Schrödinger’s Cat, qubits and the future of everything

I've spent a long time trying to get under the hood of Quantum Computing and always come back to Schrödinger's Cat.

Schrödinger's Cat is a famous thought experiment that demonstrates the idea in quantum physics that tiny particles can be in two states at once until they're observed. It asks you to imagine a cat in a box with a mechanism that might kill it. Until you look inside, the cat is both alive and dead at the same time.

This is the premise of a qubit, which is the next generation computing. It can be a 1 or a 0 at the same time, until it is accessed. This is unlike modern computing, where a bit (part of a byte) is either a 1 or 0, it cannot be both.

This will transform computing and, the other day, my friend Dave Wallace blogged about it and has kindly said that I can share his blog so, here it is ... enjoy!

Unveiling Q-Day: How quantum computing could revolutionise (and disrupt) our digital world

Until a few weeks ago, I thought that humanity’s most significant challenges were increased geopolitical unrest, climate change, social media’s corrosive impact, and the rising machines ultimately taking control.

But then, another rider of the apocalypse trotted into view when someone mentioned an additional horror: Q-Day!

I first heard about Q-Day during an interview with Sergio Gago, the Managing Director of AI and Quantum Computing at Moody’s, the global leading source of insights on risk. Sergio, who arguably has one of the best jobs in the world, oversees a business powered by data—structured and unstructured—from across the globe.

Moody’s uses this data to help customers develop a holistic view of risk, and unsurprisingly, Sergio is a big fan of generative AI. In fact, Moody’s already boasts over 800 use cases for it. But beyond AI, Sergio’s focus is on quantum computing, which brings us to the ominous concept of Q-Day.

So, what exactly is Q-Day?

According to Sergio, Q-Day is the anticipated moment when quantum computers become powerful enough to break the cryptographic systems that currently secure our digital communications and transactions. To put it bluntly, it’s the day when the encryption that safeguards our banking, shopping, and personal communications could be rendered useless—potentially leading to a global financial meltdown.

But before diving deeper into this unsettling future, let’s rewind a bit.

Three things in life truly baffle me:

1. Pensions.
2. Why my kids don’t load the dishwasher correctly.
3. The mind-bending complexity of quantum computing.

Fortunately, my interview with Sergio was the perfect opportunity to demystify the third item on that list. He explained that quantum computers represent a new type of computing architecture, using qubits instead of traditional bits. Unlike bits, which are restricted to binary states (0 or 1), qubits can exist in multiple states simultaneously—a phenomenon known as superposition. This allows quantum computers to solve complex mathematical problems much faster than classical computers.

Sergio puts it simply: “Imagine the globe is a computer. Binary computers would only be able to use the North and South Poles. Quantum computers would be able to use any point on the globe.” Even I could grasp this conceptually. Full marks to Sergio for demystification and not a single mention of a cat, dead or alive.

The implications of Q-Day

On Q-Day, it’s believed there will be a seismic shift in cybersecurity. The cryptographic algorithms that currently protect sensitive data would become vulnerable to decryption by quantum computers. Everything that is encrypted today could potentially be laid bare. Banking, commerce, and personal communications—all the pillars of our digital world—could be exposed, leading to consequences we’ve never encountered.

Thankfully, Q-Day is estimated to be five to ten years away, mainly because building a stable quantum computer is fiendishly difficult. The processors need to be cooled to near absolute zero, among other technical challenges. But make no mistake—it’s coming. Sergio stressed that businesses and countries need to prepare now. Already, some groups are harvesting encrypted data with the intention of decrypting it when quantum computing capabilities mature.

Preparing for Q-Day

Much like the Y2K bug, Q-Day requires extensive preparation. This August, the National Institute of Standards and Technology (NIST) released the first set of post-quantum encryption standards designed to withstand quantum attacks. Similarly, the UK’s National Cyber Security Centre (NCSC) advises that migrating to post-quantum cryptography (PQC) is a complex, multi-year effort that requires immediate action.

Complete migration to PQC could take over a decade for many sectors, but organisations should begin now. For larger organisations, particularly those with bespoke IT systems, the NCSC recommends starting with the following steps:

1. Assess data: Identify what data is held, its value, and how long it needs protection.
2. System inventory: Document the systems that process and store data.
3. Protection methods: Understand how data is currently protected, mainly focusing on public key cryptography.
4. Supply chain coordination: Ensure your supply chain is preparing for PQC migration.

The banking industry, in particular, needs to take heed. The potential risks are immense, and there’s much work to be done.

Quantum computing’s broader impact

Quantum computers aren’t needed for everyday tasks like basic arithmetic, word processing, or running video games. Conventional CPUs and GPUs handle these tasks efficiently. Where quantum computers excel is in solving problems involving vast possibilities—such as simulating molecular structures (crucial in pharmaceuticals for drug discovery) or optimising complex logistical challenges, like finding the most efficient delivery routes. These problems involve nearly infinite possible combinations, and quantum computers can process these far more quickly than classical systems.

In finance, quantum computers could revolutionise tasks like portfolio optimisation, stress testing, and calculating regulatory capital requirements. These activities often involve combinatorial problems and Monte Carlo simulations—areas where quantum systems could offer unprecedented power.

The symbiosis of AI and quantum computing

When asked about the relationship between AI and quantum computing, Sergio explained that the two technologies have a symbiotic relationship. Quantum computers can significantly enhance AI by optimising complex algorithms, potentially leading to better solutions for tasks where classical AI might struggle. Conversely, AI is playing a crucial role in the development of quantum computing, particularly in error correction and mitigation—a significant challenge in making quantum computers more reliable and scalable.

While quantum computing could potentially supercharge AI, it’s still uncertain whether this will be critical in achieving Artificial General Intelligence (AGI), as both technologies have different development timelines.

Final thoughts

Sergio will be featured on the Dave and Dharm Demystify podcast soon, where we’ll explore these topics in even greater depth. I highly recommend tuning in—there’s so much more to uncover about the fascinating and somewhat terrifying world of quantum computing