Learn about the benefits and use cases of quantum computing. Also, get details about quantum cryptography from an expert.

Investors dedicated $2.35 billion to quantum technology startups in 2022, according to McKinsey & Company. With quantum technologies proliferating, business leaders may be wondering whether quantum computing is appropriate and secure for their work.

I interviewed Mario Milicevic, principal engineer at connectivity hardware and software company MaxLinear and a member of IEEE, to talk about developments in quantum computing for research and cybersecurity.

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What is quantum computing?

Quantum computing is a method of performing calculations using qubits instead of binary bits. While binary bits can hold one of two values, 1 or 0, qubits can hold a combination of possible values. That combination, or “superposition,” can provide a vast array of possible values for the quantum computer to use in calculations.

Another important quality of qubits is their entanglement, meaning qubits that are not in the same physical space may still correlate with each other.

“You can solve large mathematical problems [with quantum computers] which are prohibitively expensive to solve using classical computers. [This is a problem] which we have today because the compute time just grows exponentially,” said Milicevic.

When should a business use quantum computing?

A business should use quantum computing if the mathematical problem that needs to be solved is too complex for conventional computing to complete in a practical amount of time. The pharmaceutical and materials engineering industries have found use cases for using quantum computing to find why and how certain molecule bonds matched or create new materials.

People who want to use quantum computing for business should be prepared to pay for access to a quantum computer. It can be an enormous financial burden to build and run one independently, Milicevic said.

Milicevic also pointed out quantum computing isn’t always relevant to the tasks an organization is trying to do. Setting up the infrastructure takes enormous effort and energy (e.g., quantum computers need to be cooled to near absolute zero).

“For the majority of [mathematical] problems, classical computers will actually outperform quantum computers. And more importantly, they’ll outperform quantum computers at a much lower cost,” Milicevic said.

“It’s really a matter of understanding ‘Is the problem [I’m] trying to solve complex mathematically?’” Milicevic said. “‘Are there millions of combinations? And if so, then am I really trying to optimize something? What’s the cost to run it?’”

SEE: Why IT should keep quantum computing in mind (TechRepublic)

The field of quantum computing is so new that many of the major players are still in the experimental stage. Most projects are likely to be undertaken by governments, massive organizations or telecom infrastructure giants. Still, it marks an interesting frontier for computing and communication.

What quantum computers are available to use?

To take advantage of quantum computing, a company may need to rent out space on a computer. Some options include:

• IBM provides API access to its quantum computing resources.
• Google offers a Python package library of frameworks for programming quantum computers.
• D-Wave’s Leap, which allows researchers and developers to rent time by the minute on its hardware, is different because it features quantum annealing, which is a mathematical process that can be used to find the minimum possible energy state. For example, put simply, it can be used to find the most efficient route for traveling between many locations.
• Amazon is trying to become a marketplace for quantum computing with Braket, a platform for developers working in scientific research.
• Microsoft Azure rents out time on its cloud service, which can perform a mix of quantum and conventional calculations.
• Quantinuum, which spun out of Honeywell, launched the second-generation quantum computing solution System Model H2 in May 2023. This system is quite experimental and may be most relevant to researchers.

How will quantum cryptography change cybersecurity?

When it comes to cybersecurity, quantum computing and other methods taking into account quantum states, such as quantum cryptography, could be used by attackers as much as by defenders. Quantum computers could potentially solve factoring problems to break encryption keys very quickly.

There are two elements of cybersecurity related to quantum computing to keep in mind, Milicivec said:

• Post-quantum cryptography or post-quantum encryption, in which one develops algorithms that would be resistant to attacks with a quantum computer.
• Quantum key distribution, which is enabled by using quantum computers and a fiber optic cable embedded between two physical locations.

Companies including JPMorgan Chase, Toshiba, the Canadian telecom group Ciena and ID Quantique in Switzerland are working on quantum key distribution. Research in quantum key distribution is ongoing as organizations try to solve problems such as errors introduced by the difficulty of maintaining the extremely low temperatures ideal for quantum computing and how to improve the stability of the qubits.

Quantum key distribution with fiber optics would enable organizations to quickly know whether someone had disrupted their connection.

Regarding quantum key distribution, Milicevic said, “If any attacker or eavesdropper were to somehow cut this fiber optic cable and insert some kind of device that would allow them to measure the light and then retransmit that light, they would actually disrupt what’s known as a quantum state of that light.”

That would make it “impossible” for a physical disruption to go undetected, Milicevic said.