Quantum threats: What CISOs should do to prepare

The threat from quantum is already on most security leaders’ radars, but experts argue the reality is growing near. Concerningly, the figures show a lack of preparation for quantum capabilities that will give adversaries the ability to break encryption.

Organizations could face a ticking quantum time bomb, according to research from DigiCert, with the vast majority of firms aware that they aren’t properly prepared. While an overwhelming 85% of IT and security leaders believe that quantum computing advances will break existing security standards within a decade, only 7% have deployed quantum-safe certificates so far.

According to recent data from IBM's Cost of a Data Breach Report, 69%of organizations have no plan in place for post-quantum cryptography (PQC).

With ‘harvest now, decrypt later’ attacks a real risk for firms, what steps should CISOs be taking now to ensure they are prepared?

The quantum timeline

No one can give an exact date for when quantum computing will be able to break today’s widely-used public key cryptography, but the risk is close enough that governments, standards bodies and major technology companies are already acting.

The US National Institute of Standards and Technology (NIST) released its first three final post-quantum cryptography standards in 2024, while the UK’s National Cyber Security Centre (NCSC) has set a target for organizations to complete PQC migration by 2035.

Technology giants such as Cloudflare and Google are setting their own post-quantum security milestones for 2029.

The quantum threat is often compared to the millennium “bug” (Y2K). It has even earned its own moniker: “Y2Q”, or “Q-Day”.

But unlike Y2K, there won’t be “a single moment of failure”, says Mark Hughes, global managing partner, cybersecurity services at IBM. He says the reality could see risks materialize over multiple years. “Different cryptographic systems will fail earlier than others, and that all depends on design and key size,” he predicts.

Harvest now, decrypt later

DigiCert’s survey highlights concerns about ‘harvest now, decrypt later’ attacks, where adversaries steal information for use at a later date. Over 80% say at least some of their encrypted data is vulnerable, with around one-third reckoning more than a quarter could be at risk.

Simon Pamplin, chief technology officer at Certes, describes how attackers do not need a large-scale quantum computer today to create a future breach. “They can collect encrypted data now, store it, and wait until the capability exists to decrypt it.”

He says the quantum threat timeline is “much shorter than many organizations assume”.

“Whether a cryptographically relevant quantum computer arrives in 2029, 2035, or later, the data being harvested today may still be valuable when that moment arrives.”

Firms are often unaware of the type of data at risk. “People often think about passwords and payment details, but they're usually not the biggest concern,” says Tristan Shortland, CTO of Infinity Group. He says the most exposed data is information with a long shelf life: “Intellectual property, product designs, merger and acquisition discussions, healthcare records, legal documents and sensitive communications that retain value for years.”

This matters most in sectors with complex operational or national security requirements, including critical national infrastructure, financial services, energy and manufacturing, says Ben Packman, CSO at PQShield, which helped to create the quantum standards being enforced by NIST and the NCSC. “One unsupported system, legacy platform or unprepared supplier can create risk across a much wider technology estate.”

At the same time, quantum poses other threats beyond attackers stealing data to decrypt at a later point. “If future quantum computers are able to break the cryptography behind digital signatures and certificates, attackers could potentially make malicious software, fake updates or fraudulent communications appear legitimate,” warns Packman.

Mitigating the quantum threat

With the risks in mind, it makes sense to start preparing to secure data now to mitigate the quantum threat. This means building cryptographic agility into the systems, suppliers and upgrade cycles organizations already rely on, experts say.

“Organizations need cryptography that is agile enough to evolve as standards mature, threats change, and new implementation requirements emerge,” advises Packman.

He believes preparation starts with understanding where quantum-vulnerable public-key cryptography is used, which systems are most exposed, and which suppliers' systems depend on.

Pamplin concurs. From there, companies should “prioritize long-life and high-value data”, rather than “trying to treat everything equally”, he advises.

“80% of your data loss risk sits within 20% of your applications. That is where you should focus first.”

NIST calls for vulnerable public key algorithms to start being deprecated after 2030 and generally disallowed after 2035. Yet preparation must come sooner, says Paul Holt, group VP EMEA at DigiCert.

He warns that the process of inventorying an organization’s use of cryptography across the enterprise, creating post-quantum roadmaps for each use case, and executing the transition “can span many years”.

At the same time, he points out that beyond understanding quantum, security leaders are “struggling to convince the rest of the business that budget and resources are needed now”.

This is where crypto-agility becomes essential, according to Holt. “Weathering the transition to a quantum-safe posture demands the ability to adapt and scale digital certificate management. Meanwhile, organizations must migrate cryptography to approved post-quantum algorithms.”

Finally, he says certificates must be “immediately discoverable and manageable continuously and at scale”.

Yet when considering quantum preparedness, it’s also important not to rush. The quality of implementation will matter just as much as the standards themselves,” says Packman.

“Replacing cryptography as part of a planned upgrade is cheaper and less disruptive than retrofitting it later under tighter deadlines.”

He believes every scheduled technology refresh is “a chance to introduce quantum-safe capability, assess supplier roadmaps, validate implementations or retire systems that may become difficult to support later”.

While quantum attacks are still likely to be some years away, experts think IT and security leaders should start to view the area as part of the bigger picture. Shortland believes quantum is increasingly a governance issue.

“Boards routinely assess climate, geopolitical and supply chain risk over a 10-year horizon,” Packman adds.

“Quantum belongs in that category because it has the potential to undermine decisions being made about data today.”