Post-Quantum Security: What CISOs should know now

Public-key cryptography has quietly protected the digital world for over four decades. It secures financial transactions, electronic identities, cloud workloads, authentication paths, software updates and the data streams that power modern business. For most of that time, we treated these cryptography foundations as stable, reliable and essentially permanent.

That era is ending.

Quantum computing is no longer a distant laboratory research subject. Large-scale quantum machines capable of breaking RSA and elliptic curve cryptography (ECC) are expected and when they arrive, the encryption protecting your most sensitive data will fail. This is not a theoretical academic exercise – it is a strategic security topic that will touch every enterprise, every sector and every encrypted byte of data you are responsible for protecting.

Over the last several years working with global CISOs, I have witnessed a decisive shift: the conversation has moved from awareness to urgency. Leaders no longer ask whether they should prepare for post-quantum cryptography (PQC). They ask how quickly they can execute and how to manage the transition without disrupting their business.

This new reality pivots on a single, uncomfortable truth:

The lifetime of the data – not the maturity of the quantum computer – is what defines urgency.

Adversaries don’t need a working quantum computer today to make the data you are protecting today vulnerable tomorrow. They simply need to intercept and store it now, then decrypt it later. That timeline alone fundamentally changes the security calculus for nearly every organization. PQC is a boardroom priority, not just a technical discussion.

The threat is already active

The quantum era has introduced one of the most disruptive changes: “harvest now, decrypt later” attacks. Threat actors – state-level, criminal and commercial – are already intercepting encrypted communications, storing them and waiting for the day to decrypt them.

This means the risk horizon has moved:

The confidentiality period of the data
The value of the data over time
The durability of the current cryptography
The time required to migrate at enterprise scale

If your data needs to remain confidential for 10, 20 or 30 years, then PQC is not a future requirement but a current necessity.

A shift in CISO mindset: from future plan to present priority

When I first started talking to CISOs worldwide about PQC, most organizations were still watching from the sidelines. The general comments were:

“We’ll plan once the technology is mature.”
“Quantum is far enough away.”
“We have time.”

By mid-2024, the tone had fundamentally changed. Today, CEOs, boards and CISOs are asking pressing operational questions:

Where does cryptography exist in our environment?
Which systems protect long-lived or high-value assets?
How long will migration take in reality?
What are regulators and business partners expecting from us?
Which vendors are ready and which are not?

This new posture signifies a greater maturity. Today’s CISOs understand that the biggest challenge in privacy-preserving computing is not mathematics, but scope. Cryptography touches every aspect: hardware, firmware, applications, identities, certificates, supply chains, networks and data policies.

During a recent leadership briefing, I summarized my observations across dozens of global organizations:

CISOs are no longer contemplating whether to begin PQC preparations; they are now focused on the speed of execution.

This aligns with global program trends:

PQC is no longer viewed as a mere R&D experiment
It is becoming an integral part of enterprise risk management and long-term cybersecurity planning
Organizations that commence PQC late will struggle to keep pace.

The regulatory and market push is accelerating

Across regions, signals of consistent and growing PQC adoption are clear:

NIST has chosen its first PQC algorithms, with full standards rollout.
The US federal government has mandated cryptographic inventory and transition planning.
ENISA and European agencies have issued guidance calling for similar measures.
Cloud platforms, certificate authorities, browsers and operating systems are beginning to integrate hybrid or candidate PQC algorithms.

We have crossed the tipping point; PQC adoption is no longer a question of “if,” but “when and how fast.”

Crypto visibility: The first non-negotiable (!) step

Before any organization can migrate, one essential step must be completed:

Identify where cryptography lives.

This is more difficult than many initially assume. In many enterprises, cryptography has accumulated over decades, embedded across:

Legacy applications
Modern microservices
PKI and certificate chains
Network tunnels
Databases and secure logs
OT and industrial systems
Authentication protocols
Mobile and IoT devices
Third-party platforms
Software supply chains

In fact, most organizations don’t have a complete map of their cryptographic dependencies. And that is precisely why:

Organizations can’t migrate what they can’t see, so cryptographic visibility is their number one priority.

An accurate inventory is the foundation for everything else:

Identifying attack surfaces
Assessing migration complexity
Calculating business impact
Planning phased deployment
Understanding vendor alignment

Once cryptography is visible, CISOs can take informed, structured action.

Data classification: Long-lived data drives priority

Not all data needs immediate quantum-resistant protection. The priority is given to information whose confidentiality will outlast today’s cryptography – data that will remain relevant in 2035, 2040, or beyond. Examples include:

Health records
Government archives
Identity and authentication logs
Proprietary R&D
Legal communications
Product designs and industrial IP
High-value transactions
Secure firmware and software updates

This is where many organizations are starting: securing the data that attackers would most want to decrypt with tomorrow’s computers.

Crypto-agility: The only sustainable strategy

A crucial lesson from the PQC transition is that cryptography can no longer be “hardwired” into systems. Organizations must adopt architectures that allow for flexible cryptography without redesigning their systems, whether they’re deploying NIST algorithms hybrid solutions or future refinements.

Crypto-agility enables organizations to:

Upgrade algorithms seamlessly
Respond if a vulnerability is discovered
Avoid vendor dependence
Minimize future migration cost
Maintain trust without disruption

Forward-looking organizations are designing agility in from the start, not as an afterthought.

A practical enterprise roadmap

While every organization’s environment is unique, most successful PQC programs adhere to four structured phases:

Discovery

Build a cryptographic inventory
Map data timelines and sensitivity
Understand third-party dependencies
Establish governance and ownership

Design

Define a multi-year roadmap
Introduce crypto-agility principles
Prioritize based on business risk
Align with evolving standards and vendors

Pilot

Deploy hybrid or test systems
Validate performance and compatibility
Involve customers, partners and engineering teams
Prepare internal teams for operational change

Scale

Extend PQC across systems and services
Introduce automation for cryptographic lifecycle
Continuously monitor adoption and risk
Maintain compliance with emerging guidance

Done this way, the transition becomes manageable and future cryptographic upgrades become significantly easier.

The advantage belongs to early movers

The PQC transition is not the first major cybersecurity shift but it is the most foundational since public-key cryptography became widespread. Organizations that start early will: