Demystifying Quantum Computing (DDN2-A54)

Demystifying Quantum Computing

Introduction

Quantum computing is a growing field, and one that could have massive impacts on government, organizations and critical infrastructure.

Here's the short version: Quantum computers don't rely on traditional computer chips. Instead, they perform calculations using the behaviour of tiny particles, allowing them to solve problems that are too complex for traditional computers. They'll enable radically different forms of analysis, but also require substantially more robust security and encryption protocols. Working quantum computers exist today, but not in a state that's practical for use.

What does the word quantum mean in this context?

Quantum mechanics is the physics of the very small. The field seeks to predict and explain the behaviour of atoms and molecules and involves the manipulation and control of systems at the atomic and subatomic levels.

Quantum mechanics deals with the behaviour of the smallest particles known to us, like atoms and subatomic particles. It's often counterintuitive compared to how we experience everyday life. For instance, researchers have found that particles' behaviour can influence other particles at a distance without an observable cause-effect chain. Or, that measuring or interacting with particles changes their state. So instead of knowing exactly where something is or how it behaves, we can only calculate the likelihood of it being somewhere or behaving a certain way.

What is quantum computing?

One of the main areas where quantum technology is applied today is quantum computing, which processes data in a way that's completely different from traditional computers. Quantum computing is a field that combines computer science and physics, and uses the principles of quantum mechanics to solve problems that are too complex in scope for classical computers. It is expected to create major shifts in technology and business. According to The Business and Technological Impacts of Quantum Computing, quantum computing could transform data encryption, improve decision-making in complex situations, speed up research and development, enhance financial models, and redefine AI-driven insights. As this technology develops, it could lead to changes in competition, the creation of new markets, and a shift of strategic investments.

Quantum technologies

Quantum mechanics is a branch of science that studies the behaviour of very small particles, like atoms and subatomic particles. It goes beyond just computers. Canada's National Quantum Strategy has outlined five key areas of quantum technologies:

How does quantum computing work?

Let's say you want to find a treasure chest in a lake. A classical computing approach would be to create a grid covering the whole lake, and then check each square in the grid one at a time. That solution gets slower and slower the bigger the lake is.

Quantum computing would be like dropping a stone on the lake's surface. The ripples that come off the stone would spread across the lake. The treasure chest would interfere with the ripples and create a pattern from which you could identify the location of the chest. One interaction gives you the information you need as opposed to many, sequential interactions. If the lake was really big, the ripple (quantum) approach would take a bit longer, but nothing compared to the grid (classical) approach which would take even longer. (While analogies like this aren't perfect or scientifically accurate, they can help make complex concepts easier to understand.)

Key differences between classical and quantum computers

• How they handle information
  • Classical computers use bits to store and process data. A bit can only be in one of two states: 0 or 1. Think of a light switch, it's either on or off.
  • Quantum computers use qubits, which can exist in superposition, a state where they are an evolving mixture of 0 and 1 until they are measured or interacted with.
  • For example, imagine flipping a coin. When the coin is spinning in the air, it's not just heads or tails; it could be argued that it's both at once until it lands. A qubit in superposition works in a similar way, allowing quantum computers to consider multiple possibilities at once.
• Processing capability
  • Classical computers solve problems step by step, one calculation at a time.
  • Quantum computers solve problems by exploring many options all at once, which makes them effective for complex tasks like studying molecules, analyzing huge amounts of data and potentially breaking encryption.
• Purpose
  • Classical computers are great for everyday tasks like calculations, word processing, or browsing the internet.
  • Quantum computers are not designed for everyday use. Instead, they are specialized tools for solving specific problems that are beyond the reach of classical computers, such as:
    • simulating how molecules behave to create better medicines or materials
    • finding structures in large datasets

It's important to note that quantum computers are not meant to (and will not) replace classical computers. They won't be faster at everyday tasks like addition (your phone or calculator is already perfect for that). They're powerful tools for solving specific problems that could lead to breakthroughs in science and technology. However, quantum computing, like many new technologies, brings great potential but also comes with risks.

The risk of quantum computing

According to Canada's National Quantum Strategy, while quantum computing's incredible speed for solving specific problems could lead to major advancements across many industries, it also carries risks. If misused, it could threaten personal data, financial systems, utility grids, critical infrastructures, and even national security.

Although quantum computing is currently limited, the arrival of powerful and widely accessible quantum computers is only a matter of time. When that happens, the impact could be enormous.

One of the biggest threats posed by quantum computing is the harvest now, decrypt later strategy. This means cyber threat actors might currently be collecting large amounts of encrypted data, with the expectation that future quantum computers will be able to decrypt them. Even information you thought was secure or have long forgotten like old emails, financial records, or personal messages might resurface and could be exploited in a post-quantum world.

If we don't migrate to post-quantum cryptography in time, other risks include breaking signatures, loss of secure communications and changes to identity and access management.

Breaking signatures and loss of secure communications

Quantum computing could disrupt public-key cryptography, which is the foundation of many online security systems. Here are examples of what public-key cryptography does:

• Authenticating identities, like ensuring your emails come from a trusted source or ensuring a website or software update is legitimate.
• Protecting secure communication, like encrypting messages between your phone and a banking app or keeping video calls private.

If quantum computers are able to crack these systems, it could lead to significant security risks:

• Digital signatures could be forged, increasing the risk of phishing and malware attacks.
• Encrypted communication could be intercepted and decoded, exposing private information. This would compromise the security of many services we rely on, such as online shopping, email and smart home devices.

Changes to identity and access management

Without secure cryptography, sensitive information could be exposed or stolen. For example:

• Bank accounts could be hacked, leading to financial fraud or identity theft.
• Logins for critical services, like healthcare portals or cloud storage, could be exposed, threatening privacy and security.

Protection against these threats will require post-quantum cryptography. Post-quantum cryptography refers to new encryption methods designed to protect sensitive information from the advanced capabilities of quantum computers.

Without this transition, critical data, such as personal, financial and government information, could be at risk of being exposed or compromised when current security systems are no longer effective against quantum-powered attacks.

Preparing for a post-quantum world

A post-quantum world will change how we conduct ourselves online both in our personal and professional lives.

Policy Horizons Canada has identified cyber attacks targeting critical infrastructure as one of the top 10 potential future disruptions that decision-makers should be prepared for. If you are a leader, you may need to address the quantum threat to cryptography, which includes potential disruptions to the software and hardware used in our day-to-day work.

This will be no small task; it's important to understand the scale of the changes that will be required within your organization to effectively manage these threats, including a comprehensive transition to quantum-resistant cryptography.

Rest assured, there are already some safeguards in place, and more solutions are being developed to address the remaining challenges. Consider the following:

Preparing for a post-quantum world has been described as a marathon, not a sprint. The marathon is underway; it's important to be careful and not rushed. It's time to lace up your shoes and join in; all leaders across the Government of Canada need to be aware, engaged and ready to make important decisions.

Pay attention to the evolving landscape

Canada is currently a global leader in quantum science and technology, but the field is evolving rapidly. One major challenge will be ensuring the interoperability of existing and new systems, as transitioning to new cryptographic technologies may take years, and will require collaboration with trusted allies.

Some have expressed concern that one of generative artificial intelligence's greatest cyber security risks is the potential distraction from other priorities, such as the quantum threat (Podcast: Generative AI in Cybersecurity – Innovation or Distraction?). Don't lose sight of this and other emerging threats—and opportunities!

Be ready to act

You don't need to be an expert in quantum computing. However, you do need to be prepared to adapt to emerging threats. Follow the guidance from the Canadian Centre for Cyber Security and work with your senior information technology leaders to respond effectively. As a public servant, it will be crucial to quickly address requests related to security updates, whether it's for hardware, software, protocol or all of the above. Quick action is key to keeping our systems secure.

As a leader and a decision-maker, you may need to:

• support the migration of IT systems to post-quantum cryptography
• allocate human and financial resources to the migration or transition to post-quantum readiness

You could also play a key role in developing, attracting and retaining the talent Canada needs to succeed in quantum science and technology. Talent shortages are already challenging industry and research institutions, and these challenges will grow as quantum technologies become more widely used (Canada's National Quantum Strategy).

Know where to find additional information

It's okay if you find quantum computing mystifying. American theoretical physicist and Nobel laureate Richard Feynman is credited with saying “If you think you understand quantum mechanics, you don't understand quantum mechanics.”

This is an area that is evolving quickly. Consult the resources below for additional information and let us know if you find any content in this article to be outdated.

Resources

• Article | The Race is On – Global Risk Institute Quantum Threat Primer
• Article | What Is Post-Quantum Cryptography?
• Article | What Is Quantum Computing? And Why Executives Should Care
• Other | Government of Canada's Enterprise Cyber Security Strategy
• Other | Preparing your organization for the quantum threat to cryptography (ITSAP.00.017)
• Other | Canada's National Quantum Strategy