Avasant Quantum Series: Decrypting the Quantum Threat – What Every CISO Must Know

Introduction

After the explosive rise of generative AI, quantum computing is fast emerging as the next technological frontier poised to reshape industries. Global tech giants are in a high-stakes race to scale quantum capabilities and move beyond lab experiments toward commercial readiness within this decade. While quantum computing could supercharge scientific discovery, materials design, and AI, it simultaneously threatens to break the foundation of today’s cybersecurity. This is similar to how AI-driven deepfakes are transforming the landscape of social engineering and fraud. For instance, recently, an employee at Arup transferred $25 million following a deepfake video call with supposed company executives. Quantum computers will redefine cyber risk on a much deeper level. Unlike AI-generated threats that exploit human trust, quantum threats target the very backbone of digital trust: encryption.

Current encryption standards, such as RSA and ECC, which protect everything from online banking to classified government communications, rely on the near impossibility of solving certain mathematical problems with classical computers. But with quantum algorithms such as Shor’s algorithm, these problems can be solved exponentially faster, rendering today’s public-key encryption useless almost overnight. This looming threat has led to a new urgency in cybersecurity circles. Experts are calling it the Quantum Apocalypse—a scenario where powerful quantum computers could decrypt vast troves of previously secure data. Experts fear this scenario to be only decades away. The threat is not just in the future: data harvested today can be decrypted tomorrow once quantum machines are operational. The only way forward is to upgrade our cryptographic infrastructure before it is too late.

Quantum-safe Technologies: QKD and PQC

Sensitive data, whether financial, personal, or national security-related, could be exposed once quantum machines reach full capability. To stay ahead, enterprises and governments are turning to quantum-safe security. Two leading approaches are emerging: quantum key distribution (QKD) and post-quantum cryptography (PQC).

QKD is a form of quantum cryptography that uses the laws of quantum physics, not just math, to secure communication. It works by transmitting encryption keys using particles such as photons and trapped ions. The unique property of these particles is that any attempt to intercept or tamper with the transmission changes their state, instantly alerting both sender and receiver to the breach. PQC takes a different path. Instead of relying on quantum physics, it builds new encryption methods using mathematical problems that are hard for both classical and quantum computers to solve. It is designed to replace current cryptographic algorithms, such as RSA and ECC, that will eventually become vulnerable to quantum attacks. Understanding where and how to use each is key to building a resilient, future-ready security posture.

Figure 1: Primary approaches to achieving quantum-safe security

Both approaches have distinct advantages and limitations, and selecting the right fit, or an optimal combination, requires a clear understanding of their trade-offs. Forward-looking security strategies should consider a hybrid approach: ensuring an enterprise-wide PQC deployment while piloting QKD in high-value or critical communication channels. For instance, a global bank must adopt a hybrid quantum-safe security strategy by deploying PQC across its enterprise applications, including mobile banking, internal communications, and cloud-based customer data systems, ensuring scalable protection without disrupting existing infrastructure. Simultaneously, it should implement QKD on dedicated fiber lines between its core data centers, for instance, in New York and Frankfurt, to secure high-value interbank settlement traffic. This approach would allow the bank to balance cost and security, using PQC for broad coverage and QKD for ultrasensitive operations, future-proofing its cybersecurity against both current and quantum-era threats.

Nationwide Strategies and Industry Adoption

In the emerging quantum era, the new arms race is not just about computing power; it is about who can secure their data first. Governments around the world are sprinting to deploy PQC and QKD infrastructure, not just to stay ahead of hackers but to prevent future breaches of today’s secrets. While strategies vary, from software-based resilience in the US to fiber-and-satellite QKD grids in China, the underlying mission is shared: protect national intelligence, financial systems, and critical infrastructure before adversaries can harvest and decrypt decades of sensitive data.

• China is taking a hardware-first approach by building a nationwide quantum communication network. Its landmark initiatives, such as the 2,000-kilometer Beijing–Shanghai QKD backbone and the Micius quantum satellite, leverage quantum entanglement and photon-based QKD to establish tamper-proof, ultrasafe communication links. These systems are being rapidly integrated across China’s government, defense, and financial sectors, underscoring the nation’s push for data sovereignty through infrastructure control.
• The US is leading with a software-centric strategy, focusing on PQC to secure existing digital systems. Spearheaded by NIST, the US has standardized quantum-resistant algorithms such as CRYSTALS-Kyber and Dilithium, which are compatible with current internet protocols. Under National Security Memorandum-10 (NSM-10), all federal agencies are mandated to transition to PQC. This approach emphasizes scalability, backward compatibility, and rapid deployment, making PQC a pragmatic choice for securing vast and interconnected digital ecosystems without requiring new hardware.
• The EU is pursuing a federated infrastructure model through the European Quantum Communication Infrastructure initiative. This ambitious project aims to connect all member states through QKD-enabled terrestrial fiber networks and satellite systems, coordinated by the European Commission and the European Space Agency. National fiber-based QKD testbeds such as FranceQCI, Denmark‘s CryptQ, and Germany’s QBN are driving cross-border quantum security. The goal is to build a sovereign, quantum-secure backbone for public services, defense, and critical industries across the EU.
• Beyond the major powers, countries such as India and the UK are rapidly scaling their efforts to establish sovereign quantum-secure communication infrastructure, adopting hybrid approaches that blend quantum and classical technologies. India, under the leadership of DRDO and IIT Delhi, has made significant strides in free-space quantum communication. A recent milestone includes the successful demonstration of entanglement-based QKD over a one-kilometer free-space link. The UK, guided by its National Quantum Strategy, is actively integrating QKD into its national telecom infrastructure, with the aim of establishing a quantum-secure backbone across the country. UK-based initiatives are focusing on combining terrestrial fiber, free-space optics, and PQC protocols to secure both civilian and critical government communications.

In fact, it is not just governments but enterprises handling high-value or sensitive data, too are increasingly prioritizing quantum-safe security. From global banks and telecom providers to pharmaceutical giants and energy firms, organizations across regulated industries are beginning to upgrade their encryption infrastructure using PQC and QKD.

Figure 2: Industries leading the adoption of quantum-secure solutions

Beyond early traction in these industries, sectors with critical data assets such as healthcare and life sciences (for example, electronic health records, clinical trial data, and pharmaceutical IP) and utilities (for example, power grid telemetry and SCADA commands) are showing growing interest in quantum-secure solutions. For example, the Electric Power Board of Chattanooga, Tennessee, successfully demonstrated QKD to authenticate smart grid communications over a live utility fiber network.

However, such real-world implementations remain limited across these industries, largely due to a lack of urgency around quantum readiness. This complacency is increasingly risky. Google’s recent demonstration of factoring 2048-bit RSA keys using fewer than a million noisy qubits highlights the rapid advancements in quantum capabilities and the increasing importance of transitioning to PQC as part of a forward-looking cybersecurity strategy.

Action Plan for CISOs

As quantum computing advances, organizations must shift from awareness to action. Securing enterprise data for the quantum era is not just about deploying new tools; it is about prioritizing the right data, aligning protection strategies, and ensuring long-term infrastructure agility.

1. 1. Assess and prioritize data at risk: Not all enterprise data requires the same level of protection. Before piloting quantum-safe solutions, enterprises must identify and classify sensitive data based on its lifespan, regulatory exposure, and strategic value. This enables smart decisions around deploying PQC, QKD, or a hybrid approach.
      • Long-life cycle sensitive data: Source code, product designs, and R&D blueprints
      • Regulated or legally protected data: Personally identifiable information, payment data, and KYC records
      • Strategic/competitive data: Trade secrets, AI training datasets, and vendor pricing contracts
      • Mission-critical infrastructure data: Encryption keys, API tokens, and access credentials
   2. Evaluate compatibility and integration requirements: While PQC can be integrated into the current IT infrastructure, it brings new design considerations such as larger key sizes, increased computational loads, and potential performance trade-offs, especially in IoT, embedded, or cloud-constrained environments. QKD, on the other hand, requires specialized quantum communication hardware and integration with classical networks, which may not be immediately feasible for all organizations. Enterprises must assess their current architecture, identify gaps, and explore hybrid cryptographic models that can evolve as technologies mature.
   3. Build crypto agility into cybersecurity infrastructure: As PQC standards evolve, no single algorithm can be assumed future-proof. Enterprises must design security systems with crypto agility, enabling seamless upgrades to newer algorithms without disrupting operations. This requires modular architectures and flexible key management, allowing organizations to adapt as cryptographic breakthroughs emerge and standards shift, ensuring long-term resilience and regulatory readiness.

By Chandrika Dutt, Research Director and Vaibhav Kumar, Research Intern