Quantum threats to drive overhaul of cybersecurity by 2026

Rising concerns about the future of quantum-assisted cyberattacks are reshaping organisational security priorities, as new predictions point to significant changes in encryption, infrastructure protection, and AI governance by 2026.

Quantum threat acceleration

According to Karl Holmqvist, Founder and CEO of quantum resilience leader Lastwall Networks, businesses and governments are being pressed to speed up adoption of post-quantum cryptography measures due to the threat of 'steal-now, decrypt-later' espionage campaigns. Ongoing advances in quantum processor power and large-scale quantum computing investments are shortening expected timelines for viable quantum-assisted attacks.

New cryptographic standards, such as FIPS 203, have cleared the technical path for transition, prompting organisations to overhaul legacy security systems. Authorities in several countries, including regulatory agencies in the US, have already set deadlines for public sector transition to quantum-resistant encryption, requiring inventory and replacement of all vulnerable encryption within the decade.

"In 2026, the timeline for quantum-enabled attacks will shrink dramatically, pressuring organizations to expedite their adoption of post-quantum cryptography (PQC). Breakthroughs in quantum computing, such as recent leaps in quantum processor power and the corresponding multi-billion dollar buildouts that are underway, underscore that a cryptography-breaking machine may arrive sooner than expected," said Holmqvist.

Additionally, they expect to see an increase in quantum spending next year as post-quantum cryptography (PQC) migration deadlines approach.

"U.S. federal agencies face mandates to inventory and replace vulnerable encryption within the decade. With the 2024 standardization (FIPS 203) clearing the path for deployment, 2026 will see organizations scrambling to start the overhaul of their cryptographic infrastructure," he added.

Infrastructure at risk

Critical infrastructure sectors-such as power, water, healthcare, and telecommunications are expected to face greater risk from advanced persistent threats. Tensions between major nation-states are driving coordinated preparations for cyber conflict, with mounting evidence of malware being embedded in essential systems to serve as leverage in potential disputes.

Recent discoveries of foreign actors placing malicious code in energy and water systems have prompted governments to intensify security drills and mandate stringent incident reporting across public and private operators. Some governments are also reviewing the security of national telecom networks, considering steps such as temporary nationalisation to prevent foreign interference. The increasing frequency of targeted probing and sabotage is forecast to push cyber defence from an IT concern to a central plank of national security policy.

"Cyberattacks on critical infrastructure will reach new levels in 2026, fueled by global conflict preparations and rivalries. Defence experts have pegged 2027 as a potential flashpoint for great-power conflict, and nations are racing to harden their grids and supply lines in advance. This urgency is well-founded: recent discoveries revealed Chinese state-backed hackers (Volt Typhoon) pre-positioning malware in U.S. power and water networks, ostensibly to disrupt these services if tensions over Taiwan or other issues explode into open conflict," said Holmqvist. 

"In 2026, critical systems like energy grids, water treatment facilities, healthcare networks, and telecommunications will increasingly come under stealthy intrusion and attack attempts by multiple groups of nation-state actors. We will likely see more aggressive probing of infrastructure defenses and even limited-scope sabotage to test resiliency. It is also likely that we will see disruption campaigns demonstrate capabilities in coordinated bursts."

AI system reckoning

Following several years of rapid artificial intelligence adoption with limited oversight, forecasts anticipate the first major security breach directly attributable to an autonomous AI agent in 2026. The use of generative AI to craft highly convincing phishing scams and deepfake attacks is allowing threat actors to escalate breaches that spread rapidly across organisational networks.

Organisations are expected to increase scrutiny of previously deployed AI systems, introducing stricter access controls and more robust monitoring. At the same time, pressures are mounting for regulatory frameworks to hold firms accountable for AI-induced damages. AI's capacity to produce convincing disinformation and digital forgeries is prompting renewed interest in digital authenticity solutions, such as watermarking and digital provenance tracking.

"The unchecked 'Wild West' rush to deploy AI without proper safeguards will trigger a major security and trust reckoning in 2026. Over the past year, countless AI tools and systems rolled out with minimal oversight... and the fallout is coming due. We anticipate the first high-profile security breach caused directly by an autonomous AI agent in 2026, validating warnings that poorly governed AI can create new failure modes. Attackers are already leveraging AI as a force multiplier: classic threats like phishing are being supercharged by flawless deepfake voices and personalized automation, allowing minor vulnerabilities to chain into major breaches at machine speed. In 2026, smart organizations will rein in some of their initial AI deployments with rigorous security assessments, access controls, and real-time monitoring of AI behaviors. However some will not, and the results will be devastating. Hopefully we'll see the rise of AI governance frameworks and possibly new laws holding companies accountable for AI-induced harm. Meanwhile, the deluge of deepfake-generated disinformation and fraud will prompt a fight for digital truth. As AI blurs the line between reality and fabrication, the concept of authenticity is emerging as the new pillar of cybersecurity. Companies will start investing in verification technologies (watermarks, provenance tracking, digital signatures) to ensure that what users see and hear is genuine," said Holmqvist.