Quantum-safe encryption
Why the threat to your data is already here

18th March 2026BlogAJ Thompson

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In this article:

• Quantum computers will break today’s encryption and the threat is closer than most organisations think.
• ‘Harvest now, decrypt later’ attacks are already underway. Encrypted data stolen today can be decrypted once quantum capability arrives.
• The average organisation scores just 21/100 on IBM’s Quantum-Safe Readiness Index, and full migration is expected to take 12 years.
• NIST published its first post-quantum cryptographic (PQC) standards in 2024, giving organisations the tools to begin their quantum-safe encryption journey.
• Crypto-agility and early action are the defining traits of organisations leading on quantum-safe security.

The encryption crisis: how quantum computing is challenging organisations to rethink security

Quantum-safe encryption is one of the most urgent and overlooked challenges in enterprise security today. Trust is the lifeblood of the digital economy. Every time you send an email, enter card details for a bank transfer, or log into a corporate network, encryption is silently working in the background to keep that transaction safe. For decades, cryptographic standards like RSA and Diffie-Hellman have been the bedrock of digital security. Quantum computing could leave that bedrock in tatters.

quantum-safe encryption diagram showing how a quantum computer breaks RSA encryption using Shor's algorithm and the harvest now decrypt later attack strategy

How encryption works and why it is vulnerable to quantum attack

Today’s encryption is built on mathematical problems that no classical computer could solve in a reasonable timeframe. Factoring a 2,048-bit number, for instance, would require the world’s most powerful supercomputer billions of years. It is the sheer difficulty of that mathematics that keeps your data safe.

However, a quantum computer with sufficient power can execute Shor’s algorithm — a quantum algorithm that factors large numbers exponentially faster than any classical method. Once we have cryptographically relevant quantum computers (CRQCs), the encryption safeguarding your data, your customers’ data, and your organisation’s intellectual property could be broken in minutes.

The ‘Harvest Now, Decrypt Later’ threat is already here

Cybercriminals are already stealing encrypted data today, betting they will be able to decrypt it once quantum computers become a reality. Share on X

Cybercriminals are already stealing encrypted data today, betting they will be able to decrypt it once quantum computers become a reality.

This is not a hypothetical future threat. It is happening right now. Nation-state adversaries and sophisticated threat actors are collecting encrypted communications today with a clear strategy: harvest the data now, decrypt it later when quantum capability becomes available.

Financial records, health data, intellectual property, classified communications, and personally identifiable information are all in the crosshairs. The IBM Institute for Business Value research, based on responses from 565 executives across 15 countries and 13 industries, found that despite this clear and present danger, quantum-safe awareness remains dangerously low.

The scale of the quantum-safe encryption challenge

For organisations, this is not simply a case of applying a software patch. Cryptography exists at virtually every layer of the digital enterprise — applications, networks, infrastructure, APIs, supply chains, and third-party services. Transitioning to quantum-safe cryptographic standards is an enterprise-wide exercise that can take years to complete.

The numbers speak for themselves:

Stat

What it means

21 / 100 Average Quantum-Safe Readiness Index score globally (IBM IBV research, 565 executives across 15 countries)
12 years How long organisations estimate it will take to fully integrate quantum-safe encryption standards
2035 NIST deadline for full compliance for National Security Systems
82% Of Quantum-Safe Champions already deploying crypto-agility programmes — three times the rate of the least-ready group

The arithmetic is sobering. With a 12-year integration timeline and a compliance deadline of 2035, organisations that have not yet started are already well behind the curve.

quantum-safe encryption readiness infographic showing IBM research stats: 21 out of 100 readiness score, 12 year migration timeline, and 2035 NIST compliance deadlineWhat post-quantum cryptography and NIST PQC Standards mean in practice

You do not need to own a quantum computer to become quantum-safe. Achieving quantum-safe encryption means replacing vulnerable cryptographic algorithms — particularly public-key systems — with new standards that are resistant to quantum attack.

In 2024, NIST published its first set of post-quantum cryptographic (PQC) standards, providing organisations with the algorithms they need to begin their migration. This is a significant milestone and a clear signal that the transition from legacy cryptography is no longer optional.

One critical enabler of this transition is crypto-agility: the ability to swap cryptographic algorithms quickly without overhauling entire systems. The top 10% of organisations in IBM’s readiness index — the Quantum-Safe Champions — are already deploying crypto-agility programmes at three times the rate of their least-prepared peers.

Quantum-safe security as a competitive differentiator

Security is no longer simply a cost of doing business. Organisations that achieve quantum-safe status will demonstrate a measurably higher level of trust and resilience to their customers, partners, and regulators.

In financial services, healthcare, telecommunications, and government contracting, quantum-safe encryption will gradually become a licence to operate and a genuine competitive differentiator for those who move first.

In the words of Sujith Surendranathan, Director of Database Security and Data Protection at Sun Life:
“Every organisation has exposure to quantum threats, even if they do not themselves use quantum computing. The threat is universal. The response must be too.”

Where should organisations start?

The path to quantum-safe security begins with visibility. Organisations need to understand where cryptography lives across their estate, across applications, infrastructure, APIs, and supply chain, before they can begin to prioritise migration.

At Northdoor, we help organisations build that picture and develop a structured roadmap to quantum-safe readiness. If you would like to understand your current exposure and where to start, speak to our team about quantum-safe security.

Related reading: The Quantum Revolution 

Infographic explaining the urgency of quantum-safe encryption, highlighting the harvest-now-decrypt-later threat, low global readiness scores, the 12‑year migration gap, and steps toward NIST-aligned quantum-safe readiness.

Frequently Asked Questions (FAQ’s) on quantum-safe encryption

What is quantum-safe encryption?

Quantum-safe encryption means replacing the cryptographic algorithms that currently protect most data, particularly public-key systems like RSA and Diffie-Hellman, with new standards that quantum computers cannot easily break. Importantly, you do not need to own a quantum computer to implement these protections. It is about adopting mathematics that quantum algorithms cannot quickly solve.

Why is quantum computing a threat to current data security?

Today’s encryption is built on mathematical problems that would take classical supercomputers billions of years to crack. A sufficiently powerful quantum computer changes that equation entirely. By running something called Shor’s algorithm, a quantum machine can factor the large numbers underpinning current encryption exponentially faster than any classical method — potentially breaking protections that were once considered unassailable, in minutes.

What is the “Harvest Now, Decrypt Later” threat?

This is where the threat becomes immediate rather than theoretical. Nation-state adversaries and cybercriminals are already collecting encrypted data today, banking on the fact that quantum computers capable of decrypting it will eventually arrive. Financial records, health data, intellectual property — all of it is being quietly stockpiled. The encryption protecting it today may not protect it for much longer.

How long does it take an organisation to become quantum-safe?

Longer than most people expect. On average, organisations estimate the full transition to quantum-safe standards will take around 12 years. That reflects the reality that cryptography is embedded across almost every layer of the modern enterprise — applications, networks, infrastructure, APIs, and supply chains. This is not a patch. It is a programme.

What are the NIST post-quantum cryptographic standards?

In 2024, the National Institute of Standards and Technology published its first set of post-quantum cryptographic standards, giving organisations the specific algorithms they need to begin migrating away from legacy systems. NIST has also set 2035 as the compliance deadline for National Security Systems. Given the 12-year average transition timeline, that deadline is already pressing.

What is crypto-agility and why does it matter?

Crypto-agility is the capacity to swap cryptographic algorithms quickly without having to rebuild entire systems from the ground up. It matters because the threat landscape will continue to evolve, and organisations need to be able to respond without starting from scratch each time. Among the most quantum-ready organisations globally, the overwhelming majority already have crypto-agility programmes in place. This is roughly three times the rate of their least-prepared peers.

Where should organisations start with quantum-safe security?

Visibility comes first. Before any migration can be planned, organisations need to understand where cryptography actually lives across their estate. That means every application, infrastructure layer, API, and third-party dependency. Most organisations have not done this yet. The average score on IBM’s Quantum-Safe Readiness Index is 21 out of 100. For most, the starting point is simply knowing what they have to protect.

Interested in quantum-safe encryption?

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