, and the probability that the light pulse is reflected in the opposite direction of the travel direction by the increased refractive index is also increased. do.

The weak light pulse 510 is a light pulse output by the second light source 506, and is then reflected 510a on the optical communication line 512 and returned to the transmitting end.

The reflected wave 509a of the strong light pulse 509 is transmitted to the optical receiver 514a through the WDM filter 508 and the first circulator 505, and the reflected wave 510a of the weak light pulse 510 is the WDM filter. 508 and the second circulator 507 may be delivered to the optical receiver 514b.

The optical communication line 512 is a path for transmitting an optical signal, and becomes an object to be monitored by the OTDR system. Here, the optical communication line 512 may include impurities or defects 513 in the optical communication fiber (communication line).

The

optical receivers

514a, 514b, and APD perform a function of detecting an optical signal reflected from the optical communication line 512 and return the detected result to the controller 515.

The controller 515 may analyze or predict a state of the optical communication line 512, that is, a leak of a signal, based on the results detected by the

optical receivers

514a and 514b. In the case of FIG. 5, since the amount of reflected light is large, the state of the optical communication line 512 can be detected more sensitively and accurately.

6 illustrates bidirectional communication. In the conventional unidirectional communication, the channel capacity of the sender (alice) and the eavesdropper (eve) may be better than the channel capacity of the sender (alice) and the receiver (bob). This is because in the case of conventional unidirectional communication, it is advantageous for the eavesdropper (eve) to obtain a signal at a location close to the sender (alice), so that the distance between the alice and the eaves is It may be shorter than the distance between the receiver (bob). In the case of such a conventional one-way communication, according to the information theory approach of wyner described above, the key generation rate that guarantees perfect security may be lowered, and thus the probability of eavesdropping by the eavesdropper may increase.

Accordingly, an embodiment of the present invention uses an algorithm K1 + K2 for generating the encryption key 640 using bidirectional communication. Accordingly, an eavesdropper (eve) who wishes to eavesdrop on two-way communication included in the present invention must necessarily eavesdrop in both directions to obtain

algorithms

611 and 621 and encryption key 640.

As such, the best location for eavesdropping in the position of a single eavesdropper who wants to eavesdrop on two-way communication is an intermediate position between the communicator users (the first communication user 610 and the second communication user 620). This is because assuming that

communicator users

610 and 620 are monitoring the eavesdropper, it would be advantageous for the eavesdropper to hide himself from the transmitting end.

In this case, compared to unidirectional communication, the location of the eavesdropper (eve) is far from the sender (alice), and the channel capacity between the

communication users

610 and 620 is the channel between the sender 610 and the eavesdropper (eve). It will be larger than the capacity. As a result, the channel capacity of the eavesdropper is limited compared to unidirectional communication.

FIG. 7 illustrates a method of transmitting at least two or more transmission signals to which at least two pure random noise signals are applied through the

multipaths

731, 732, and 73m. Complementary noise generator 712 may be used in the security-enhanced high-speed communication method and system according to the present invention to implement such a scheme. Here, the complementary noise generator 712 refers to a device in which a sum sum of all generated at least two noises is zero. That is, the complementary noise generator 712 may generate m noises, and the sum of the m noises is zero.

The present invention can inject such m noises into a plurality of transmission signals transmitted on m

different paths

731, 732, and 73m. Here, each channel in which noise is injected reduces the channel capacity due to noise, thereby making it difficult to single tap. In contrast, a receiver receiving a plurality of noise-injected transmissions receives signals for all m paths and sums them, so the noise is canceled and the original signal (random key K) the sender wishes to transmit is canceled. It can be effectively received. However, since it is not easy for an eavesdropper to receive all of a plurality of noise-injected transmission signals, the security of the communication system to which the security-enhanced high-speed communication method and system according to the present invention is applied is completely guaranteed. Can be.

Referring to FIG. 8, first, an output of a broken light source 801 (BLS) having a relatively wide wavelength band is passed through an AWG (arrayed waveguide grating) 802 to distribute the light source to each channel of the AWG 802. do.

Here, the optical sources distributed to each channel are noisy due to the beating noise. Some of these noisy sources are combined into a BS (beam splitter) 803 and injected into a reflective semiconductor optical amplifier (RSOA) 804. .

With RSOA's strong gain saturation, the amount of noise in each channel does not change much. On the other hand, the sum of total intensity is very small. That is, as shown in Fig. 8, complementary noises? 1,? 2,? 3, and? 4 are formed.

Meanwhile, the BLS 801 described above may be replaced with another light source such as an F-P LD. The AWG 802 may be any optical component for distributing an optical filter or a beam. In addition, the position of each component is not limited to the position shown in FIG. 8, and may change according to circumstances. In addition, although the number of light sources shown in FIG. 8 is four, this is for convenience of explanation and may be changed.

As described with reference to FIG. 8, only two modes of the output of the FP LD 901 oscillating in the multi-mode are separated by the band pass filter 902 and injected into the RSOA 903 to compensate for the complementary noises λ 1 and λ 2. ) Can be created.

First, FIG. 10 shows two

noises

1001 and 1002 before being injected into the RSOA and a result 1003 of the sum of the two noises. Referring to FIG. 10, before injection into the RSOA, the

noises

1001 and 1002 of each mode have low correlations with each other, and thus the noises 1003 are not significantly reduced even when the two noises are combined.

11 shows two

noises

1101 and 1102 after being injected into the RSOA and the combined result 1103. Referring to FIG. 11, after injection into the RSOA, the two

noise sources

1101 and 1102 have a strong correlation, and when the two modes are combined, the noises 1103 cancel each other out. Specifically, when the two

noise sources

1101 and 1102 are combined (1103), the noise is reduced by about 20 dB than the respective noise sources.

Referring to FIG. 12, it can be seen that the secure capacity is 3.01 bits / symbol maximum based on single polarization (difference between 1202 and 1201). If both polarizations are used, the secure capacity can be up to 6.02 bits / symbol.

Referring to FIG. 8, examples of applying the multipath security system include secure data 1301, multimode laser 1302, amplified spontaneous emission (ASE) source 1303, and a first WDM filter ( 1304, a signal modulator 1305, an optical communication line 1306, a signal demodulator 1307, a decoder, a second WDM filter 1308, a receiver 1309, and the like.

Secure data 1301 refers to information that a sender would like to secretly convey to or share with a recipient.

The multimode laser 1302 refers to a laser having a plurality of oscillation modes in a specific wavelength band. Specifically, the multimode laser 1302 may include a Fabry-Perot laser diode.

The ASE source 1303 is a light source that outputs light of a wide wavelength band, and injects the output light into the multi-mode laser 1302 to suppress noise in each mode of the multi-mode laser 1302.

The first WDM filter 1304 is an optical filter that receives light of a wide wavelength band and distributes the light in various paths according to the wavelength. Specifically, the first WDM filter 1304 may include an arrayed waveguide grating (AWG). The first WDM filter 1304 may divide the multi-mode light transmitted from the multi-mode laser 1302 into various paths according to wavelengths and distribute the multi-mode light. In this case, when the multiple modes are put together, the noise is low, but the individual modes are noisy. Therefore, the light of each path divided by the first WDM filter 1304 is the light before the first WDM filter 1304 is divided. The noise may be severe in comparison with.

The signal modulator 1305 may serve to modulate the signal transmitted from the first WDM filter 1304 in various forms.

The optical communication line 1306 is a communication line through which a signal that a sender wants to send to a receiver passes, and may include a multipath as illustrated in FIG. 13.

The signal demodulator 1307 is a device for demodulating a signal transmitted to the sender through the optical communication line 1306. The signal demodulator 1307 compensates different communication lengths for each path of the optical communication line 1306 to remove source noise due to system characteristics. You can perform such operations as.

The second WDM filter 1308 is an optical device that combines light of different short wavelength bands into one path and combines them to move in a single path. Can be. As a result, the total noise of the signal delivered to the receiver 1309 is reduced.

The receiver 1309 may be a device that receives an optical signal and reads information, or may use a coherent detection method to increase the sensitivity to the signal.

The multipath security system described with reference to FIG. 13 may be applied to the case of using a wired communication and a wireless communication channel as well as an optical communication line.

Specifically, the present invention may be applied to a multipath security system of wired communication and wireless communication, a multipath security system of wireless communication and wireless communication, and a multipath security system of wired communication and wired communication. Here, the wired communication may be an optical communication line, a communication using a copper wire, and the like, and the wireless communication may be a cellular phone network and a Wi-Fi. In particular, the mobile phone network may be a receiver / receiver. Can be used for operations required to generate cryptographic keys.

In addition, in the MIMO communication method using noise, only one path may be used for a wired network path in a multipath security system, and a beam using an antenna, which is a technology for adjusting a signal to be concentrated toward a receiver, in a wireless communication Forming (beam forming) may be usefully used.

Before being transmitted through the signal source, the security information is divided into a plurality of

transmission signals

1411 and 1412 via a signal splitter or the like, where at least two or more noises generated by the complementary noise device 1415 are injected. Each of the plurality of noise-injected transmission signals is transmitted to the receiver through a plurality of different paths 1430.

The receiver 1420 combines a plurality of noise-transmitted transmission signals received through a plurality of different paths 1430 through a signal combiner 1421 or the like.

Here, since the total of at least two or more noises generated by the complementary noise device 1415 becomes zero, the receiver 1420 may accurately acquire security information that the sender 1410 intends to transmit. Here, the laser used as the light source may be a single mode or multiple modes. In addition, the bandwidth may be so narrow that communication is impossible when only one path is used, which makes it possible to more fully defend the eavesdropper.

More specifically with reference to FIG. 14, the transmitting end 1410 includes a pure noise generator 1415 which generates complementary pure random noise, wherein each channel 1411 includes at least two noises generated therefrom. , 1412). Here, Channel 1 1411 and Channel 2 1412 are channels to which any communication signal is applied and may include all communication channels including optical communication and wireless communication. In addition, the

modulators

1413 and 1414 may include a first modulator 1413 and a second modulator 1414 provided in each channel, by using at least two or more noises transmitted from the pure noise generator 1415. It is possible to modulate the signal transmitted from each

channel

1411, 1412.

Here, by setting the modulation of the first 1413 and the second modulator 1414 to be opposite to each other, the receiving end 1420 can combine the signals of the two channels (1421) to cancel the complementary pure random noise. Thereafter, the noise-injected information is transmitted to the receiving end 1420 through a plurality of different paths, and the receiving end 1420 combines the noise-injected information 1421 to cancel the complementary noise, and the transmitting end 1410. Will correctly and correctly obtain the information to be transmitted.

As shown in FIG. 15, if one path of noise is taken by the first communication user 1510 and the two-way communication is performed using the other path, the eavesdropper cannot effectively eavesdrop because there is no way to cancel the noise. do.

In more detail with reference to FIG. 15, when the signal source 1511 generates a signal in which complementary noise is mixed, any one of the signals is transmitted through the first circulator 1514 to the second communication line 1530. The other signal is transmitted to the first communication line 1513 provided in the transmitter 1510. That is, only one signal transmitted to the second communication line 1530 is shared between the first communication user 1510 and the second communication user 1520. The second communication user 1520, which has received any one signal from the first communication user 1510 with the complementary noise signal, receives the signal using a pure random number generator (PRNG) 1522. After the modulation, the modulated signal is transmitted to the first communication user 1510, and the first communication user 1510 transmits the other signal and the second communication user 1520 to the first communication line 1513. The modulated signal returned from the C1) is combined to cancel the noise, and a signal transmitted by the second communication user 1520 is obtained.

Here, the signal source 1511 outputs a signal containing complementary noise to limit the eavesdropping of the eavesdropper, and each of the signals having the complementary noise is mixed with the first communication line 1513 and the second communication line 1530. Can be delivered to.

g (t) and g-1 (t) are encryption keys shared secretly by the first communication user 1510 and the second communication user 1520 to each other to maintain security when the signal is modulated and demodulated. Can be used.

The first communication line 1513 is a separate path from the second communication line 1530 connected to the second communication user 1520. The first communication line 1513 is internally managed by the first communication user 1510 and the first communication line. The length of 1513 should be twice the length of the second communication line 1530.

The first circulator 1514 receives the signal encrypted by g (t) and transmits the signal to the second communication line 1530, and transmits a signal transmitted through the second communication line 1530 to the controller 1519. It is an optical device.

The second communication line 1530 is a communication channel in which the first communication user 1510 and the second communication user 1520 share a signal, and the control unit 1519 uses a signal to and from the second communication line 1530. To remove the noise, the length of the first communication line 1513 should be twice the length of the second communication line 1530.

The second circulator 1521 transmits a signal transmitted through the second communication line 1530 to the modulator 1523, and transmits the signal modulated by the modulator 1523 to the second communication line 1530. Device.

The pure random number generator 1522 is a device that generates a random number that does not have any correlation and thus cannot predict the pattern. The pure random number generator 1522 makes the pattern unpredictable when the eavesdropper taps the encryption key.

The modulator 1523 is a device for modulating the signal source transmitted through the second circulator 1521, and the modulation value reflects the random number generated by the pure random number generator 1522.

The controller 1519 combines the signal transmitted to the first communication line 1513 and the signal transmitted from the second communication user 1520 through the second communication line 1530 to cancel the noise, and the second communication user 1520 ) Reads a modulated signal (for example, an encryption key) through the modulator 1523.

Referring to FIG. 16, examples of bidirectional multipath security schemes include

source noise

1611, 1621,

equalizers

1612, 1622, equalizers, signal receivers, and

processors

1613, 1623, Rx and processor.

Signal transmitters

1614, 1624, Tx, and multichannel 1630.

Source noise

1611 and 1621 may be a signal source that generates a signal with mixed noise and transmits it to

transmitters

1614 and 1624.

The

equalizers

1612 and 1622 suppress noise before the signal receivers and the

processors

1613 and 1623 receive the signal received from the other party, and physically compensate for the distortion of the signal generated while passing through the multi-channel 1630. Play a role.

Signal receivers and

processors

1613 and 1623 may be devices that receive signals from

equalizers

1612 and 1622 and process the received signals.

Each of the

transmitters

1614 and 1624 may be a device that modulates a mixed signal transmitted from the

source noises

1611 and 1621 and transmits the mixed signal to the multichannel 1630.

The multi-channel 1630 is a communication line through which the first communication user 1610 and the second communication user 1620 exchange signals, and may be various wireless communication and wired communication channels as well as an optical communication line.

Here, each channel included in the multichannel 1630 makes it difficult to distinguish a signal, and bidirectional communication is implemented. If a single eavesdropper attacked with one eavesdropper, as described above, the mixed signal would not be able to distinguish the correct signal, and in order to remove the noise, the eavesdropper would eavesdrop the signal on all paths of the multichannel. Should be.

Meanwhile, in FIG. 16, the multichannel 1630 is illustrated as two paths. However, the present invention is not limited thereto, and the multichannel 1630 may include at least one path. In addition, in FIG. 16, two

transmitters

1614 and 1624 are shown to be included in separate communication users. However, this is for convenience of description and the present invention may include at least two

transmitters

1614 and 1624. .

In addition, since each channel included in the multi-channel performs bidirectional communication, at least two eavesdroppers in each channel should be eavesdropping at the position as close to the communicator as it is easy to eavesdropping when the channel capacity is increased. You must try. That is, in the case of FIG. 16, at least four eavesdroppers attempt to eavesdrop to increase the likelihood of successful eavesdropping. However, the plurality of eavesdroppers have a hard time concealing their existence from the security system.

As described above, the high-speed communication method and system with improved security according to the present invention can be applied to different communication networks, and it is possible to make eavesdropping by eve by implementing each communication network in a different path. For example, if the first path included in the communication network is implemented as a cellular network, the second path is implemented as an optical communication network, and the third path is implemented as a Wi-Fi network, a mixture of them is transmitted to transmit information. eavesdropping becomes more difficult, and the security of the network can be more complete.

As a result, the security-enhanced high-speed communication method and system according to the present invention can block the possibility of eavesdropping by using the physical characteristics inherent in the channel, and increase the encryption key generation rate up to the transmission rate of information. It may be applied to or used in various communication channels including various technologies.

The above detailed description should not be construed as limiting in all respects but should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

Claims

In a security-enhanced high-speed communication system including an optical time domain reflectometer (OTDR) with increased sensitivity,

The optical loss meter with increased sensitivity,

A first light source for applying a first light pulse to the optical communication line;

A coupler for dividing and outputting the first optical pulse into at least two paths;

An optical detector for determining a time point at which the first optical pulse is applied to the optical communication line;

A second light source configured to apply a second light pulse having a lower intensity than the first light pulse to the optical communication line in response to the time when the first light pulse is applied to the optical communication line;

An optical receiver which receives an optical signal reflected from the optical communication line and returned; And

And a controller configured to analyze or predict a signal leak of the optical communication line based on the result detected by the optical receiver.
The method of claim 1,

A first circulator for transmitting a first optical pulse output from the coupler to the optical communication line, and transmitting an optical signal from which the first optical pulse is reflected from the optical communication line to the optical receiver; And

And a second circulator for transmitting a second optical pulse output from the second light source to the optical communication line, and transmitting an optical signal from the optical communication line to the optical receiver, in which the second optical pulse is reflected. High speed security system with improved security.
The method of claim 2,

A signal connected to the photo detector and transmitting a signal controlling the operation of the second light source and the light receiver to the second light source and the light receiver based on a time point at which the first light pulse is applied to the optical communication line. Security-enhanced high speed communication system further comprising a delay line.
The method of claim 2,

It is provided between the first circulator and the second circulator and the optical communication line, and receives optical pulses of different wavelengths from the first circulator and the second circulator to transmit to the optical communication line, in the optical communication line And a wavelength division multiplexing filter (WDM filter) for dividing each of the optical signals having different wavelengths and returning the reflected light signals to the first circulator and the second circulator.
The method of claim 2,

The optical signal that the second optical pulse is reflected back from the optical communication line,

And a light signal reflected by the second light pulse according to a refractive index corresponding to a point in time at which the second light pulse catches up with the first light pulse.
Generating, by the first communication user, the first key K1 and transmitting it to the second communication user;

Generating, by the second communication user, a second key K2 and transmitting it to the first communication user; And

Obtaining, by the first communication user or the second communication user, an encryption key based on the first key and the second key.
The method of claim 6,

The first communication user and the second communication user,

Connected to each other through at least one communication path,

Channel capacity between the first communication user and the second communication user,

And improved security greater than the channel capacity between the first communication user or the second communication user and the eavesdropper.
Transmitting, by the first communication user, the transmission signal injected with each of n noises (n is one or more natural numbers) to the second communication user through m communication paths (m is one or more natural numbers); And

And obtaining, by the second communication user, the transmission signal based on the transmission signal including each of the n noises received.
The method of claim 8,

The sum of the n noises is zero,

The second communication user,

A security enhanced security method for canceling the n noises to obtain the transmission signal.
The method of claim 8,

The n noises are generated through a complementary noise generator,

The first communication user transmits a transmission signal injected with each of n noises (n is a natural number of 1 or more) to a second communication user through m communication paths (m is a natural number of 1 or more).

And modulating the signal based on any one of the n noises and the transmission signal, and distributing the signal to the m communication paths.
The method of claim 8,

Generating the n noises,

Generating the n noises,

Distributing a light source having a broad wavelength band through a first arrayed waveguide grating (AWG) to distribute the light source into the p channels (p is a natural number of n or more);

Combining the n light sources among the light sources distributed in the p channels into a beam splitter (BS) and injecting the same into a reflective semiconductor optical amplifier (RSAA); And

And passing the output of the RSOA through a second AWG to separate the n noises.
Outputting a light source corresponding to at least two modes based on the security data and the multimode laser;

Distributing the light source into at least two paths based on a first WDM filter;

Based on a signal modulator, modulating a signal transmitted from the first WDM filter;

Based on a signal demodulator, demodulating a signal transmitted through an optical communication line;

Canceling noises included in the individual modes of the demodulated signals, based on the second WDM filter; And

Obtaining improved security data.
The method of claim 12,

Based on the security data and the multi-mode laser, outputting a light source corresponding to at least two modes,

Injecting an output of an AMP (amplified spontaneous emission) into the multimode laser, thereby suppressing noise present in the at least two or more modes.
Dividing the security data into at least two transmission signals;

Modulating at least two signals on the at least two noise sources;

Transmitting each of the at least two or more transmitted signals in which the at least two or more noises are injected to the receiver through the same or different paths; And

And obtaining, by the receiver, the secure data based on at least two transmitted signals including the at least two noises received.
The method of claim 14,

The sum of the at least two noises is zero,

The recipient,

A security enhanced high speed communication method for canceling the at least two or more noises to obtain the security data.
Transmitting, by the first communication user, a signal including the noise of some of the plurality of complementary noises to the second communication user through a single path, and storing the remaining of the plurality of noises through another path;

The second communication user modulating the received signal to generate a transmission signal, and transmitting the transmission signal to the first communication user via the single path; And

Obtaining, by the first communication user, the transmission signal based on the modulated signal returned from the second communication user and the stored residual noise.
The method of claim 16,

Acquiring the transmission signal based on the modulated signal received by the first communication user from the second communication user and the stored residual noise;

Security-enhanced high-speed communication comprising the first communication user adding the modulated signal returned from the second communication user and the stored residual noise to cancel the complementary plurality of noises and obtaining the transmission signal Way.
The method of claim 16,

The first communication user and the second communication user,

High-speed communication method with improved security for secretly sharing encryption keys used for signal modulation and demodulation.
The method of claim 16,

The length of the other path is,

A security-enhanced high-speed communication method that doubles the length of the single path.
Modulating a signal to noises based on at least two signal transmitters and source noise by each of the first communication user or the second communication user;

Transmitting each of the first communication user and the second communication user to another user through at least one path; And

Suppressing noise included in the received signal by each of the first communication user or the second communication user, and compensating for distortion of the signal;

The at least one route is,

A security enhanced high speed communication method comprising at least one communication network of an optical communication line, a wireless communication channel, and a wired communication channel for implementing bidirectional communication.