Quantum Computing Poses Urgent Cybersecurity Threats–And Opportunities

WASHINGTON, March 26, 2026 — Quantum technology is rapidly advancing on multiple fronts, creating both an urgent need to upgrade global encryption standards and new opportunities in computing, communications and sensing.

That was the message at a Broadband Breakfast Live Online session on Wednesday.

The discussion, moderated by Broadband Breakfast CEO Drew Clark, gathered specialists in quantum physics, cybersecurity, photonics and technology policy to survey a field that panelists described as entering a new phase in which decades of theoretical physics research may finally be translating into practical applications.

Rick Mukherjee, director of the Quantum Center at the University of Tennessee at Chattanooga and an associate professor of physics, opened by outlining the three pillars of quantum technology. 

Quantum computing uses entangled qubits to perform processing that could be orders of magnitude faster than today's most powerful supercomputers. Quantum sensing exploits the extreme sensitivity of quantum objects to measure electric fields, magnetic fields and gravitational forces with precision beyond classical sensors. And quantum networking connects quantum devices over distance, generally through fiber optic networks, to enable secure communication and distributed computing.

Mukherjee, a self-described optimist, said advances in quantum machine learning could eventually address one of classical AI's most pressing problems: Energy consumption. Fully realized quantum machine learning methods, he said, could use "a tiny fraction of energy" compared with the massive data centers required to train today's large language models,  while still delivering comparable capabilities.

Quantum and classical computing side-by-side

Yong Meng Sua, chief technology officer at Quantum Computing Inc. and a research assistant professor of physics at Stevens Institute of Technology, described his company's approach of building room-temperature quantum photonics products that leverage existing silicon photonics infrastructure, and avoiding the extreme cooling requirements of other quantum computing modalities.

"The mission of the company is to put quantum into the hands of billions of people," Sua said.

He emphasized that quantum and classical communications will work together rather than compete. "The best way for quantum communication to actually move forward is actually to work with classical and to provide the additional physical layer on top of the classical system to begin with," Sua said.

Celia Merzbacher, executive director of the Quantum Economic Development Consortium, provided context on the broader ecosystem. QEDC, a roughly 250-member global industry consortium managed by SRI International, was established at the direction of Congress under the 2018 National Quantum Initiative Act to bridge the public and private sectors.

Merzbacher described a "quantum plus" paradigm in which quantum capabilities augment rather than replace conventional technologies. "It's not classical or quantum," she said. "In all likelihood, whether it's computing or networking or sensing, there's going to be a fusion of traditional classical systems and quantum systems."

She said QEDC is preparing to release a quantum network applications roadmap in the coming weeks, and she urged continued federal investment as the reauthorization of the National Quantum Initiative Act moves forward. Merzbacher, who spent the day before the panel meeting with members of Congress, also highlighted quantum-based clock systems as an underappreciated application with significant implications for GPS, navigation and timing infrastructure.

Cybersecurity dimension demands immediate attention

At the same time, panelists made clear that the security dimension of quantum computing demands immediate attention.

Rebecca Krauthammer, CEO and cofounder of post-quantum cybersecurity firm QuSecure, said adversaries are already employing "harvest now, decrypt later" tactics — intercepting and stockpiling encrypted data today in anticipation of future quantum decryption capabilities.

"The most important thing to understand, regardless of what day this happens, is that it's already a problem," Krauthammer said.

She pointed to a looming federal deadline: Beginning Jan. 1, 2027, no new technology acquisitions for national security systems may proceed without support for post-quantum cryptographic standards under CNSA 2.0. Telecommunications companies that sell into the U.S. government are already working to meet that requirement, she said.

Krauthammer noted that post-quantum cryptographic algorithms standardized by the National Institute of Standards and Technology (NIST) run on existing infrastructure and do not require quantum computers to implement. 

"You do not need a quantum computer or quantum technologies necessarily to defend against the quantum attack that we're talking about," she said.

But the scale of the migration is daunting. Krauthammer compared it to the Y2K remediation effort, which cost an estimated $600 billion to $1.1 trillion in today's dollars, noting that the current digital landscape is far larger.

Merzbacher echoed the concern, saying companies that assist with migration consistently find legacy systems to be more complex than anticipated. "Even if it's 10 years until we have a quantum computer that can break encryption," she said, "now is the time to be thinking about this."