CN104467922A - Information leakage prevention device - Google Patents
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- CN104467922A CN104467922A CN201410829258.2A CN201410829258A CN104467922A CN 104467922 A CN104467922 A CN 104467922A CN 201410829258 A CN201410829258 A CN 201410829258A CN 104467922 A CN104467922 A CN 104467922A
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Abstract
The invention provides an information leakage prevention device, and belongs to the technical field of information safety. The information leakage prevention device comprises a noise generation device. The noise generation device is used for generating white noise. The white noise is coupled to a power line through a coupler. According to the information leakage prevention device, a broadband power filter is adopted and used for filtering out useful information loaded on the power line of an electric device, meanwhile, a broadband white noise source is additionally arranged to interfere with the space radiation information, and information shielding between the line and the space is achieved; a triode is adopted to break down a circuit of the white noise source, the white noise source is changed into a medium-power white noise signal after being amplified and then is filtered through a low-pass filter, and the white noise of a certain bandwidth is generated; the radiation signal of the electric device can be disturbed effectively, and normal operation of other devices is not affected. The information leakage prevention device is simple in structure, small in size and capable of solving the problem of information leakage caused by electromagnetic radiation signals of the electric device effectively through a test.
Description
Technical field
The present invention relates to a kind of Tempest device, particularly relate to a kind of anti-power line leakage of information device, belong to field of information security technology.
Background technology
Along with the high speed development of social informatization, electronic message unit is constantly progress also, thus meets the needs that in people's daily life, information is interconnected.But electronic message unit is while information exchange, all to produce certain electromagnetic radiation, thus cause two kinds of results: the leakage of electromagnetic mutual interference and installation electromagnetical information, wherein electromagnetic mutual interference problem is the problem of people's extensive concern, the time that it is found relatively early, electromagnetic compatibility (EMC) technology produces for solving electromagnetic mutual interference problem, there now have been the Theory and technology basis of comparative maturity.The problem of electromagnetic information leakage was just taken seriously and concern in nearly decades, and compared with electromagnetic mutual interference problem, electromagnetic information leakage treatment technology more lays particular emphasis on information security field, and it causes serious threat to the security work of information.
Although electromagnetic information leakage protection is with detection technique and electromagnetic compatibility technology all based on electromagnetic radiation problem, and it exists difference with general electromagnetic compatibility technology again.Electromagnetic information leakage protection and detection technique are compared with general electromagnetic compatibility problem, it more lays particular emphasis on the weak electromagnetic wave radiation of electronic information technology equipment and the leakage of information caused, and general electromagnetic compatibility problem focuses on the microwave radiation at work of electronic equipment and the interference to other electronic equipment, it is indifferent to the information entrained by electromagnetic wave.In addition, process electromagnetic information leakage protection and more require that there is professional detection and testing equipment with test problems than electromagnetic compatibility problem.Further, electromagnetic information leakage protection will follow TEMPEST standard with detection.In a word, electromagnetic information leakage protection and detection technique are compared with the electromagnetic interference problem of electronic equipment, and its technical requirement is higher, electromagnetic environment is more complicated, testing standard is stricter.
Along with the development of the Internet, computer has become a part indispensable in people's life.But computer, can constantly to a large amount of electromagnetic wave signal of radiation in space during its work as the equipment of a kind of information processing and exchange.This electromagnetic wave signal given off likely carries the important information that computer is processing, thus brings huge hidden danger to information security issue.At work, its mainboard, display and all kinds of interface data wire, cable etc. all can launch intensity electromagnetic radiation in various degree to computer.From the angle of electromagnetic radiation theory, these useful informations given off all may be received and reduce.
For relating computer, it is same radiated electromagnetic wave at work, and security information wherein is just likely received thus decodes, the leakage of this mode, has walked around the fire compartment wall of computer and hardware isolated in interior a series of safeguard procedures.In this case, even if computer is not connected with any miscellaneous equipment the data that can be stolen too, so be not difficult to block passage of divulging a secret through the computer of special electromagnetic information safety and Protection.In general, the primary radiation source of computer concentrates on cable part, if its cable can not provide effective shielding or filtering, the radiation intensity of its electromagnetic leakage will strengthen greatly.
Summary of the invention
For overcoming the shortcoming existed in prior art, goal of the invention of the present invention is to provide a kind of Tempest device, the leakage of information that this device can effectively prevent power line radiation and cause.
For realizing described goal of the invention, the invention provides a kind of Tempest device, it comprises noise-producing equipment, and described noise-producing equipment is for generation of white noise, and described white noise is coupled on power line by coupler.
Preferably, Tempest device also comprises power-supply filter, and described power-supply filter is power line carrier wave information on filter out power line.
Preferably, Tempest device also comprises AC/DC amplifier, and described AC/DC amplifier for taking out part AC power from power line, and is converted to DC power supply.
Preferably, Tempest device also comprises amplifier, the white noise information that described amplifier produces for amplifying noise-producing equipment.
Preferably, Tempest device also comprises low pass filter, and described low pass filter is used for carrying out filtering to the white noise information that amplifier amplifies.
Preferably, Tempest device also comprises working state monitoring and display unit, and described working state monitoring and display unit for monitoring operating current and the operating time of Tempest device, and show.
Preferably, the stopband operating frequency range of power-supply filter is 150KHz to 400MHz.
Preferably, the cut-off frequency of low pass filter is 300MHz.
Preferably, described coupler is capacity coupler or inductive coupler.
Compared with prior art, Tempest device provided by the invention can effectively prevent power line radiation and the leakage of information caused.
Accompanying drawing explanation
Fig. 1 is the composition frame chart that the invention provides Tempest device;
Fig. 2 is the circuit diagram of noise generating device provided by the invention;
Fig. 3 is the composition frame chart of working state monitoring provided by the invention and display unit;
Fig. 4 is the circuit diagram of amplifier provided by the invention;
Fig. 5 is the circuit diagram of working state monitoring circuit provided by the invention;
Fig. 6 is the circuit diagram of low pass filter provided by the invention.
Embodiment
The present invention is described in detail below in conjunction with accompanying drawing.
Fig. 1 is the composition frame chart that the invention provides Tempest device.As shown in Figure 1, Tempest device provided by the invention, comprise power-supply filter, AC/DC transducer, noise-producing equipment, amplifier, low pass filter and working state monitoring and display unit, described power-supply filter is power line carrier wave information on filter out power line, preferably, the stopband operating frequency range of power-supply filter is 150KHz to 400MHz; AC/DC transducer, for being converted into DC power supply from the taking-up AC power on power line, mainly produces+5V and+7V DC power supply, for follow-up noise-producing equipment, amplifier, operating state and display unit provide DC power supply.Described noise-producing equipment is for generation of white noise; Described amplifier produces white noise information for amplifying noise-producing equipment; Described low pass filter is used for carrying out filtering to the white noise information that amplifier amplifies, and preferably, the passband operating frequency range of low pass filter is 0MHz to 300MHz; Described white noise is coupled on power line by coupler, and described coupler is inductive coupler or capacity coupler.
Fig. 2 is the circuit diagram of noise generating device provided by the invention.As shown in Figure 2, noise generating device provided by the invention comprises low pass filter and white noise generator, described low pass filter is made up of inductance L 5, electric capacity C9, electric capacity C15 and electric capacity C16, the cathode output end of+7V direct current supply line connects the first end of described inductance L 5, second end of inductance L 5 all connects the first end of electric capacity C9, electric capacity C15 and electric capacity C16, the second end ground connection of electric capacity C9, electric capacity C15 and electric capacity C16; Second end of inductance L 5 is connected to the first end of resistance R3, and second end of resistance R3 is connected to the emitter of the transistor Q1 in white noise generator, and that is ,+7V power supply provides electric energy then to white noise generator through low pass filter filtering ripple.Described inductance L 5 exchanges logical direct current for hindering.The present invention adopts a jumbo electric capacity C9, and the mode that is in parallel of the electric capacity C15 of two low capacities and electric capacity C16 substantially increases the filtering characteristic of ripple.White noise generation device is made up of transistor Q1, the base earth of transistor Q1, and collector electrode is unsettled, and emitter connects second end of current-limiting resistance R3, is connected to the first end of coupling capacitance C17 simultaneously, namely outwards provides white noise information by coupling capacitance C17.White noise generator utilizes the breakdown characteristics of PN junction to produce wide band white noise.
Fig. 3 is the composition frame chart of working state monitoring provided by the invention and display unit.As shown in Figure 3, working state monitoring and display unit are made up of single-chip microcomputer, LCDs, clock chip, Hall element and working state monitoring circuit, can show the operating time, flow through the electric current of power-supply filter and current operating state.Described Hall element flows through the electric current of power-supply filter for monitoring, and export one with the voltage signal of current in proportion flowing through power line, be then supplied to single-chip microcomputer; If the quiescent potential of working state monitoring main circuit to amplifier judges, see that whether its DC static working point is at normal voltage range; Single-chip microcomputer mainly processes the information of Hall element output and the information of working state monitoring circuit output, and show in LCDs, clock chip is for providing current temporal information, and the temporal information that single-chip microcomputer also provides according to clock chip is in the operating time of the current date Hour Minute Second of liquid crystal display screen display and this device.
Fig. 4 is the circuit diagram of amplifier provided by the invention.As shown in Figure 4, amplifier provided by the invention comprises three grades, the white noise information that described amplifier produces for amplifying noise generator, and third stage amplifier successively dialogue noise information amplifies.First order amplifier, for amplifying the white noise signal that noise generating device produces, be supplied to second level amplifier after amplification to continue to amplify, it is made up of the first amplification chip MAR-8+ and peripheral circuit thereof, wherein, second end of the 1st pin butt coupling electric capacity C17 of the first amplification chip MAR-8+, the 2nd and 4 pin ground connection, the first end of the 3rd pin butt coupling electric capacity C18, provides drive singal through coupling capacitance C18 to second level amplifier; Power supply+5V provides suitable quiescent point to amplification chip MAR-8+ through biasing resistor R1 and inductance L 6 successively simultaneously, and electric capacity C11 and C12 plays the effect of ac short circuit ground connection.The white noise signal that second level amplifier amplifies for amplifying first order amplifier, be supplied to third level amplifier after amplification to continue to amplify, it is made up of the second amplification chip MAR-8+ and peripheral circuit thereof, wherein, second end of the 1st pin butt coupling electric capacity C18 of the second amplification chip MAR-8+, 2nd and 4 pin ground connection, the first end of the 3rd pin butt coupling electric capacity C19, provides drive singal through coupling capacitance C19 to third level amplifier; Power supply+5V provides suitable quiescent point to amplification chip MAR-8+ through biasing resistor R2 and inductance L 7 successively simultaneously, and electric capacity C13 and C14 plays the effect of ac short circuit ground connection, and electric capacity C10 is used for the ripple of filtering+5V power supply.The white noise signal that third level amplifier amplifies for amplifying second level amplifier, be supplied to rear class low pass filter after amplification and carry out filtering, it is made up of the 3rd amplification chip MAR-8+ and peripheral circuit thereof, wherein, second end of the 1st pin butt coupling electric capacity C23 of the 3rd amplification chip MAR-8+, the first end of electric capacity C23 is connected to second end of resistance R9, and the first end of resistance R9 is connected to second end of electric capacity C19; Resistance R9 is for controlling power output; 2nd and the 4 pin ground connection of the 3rd amplification chip MAR-8+, the first end of the 3rd pin butt coupling electric capacity C24, provides signal through coupling capacitance C24 to low pass filter; Power supply+5V provides suitable quiescent point to amplification chip MAR-8+ through biasing resistor R4 and inductance L 8 successively simultaneously, and electric capacity C21 and C22 plays the effect of ac short circuit ground connection, and electric capacity C20 is used for the ripple of filtering+5V power supply.
Fig. 5 is the circuit diagram of working state monitoring circuit provided by the invention.As shown in Figure 5, working state monitoring circuit provided by the invention comprises: comparator, level translator and indicating device, the quiescent operation point voltage of the every one-level of three grade of described comparator respectively in comparison amplifier and threshold values are to judge that whether every grade of amplifier operation is normal, level translator is used for providing threshold voltage, and comparative result is converted to high level or low level; Whether indicating device is used to indicate amplifier operation normal, when indicator light is bright, represents working properly, when indicator light does not work, represents that work is abnormal.Comparator comprises the first electric switch, the second electric switch, the 3rd electric switch, the 4th electric switch, the 5th electric switch and the 6th electric switch, wherein, first electric switch is made up of transistor Q4, resistance R14, resistance R16 and diode D5, the emitter of transistor Q4 is connected to power supply+5V through resistance R14, collector electrode is connected to ground through resistance R16, also be connected to the negative pole of diode D5, base stage is connected to the test side DT1 of the first order amplifier in amplifier; The positive pole of diode D5 is connected to the input of level translator, i.e. the intermediate node of resistance R7 and resistance R10; Second electric switch is made up of transistor Q5, resistance R17, resistance R21 and diode D8, the emitter of transistor Q5 is connected to power supply+5V through resistance R17, collector electrode is connected to ground through resistance R21, also be connected to the negative pole of diode D8, base stage is connected to the test side DT2 of the second level amplifier in amplifier; The positive pole of diode D8 is connected to the input of level translator, i.e. the intermediate node that is in series of resistance R7 and resistance R10; 3rd electric switch is made up of transistor Q6, resistance R18, resistance R22 and diode D9, the emitter of transistor Q6 is connected to power supply+5V through resistance R18, collector electrode is connected to ground through resistance R22, also be connected to the negative pole of diode D9, base stage is connected to the test side DT3 of the third level amplifier in amplifier; The positive pole of diode D9 is connected to the input of level translator, i.e. the intermediate node that is in series of resistance R7 and resistance R10.4th electric switch is made up of diode D1, and the negative pole of diode D1 is connected to the test side DT1 of the first order amplifier in amplifier, and positive pole is connected to the input of level translator, i.e. the intermediate node of resistance R7 and resistance R10; 5th electric switch is made up of diode D2, and the negative pole of diode D2 is connected to the test side DT2 of the second level amplifier in amplifier, and positive pole is connected to the input of level translator, i.e. the intermediate node of resistance R7 and resistance R10.6th electric switch is made up of diode D3, and the negative pole of diode D3 is connected to the test side DT3 of the third level amplifier in amplifier, and positive pole is connected to the input of level translator, i.e. the intermediate node that is in series of resistance R7 and resistance R10.
Level translator is made up of resistance R7, resistance R10, electric capacity C26, transistor Q2, resistance R5, resistance R8, resistance R11, resistance R13, transistor Q3 and resistance R6, wherein, resistance R7 and R10 is in series, and be connected between power supply+5V and ground, its intermediate node is the input of level translator, electric capacity C26 is also connected in resistance R10 two ends, for filtering ripple, to prevent misoperation.Resistance R5 and R8 is in series, and be connected between power supply+5V and ground, the emitter that its intermediate node is transistor Q2 provides a suitable quiescent point, and the collector electrode of transistor Q2 is through resistance R13 ground connection, and base stage is connected to the intermediate node that resistance R7 and R10 is in series.Transistor Q3 works on off state, and its collector electrode is connected to power supply+5V through resistance R6, grounded emitter, and base stage is connected to the collector electrode of transistor Q2 through resistance R11.
The quiescent point of amplification chip MAR-8+ is when 2.8-4V, be in normal operating conditions, when first order normal amplifier operation, the transistor Q4 being connected to DT1 is in conducting state, diode D5 is in cut-off state, diode D1 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series is unaffected, transistor Q2 is in cut-off state, the voltage at resistance R13 two ends is zero, transistor Q3 is also in cut-off state, R6 and R23 intermediate node voltage is+5V, for an input of single-chip microcomputer provides high level, simultaneously light-emitting diode D13 connects electricity and luminous, represent that first order amplifier operation is normal.When the quiescent point of the first amplifier MAR-8+ is higher than 4V, be in abnormal operating state, the diode D1 being connected to DT1 is in cut-off state, transistor Q4 is in cut-off state, diode D5 is in conducting state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact that Q4 ends and is less than+2V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that first order amplifier operation is abnormal, when the quiescent point of the first amplification chip MAR-8+ is lower than 2.8V, be in abnormal operating state, the diode D1 being connected to DT1 is in conducting state, transistor Q4 is in conducting state, diode D5 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact of D1 conducting and is less than+3.5V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that first order amplifier operation is abnormal.
When second level normal amplifier operation, the transistor Q5 being connected to DT2 is in conducting state, diode D8 is in cut-off state, diode D2 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series is unaffected, transistor Q2 is in cut-off state, the voltage at resistance R13 two ends is zero, transistor Q3 is also in cut-off state, R6 and R23 intermediate node voltage is+5V, for an input of single-chip microcomputer provides high level, simultaneously light-emitting diode D13 connects electricity and luminous, and expression second level amplifier operation is normal.When the quiescent point of the second amplification chip MAR-8+ is higher than 4V, be in abnormal operating state, the diode D2 being connected to DT2 is in cut-off state, transistor Q5 is in cut-off state, diode D8 is in conducting state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact that Q5 ends and is less than+2V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that second level amplifier operation is abnormal, when the quiescent point of the second amplification chip MAR-8+ is lower than 2.8V, be in abnormal operating state, the diode D2 being connected to DT2 is in conducting state, transistor Q5 is in conducting state, diode D8 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact of D2 conducting and is less than+3.5V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that second level amplifier operation is abnormal.
When third level normal amplifier operation, the transistor Q6 being connected to DT3 is in conducting state, diode D9 is in cut-off state, diode D3 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series is unaffected, transistor Q2 is in cut-off state, resistance R13 both end voltage is zero, transistor Q3 is also in cut-off state, R6 and R23 intermediate node voltage is+5V, for an input of single-chip microcomputer provides high level, simultaneously light-emitting diode D13 connects electricity and luminous, and expression third level amplifier operation is normal.When the quiescent point of the 3rd amplification chip MAR-8+ is higher than 4V, be in abnormal operating state, the diode D3 being connected to DT3 is in cut-off state, transistor Q6 is in cut-off state, diode D9 is in conducting state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact that Q6 ends and is less than+2V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that second level amplifier operation is abnormal, when the quiescent point of the 3rd amplification chip MAR-8+ is lower than 2.8V, be in abnormal operating state, the diode D3 being connected to DT3 is in conducting state, transistor Q6 is in conducting state, diode D9 is in cut-off state, the intermediate node voltage that resistance R7 and R10 is in series becomes by the impact of D3 conducting and is less than+3.5V, transistor Q2 is in conducting state, the voltage at resistance R13 two ends is greater than 1V, transistor Q3 is in saturation conduction state, R6 and R23 intermediate node voltage is less than 1V, for an input of single-chip microcomputer provides low level, simultaneously light-emitting diode D13 power-off and not luminous, represent that third level amplifier operation is abnormal.
Fig. 6 is the circuit diagram of low pass filter provided by the invention, as shown in Figure 6, low pass filter provided by the invention is 7 rank Chebyshev filters, is made up of inductance L 10, inductance L 11, inductance L 9, inductance L 12, electric capacity C27, electric capacity C28, electric capacity C29, electric capacity C25.Because triode punctures produced noise signal, broader bandwidth, if without restriction, probably affect other signal, so after generation noise, passed through low pass filter, make its bandwidth restriction within the specific limits, the preferred passband operating frequency range of the present invention is 0MHz to 300MHz.
Below done to elaborate to design of the present invention and example by reference to the accompanying drawings; but those skilled in the art will be appreciated that; under the prerequisite not departing from the present invention's design, any improvement of making based on the present invention and convert the content still belonged in scope.
Claims (9)
1. a Tempest device, is characterized in that, comprises noise-producing equipment, and described noise-producing equipment is for generation of white noise, and described white noise is coupled on power line by coupler.
2. Tempest device according to claim 1, is characterized in that, also comprise power-supply filter, and described power-supply filter is power line carrier wave information on filter out power line.
3. Tempest device according to claim 2, is characterized in that, also comprises AC/DC amplifier, and described AC/DC amplifier for taking out AC power from power line, and is converted to DC power supply.
4. Tempest device according to claim 3, is characterized in that, also comprise amplifier, and described amplifier produces white noise information for amplifying noise-producing equipment.
5. Tempest device according to claim 4, is characterized in that, also comprise low pass filter, and described low pass filter is used for carrying out filtering to the white noise information that amplifier amplifies.
6. Tempest device according to claim 5, is characterized in that, also comprises working state monitoring and display unit, and described working state monitoring and display unit for monitoring operating current and the operating time of Tempest device, and show.
7. Tempest device according to claim 6, is characterized in that, the stopband operating frequency range of power-supply filter is 150KHz to 400MHz.
8. Tempest device according to claim 7, is characterized in that, the band connection frequency cut-off frequency of low pass filter is 300MHz.
9. the Tempest device according to any one of claim 1-8, is characterized in that, described coupler is capacity coupler or inductive coupler.
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CN201410829258.2A CN104467922B (en) | 2014-12-29 | 2014-12-29 | Tempest device |
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CN201410829258.2A CN104467922B (en) | 2014-12-29 | 2014-12-29 | Tempest device |
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CN104467922B CN104467922B (en) | 2019-03-15 |
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CN201410829258.2A Expired - Fee Related CN104467922B (en) | 2014-12-29 | 2014-12-29 | Tempest device |
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