Return to Main Page Help/Feedback Log Out About the Journal Preparing Your Manuscript Contact Editorial Office Print Email Date: 22-Aug-2019 08:36:15 Last Sent: 22-Aug-2019 08:36:15 Triggered By: Redacted BCC: Redacted Subject: APL: MS #APL19-AR-06644 Decision Letter Message: Dear Prof. Kurtsiefer, Your manuscript, referenced below, has been reviewed for Applied Physics Letters. "Asymmetric delay attack on an entanglement-based bidirectional clock synchronization protocol" APL19-AR-06644 We received mixed comments from our reviewers. Their comments are included below and/or attached. Please indicate how the manuscript has been revised in a separate Response Letter file so that the editors can see whether you have complied with the reviewers' comments. Please use add file to upload the Response Letter file and use replace for any files that have been revised or changed. This could save a second request to the reviewer and the resultant delay in publication. Revised manuscripts must be submitted through the online submission system. They are not accepted by email. The revised manuscript should be returned to the Editor promptly. Your revision is due by 20-Sep-2019. A manuscript returned more than 30 days from today should be submitted as a new manuscript and will be given a new receipt date. Please go to the URL below to submit the revised version. To meet AIP Production requirements, please provide a separate figure file for each cited figure number (all parts in one file), in addition to your article-text file. https://apl.peerx-press.org/cgi-bin/main.plex If clicking on the above URL address directly from your mail program is unsuccessful, please copy and paste the complete address into your browser.) If you have any questions, feel free to contact us at apl-edoffice@aip.org. Sincerely yours, Kenjiro Miyano Associate Editor Applied Physics Letters AIP Publishing 1305 Walt Whitman Road Suite 300 Melville, NY 11747-4300 USA phone: +1-516-576-2344 e-mail: apl-edoffice@aip.org ----------------------------------------------------------------- ---- Manuscript #APL19-AR-06644: Reviewer Comments: Reviewer #1 Evaluations: Does this paper meet APL's standards: Yes Is the paper scientifically sound with the assertions made and conclusions drawn well supported: Yes Is the discussion of related work and associated references adequate?: Yes Is the English satisfactory?: Yes Is the title short, interesting, and descriptive of the contents?: Yes Is the paper well organized and understandable?: Yes Reviewer #2 Evaluations: Does this paper meet APL's standards: No Is the paper scientifically sound with the assertions made and conclusions drawn well supported: No Is the discussion of related work and associated references adequate?: Yes Is the English satisfactory?: Yes Is the title short, interesting, and descriptive of the contents?: Yes Is the paper well organized and understandable?: Yes Reviewer #1 The manuscript ‘Asymmetric delay attack on an entanglement-based bidirectional clock synchronization protocol’ by Lee et al presents a successful attack on a clock synchronization protocol. Such protocols are meant to estimate the absolute time offset between remote clocks held by the usual suspects, i.e., Alice and Bob. The (accuracy of the) scheme under discussion, proposed by the same set of authors in Ref. 10, is based on the tight time correlations between entangled photons prepared by spontaneous parametric down conversion (SPDC) and distributed by Alice and Bob to each other. The attack here by Eve is implemented by rerouting these SPDC photons, as they are traversing on the remote channel, with a pair of circulators that impose – as a consequence of the Faraday effect – a direction-dependent propagation delay. The authors therefore call this a circulator-based asymmetric delay attack (CADA). Two of the co-authors separately proposed (Ref. 15 in the manuscript) that CADA can actually be foiled as it results in an unavoidable non-local geometric phase, which could be revealed if Alice and Bob performed polarization measurements in appropriate bases. However, in Faraday rotation, the electric field vector picks a dynamical phase in addition to the geometric phase. In Ref. 15, it was wrongly assumed that this dynamical phase is, “zero, or is known and compensated for”. In the current work, they find that this dynamical phase is likewise non-local and, more relevantly, combines with the geometric phase to produce no measurable net change in the state. They support this claim via an experimental quantum state tomography on the SPDC output. To elaborate, they obtain and compare the density matrices with and without the circulator pair before Bob’s avalanche photodiode. In addition, they also perform the actual attack with the circulators and show the clock offset estimation going awry. The manuscript is quite well-written, well-explained, and nicely illustrated, so I whole-heartedly recommend its publication. I have only a few minor remarks: • Add labels to the Y axes in Fig. 5. • Caption of Fig. 3: a remark about why ∆T remains the same from Block 15 to 16 could be added. • Names of the various polarizations |Hi, . . . |Ai, . . . |Ri on pg 3 (left column) could be added. Maybe as a last comment: I feel the authors should be somewhat more forthcoming about the wrong assumption made in Ref. 15. For example, in the penultimate paragraph in the Supplementary material: Recent work assumed → Recent work erroneously assumed. Reviewer #2 (Remarks to the Author(s):): This manuscript experimentally demonstrates an undetectable asymmetric delay attack on an entanglement-based bidirectional clock synchronization protocol using polarization-insensitive circulators. Although I do not query about the correctness of theoretical derivation and experimental realization, I do not recommend to publish the paper in its present form for its novelty and generality. In paragraph 5, page 1, the authors claim that "We briefly review the clock synchronization protocol considered [15]". I think that the protocol mentioned by the authors should be cited as [10]. The attacking method in this paper has been proposed in [15], and the experiment system is similar to [10] except additional circulators. Comparing with the citations [10] and [15], this work is more like a demonstrated comment to claim that the security measure proposed in [10] is invalid according to the attacking method in [15]. Although circulator is a conventional device using in optical systems, the attacking method and its objective are too detailed. Thus, I do not think the novelties of the method and experiment in this work are sufficient to be published in APL. ----------------------------------------------------------------- ---- * Please add a section heading in the manuscript labeled "Supplementary Material" and include a brief description of the supplemental material. It should be placed after the Conclusion and before the Acknowledgment. AIP Publishing will insert a link that will allow successful linking between the published paper and the associated supplementary material. Please refer to supporting data guidelines at https://aip.scitation.org/apl/authors/manuscript for an example. * Please do not use "new" and "novel"; if the findings are not new or novel, they should not be submitted to APL. Other priority claims, such as "for the first time", should be eliminated. Similarly, "to our knowledge" and "successfully" are not allowed. Attachment: Reviewer 1 Review Attachment 1 - 21-Aug-2019 20:51:41 Print Email Visit APL Online Privacy Policy Terms of Use Cookie Settings © 2019 AIP Publishing LLC 1305 Walt Whitman Road, Suite 300, Melville, NY 11747-4300 USA