Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Detailed Action
The objection to the abstract has been overcome due to applicant’ amendments
USC 112(b) rejection for 3, 9, 15, and 18. The rejection has been overcome due to these claims being cancelled.
Claims 1, 5, 7, 13, and 16 have been amended
Claims 2, 3, 8, 9, 14, 15, 17, and 18 have been cancelled
Claims 1, 4-7, 10-13, and 16 are pending
Priority
This application claims domestic priority to application PCT/SG2021/050408 filed on 07/13/2021 and further claims foreign priority to application SINGAPORE 10202006706W filed on 07/14/2020. All priority documents have been received. Therefore, the effective filling date of this application is 07/14/2020.
Response to Arguments
Applicant’s arguments filed on 11/18/2025 have been fully considered.
With respect to the objection to the abstract. The objection has been overcome due to applicant’s amendments.
With respect to USC 112(b) rejection for 3, 9, 15, and 18. The rejection has been overcome due to applicant cancelling these claims.
With respect to the USC 112(f) claim interpretation applicant has mentioned that the amendments overcome the interpretation. Examiner respectfully disagrees. Simply omitting “configured to” while maintaining the functional language does not overcome 112(f) claim interpretation. Examiner suggests amending the claim limitations that invoke 112(f) with a structural modifier to overcome the interpretation. Further the USC 112(b) rejection for claim 5 “time delay modules performing” invokes 112(f) and the rejection is being maintained due to the written description failing to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function.
With respect to the newly added limitation of “and wherein the energy bounding component comprises a power limiter limiting the re-transmitted modulated optical pulses to a maximum intensity during a THA”, this necessitated a new ground of rejection. Examiner is now modifying the rejection for independent claims 1, 7, 13, and 16 from a USC 102 rejection to a single reference USC 103 rejection. Applicant has argued that LI fails to teach this limitation. Applicant has stated that a power limiter outputs a fixed power/intensity and that the output power is fixed to the same maximum power/intensity. LI teaches ([LI, Section 2.1, page 2194-2195] “At Alice’s (Bob’s) device, the light pulses are filtered by an optical filter for removing unwanted optical signals. Then, part of light pulses are used to estimate the acquired photon number distribution (PND) by a beam splitter (BS3) and intensity detector (ID). This is for countering against possible Trojan-horse attack … The pulses are attenuated to single-photon level by an attenuator (Att), then pass through the polarization beam splitter and go back to Charlie. … Post-processing. Alice and Bob perform information reconciliation for error correction and privacy amplification for removing the leaked information”). The attenuator of LI is analogous to a power limiter recited in the claim. The attenuator of LI also attenuates the pulses to a fixed single-photon level. The maximum power intensity is the single photon level. Furthermore, the applicant has argued that the power limiter applies a dynamic loss depending on the input power. However, this feature is not recited in the claim language. Therefore, LI teaches all limitations of claim 1.
Additional arguments are moot in view of new grounds of rejection necessitated by the claim amendments.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
This application includes one or more claim limitations that do not use the word “means,” but are nonetheless being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because the claim limitation(s) uses a generic placeholder that is coupled with functional language without reciting sufficient structure to perform the recited function and the generic placeholder is not preceded by a structural modifier. Such claim limitations are:
“… user system receiving …” in claims 1
“… user system modulating …” in claims 1
“… user system re-transmitting …” in claims 1
“ … energy bounding component for” in claims 1 and 13
“… one or more detectors for …” in claim 4
“… time delay modules performing …” in claim 5
“… a modulator modulating …” in claim 13
“a power limiter limiting …” in claims 1 and 13
Because these claim limitation(s) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, they are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
See para. [0044, 0050, 0051, 0056] for functional support for “user system … receiving …modulating … re-transmitting”
See para. [0064 and 0065] for hardware support for “user system”
See para. [0024, 0045] for functional support for “energy bounding component”
See para. [0029, 0040] for hardware support for “energy bounding component”
See para. [0040, 0052] for functional support for “power limiter limiting”
See para. [0040] for hardware support for “power limiter”
See para. [0033, 0037, 0048, 0054] for functional support for “time delay modules”
See para. [0041, 0056] for functional support for “a modulator modulating”
See para. [0032, 0041] for hardware support for “a modulator”
If applicant does not intend to have these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claims 1, 7, 13, and 16 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claims contain subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention. These claims recite the limitation of “wherein the energy bounding component comprises a power limiter limiting the re-transmitted modulated optical pulses to a maximum intensity during a THA”. The claim limitation clearly recites that during a Trojan Horse attack a power limiter limits the re-transmitted modulated optical pulses to a maximum intensity. However, the specification of the current application recites in para. 0040 “a passive power limiter may be used at the user systems Alice/Bob, in a modified plug-and-play system 200 shown in FIG. 2, and hence the maximum input power is limited. Thus the maximum intensity of the reflected/re-transmitted light from Alice/Bob to Charlie can also be bounded, to limit THA”. The specification outlines limiting THA by bounding the maximum intensity reflected/re-transmitted light. The specification does not describe or provide support for power limiter limiting the re-transmitted modulated optical pulses to a maximum intensity during a THA. The specification provides support for limiting THA but not of limiting the re-transmitted modulated optical pulses specifically during a THA. Examiner suggests amending the claim language to be consistent with the support in the specification. Appropriate correction is required.
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claim 16 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 16 recites the limitation " the energy bounding component comprises". There is insufficient antecedent basis for this limitation in the claim. For the purpose of examination examiner is interpreting this limitation as “the energy bounding comprises …”. Appropriate correction is required.
Claim limitation “time delay modules performing” in claim 5 invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. However, the written description fails to disclose the corresponding structure, material, or acts for performing the entire claimed function and to clearly link the structure, material, or acts to the function. The specification does not describe of any hardware support to implement the time delay modules. Therefore, the claim is indefinite and is rejected under 35 U.S.C. 112(b) or pre-AIA 35 U.S.C. 112, second paragraph.
Applicant may:
(a) Amend the claim so that the claim limitation will no longer be interpreted as a limitation under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph;
(b) Amend the written description of the specification such that it expressly recites what structure, material, or acts perform the entire claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(c) Amend the written description of the specification such that it clearly links the structure, material, or acts disclosed therein to the function recited in the claim, without introducing any new matter (35 U.S.C. 132(a)).
If applicant is of the opinion that the written description of the specification already implicitly or inherently discloses the corresponding structure, material, or acts and clearly links them to the function so that one of ordinary skill in the art would recognize what structure, material, or acts perform the claimed function, applicant should clarify the record by either:
(a) Amending the written description of the specification such that it expressly recites the corresponding structure, material, or acts for performing the claimed function and clearly links or associates the structure, material, or acts to the claimed function, without introducing any new matter (35 U.S.C. 132(a)); or
(b) Stating on the record what the corresponding structure, material, or acts, which are implicitly or inherently set forth in the written description of the specification, perform the claimed function. For more information, see 37 CFR 1.75(d) and MPEP §§ 608.01(o) and 2181.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 4, 7, 10, 13, 16 are rejected under 35 U.S.C. 103 as being unpatentable over LI (“Reference-frame-independent and measurement-device-independent quantum key distribution using one single source”).
Regarding claim 1, LI teaches “A measurement-device-independent (MDI) quantum key distribution (QKD) network comprising: ([LI, Section 2.2, page 2195] “Here, we discuss the security of the proposed protocol. Firstly, the security of MDI-QKD protocol is equivalent to that of time-reversal EPR protocol [48–50]. While, the security of EPR protocol is based on quantum entanglement protocol. So, the MDI-QKD protocol is secure. … . In this protocol, efficient intensity monitor at Alice (Bob) can help to counter against the attacks derived from untrusted source. Alice and Bob can verify the outputs of Charlie”) a common server with a laser source for optical pulse generation and distribution; ([LI, Section 2.2, page 2194-2195] “The proposed RFI MDI-QKD system uses only one source, as shown in Fig. 1. There is one laser at Charlie who also has a Bell state measurement (BSM) device. … Light generation. The light pulse from the laser at Charlie is split into two pulses by a beam splitter (BS2). One is sent to Alice through a polarization beam splitter while the other is sent to Bob through another PBS”) a plurality of user systems, each user system: receiving the optical pulses from the common server; ([LI, Section 2.2, page 2194-2195] “the laser is sent to Alice and Bob and encoded in X-basis, Y-basis or Z-basis by Alice and Bob independently and randomly. … Encoding. At Alice’s (Bob’s) device, the light pulses are filtered by an optical filter for removing unwanted optical signals.”) modulating the optical pulses for quantum communication; and re-transmitting the modulated optical pulses to the common server; ([LI, Section 2.2, page 2194-2195] “Encoding. At Alice’s (Bob’s) device … the light pulses pass through a polarization beam splitter (PBS1) and are phase-randomized by a phase modulator (PM1). The decoy states are got by intensity modulators (IM1). The intensities of output signal states and the two decoy states are (μ, ν, o). After the light pulses are reflected by FM and go through the PBS2. The encoding circuit has two beam splitters which construct an AMZI, two intensity modulators (IM2 and IM3), and a phase modulator (PM2). By AMZI, the pulses are splitting into early ones and late ones, which are in two eigenstates of time-bin base. … The pulses are attenuated to single-photon level by an attenuator (Att), then pass through the polarization beam splitter and go back to Charlie”) wherein each user system comprises an energy bounding component for limiting Trojan horse attack (THA) ([LI, Section 2.2, page 2194-2195] “At Alice’s (Bob’s) device, the light pulses are filtered by an optical filter for removing unwanted optical signals. Then, part of light pulses are used to estimate the acquired photon number distribution (PND) by a beam splitter (BS3) and intensity detector (ID). This is for countering against possible Trojan-horse attack … The pulses are attenuated to single-photon level by an attenuator (Att), then pass through the polarization beam splitter and go back to Charlie.”) and wherein the energy bounding component comprises [a power limiter] limiting the re-transmitted modulated optical pulses to a maximum intensity during a THA. ([LI, Section 2.1, page 2194-2195] “At Alice’s (Bob’s) device, the light pulses are filtered by an optical filter for removing unwanted optical signals. Then, part of light pulses are used to estimate the acquired photon number distribution (PND) by a beam splitter (BS3) and intensity detector (ID). This is for countering against possible Trojan-horse attack … The pulses are attenuated to single-photon level by an attenuator (Att), then pass through the polarization beam splitter and go back to Charlie. … Post-processing. Alice and Bob perform information reconciliation for error correction and privacy amplification for removing the leaked information”).
LI does not explicitly disclose “power limiter”, however, given the teaching of LI, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to modify LI to include a “power limiter” because the attenuator of LI limits the intensity of pulses to a maximum level (single-photon level) and therefore it is equivalent or similar to a power limiter. It is obvious to replace one component with another component that performs the same function.
Regarding claim 7, this claim recites of a method claim that performs the features of network claim 1. Therefore, claim 7 is rejected in a similar manner as in the rejection of claim 1. LI teaches of “A method of operating an MDI QKD network” ([LI, Section 2.2, page 2195] “Here, we discuss the security of the proposed protocol. Firstly, the security of MDI-QKD protocol is equivalent to that of time-reversal EPR protocol [48–50]. While, the security of EPR protocol is based on quantum entanglement protocol. So, the MDI-QKD protocol is secure”)
Regarding claim 13, this claim recites of a user system for a measurement-device-independent (MDI) quantum key distribution (QKD) network that performs the features of network claim 1. Therefore, claim 13 is rejected in a similar manner as in the rejection of claim 1. LI further teaches “user system” ([LI, Fig. 1 Schematic diagram of our RFI-MDI-QKD with an untrusted laser source)
Regarding claim 16, this claim recites of a method to operate the user system of claim 13. The method of claim 16 recites of similar features of claim 1. Therefore, claim 16 is rejected in a similar manner as in the rejection of claims 1 and 13.
Regarding claims 4 and 10, LI teaches all limitations of claims 1 and 7. LI further teaches “wherein the common server comprises one or more detectors for generating measurement results from the re-transmitted modulated optical pulses from a pair of user systems” ([LI, Section 2.1, page 2194-2195] “Bell state measurement. Charlie performs Bell state measurement by BS1 and two single-photon detectors (SPD1 and SPD2). When the input photons are projected into the state … i.e., the two SPDs coincide in two alternate time bins (early or late), Charlie will announce successful outputs.”).
Claims 5 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over LI in view of TRIFONOV (US-20090022322-A1).
Regarding claims 5 and 11, LI teaches all limitations of claims 4 and 10. However, LI does not teach “wherein the common server comprises one or more time delay modules for timing calibration of the re-transmitted modulated optical pulses from the pair of user systems.”.
In analogous teaching TRIFONOV teaches “wherein the common server comprises one or more time delay modules for timing calibration of the re-transmitted modulated optical pulses from the pair of user systems.” ([TRIFONOV, para. 0007] “QKD systems and methods having time-bin entanglement and active phase tracking and stabilization are disclosed. The method includes generating in an initial state preparation stage ("Charlie") pairs of coherent photons at a first wavelength, such as a known telecommunications wavelength. … A phase loop in Charlie is used to provide a phase delay between the first-wavelength coherent "pump" photons. State detection stages (Alice and Bob) are optically coupled to Charlie and each receive respective entangled photons from Charlie. These photons are given respective second and third phase delays by respective phase delay loops in Alice and Bob. The relative phase delays are tracked using reference optical signals generated by Charlie”).
Thus, given the teaching of TRIFONOV, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to combine the teaching of time delay modules by TRIFONOV into a measurement-device-independent (MDI) quantum key distribution (QKD) network by LI. One of ordinary skill in the art would have been motivated to do so because TRIFONOV recognizes the need to improve quantum key distribution ([TRIFONOV, para, 0015] “The present invention improves upon the QKD system disclosed in Brendel, and utilizes the stabilization method disclosed … The invention allows state preparation and state detection at one telecommunication (“telecom”) wavelength, plus convenient stabilization and synchronization of three QKD stations.”).
Claims 6 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over LI in view of FU (US-20200169398-A1).
Regarding claims 6 and 12, LI teaches all limitations of claims 4 and 10. However, LI does not teach “comprising a classical communication channel between the common server and each of the user systems for communicating the measurement results.”.
In analogous teaching FU teaches “comprising a classical communication channel between the common server and each of the user systems for communicating the measurement results.” ([FU, para. 0034] “During actual implementations, each of the QKD devices of the sender and the receiver, each of the QKS devices of the sender and the receiver, and each of the data devices of the sender and the receiver may be connected via classical channels in wired, wireless, or other forms, to perform operations such as negotiations and data transmission”).
Thus, given the teaching of FU, it would have been obvious to one of ordinary skill in the art before the effective filling date of the claimed invention to combine the teaching of classical channels by FU into a measurement-device-independent (MDI) quantum key distribution (QKD) network by LI. One of ordinary skill in the art would have been motivated to do so because FU recognizes the need to improve security ([FU, para. 0096] “The flow of using a real-time acquisition mechanism has been described through step 301 to step 306. To improve security, all data interaction in a classical channel in the above processing flow can be carried out based on HTTPS connection”)
Pertinent Art
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure.
LI (US-20210399810-A1): This prior art teaches of quantum communications system includes a quantum key generation system having a photonic quantum bit generator, a low loss dispersion limiting fiber having a length L, for example greater than 200 km, and a photon detector unit and a communications network having a signal generator, a signal channel, and a signal receiver. The low loss dispersion limiting fiber extends between and optically couples the photonic quantum bit generator and the photon detector unit. Further, the low loss dispersion limiting fiber is structurally configured to limit dispersion at an absolute dispersion rate of about 9 ps/(nm)km or less, and preferably 0.5 ps/(nm)km or less, and induce attenuation at an attenuation rate of about 0.175 dB/km or less such that the quantum key bit information of a plurality of photons output by the one or more photonic quantum bit generators is receivable at the photon detector unit at a bit rate of at least 10 Gbit/sec.
HUGHES (US-20160248586-A1): This prior art teaches of message authenticators for quantum-secured communications facilitate low-latency authentication with assurances of security. Low-latency message authenticators are especially valuable in infrastructure systems where security and latency constraints are difficult to satisfy with conventional non-quantum cryptography. For example, a message transmitter receives a message and derives an authentication tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message transmitter outputs the message and its authentication tag. A message receiver receives a message and authentication tag for the message. The message receiver derives a comparison tag for the message based at least in part on an authenticator that uses one or more quantum keys. The message receiver checks whether the message is authentic based on a comparison of the authentication tag and the comparison tag. In example implementations, the authenticator uses stream-wise cyclic redundancy code operations.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/A.A./
02/05/2026
/AFAQ ALI/Examiner, Art Unit 2434
/NOURA ZOUBAIR/Primary Examiner, Art Unit 2434