The Quantum Leap in Secure Communication: A Look at Quantum Key Distribution
Research Blog Post Edition
The digital landscape is under constant siege, with cyber threats growing in sophistication and frequency. As our reliance on interconnected systems deepens, the need for robust security measures becomes paramount. A particularly concerning future threat, short of also being a promising well-intentioned technology, looms on the horizon: quantum computers. These powerful machines, leveraging the principles of quantum mechanics, possess the potential to render many of our current encryption standards, such as RSA and Elliptic Curve Cryptography (ECC), obsolete 1. This vulnerability has spurred intense research into quantum-safe security solutions, and among the most promising is Quantum Key Distribution (QKD). QKD offers a revolutionary approach to securing communications, moving beyond mathematical complexity to harness the fundamental laws of physics for potentially unbreakable encryption 1. The urgency of this transition is underscored by the "harvest now, decrypt later" (HNDL) threat, where malicious actors are already storing encrypted data with the anticipation of decrypting it once quantum computers become sufficiently advanced 5.
Demystifying Quantum Key Distribution
At its core, QKD is a secure communication method that utilizes the principles of quantum mechanics to generate and distribute cryptographic keys between two parties 4. Unlike traditional cryptography, which relies on the computational difficulty of mathematical problems, QKD's security is rooted in the fundamental laws of quantum physics, such as the no-cloning theorem 3. This theorem states that it is impossible to create an exact copy of an unknown quantum state. In the context of QKD, this means that any attempt by an eavesdropper to intercept the quantum key will inevitably disturb the quantum states carrying the key information, and this disturbance can be detected by the legitimate communicating parties 3. This inherent ability to detect eavesdropping is what makes QKD a potentially revolutionary security technology.
Several protocols have been developed to implement QKD, each leveraging different aspects of quantum mechanics. One of the earliest and most well-known is the BB84 protocol, developed in 1984 8. This protocol uses the polarization states of single photons to encode bits of the secret key 11. The sender (often called Alice) randomly prepares photons in one of four polarization states and sends them to the receiver (Bob). Bob then randomly measures the polarization of the received photons using one of two possible bases. By publicly comparing a subset of their measurement bases, Alice and Bob can identify the measurements where they used the same basis. These measurements form the basis of their shared secret key. Because any attempt by an eavesdropper (Eve) to measure the polarization of the photons will inevitably disturb their state, Alice and Bob can detect Eve's presence by analyzing the error rate in their shared key 8. The BB84 protocol's reliance on the uncertainty principle, where defining a quantum state in one basis inherently makes it undefined in another, is key to its security 11. An eavesdropper guessing the wrong measurement basis has a 50% chance of disturbing the photon's state, introducing detectable errors 13.
Another significant QKD protocol is the E91 protocol, which relies on the phenomenon of quantum entanglement 11. In this protocol, pairs of entangled photons are distributed between Alice and Bob. The security of E91 stems from the perfect correlations between entangled particles; measuring one particle instantaneously affects the state of the other, regardless of the distance separating them 13. Any attempt by an eavesdropper to measure one of the entangled photons will destroy these correlations in a detectable way, allowing Alice and Bob to identify potential security breaches 13. The device-independent nature of E91, where security does not rely on the trustworthiness of the devices used, gives it a unique advantage in certain scenarios.
Continuous-variable QKD (CV-QKD) represents a different approach, utilizing the continuous quantum variables of light, such as amplitude and phase, rather than discrete properties like polarization 16. This method has the advantage of being potentially more compatible with existing telecommunications infrastructure, as it can utilize standard optical elements and fiber optic cables 17. CV-QKD encodes information in the modulation of these continuous variables, and security is achieved through the quantum nature of these modulations and the detection of any disturbances 17.
It is crucial to understand that QKD itself does not transmit the actual message data. Instead, it is used to securely generate and distribute a secret key between two parties 4. This shared secret key can then be used with a classical encryption algorithm, such as the one-time pad (which offers provable security when used with a truly random key of the same length as the message) or the Advanced Encryption Standard (AES), to encrypt and decrypt the message data, which is transmitted over a standard, potentially insecure communication channel 4. Thus, QKD acts as a key enabler for secure communication by providing a quantum-secured method for key exchange 4.
The Current State of QKD Technology: From Theory to Reality
The field of QKD has witnessed remarkable progress in recent years, transitioning from theoretical concepts to practical deployments in communication infrastructures around the globe 1. Several QKD networks are already operational or under construction, signifying a growing recognition of its importance in future secure communication strategies. In the United Kingdom, for instance, metropolitan quantum networks have been established in Cambridge and Bristol, connected by a long-distance link via London 1. In Asia, a 2000 km quantum backbone connects Beijing and Shanghai in China, demonstrating the feasibility of long-distance terrestrial quantum communication 1. Furthermore, China's Micius satellite has successfully extended QKD to global distances, showcasing the potential of space-based quantum communication 1. These advancements highlight the increasing maturity and capabilities of QKD technologies.
The market for QKD is also experiencing significant growth, reflecting the increasing demand for quantum-safe security solutions. According to a recent report, the global QKD market is projected to expand from USD 0.48 billion in 2024 to USD 2.63 billion by 2030, exhibiting a compound annual growth rate (CAGR) of 32.6% 5. A primary driver of this growth is the escalating deployment of quantum communication in satellite-based networks, which are crucial for applications requiring global reach and high security, such as defense and national security 5. The increasing awareness of the HNDL attack vector is also contributing to the growing interest in QKD 5. Geographically, North America is anticipated to hold a substantial share of the QKD market, driven by significant investments in quantum research, strong government support, and the presence of leading technology firms 5.
Year Market Value(Bilions of Dollars)
2024 0.48
2030 2.63
CAGR (2024-2030) 32.6%
Commercial QKD systems are now available from several companies, including pioneers like ID Quantique (IDQ) and Toshiba 3. IDQ, for example, offers its fourth-generation QKD solutions, the XG and XGR Series, designed for commercial and research deployments, respectively, with varying key transmission rates and ranges 6. Toshiba has also made significant strides, developing large-scale QKD network control technologies and high-speed QKD systems aimed at realizing global-scale quantum cryptography communications 38. These commercial offerings indicate a growing maturity of QKD technology and its increasing readiness for practical applications across various sectors 30.
To facilitate the integration of quantum communications into existing networks and to promote the widespread adoption of QKD, standardization efforts are actively underway by international organizations such as the European Telecommunications Standards Institute (ETSI), the International Telecommunication Union (ITU), the International Organization for Standardization (ISO), and the Institute of Electrical and Electronics Engineers (IEEE) 1. ETSI, for instance, has already published several technical specifications covering various aspects of QKD, including use cases, security proofs, module specifications, and interfaces 1. These standardization initiatives are crucial for ensuring interoperability between different QKD systems, establishing security benchmarks, and ultimately fostering the commercialization of this technology 1.
Navigating the Challenges on the Quantum Path
Despite the significant advancements, the widespread adoption of QKD still faces several challenges and limitations. One of the primary hurdles is the high implementation cost associated with deploying QKD systems 2. QKD requires specialized hardware, including single-photon sources, highly sensitive photon detectors, and often dedicated fiber optic connections 5. The expense of deploying new fiber networks or leasing "dark fiber" (unused fiber optic cables) can be substantial, posing a barrier to entry for many organizations 24. Unlike software-based encryption solutions, QKD's reliance on specific physical infrastructure contributes to these high costs.
Another significant limitation is the range of QKD over optical fibers, which is constrained by photon loss 6. As photons travel through the fiber, some are absorbed or scattered, weakening the signal. Due to the no-cloning theorem, traditional optical amplifiers cannot be used to boost the quantum signal without destroying the quantum information 9. While experimental systems have achieved impressive distances, exceeding 500 km using specialized ultralow-loss fibers and techniques, these often come with very low key generation rates 9. Overcoming this distance limitation is a key focus of ongoing research, with quantum repeaters emerging as a potential solution 25. Quantum repeaters aim to extend the communication range by using entanglement and quantum memories to relay quantum information across longer distances without the need for trusted intermediate nodes 25.
Furthermore, QKD, in its basic form, lacks a built-in mechanism for authentication 4. It secures the key exchange process, ensuring that the key is not intercepted without detection, but it does not inherently verify the identities of the communicating parties 9. This means that QKD typically needs to be supplemented with classical cryptographic methods to authenticate the sender and receiver, mitigating the risk of man-in-the-middle attacks 9.
The very sensitivity of QKD to any disturbance, which is the basis of its security, also makes it vulnerable to denial-of-service (DoS) attacks 9. Any attempt to interfere with the quantum channel, even if not aimed at extracting the key, can disrupt the key exchange process, potentially halting communication 9.
The security of practical QKD systems is highly dependent on their implementation 3. While theoretical security proofs assume ideal devices, real-world QKD systems can have imperfections that might be exploited by sophisticated eavesdroppers through side-channel attacks 3. Researchers are exploring device-independent (DI) QKD protocols as a way to address these vulnerabilities, as these protocols do not rely on assumptions about the internal workings of the QKD devices 3.
Finally, it's important to note that QKD is not a complete security solution in itself 24. It primarily focuses on the secure distribution of encryption keys. To achieve confidentiality of the actual data transmission, these keys need to be used with an encryption algorithm 24. Additionally, other security aspects like data integrity and authentication might require separate mechanisms beyond QKD 24. Therefore, QKD is best viewed as a crucial component within a broader security architecture.
The Future Horizon: Quantum Promises
Looking ahead, the future of QKD technology is filled with promise as researchers and engineers continue to address current limitations and explore new possibilities. Advancements in quantum communication infrastructure are constantly being made, leading to the development of more efficient and longer-range QKD systems 5. For instance, Toshiba is actively working on Twin Field QKD technology and satellite QKD systems to significantly extend the distances over which secure keys can be distributed 53. Twin-field QKD, in particular, holds great potential for surpassing the traditional rate-distance limits of QKD 48.
Miniaturization of QKD devices through the use of integrated photonics is another exciting area of development 3. Integrated quantum photonics offers a stable, compact, and robust platform for implementing complex photonic circuits required for QKD, and it is amenable to mass manufacturing, which could significantly reduce the cost and size of QKD systems, making them more practical for widespread adoption 3.
The development of quantum repeaters is crucial for realizing truly long-distance QKD networks without relying on potentially vulnerable trusted nodes 25. By leveraging entanglement swapping and quantum memories, these repeaters can relay quantum information over extended distances, paving the way for inter-city, inter-country, and even intercontinental quantum-secured communication 25.
Beyond its primary application in secure communication, QKD is also being explored for a range of other potential uses 27. These include enhancing the security of voting systems, protecting the burgeoning Internet of Things (IoT), and even contributing to advancements in quantum information processing 27. The unique security properties of QKD make it valuable for protecting highly sensitive data across various sectors, including banking, finance, healthcare, government, and defense 5. Furthermore, the integration of QKD with emerging technologies like 5G and IoT networks is expected to play a vital role in securing these increasingly interconnected domains 5.
QKD in the Quantum-Safe Security Landscape
QKD is a key component of the broader landscape of quantum-safe security technologies being developed to counter the threat posed by quantum computers. Another major approach is Post-Quantum Cryptography (PQC), which focuses on developing classical cryptographic algorithms that are believed to be resistant to attacks from both classical and quantum computers 2. Organizations like the National Institute of Standards and Technology (NIST) have been actively working to standardize PQC algorithms 2. While QKD offers security based on the laws of physics, PQC relies on mathematical complexity, and each approach has its own set of advantages and disadvantages 2.
Given the strengths and weaknesses of both QKD and PQC, hybrid approaches that combine these technologies are also being explored 2. By leveraging QKD for secure key distribution and PQC for data encryption and authentication, a layered security approach can be achieved, potentially offering a more robust defense against future threats 2.
Conclusion: Embracing the Quantum Frontier of Security
Quantum Key Distribution stands at the forefront of a new era in secure communication, offering the potential for truly unbreakable encryption in a world increasingly vulnerable to sophisticated cyberattacks, especially those anticipated from quantum computers. While challenges such as cost, range limitations, and the need for integration with existing systems remain, the rapid pace of research and development is continuously pushing the boundaries of QKD technology. Advancements in areas like integrated photonics and quantum repeaters promise to overcome many of these hurdles.
Organizations, particularly those dealing with highly sensitive data that needs to remain secure for decades to come, should pay close attention to the ongoing progress in QKD and consider its role in their long-term security strategies, alongside other quantum-safe solutions like post-quantum cryptography. While widespread commercial adoption may still be some years away, early adoption in high-security sectors is already happening and is expected to grow as the technology matures and becomes more accessible 5. The quantum leap in secure communication is underway, and QKD is poised to be a critical technology in safeguarding our digital future.
References and Works cited:
1. Quantum Key Distribution (QKD) - ETSI, accessed on March 17, 2025, https://www.etsi.org/technologies/quantum-key-distribution
2. Why the new NIST standards mean quantum cryptography may just have come of age, accessed on March 17, 2025, https://www.weforum.org/stories/2024/10/quantum-cryptography-nist-standards/
3. Advances in Chip-Based Quantum Key Distribution - PMC, accessed on March 17, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC9600573/
4. Quantum key distribution - Wikipedia, accessed on March 17, 2025, https://en.wikipedia.org/wiki/Quantum_key_distribution
5. Quantum Key Distribution Global Market Forecast to 2030: - GlobeNewswire, accessed on March 17, 2025, https://www.globenewswire.com/news-release/2025/03/13/3042411/0/en/Quantum-Key-Distribution-Global-Market-Forecast-to-2030-Growing-Deployment-of-Quantum-Communication-in-Satellite-based-Networks.html
6. Quantum Key Distribution | QKD | Quantum Cryptography - ID Quantique, accessed on March 17, 2025, https://www.idquantique.com/quantum-safe-security/quantum-key-distribution/
7. Quantum Key Distribution - What Is QKD? How Does It Work? - Toshiba Europe, accessed on March 17, 2025, https://www.toshiba.eu/quantum/products/quantum-key-distribution/
8. Comprehensive Analysis of BB84, A Quantum Key Distribution Protocol - arXiv, accessed on March 17, 2025, https://arxiv.org/html/2312.05609v1
9. TrUE vs. QKD vs. PQC – Know the Difference - Quantropi, accessed on March 17, 2025, https://www.quantropi.com/true-vs-qkd-vs-pqc-know-the-difference/
10. BB84 - Wikipedia, accessed on March 17, 2025, https://en.wikipedia.org/wiki/BB84
11. Quantum Key Distribution (QKD) - QuIC Lab, accessed on March 17, 2025, https://www.rri.res.in/quic/qcommconcepts.php
12. Quantum Cryptography Analogy Demonstration Kit - Thorlabs, accessed on March 17, 2025, https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=9869
13. An Overview of Quantum Key Distribution Protocols and Experimental Implementations, accessed on March 17, 2025, https://wp.optics.arizona.edu/opti646/wp-content/uploads/sites/55/2022/12/Zhai_Term_Paper.pdf
14. qiskit-community-tutorials/awards/teach_me_qiskit_2018/e91_qkd/e91_quantum_key_distribution_protocol.ipynb at master - GitHub, accessed on March 17, 2025, https://github.com/qiskit-community/qiskit-community-tutorials/blob/master/awards/teach_me_qiskit_2018/e91_qkd/e91_quantum_key_distribution_protocol.ipynb
15. Quantum key distribution protocols (BB84, E91) | Quantum Optics Class Notes | Fiveable, accessed on March 17, 2025, https://library.fiveable.me/quantum-optics/unit-12/quantum-key-distribution-protocols-bb84-e91/study-guide/Jl4blarRnErO4h3A
16. Field test of continuous-variable quantum key distribution with a true local oscillator | Phys. Rev. Applied - Physical Review Link Manager, accessed on March 17, 2025, https://link.aps.org/doi/10.1103/PhysRevApplied.21.014056
17. Security of discrete-modulated continuous-variable quantum key distribution, accessed on March 17, 2025, https://quantum-journal.org/papers/q-2024-07-18-1418/
18. Continuous-variable quantum key distribution at 10 GBaud using an integrated photonic-electronic receiver - Optica Publishing Group, accessed on March 17, 2025, https://opg.optica.org/optica/abstract.cfm?uri=optica-11-9-1197
19. Continuous-Variable Quantum Key Distribution - Ansys Optics, accessed on March 17, 2025, https://optics.ansys.com/hc/en-us/articles/28594300696979-Continuous-Variable-Quantum-Key-Distribution
20. Continuous-variable quantum key distribution system: Past, present, and future, accessed on March 17, 2025, https://pubs.aip.org/aip/apr/article/11/1/011318/3279669/Continuous-variable-quantum-key-distribution
21. Products | Quantum Cybersecurity from QuintessenceLabs, accessed on March 17, 2025, https://www.quintessencelabs.com/products
22. 1 Quantum cryptography: BB84 quantum key distribution, accessed on March 17, 2025, http://www.qi.damtp.cam.ac.uk/files/PartIIQIC/QIC-6.pdf
23. Advances in Chip-Based Quantum Key Distribution - MDPI, accessed on March 17, 2025, https://www.mdpi.com/1099-4300/24/10/1334
24. Quantum Key Distribution (QKD) and Quantum Cryptography QC - National Security Agency, accessed on March 17, 2025, https://www.nsa.gov/Cybersecurity/Quantum-Key-Distribution-QKD-and-Quantum-Cryptography-QC/
25. Quantum Repeaters: The Key to Long-Distance Quantum Communication and Security, accessed on March 17, 2025, https://postquantum.com/post-quantum/quantum-repeaters/
26. The Impact of Quantum Technology on Data Security - AZoQuantum, accessed on March 17, 2025, https://www.azoquantum.com/Article.aspx?ArticleID=524
27. Quantum Communications in Real World Applications, accessed on March 17, 2025, https://quantumxc.com/blog/quantum-communications-real-world-applications/
28. Space-Based Quantum Key Distribution: A Deep Dive Into QKD's Market Map And Competitive Landscape, accessed on March 17, 2025, https://thequantuminsider.com/2025/03/05/space-based-quantum-key-distribution-a-deep-dive-into-qkds-market-map-and-competitive-landscape/
29. Quantum Leap: Unbreakable Data Security's Future - Queen's Business Review, accessed on March 17, 2025, https://www.queensbusinessreview.com/articles/quantum-leap-unbreakable-data-securitys-future
30. Top 15 Leading Quantum Cryptography Companies in 2025 - WeeTech Solution, accessed on March 17, 2025, https://www.weetechsolution.com/blog/top-quantum-cryptography-companies
31. Top 10 Companies in Quantum Cryptography Market in 2024 - Emergen Research, accessed on March 17, 2025, https://www.emergenresearch.com/blog/top-10-companies-in-quantum-cryptography-market
32. Quantum Key Distribution (QKD) Companies - GitHub Pages, accessed on March 17, 2025, https://brunorijsman.github.io/quantum-resource-list/companies-qkd.html
33. CASE STUDY: ID Quantique - Covesion, accessed on March 17, 2025, https://covesion.com/knowledge-hub/case-study-id-quantique/
34. IonQ to Acquire Geneva-Based ID Quantique, Enters Into Global Quantum Strategic Partnership with SK Telecom, accessed on March 17, 2025, https://investors.ionq.com/news/news-details/2025/IonQ-to-Acquire-Geneva-Based-ID-Quantique-Enters-Into-Global-Quantum-Strategic-Partnership-with-SK-Telecom/default.aspx
35. Experiment QKD in your lab - ID Quantique, accessed on March 17, 2025, https://www.idquantique.com/experiment-qkd-in-your-lab/
36. Digital Solutions - Toshiba, accessed on March 17, 2025, https://toshiba-india.com/newsletter-digital-solutions-qkd.aspx
37. Quantum Key Distribution | TOSHIBA DIGITAL SOLUTIONS CORPORATION, accessed on March 17, 2025, https://www.global.toshiba/ww/products-solutions/security-ict/qkd.html
38. Toshiba Develops Large-Scale Quantum Key Distribution Network Control Technology and High-Speed Quantum Key Distribution Technology Toward Realizing Global-Scale Quantum Cryptography Communications -Expanding the scope of secure communications services by scaling up and accelerating quantum cryptography communications- | Corporate Research & Development Center | Toshiba, accessed on March 17, 2025, https://www.global.toshiba/ww/technology/corporate/rdc/rd/topics/24/2409-02.html
39. QKD & Quantum Security Solutions - Toshiba Europe, accessed on March 17, 2025, https://www.toshiba.eu/quantum/
40. Toshiba Europe And Single Quantum Partner to Provide Extended Long-Distance QKD Deployment Capability, accessed on March 17, 2025, https://thequantuminsider.com/2024/04/23/toshiba-europe-and-single-quantum-partner-to-provide-extended-long-distance-qkd-deployment-capability/
41. Quantum Key Distribution: A Viable Solution for Businesses? - BizTech Magazine, accessed on March 17, 2025, https://biztechmagazine.com/article/2025/03/quantum-key-distribution-qkd-perfcon
42. (PDF) Limitations on Practical Quantum Cryptography - ResearchGate, accessed on March 17, 2025, https://www.researchgate.net/publication/12330710_Limitations_on_Practical_Quantum_Cryptography
43. Challenges and Opportunities in Quantum Cryptography - EMB Global, accessed on March 17, 2025, https://blog.emb.global/challenges-and-opportunities-in-quantum-cryptography/
44. Challenges of implementing quantum key distribution - HLK - IP, accessed on March 17, 2025, https://www.hlk-ip.com/news-and-insights/challenges-of-implementing-quantum-key-distribution/
45. Large scale quantum key distribution: challenges and solutions [Invited], accessed on March 17, 2025, https://opg.optica.org/oe/abstract.cfm?uri=oe-26-18-24260
46. Quantum Repeaters - Quantum Flagship, accessed on March 17, 2025, https://qt.eu/quantum-principles/communication/quantum-repeaters
47. (PDF) Quantum repeaters and quantum key distribution: Analysis of secret-key rates, accessed on March 17, 2025, https://www.researchgate.net/publication/230648863_Quantum_repeaters_and_quantum_key_distribution_Analysis_of_secret-key_rates
48. Overcoming the rate-distance limit of quantum key distribution without quantum repeaters - PubMed, accessed on March 17, 2025, https://pubmed.ncbi.nlm.nih.gov/29720656/
49. Quantum Memories for Quantum Networking, accessed on March 17, 2025, https://www.aliroquantum.com/quantum-memories-for-quantum-networking
50. Faithfully Simulating Near-Term Quantum Repeaters - Physical Review Link Manager, accessed on March 17, 2025, https://link.aps.org/doi/10.1103/PRXQuantum.5.010351
51. Enhancing Quantum Key Distribution Protocols for Extended Range and Reduced Error, accessed on March 17, 2025, https://www.researchgate.net/publication/384802378_Enhancing_Quantum_Key_Distribution_Protocols_for_Extended_Range_and_Reduced_Error
52. Current Status and Future Development of Quantum Cryptographic Protocols - Engineering, accessed on March 17, 2025, https://www.engineering.org.cn/sscae/EN/10.15302/J-SSCAE-2022.04.015
53. (Part 4) The Future of Quantum Key Distribution Technology - Looking Towards the Coming Quantum Internet Age, accessed on March 17, 2025, https://www.global.toshiba/ww/company/digitalsolution/articles/tsoul/tech/t0204.html
54. Integrated silicon photonics for high-speed quantum key distribution - Optica Publishing Group, accessed on March 17, 2025, https://opg.optica.org/optica/abstract.cfm?uri=optica-4-2-172
55. Integrated Photonics for Quantum Communications and Metrology - Physical Review Link Manager, accessed on March 17, 2025, https://link.aps.org/doi/10.1103/PRXQuantum.5.010101
56. Photonic integrated quantum key distribution - Eindhoven University of Technology, accessed on March 17, 2025, https://www.tue.nl/en/research/research-groups/electro-optical-communication/terahertz-photonic-systems/photonic-integrated-quantum-key-distribution
57. [2310.16702] Quantum Key Distribution With an Integrated Photonic Receiver - arXiv, accessed on March 17, 2025, https://arxiv.org/abs/2310.16702
58. Resource-efficient quantum key distribution with integrated silicon photonics | Request PDF, accessed on March 17, 2025, https://www.researchgate.net/publication/370859401_Resource-efficient_quantum_key_distribution_with_integrated_silicon_photonics
59. A measurement-device-independent quantum key distribution network using optical frequency comb - arXiv, accessed on March 17, 2025, https://arxiv.org/html/2502.11860v1
60. Provably secure and high-rate quantum key distribution with time-bin qudits - PMC, accessed on March 17, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC5706749/
61. Practical high-dimensional quantum key distribution protocol over deployed multicore fiber, accessed on March 17, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10891113/
62. "Unlocking Quantum Secrets: The Future of Secure Key Distribution" - DEV Community, accessed on March 17, 2025, https://dev.to/gilles_hamelink_ea9ff7d93/unlocking-quantum-secrets-the-future-of-secure-key-distribution-5fg3
63. The Future of Quantum Cyber Security | by Juan España | ByteHide | Feb, 2025 | Medium, accessed on March 17, 2025, https://medium.com/bytehide/the-future-of-quantum-cyber-security-4bdb249bfe0f
64. Quantum Key Distribution & the Path to Post-Quantum Computing - Cisco Blogs, accessed on March 17, 2025, https://blogs.cisco.com/security/quantum-key-distribution-and-the-path-to-post-quantum-computing
65. The Quantum Threat Timeline: Why Organizations Must Act Now - evolutionQ, accessed on March 17, 2025, https://www.evolutionq.com/post/the-quantum-threat-timeline-why-organizations-must-act-now
66. Position Paper on Quantum Key Distribution - BSI, accessed on March 17, 2025, https://www.bsi.bund.de/SharedDocs/Downloads/EN/BSI/Crypto/Quantum_Positionspapier.pdf?__blob=publicationFile&v=4