Which Healthcare Data Should You Protect Against Quantum Risks First?

The healthcare data you need to protect against quantum risks first are patient records, genetic profiles, psychiatric data, and other special categories of personal data that remain sensitive for decades. Attackers can already intercept and store encrypted healthcare traffic today to decrypt it later once powerful quantum computers become available. In this article, we answer the most urgent questions about quantum risks in healthcare, from the nature of the threat to the first concrete step toward quantum-safe infrastructure.

Which healthcare data is most at risk in a quantum attack?

Healthcare data with the highest sensitivity and the longest shelf life is most at risk. Think of electronic patient records, genetic test results, psychiatric reports, HIV statuses, and oncological treatment plans. These are data that not only need to be protected now, but that could still cause harm ten, twenty, or thirty years from now if they fall into the wrong hands.

Quantum computers break the mathematical assumptions underlying current encryption, such as RSA and elliptic curve cryptography. This makes all data vulnerable that is currently secured with those algorithms. Healthcare faces a particularly high level of urgency because medical data falls under the strictest privacy legislation, including the GDPR and the NIS2 directive, and because the damage from a data breach is not only legal but also personal and societal in scale.

In addition to patient data, critical operational data is also vulnerable: authentication certificates for medical devices, encryption keys for connections between hospital systems, and data transmitted over public networks to laboratories, general practitioners, or pharmacies.

What is a ‘harvest now, decrypt later’ attack and why does it affect healthcare?

A “harvest now, decrypt later” attack is a strategy in which attackers intercept and store encrypted data traffic today, with the intention of decrypting it later once quantum computers are powerful enough. The attacker does not need to be able to read anything now — only to store it. The threat is therefore already real, even though the powerful quantum computer does not yet exist.

Healthcare is an attractive target for this type of attack for several reasons. First, medical data remains valuable for decades for identity fraud, blackmail, insurance manipulation, or targeted disinformation. Second, healthcare organizations transmit large volumes of sensitive information daily over networks that still run on conventional encryption protocols. Third, systems in healthcare are often complex and outdated, making migration to new security standards more time-consuming.

That time gap is precisely the problem. If an attacker intercepts healthcare traffic today, and in five to ten years deploys a quantum computer to break the encryption, the consequences for patients are real — even if those patients have long since completed their treatment. This makes the quantum threat in healthcare fundamentally different from a classic cyberattack.

How do you prioritize healthcare data for quantum security?

The priority of healthcare data for quantum security is determined by two factors: the sensitivity of the data and its expected lifespan. Data that remains sensitive for a long time and is already being transmitted over networks has the highest priority. Start with a data classification that combines these two dimensions.

A practical approach works in three steps:

1. Inventory what data the organization processes and transmits. Which systems communicate with each other? Which connections run over external networks?
2. Classify data by sensitivity and retention period. Genetic and psychiatric data score high on both axes. Administrative planning data scores lower.
3. Map out which encryption protocols are currently in use. Connections running on RSA or elliptic curve algorithms are the most urgent to migrate.

The result is a risk map that allows you to deploy available resources in a targeted way. Not everything needs to be addressed at once, but the most critical data flows must be protected first. Protecting sensitive data starts with knowing what you have and what it is worth to an attacker.

What difference does it make whether data is at rest or in transit?

Data in transit is more vulnerable to harvest now, decrypt later attacks than data at rest, because intercepting network traffic can occur remotely without physical access to systems. Data at rest, stored on servers or in databases, typically requires direct access to the storage environment, which represents a higher barrier for attackers.

That said, data at rest also deserves attention. If an attacker ever gains access to a storage system, an encrypted archive can later be decrypted with a quantum computer. For healthcare, this means that both connections and storage layers need to be assessed.

The distinction also has implications for the migration strategy. For data in transit, the priority is replacing transport encryption — for example, TLS connections currently running on vulnerable algorithms. For data at rest, the focus is on encrypting databases and archives. Both layers require a different technical approach, but the urgency for data in transit is highest in most healthcare environments, because those connections are already actively in use and potentially being intercepted.

Want insight into how your network connections are currently secured? Real-time fiber optic monitoring gives healthcare organizations visibility into what is traversing their network and where vulnerabilities exist.

When should a healthcare organization start migrating to post-quantum encryption?

A healthcare organization should start preparing for post-quantum encryption now — not wait until powerful quantum computers become available. The reason is simple: data traveling over the network today can already be intercepted. And migrating to new cryptographic standards takes time — sometimes years — depending on the complexity of the infrastructure.

By 2026, the first post-quantum standards from the American standards body NIST will have been definitively established. Vendors of network equipment and security software are actively integrating these standards into their products. This is the moment when healthcare organizations can begin planning and executing the transition — not as a future project, but as an ongoing program.

The urgency is especially high for organizations that process data with a long retention period. If a hospital retains patient data for twenty years, and that data is already being intercepted, the damage ten years from now is real — even if the quantum computer only arrives then. The time horizon of the data determines the urgency of the action.

What is the first step a healthcare organization takes toward quantum-safe infrastructure?

The first concrete step toward a quantum-safe infrastructure is a cryptographic inventory: map out which encryption algorithms and protocols your organization currently uses, where, and for which data. Without this overview, targeted action is not possible.

From that inventory, you work toward a phased migration strategy:

• Identify the most critical data flows and the protocols securing those connections.
• Assess current vendors and equipment for their roadmap for post-quantum support.
• Test post-quantum encryption on a defined part of the infrastructure — for example, the connection between two locations or a specific system.
• Develop a migration plan aligned with the replacement cycles of existing equipment, so the transition is cost-efficient.

For many healthcare organizations, this is a complex undertaking — especially when the infrastructure consists of a combination of legacy systems, medical devices, and modern cloud environments. We help healthcare organizations navigate this journey, from inventory and advice to the implementation of encryption solutions tailored to the specific requirements of the sector. Our expertise is fully in-house, from layer 1 through the application layer, so you don’t need to coordinate with multiple parties to get a coherent response to the quantum threat.