Quantum Computing and Cybersecurity’s Coming Reckoning

Vijhai Grayan | Cyber, Tech and Space Fellow

Image sourced from Planet Volumes via Unsplash.

The cryptographic scaffolding on which global digital infrastructure precariously rests was never designed to be timeless. But we are treating it as if it were.

In the early 1940s, physicists on the Manhattan Project confirmed a theoretical possibility: that splitting the atom could trigger a self-sustaining chain reaction. There was no explosion — yet. But the discovery irrevocably altered the trajectory of history. From that point forward, the question changed from if an atomic bomb could be built, to when, and what kind of world would emerge in its wake.

Microsoft’s recent breakthrough in topological quantum computing carries a comparable historical gravity. Quiet, technical, and still years away from its full implications — but undeniably historic. By demonstrating fault-tolerant qubits, Microsoft has laid a credible foundation for scalable quantum machines. Machines that, in time, could render obsolete the encryption safeguarding everything from national defence systems to the contents of a suburban bank account.

It wasn’t a detonation. But it confirmed the reaction works.

Yet public policy, security architecture, and even strategic planning continue to operate as though the quantum threat is perpetually on the horizon. This is beyond simply a failure of preparedness. It is a collective act of negligent procrastination. Australia must abandon this posture of passive observation and urgently initiate a coordinated national transition to quantum-resilient cryptography—before the theoretical becomes irreversible.

The promise and peril of quantum capability

Quantum computers harness the counterintuitive principles of quantum mechanics —superposition, entanglement, and quantum interference — to perform certain types of computations exponentially faster than classical systems. While still nascent, they pose a singular threat to widely-used encryption schemes.

While no such computer currently exists, the field is accelerating at lightning speed. Google, IBM, and China's National Laboratory for Quantum Information Science are all racing towards quantum supremacy.

Governments know this. The U.S. National Institute of Standards and Technology has already selected four quantum-resistant encryption algorithms. The United Kingdom and Germany have followed suit with detailed transition strategies. These nations have treated the splitting of the cryptographic atom as an urgent structural risk. Australia has not.

Microsoft’s moment — and what it means

For decades, one of the most significant barriers to quantum computing has been the instability of qubits. They are notoriously error-prone and difficult to scale. Microsoft tackled this by designing a chip using Majorana zero modes, a kind of exotic quantum particle theorised to offer more robust, fault-tolerant qubits.

Their chip met key performance thresholds required for scalable systems. While we may not have a machine capable of breaking encryption today, we now have a viable path to building one. We may not have built the bomb — but we’ve enriched the uranium.

The case for mandatory crypto-agility

Australia’s 2023–2030 Cyber Security Strategy categorises quantum computing as a "horizon threat." The implication is clear: this is a problem for another day. But Microsoft’s chip shortens the horizon and so Australia must act, now, with precision and scale. The first and most critical reform should be to mandate crypto-agility across critical sectors.

Crypto-agility refers to the ability of systems to rapidly swap cryptographic algorithms as threats evolve. This is not a new concept. It has long been advocated by cryptographers at NIST and the U.S. Cybersecurity and Infrastructure Security Agency. But it has rarely been operationalised at scale.

A diligent Australian crypto-agility mandate should include:

• A national cryptographic audit of all systems within government, defence, and critical infrastructure.

• A phased migration plan to quantum-resistant encryption, starting with NIST’s approved post-quantum algorithms.

• Funding incentives and technical support for SMEs and regional operators to transition securely.

• Mandatory crypto-agility architecture in new digital infrastructure projects and procurement guidelines.

Critics may argue this is premature, that time and cost constraints are prohibitive, and that current threats — like ransomware and nation-state hacking — deserve greater attention. However, this is not an either/or scenario. Quantum is not a replacement risk. It is a compounding multiplier. It makes existing vulnerabilities worse, not irrelevant.

The precarious and fragile global norm

Australia is not alone in its inertia. The global cryptographic commons are equally brittle. Billions of devices — routers, satellites, payment terminals — rely on hardcoded encryption libraries that cannot be patched. Software supply chains are long, opaque, and borderless. The work of migrating away from these systems will be as political as it is technical.

There is an opportunity here for Australia to lead — in research and investment, but also in norm-setting. An Australian-led initiative, modelled on the EU’s Cyber Resilience Act and focused on quantum cryptography, could establish:

• Minimum post-quantum standards for digital exports.

• Shared interoperability frameworks for Five Eyes partners.

• International funding pools to support quantum transition in developing nations.

If quantum computing undermines trust, international coordination must be the counterbalance. Standards cannot stop at the firewall.

Preparing for the unpatchable future

Within the next 10 years, quantum computing will render the system’s foundational assumptions invalid. Australia and the world must move beyond reactive security and build systems that do not collapse when the laws of mathematics change.

Microsoft's Majorana 1 chip may not usher in the quantum era overnight, but it is a signal flare. The future is not speculative. It is arriving.

The time to secure that future was yesterday. The second-best time is now.

Vijhai Grayan is the Cyber, Tech and Space Fellow for Young Australians in International Affairs. He is a lawyer at a leading Australian technology company and an MBA candidate at the University of Sydney, where he received the Future Leaders Scholarship. With expertise in law, cyber, and technology, he is passionate about the rapid evolution of technology, its profound impact on global society, and its transformative potential to reshape international affairs.

Our 2025 Cyber, Tech and Space Fellow is sponsored by .au Domain Administration (auDA). For more information, visit their website here.