Quantum Key Distribution and Hybrid Quantum–Classical Cryptography for Secure Cloud Storage a Critical Review

Protecting cloud-stored information against quantum-era threats requires more than selecting a key-establishment mechanism. Quantum key distribution (QKD) must operate alongside authenticated classical communication, secure key delivery, reliable endpoints, and appropriate data encryption. This critical narrative review examines how these dependencies are represented in QKD and hybrid quantum–classical security research. The synthesis draws on targeted literature searches, primary publisher and institutional records, reference-list tracing, and official standards and agency publications. Thirty sources were retained, including fourteen studies mapped comparatively. Full-text consultation is distinguished from abstract or record-only access, and no systematic completeness or independent dual screening is claimed. The analysis uses three consistent research questions concerning mechanism integration, demonstrated security and performance, and deployment requirements. The synthesis identifies four distinct integration purposes: classical-channel authentication, combination of independent key sources, protocol-level efficiency enhancement, and application-facing key delivery. Optical authentication experiments, hardware prototypes, formal hybrid protocols, and deployed-network benchmarks provide stronger integration evidence than an interpretation based only on simulated disturbance. Nevertheless, these contributions do not independently demonstrate authenticated cloud-object storage and recovery across all relevant threats. A security-assumption taxonomy separates device, authentication, key-processing, combiner, delivery, endpoint, and availability dependencies. The comparative mapping records authentication, implementation setting, security measures, metrics, access status, and evidence type. ETSI interfaces and national security agency guidance expose further operational constraints, while a disclosed coauthored study is assessed using the same criteria as other sources. The review concludes with staged evaluation requirements linking key establishment to authenticated object retrieval. No new cryptographic protocol, implementation, or experimental result is claimed.

Quantum key distribution, post-quantum cryptography, cloud storage security, authentication

1. Bennett, C. H., & Brassard, G. (1984). Quantum cryptography: Public key distribution and coin tossing. In Proceedings of the IEEE International Conference on Computers, Systems and Signal Processing (pp. 175–179). IEEE. https://arxiv.org/abs/2003.06557 [Google Scholar] [Crossref]

2. Buruaga, J. S., Brito, J. P., & Martin, V. (2026). Benchmarking hybrid quantum-safe cryptography over real-world infrastructures. EPJ Quantum Technology, 13, Article 75. https://doi.org/10.1140/epjqt/s40507-026-00521-y [Google Scholar] [Crossref]

3. Buruaga, J. S., Bugler, A., Brito, J. P., Martin, V., & Striecks, C. (2025). Versatile quantum-safe hybrid key exchange and its application to MACsec. EPJ Quantum Technology, 12, Article 84. https://doi.org/10.1140/epjqt/s40507-025-00382-x [Google Scholar] [Crossref]

4. Dworkin, M. (2007). Recommendation for block cipher modes of operation: Galois/Counter Mode (GCM) and GMAC (NIST SP 800-38D). National Institute of Standards and Technology. https://doi.org/10.6028/NIST.SP.800-38D [Google Scholar] [Crossref]

5. European Telecommunications Standards Institute. (2019). Quantum key distribution (QKD); Protocol and data format of REST-based key delivery API (ETSI GS QKD 014 V1.1.1). https://www.etsi.org/deliver/etsi_gs/QKD/001_099/014/01.01.01_60/gs_qkd014v010101p.pdf [Google Scholar] [Crossref]

6. European Telecommunications Standards Institute. (2020). Quantum key distribution (QKD); Application interface (ETSI GS QKD 004 V2.1.1). https://www.etsi.org/deliver/etsi_gs/QKD/001_099/004/02.01.01_60/gs_qkd004v020101p.pdf [Google Scholar] [Crossref]

7. Fiorini, F., Pagano, M., Garroppo, R. G., & Osele, A. (2024). Estimating interception density in the BB84 protocol: A study with a noisy quantum simulator. Future Internet, 16(8), Article 275. https://doi.org/10.3390/fi16080275 [Google Scholar] [Crossref]

8. Garms, L., Paraïso, T. K., Hanley, N., Khalid, A., Rafferty, C., Grant, J., Newman, J., Shields, A. J., Cid, C., & O’Neill, M. (2024). Experimental integration of quantum key distribution and post-quantum cryptography in a hybrid quantum-safe cryptosystem. Advanced Quantum Technologies, 7(4), Article 2300304. https://doi.org/10.1002/qute.202300304 [Google Scholar] [Crossref]

9. Kim, C., Kim, S., Sohn, K., Son, Y., Kumar, M., & Kim, S. (2025). Secure and scalable file encryption for cloud systems via distributed integration of quantum and classical cryptography. Applied Sciences, 15(14), Article 7782. https://doi.org/10.3390/app15147782 [Google Scholar] [Crossref]

10. Krawczyk, H., & Eronen, P. (2010). HMAC-based extract-and-expand key derivation function (HKDF) (RFC 5869). RFC Editor. https://doi.org/10.17487/RFC5869 [Google Scholar] [Crossref]

11. Lee, C., Sohn, I., & Lee, W. (2022). Eavesdropping detection in BB84 quantum key distribution protocols. IEEE Transactions on Network and Service Management, 19(3), 2689–2701. https://doi.org/10.1109/TNSM.2022.3165202 [Google Scholar] [Crossref]

12. Maned, V. R., Rath, S., Ramalingam, J., & Kuppusamy, L. (2026). Enhancing quantum key distribution via McEliece-based hybrid PQC-QKD architecture. EPJ Quantum Technology, 13, Article 33. https://doi.org/10.1140/epjqt/s40507-026-00498-8 [Google Scholar] [Crossref]

13. Mosca, M., Stebila, D., & Ustaoglu, B. (2013). Quantum key distribution in the classical authenticated key exchange framework. In P. Gaborit (Ed.), Post-quantum cryptography (Lecture Notes in Computer Science, Vol. 7932, pp. 136–154). Springer. https://doi.org/10.1007/978-3-642-38616-9_9 [Google Scholar] [Crossref]

14. National Cyber Security Centre. (2020, March 24). Quantum security technologies (Version 1.0). https://www.ncsc.gov.uk/paper/quantum-security-technologies [Google Scholar] [Crossref]

15. National Institute of Standards and Technology. (2024). Module-lattice-based digital signature standard (FIPS 204). https://doi.org/10.6028/NIST.FIPS.204 [Google Scholar] [Crossref]

16. National Institute of Standards and Technology. (2024). Module-lattice-based key-encapsulation mechanism standard (FIPS 203). https://doi.org/10.6028/NIST.FIPS.203 [Google Scholar] [Crossref]

17. National Security Agency. (n.d.). Quantum key distribution (QKD) and quantum cryptography (QC). https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-QKD-and-Quantum-Cryptography-QC/ [Google Scholar] [Crossref]

18. Pirandola, S., Andersen, U. L., Banchi, L., Berta, M., Bunandar, D., Colbeck, R., Englund, D., Gehring, T., Lupo, C., Ottaviani, C., Pereira, J. L., Razavi, M., Shamsul Shaari, J., Tomamichel, M., Usenko, V. C., Vallone, G., Villoresi, P., & Wallden, P. (2020). Advances in quantum cryptography. Advances in Optics and Photonics, 12(4), 1012–1236. https://doi.org/10.1364/AOP.361502 [Google Scholar] [Crossref]

19. Portmann, C., & Renner, R. (2022). Security in quantum cryptography. Reviews of Modern Physics, 94(2), Article 025008. https://doi.org/10.1103/RevModPhys.94.025008 [Google Scholar] [Crossref]

20. Prathyusha, G., Anandan, R., Venkata Krishna, P., & Saritha, V. (2026). Quantum-resilient multi-cloud encryption framework for securing big data using post-quantum lattice-based cryptography and chaotic slicing. International Academic Journal of Science and Engineering, 13(1), 30–43. https://doi.org/10.71086/IAJSE/V13I1/IAJSE1304 [Google Scholar] [Crossref]

21. Rubio García, C., Rommel, S., Takarabt, S., Vegas Olmos, J. J., Guilley, S., Nguyen, P., & Tafur Monroy, I. (2024). Quantum-resistant Transport Layer Security. Computer Communications, 213, 345–358. https://doi.org/10.1016/j.comcom.2023.11.010 [Google Scholar] [Crossref]

22. Rukhin, A., Soto, J., Nechvatal, J., Smid, M., Barker, E., Leigh, S., Levenson, M., Vangel, M., Banks, D., Heckert, A., Dray, J., Vo, S., & Bassham, L. E., III. (2010). A statistical test suite for random and pseudorandom number generators for cryptographic applications (NIST SP 800-22 Rev. 1a). National Institute of Standards and Technology. https://doi.org/10.6028/NIST.SP.800-22r1a [Google Scholar] [Crossref]

23. Sarjiyus, O., Adamu, U. F., & Umar, S. (2026). Enhancing cloud data security using quantum key distribution (QKD) and quantum cryptography. Proceedings of the Nigerian Society of Physical Sciences, 3, Article 266. https://doi.org/10.61298/pnspsc.2026.3.266 [Google Scholar] [Crossref]

24. Singamaneni, K. K., Muhammad, G., & Ali, Z. (2024). A novel multi-qubit quantum key distribution ciphertext-policy attribute-based encryption model to improve cloud security for consumers. IEEE Transactions on Consumer Electronics, 70(1), 1092–1101. https://doi.org/10.1109/TCE.2023.3331306 [Google Scholar] [Crossref]

25. Smiles, Y. W., & Sevugarajan, S. (2026). QuantumShield-IoT: A quantum-resilient hybrid framework for secure data transmission using quantum key distribution, lightweight cryptography, and blockchain technology. International Journal of Innovative Science and Research Technology, 11(7), 928–940. https://doi.org/10.38124/ijisrt/26jul281 [Google Scholar] [Crossref]

26. Tomamichel, M., Lim, C. C. W., Gisin, N., & Renner, R. (2012). Tight finite-key analysis for quantum cryptography. Nature Communications, 3, Article 634. https://doi.org/10.1038/ncomms1631 [Google Scholar] [Crossref]

27. Ul Ain, N., Waqar, M., Bilal, A., Kim, A., Ali, H., Ullah Tariq, U., & Shahroz Nadeem, M. (2025). A novel approach based on quantum key distribution using BB84 and E91 protocol for resilient encryption and eavesdropper detection. IEEE Access, 13, 32819–32833. https://doi.org/10.1109/ACCESS.2025.3539178 [Google Scholar] [Crossref]

28. Wang, L.-J., Zhang, K.-Y., Wang, J.-Y., Cheng, J., Yang, Y.-H., Tang, S.-B., Yan, D., Tang, Y.-L., Liu, Z., Yu, Y., Zhang, Q., & Pan, J.-W. (2021). Experimental authentication of quantum key distribution with post-quantum cryptography. npj Quantum Information, 7, Article 67. https://doi.org/10.1038/s41534-021-00400-7 [Google Scholar] [Crossref]

29. Wegman, M. N., & Carter, J. L. (1981). New hash functions and their use in authentication and set equality. Journal of Computer and System Sciences, 22(3), 265–279. https://doi.org/10.1016/0022-0000(81)90033-7 [Google Scholar] [Crossref]

30. Xu, F., Ma, X., Zhang, Q., Lo, H.-K., & Pan, J.-W. (2020). Secure quantum key distribution with realistic devices. Reviews of Modern Physics, 92(2), Article 025002. https://doi.org/10.1103/RevModPhys.92.025002 [Google Scholar] [Crossref]

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