ETSI GS QKD 003-2010 Quantum Key Distribution (QKD) Components and Internal Interfaces (V1 1 1)《量子密钥分配(QKD) 部件和内部接口(版本1 1 1)》.pdf

1、 ETSI GS QKD 003 V1.1.1 (2010-12)Group Specification Quantum Key Distribution (QKD);Components and Internal InterfacesDisclaimer This document has been produced and approved by the Quantum Key Distribution (QKD) ETSI Industry Specification Group (ISG) and represents the views of those members who pa

2、rticipated in this ISG. It does not necessarily represent the views of the entire ETSI membership. ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 2Reference DGS/QKD-0003_CompInternInterf Keywords interface, Quantum Key Distribution ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33

3、 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N 348 623 562 00017 - NAF 742 C Association but non lucratif enregistre la Sous-Prfecture de Grasse (06) N 7803/88 Important notice Individual copies of the present document can be downloaded from: http:/www.etsi.org The present document may be made availa

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7、ll media. European Telecommunications Standards Institute 2010. All rights reserved. DECTTM, PLUGTESTSTM, UMTSTM, TIPHONTM, the TIPHON logo and the ETSI logo are Trade Marks of ETSI registered for the benefit of its Members. 3GPPTM is a Trade Mark of ETSI registered for the benefit of its Members an

8、d of the 3GPP Organizational Partners. LTE is a Trade Mark of ETSI currently being registered for the benefit of its Members and of the 3GPP Organizational Partners. GSM and the GSM logo are Trade Marks registered and owned by the GSM Association. ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 3Contents Inte

9、llectual Property Rights 4g3Foreword . 4g31 Scope 5g32 References 5g32.1 Normative references . 5g32.2 Informative references 5g33 Definitions and abbreviations . 6g33.1 Definitions 6g33.2 Abbreviations . 6g34 QKD System Components . 7g34.1 Generic Description 7g34.2 Weak Laser Pulse QKD . 7g34.2.1

10、One-Way Mach-Zehnder Implementation 8g34.2.2 Send and Return Mach Zehnder Implementation . 9g34.2.3 Phase-Intensity Modulator Implementation 10g34.3 Entanglement-based QKD 10g34.4 Continuous-Variable QKD . 11g34.4.1 Principle of Continuous-Variable QKD Protocols 11g34.4.2 Implementation Example of t

11、he CV QKD protocol. 11g35 Photon Detector 12g35.1 Single-Photon Detector 12g35.1.1 Generic Description and Parameterisation 12g35.1.2 Test Measurements . 15g35.1.3 InGaAs Avalanche Photodiodes . 17g35.2 Photon Detector for a CV-QKD Set-up 19g35.2.1 Coherent Detection . 19g35.2.2 Multiplexing . 20g35

12、.2.3 Homodyne Detection 20g35.2.4 Heterodyne Detection . 20g36 QKD Source . 20g36.1 Generic Description and Parameterisation . 20g36.2 Test Measurements . 22g36.3 Single-Photon Sources . 24g36.4 Weak Pulses . 25g36.4.1 Weak Laser . 25g36.4.2 Intensity-Modulated Weak Laser 26g36.4.3 Composite Weak La

13、ser . 27g36.5 Continuous-Variable QKD Source . 27g37 Modulators . 28g3History 30g3ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 4Intellectual Property Rights IPRs essential or potentially essential to the present document may have been declared to ETSI. The information pertaining to these essential IPRs, if

14、 any, is publicly available for ETSI members and non-members, and can be found in ETSI SR 000 314: “Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of ETSI standards“, which is available from the ETSI Secretariat. Latest updates are availabl

15、e on the ETSI Web server (http:/webapp.etsi.org/IPR/home.asp). Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web server

16、) which are, or may be, or may become, essential to the present document. Foreword This Group Specification (GS) has been produced by ETSI Industry Specification (ISG) Group Quantum Key Distribution (QKD). ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 51 Scope The present document is a preparatory action fo

17、r the definition of properties of components and internal interfaces of QKD Systems. Irrespective of the underlying technologies, there are certain devices that appear in most QKD Systems. These are e.g. quantum physical devices such as photon sources and detectors, or classical equipment such as pr

18、otocol processing computer hardware and operating systems. For these components, relevant properties must be identified that will subsequently be subject to standardisation. Furthermore, a catalogue of relevant requirements for interfaces between components must be established, to support the upcomi

19、ng definition of internal interfaces. 2 References References are either specific (identified by date of publication and/or edition number or version number) or non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the reference doc

20、ument (including any amendments) applies. Referenced documents which are not found to be publicly available in the expected location might be found at http:/docbox.etsi.org/Reference. NOTE: While any hyperlinks included in this clause were valid at the time of publication ETSI cannot guarantee their

21、 long term validity. 2.1 Normative references The following referenced documents are necessary for the application of the present document. Not applicable. 2.2 Informative references The following referenced documents are not necessary for the application of the present document but they assist the

22、user with regard to a particular subject area. i.1 J. F. Dynes et al, Opt. Express 15, 8465 (2007). i.2 N Gisin et al, Rev.Mod. Phys. 74, 145 (2002). i.3 L.Duraffourg et al, Opt. Lett 26, 18 (2001). i.4 A. Ekert, Phys. Rev. Lett. 67, 661 (1991). i.5 J. Clauser et al., Phys. Rev. Lett. 23, 880-884 (1

23、969). i.6 C. H. Bennett, G. Brassard and N. D. Mermin Phys. Rev. Lett. 68, 557 (1992). i.7 Fossier et al., New J. Phys. 11 045023 (2009. i.8 Leverrier and ii) preventing so-called Trojan horse attacks. The transmitted pulses are then reflected by a Farady mirror (FM) to compensate any birefringence

24、effects of the quantum channel. An attenuator (AT) allows reducing the intensity of the pulses to a suitably weak intensity (depending on the protocol used). A phase difference 1 is then introduced between the delayed pulses in order to encode a bit value. At the receiving unit, the pulses are separ

25、ated by the polarization splitter PS and a phase 2 is applied to one of the two pulses to implement the measurement basis choice. Single-photon detectors D1 and D2 are then used to indicate which output port was chosen by the photon. A circulator C ensures the isolation between the laser source and

26、the photon detectors. Figure 4.3: Plug and Play phase-intensity modulator system ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 104.2.3 Phase-Intensity Modulator Implementation Figure 4.4 depicted a simplified Single Sideband (SSB) system, according to L.Duraffourg et al, Opt. Lett 26, 18 (2001) i.3. The sou

27、rce S1 is an attenuated pulsed laser diode operating at optical frequency 0(quantum signal). An unbalanced integrated Mach-Zehnder modulator MZ1 modulates the intensity of the reference beam at 1 for a composite source. Second order correlation function g(2)(0) Unitless The second order correlation

28、function at zero time delay g(2)(0) quantifies the photon number statistics. g(2)(0) = 1 for a perfect coherent source, while g(2)(0) = 0 for a perfect single photon source. Wavelength nm Wavelength of photons that are emitted. Spectral linewidth Nm Bandwidth of the emitted photons by a QKD source.

29、is quantifiable using the full width at the half maximum in the emission spectrum. Timing jitter tjitterps/ns The uncertainty in the emission time of a photon at the optical output. Spectral indistinguishability sind Unitless A quantity to quantify the extent to which two qubits can be distinguished

30、 through spectral measurement. 0 sind 1. sind = 0 means a complete distinguishability between qubits, while sind = 0 means a complete indistinguishabilty. Temporal indistinguishability tind Unitless A quantity to quantify the extent to which two qubits can be distinguished through temporal measureme

31、nt. 0 tind 1. tind = 0 means a complete distinguishability between qubits, while tind = 1 means a complete indistinguishabilty. Table 6.2: Operating conditions that shall be specified for a QKD source Operating Condition Symbol Units Definition Emitter Temperature T C or K Physical temperature of th

32、e emitting element during operation. Environmental Requirement N/A N/A The environment conditions under which a detector module operates. These conditions include environmental temperature, humidity, pressure, and requirement for surrounding electromagnetic radiation. Mode of Operation N/A N/A Descr

33、ibes the condition upon which a QKD source emits an optical pulse. Two modes of operation are common: triggered and heralded. Table 6.3: Additional attributes to be specified for a single-photon detector Parameter Definition Electrical input Defines electrical input signals to the device along with

34、the type of connector used. Input signals may be used for providing a trigger signal or as a power supply. Optical output Defines the format of the optical output from the device. Often this is through SM or MM optical fibre. The fibre connector should also be specified, e.g. FC/PC. Electrical outpu

35、t Defines the format of electrical output signal from the device upon photon emission, such as ECL, TTL, NIM, etc., as well as the type of connector, e.g. BNC, SMA. This output is compulsory for a heralded QKD source. Physical dimensions The physical size of a QKD source module that is independently

36、 operational. Power consumption Power consumption is the total power that is needed to continuously operate a QKD source. Handling instructions Instructions for the safe handling of the source, such as information regarding toxicity and the presence of high voltages. 6.2 Test Measurements As discuss

37、ed above, the most important parameters to specify a light source for operation in a QKD system are the indistinguishability and photon number distribution. In this clause we describe how these shall be determined. ETSI ETSI GS QKD 003 V1.1.1 (2010-12) 23In QKD, an optical pulse is used to represent

38、 a qubit. Apart from the encoding degree of freedom, these optical qubits must be indistinguishable in all other degrees of freedom, such as wavelength, spectral width and temporal profile etc. Distinguishability in the non-encoding degree of freedom can therefore act as a side-channel, through whic

39、h an eavesdropper can gain information. In particular, for QKD systems that use a composite source, each light emitting element shall be tested to quantify distinguishability among elements. Indistinguishabilty tests shall include spectral, temporal, and other possible physical properties associated

40、 with the encoding process. Parameters, such as spectral indistinguishability sindor temporal indinguishability tind, shall be used for quantification. Spectral indistinguishability sindquantifies the extent to which two qubits can be distinguished through spectral measurements. Figure 6.2 shows pro

41、bability distributions in wavelength of a photon for two different qubits A, B. 1)()(= dpdpBA. Mathematically, sindshall be defined as: dppsBAind= )()(211 . For indistinguishable qubits, BApp and therefore sind = 1. For the opposite case, i.e., spectrally distinguishable qubits, sind= 0, because BAB

42、Apppp += . A QKD source shall be specify with sind values for all combination of a pair of different qubits. Similar to the spectral indistinguishability, temporal indistinguishability tindshall be defined. Let pA(t), and pB(t) be the probability distributions of the time for qubits A and B respecti

43、vely. .1)()(=tBtAdttpdttp Temporal indistinguishability tindshall be defined as dttptpttBAind= )()(211 . Again, tind = 1 represents temporal indistinguishabilty while tind = 0 means temporal distinguishability. Wavelength, Probability,p()Qubit A Qubit BFigure 6.2: Probability distributions in wavele

44、ngth for photons encoded with qubit A or B Photon number distribution tests shall include (1) source intensity, (2) source stability and (3) the photon number statistics. Source intensity, defined as the average number of photons per signal pulse () when leaving Alices apparatus, shall be measured o

45、ver a duration that is comparable to a QKD session. Calibrated photon detectors shall be used. In case of single-photon sources, single-photon detectors shall be used. For attenuated laser sources, source intensity shall be determined by measurement of the unattenuated laser and calibration of the a

46、ttenuation. Source stability shall be tested continuously at least for a 24-hour period under ambient conditions that are specified by the QKD system. Source intensity bounds shall be given through this test, and the worst-case scenario shall be considered in the QKD security analysis. ETSI ETSI GS

47、QKD 003 V1.1.1 (2010-12) 24Photon number statistics shall be measured using a Hanbury-Brown and Twiss setup as shown in figure 6.3. In this setup, a source under test is fed into a beam splitter with each output monitored by a single-photon detector. The photon arrival times are analyzed using a tim

48、e-interval analyser. BeamSplitterSourceSingle photon detectorSingle photon detectorAnalyzerFigure 6.3: A Hanbury-Brown and Twiss setup for measurement of the second order correlation function Figure 6.4 shows a correlation spectrum that can be obtained by the setup of figure 6.3 for a pulsed optical

49、 source. In this correlation spectrum, coincidence count rate is plotted as a function of the time interval between detection events by two single-photon detectors. For a Poissonian source, coincidence peaks at each interval should have identical height, within experimental uncertainties. By normalising the coincidence rates to the average rate at non-zero time intervals, the value for the second order correlation function is readily obtainable. As shown by the example in figure 6.6, g(2)(0), the value of th