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Why Quantum threatens today’s encryption
Quantum computing is no longer just a theoretical breakthrough – it introduces real-world risks to the cryptography that underpins today’s digital economy. While classical encryption has been trusted for decades, emerging quantum capabilities could shorten its lifespan and expose sensitive data. This article explains why current encryption is vulnerable, why the risk starts now, and how organisations can begin preparing for a post-quantum future.
Jump to:
- Why current encryption is vulnerable
- The risk starts before quantum is ready
- A powerful technology with real security implications
- What organisations should do now
For decades, modern encryption has been built on a simple assumption: some mathematical problems are so difficult for classical computers that breaking them would take an impractical amount of time. That assumption has served us extremely well. It is one of the reasons we can trust online banking, digital contracts, software updates and private communications to work safely at scale.
Quantum computing changes the picture. It is not simply a faster version of the computers we use today. It processes certain problems in a fundamentally different way, which means some of the cryptographic systems that protect today’s digital economy may no longer be safe in the future. For business leaders, the important point is not the physics itself. It is the fact that encryption designed to last for decades may have a shorter life than expected.
Why current encryption is vulnerable
Much of today’s secure communication depends on asymmetric cryptography such as RSA and elliptic curve cryptography. These methods are widely used for key exchange and digital signatures – in other words, they help systems prove identity, establish trust and exchange data securely. They are trusted because the maths behind them is extremely hard for classical computers to reverse.
Quantum computers approach some of these problems differently. While a classical computer works through possibilities in sequence, a quantum computer can exploit quantum effects to process certain classes of problems far more efficiently. In practical terms, that means algorithms which appear safe today because they would take a conventional machine far too long to crack may become vulnerable once cryptographically relevant quantum systems emerge.
From a cybersecurity perspective, the most immediate issue is confidentiality. If an attacker can break the cryptography protecting sensitive information, data that was meant to remain private may no longer stay private. That includes intellectual property, long-term contracts, regulated records, customer information and strategic communications.
The risk starts before quantum is ready
This is where the discussion becomes more urgent. Even if a quantum computer cannot break your encryption today, an attacker may still collect encrypted data now with the intention of decrypting it later. This is known as harvest now, decrypt later. For organisations holding information that must remain confidential for many years, that is a serious concern.
Not all data has the same shelf life. Some information loses value quickly. Other information does not. Trade secrets, legal agreements, product designs, health-related records, critical infrastructure data and sensitive communications may need to stay protected well beyond the lifetime of classical cryptography. If that data is stolen today and decrypted years from now, the damage may still be very real. In that sense, the quantum threat is not only a future issue – it is a present-day data protection issue.
A powerful technology with real security implications
None of this means quantum computing is purely a threat. The same technology may unlock major advances in areas such as healthcare, materials science, logistics and climate modelling. But every major computing shift changes the security landscape as well as the commercial one. Classical computing enabled the modern internet, and over time we learned where its weaknesses were. Quantum computing will bring new capabilities, but it will also force us to rethink some of the assumptions behind today’s trust models.
The exact timing is still uncertain. No responsible organisation should build its strategy around a single prediction for Q-Day. However, that uncertainty is precisely why waiting is risky. Migration away from vulnerable cryptography is not something most organisations can do quickly. In many environments, cryptography is deeply embedded in applications, devices, infrastructure and third-party products. Replacing it takes time, planning and coordination.
Infrastructure
Infrastructure is often the most portable part of a cloud setup. While organisations buy compute and storage from hyperscalers, the underlying technologies can usually run elsewhere. Workloads running on Kubernetes can be dynamically moved between on-prem Kubernetes clusters and clusters running at a European provider, offering far more flexibility than software tools.
However, infrastructure moves still come with trade-offs. Cloud platforms bundle services like firewalls, monitoring and proxies, which must be replaced or rebuilt if workloads are brought home.
A hybrid approach is therefore the most realistic option, with sensitive or performance-critical systems running locally and the rest remaining in the cloud. Lock-in, skills and complexity all mean that infrastructure migration requires careful planning about what should move and what is better left where it is.
What organisations should do now
The first step is not a wholesale technology replacement. It is understanding where you rely on cryptography today. That means identifying which systems use RSA, elliptic curve cryptography and related protocols, which data must remain confidential for the longest time, and which business services would be most exposed if trust in digital signatures or encrypted communications were weakened.
From there, organisations need to build cryptographic agility. In simple terms, that means making it easier to replace or update algorithms without redesigning entire systems. The organisations that begin this work early will be in a far stronger position to adopt post-quantum cryptography in a controlled way, rather than under pressure later.
Quantum computing may still feel like an emerging technology, but the encryption challenge it creates is already relevant. The issue is not simply whether a quantum computer can break today’s systems tomorrow. It is whether the data and services you rely on now will still be protected in the years ahead. For many organisations, the right time to start preparing is not when the deadline is certain. It is before the window for an orderly transition begins to close.
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About the author
Peter Jones
Cyber Security Specialist, Conscia UK
Peter Jones is a Cyber Security Specialist at Conscia UK. He has been in the IT industry for over 30 years, providing consulting and advisory services to both Commercial and Public Sector Accounts throughout Europe. Having previously worked for both Cisco and Microsoft, Peter combines professional and academic achievements with real world experience to support our UK business. He currently holds CISSP, CISM and CCSP certifications.
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