Former Israeli Cyber Chief Warns of ‘Q-Day’ Threat to Global Security

Tel Aviv, Israel – A major breakthrough in quantum computing could pose a grave threat to global cybersecurity as early as 2025, potentially enabling the hacking of nuclear weapons programs, former Israel National Cyber Directorate (INCD) chief Yigal Unna warned on Tuesday at the Cybertech Conference in Tel Aviv.

Speaking about “Q-Day,” Unna raised concerns over whether quantum computing advancements will cross a critical threshold next year, rendering most existing encryption methods—particularly those relying on RSA encryption—obsolete.

He suggested that this moment may already have arrived, citing reports that Chinese hackers allegedly breached a military-grade cyber defense system in late 2024.

While some experts believe such a quantum leap is still years away, Unna’s remarks underscore the growing urgency surrounding quantum cybersecurity.

If realized, Q-Day could compromise the integrity of financial systems, government infrastructure, and even nuclear arsenals, presenting an unprecedented global security risk.

Iran’s Expanding Cyber Threat

Gaby Portnoy, who served as INCD chief from early 2022 until February, echoed Unna’s concerns and highlighted Iran’s increasing cyber aggression.

“Iran, with a click of a button, can attack Israel and is doing so three times more than before,” Portnoy stated. “But they can also target the US, UK, Albania, and even the UAE and Saudi Arabia.”

Portnoy emphasized the evolving nature of cyber threats and the need for countries to adopt a proactive approach to cybersecurity.

He warned of the potential for a “cyber October 7,” referencing Hamas’s attack on Israel in 2023, and questioned whether the global cyber community was prepared for such a large-scale, coordinated attack.

“To meet this kind of challenge, we need to build better resilience, improve the culture of sharing, and constantly evolve… It’s not just about critical infrastructure. We must also look at our supply chain, our service providers, and a wider range of small and medium businesses,” he added.

Israel’s Cyber Defense Amid Rising Attacks

Despite a 300% surge in cyberattacks by Iran and Hezbollah since the outbreak of the Israel-Gaza war, Israel has successfully prevented any major breaches of national infrastructure or military systems, according to current acting INCD chief Nitzan Amar.

“We managed a zero success rate for major cyberattacks against Israel since October 7,” Amar said. “Our enemies could not harm Israeli national infrastructure or IDF operational freedom.”

Israel has long been regarded as a global leader in cybersecurity, continuously upgrading its defense capabilities to counter threats from state-sponsored hackers and cybercriminal groups.

However, the warnings from Unna and Portnoy indicate that the battlefield is rapidly shifting, with quantum computing potentially upending conventional security frameworks.

As concerns over Q-Day mount, cybersecurity experts are urging governments and private sectors worldwide to accelerate efforts in quantum-resistant encryption and digital resilience strategies.

The coming years will determine whether global cyber defenses can keep pace with the next generation of threats.