Zero Trust for Medical Device Security
Post Summary
Hospitals rely on connected devices like infusion pumps and MRI machines for critical care. But these devices often run outdated software, making them vulnerable to cyberattacks. A single breach can disrupt hospital operations, delay surgeries, or even compromise patient safety.
The solution? Zero Trust Architecture. Unlike traditional security models that assume internal devices are safe, Zero Trust continuously verifies every device, user, and connection. This approach works especially well in healthcare, where many devices can't support traditional security tools.
Key Takeaways:
- Attack Surface: Medical devices make up 5–11% of hospital endpoints, with IoT and OT devices accounting for 30% of infrastructure.
- Challenges: Many devices use outdated firmware, default credentials, and lack visibility in clinical networks.
- Zero Trust Benefits: Continuous monitoring, network segmentation, and identity-based access reduce risks without disrupting patient care.
- Implementation: Start with cybersecurity benchmarks for a baseline assessment, pilot testing, and gradual rollout of measures like micro-segmentation and encryption.
Zero Trust isn't just about securing devices - it's about protecting patient safety and ensuring uninterrupted care.
Navigating the Challenges of Protecting Medical Devices by Applying a Zero Trust Security Strategy
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The Medical Device Security Problem in Healthcare
Medical devices play a critical role in patient care, but they also come with vulnerabilities that standard IT security tools struggle to address.
How Connected Medical Devices Expand the Attack Surface
Every connected medical device represents a potential gateway for cyberattacks. Devices like infusion pumps, patient monitors, imaging systems, and lab analyzers all rely on clinical networks to function. These devices connect through various interfaces - Wi‑Fi, Bluetooth, BLE, cellular networks, USB, and even serial ports - each adding another layer of risk [2].
The situation is further complicated by healthcare supply chain security challenges. Many devices depend on third-party or open-source software that may already have known security flaws before the devices are even deployed [2]. This creates a sprawling network of entry points that many IT teams are ill-equipped to secure, leaving hospitals exposed to compounded risks.
Key Risks in Medical Device Security
The growing number of connected devices amplifies the risks, particularly with older equipment. Many medical devices remain in use for decades, often long after their software becomes outdated and unpatchable. These devices were not designed with modern cybersecurity practices in mind. They frequently rely on hardcoded or default credentials, making them easy targets. Even when vulnerabilities are identified, manufacturers may not release patches to address them [1].
Another significant challenge is visibility. Without effective discovery tools, IT and security teams often don’t have a clear inventory of the devices connected to their networks. This creates "invisible" risks - devices running outdated firmware that go unnoticed. Compounding this issue is the fact that many of these devices handle sensitive patient data, such as protected health information (PHI). A single compromised device can lead to widespread exposure of patient data across the clinical network.
"Cybersecurity engineering is about preventing devices from doing tasks you don't want or expect. The FDA identified this as a software quality issue, which is important because protecting device functionality ensures they remain safe for patient use." - Phil Englert, Director of Medical Device Security, Health‑ISAC [1]
Why Securing Devices Without Disrupting Care Is Difficult
One of the biggest challenges in securing medical devices is that traditional IT security tools can inadvertently harm them. Vulnerability scanners, which work by injecting traffic to identify weaknesses, can cause crashes, memory issues, or other malfunctions in the sensitive software that powers these devices [2]. This is a risk healthcare providers cannot afford to take, especially when devices are actively monitoring or treating patients.
As a result, healthcare organizations often turn to passive monitoring. This approach identifies issues without interfering with device operations, but it requires specialized tools and expertise. Unfortunately, many health systems - especially smaller or rural providers - lack the resources to implement such solutions [1]. As Phil Englert points out:
"The key to solving the legacy problem is understanding where the risks reside and incorporating cybersecurity into replacement planning." [1]
Adding to the complexity, security measures must align with clinical schedules. Maintenance windows are limited, and downtime is rarely an option. Moreover, the individuals managing these devices are often clinicians, not cybersecurity professionals. This disconnect between operational needs and security requirements allows vulnerabilities to persist. These challenges highlight the growing importance of adopting a Zero Trust framework to better protect healthcare environments.
Why Zero Trust Works for Medical Device Environments
The challenges of legacy devices and hidden endpoints share one big issue: traditional perimeter-based security assumes that everything inside the network is trustworthy. In healthcare, that assumption can lead to serious risks. Zero Trust flips this idea by assuming nothing is inherently safe.
What Zero Trust Architecture Means
At its core, Zero Trust operates on the principle: "never trust, always verify." For medical devices where installing on-device software isn't an option, this means every connection is evaluated based on identity, device posture, and policies. Instead of relying on device-level protections, Zero Trust monitors network activity and traffic at the infrastructure level. This eliminates the need for software installations on devices themselves.
Authentication is handled automatically through tools like PKI (Public Key Infrastructure) and digital certificates, streamlining the process for clinical staff. This ensures that security measures don’t slow down critical, time-sensitive care. By sidestepping device limitations, Zero Trust enables smarter, more dynamic risk management tailored for healthcare.
How Zero Trust Addresses Healthcare Security Needs
Healthcare has unique security priorities compared to standard IT systems. Phil Englert from Health-ISAC explains:
"Cybersecurity engineering is about preventing devices from doing tasks you don't want or expect. The FDA identified this as a software quality issue, which is important because protecting device functionality ensures they remain safe for patient use." [1]
Zero Trust supports this by enforcing least-privilege access and segmenting the network. If one device is compromised, attackers are immediately contained to that segment, preventing the breach from spreading to other systems. This containment is critical in hospitals, where the infrastructure is vast and interconnected. For context, medical devices make up 5% to 11% of hospital endpoints, while IoT and operational technology (OT) account for roughly 30% of connected infrastructure [1]. A traditional flat network design would leave all these systems vulnerable if even one device were breached.
Zero Trust as a Multi-Layer Framework
Zero Trust doesn’t rely on a single solution. Instead, it layers multiple controls to address the vulnerabilities of medical devices, including legacy systems and supply chain risks. These layers include identity management, network micro-segmentation, device attestation, data encryption, and continuous monitoring. Each plays a role, and together they create a security posture capable of managing the complexities of healthcare environments.
| Security Objective | What It Means in a Zero Trust Context |
|---|---|
| Authenticity | Verifies that devices and data remain untampered [3] |
| Authorization | Restricts access to only verified users and devices [3] |
| Availability | Ensures devices and data stay functional for patient care [3] |
| Confidentiality | Safeguards PHI (Protected Health Information) from unauthorized access [3] |
| Updatability | Allows secure patching to defend against emerging threats [3] |
Each of these layers addresses gaps left by traditional security approaches. Together, they make Zero Trust not just a theoretical improvement, but a practical solution for the specific challenges of securing medical devices in healthcare environments.
Core Zero Trust Controls for Medical Devices
Zero Trust isn't a one-and-done solution. Instead, it's a layered approach designed to minimize enterprise risk across all devices in your healthcare environment.
Identity and Access Management
In healthcare networks, machine identities outnumber human users by a staggering 82:1 [5]. This imbalance makes traditional password-based systems impractical. Zero Trust solves this by using automated authentication with PKI and digital certificates, verifying devices at the network level without requiring clinical staff to intervene.
Two key access control models underpin this system: Role-Based Access Control (RBAC), which assigns permissions based on job roles, and Identity-Based Access Control (IBAC), which links access to the unique identity of each device [6]. For example, if an imaging machine starts acting oddly, its identity can be immediately isolated - no need for manual action [5].
"Zero Trust is a framework of policies and processes designed to harden your security. And, when applied correctly to IoMT devices, Zero Trust requires absolutely no interaction from clinical staff." - KeyData Cyber [5]
A growing trend is zero-touch provisioning, where devices are automatically assigned digital identities as soon as they connect to the network. This eliminates the need for manual credentialing, which is error-prone at scale - especially with 10,000+ devices [5]. Once identities are established, continuous discovery and validation ensure these devices stay secure.
Device Discovery and Posture Validation
Before any Zero Trust policies can be enforced, complete and continuous device discovery is critical. Posture validation takes this a step further by ensuring devices aren't just present but are trustworthy - running approved firmware, properly configured, and behaving as expected.
"Identity becomes significantly more useful when it is not isolated from the device state. Every trustworthy device record should bind the device identifier to the approved firmware version, configuration profile, and cryptographic attestation evidence." - Verified.vc [4]
Since many medical devices can't support traditional security agents, agentless methods are used to monitor network traffic and verify device behavior without requiring on-device software [5].
Network Segmentation and Micro-Segmentation
Once devices are identified, they need to be isolated based on their function and risk levels. Micro-segmentation breaks the network into smaller zones, ensuring that a compromised device, like an infusion pump, can't be used to access critical systems like electronic health records (EHR) or life-support devices.
In May 2026, Greg Sieg, CISO of Michigan Medicine, implemented Cisco's Identity Services Engine (ISE) to automate segmentation across the University of Michigan Regional Health Network. This system ensures devices are assigned to the correct virtual network automatically, regardless of the physical port used. If a consumer device replaces a medical device, the port locks itself [7].
"As long as the switch has ISE enabled, it's going to do that [automation]... it doesn't matter where I plug it into a switch." - Greg Sieg, CISO, University of Michigan Regional Health Network [7]
A good starting point is dividing systems into distinct categories, such as building management (e.g., HVAC, elevators), medical devices, biomedical engineering systems, and standard IT equipment. These groups should never share the same network [7].
Encryption and Secure Data Transfer
After segmentation, encrypting communication between devices adds another layer of security. Data in transit must always be protected. Mutual TLS (mTLS) is a popular method in Zero Trust medical networks, requiring both the device and network to verify each other's identity before exchanging data. This prevents man-in-the-middle attacks [6].
In 2026, engineers at SVNIT secured IoT medical sensors using mTLS combined with AES-256 encryption. This approach ensured that even if traffic was intercepted, the data remained unreadable [6].
Encryption isn't just for data in transit. It also applies to data at rest, such as patient records, device logs, and configuration files. Unencrypted protected health information (PHI) stored on a device or server is a vulnerability, no matter how secure the network perimeter may be.
Continuous Monitoring and Policy Enforcement
Initial authentication only confirms a device was trustworthy when it first connected. Continuous monitoring ensures it remains trustworthy over time. Firmware can be tampered with, configurations may drift, and devices can be relocated to unauthorized areas - all of which would go unnoticed without ongoing checks. Combined with segmentation and identity controls, continuous monitoring keeps security intact. This proactive stance is equally vital when managing vendor solutions to ensure third-party compliance.
Here’s how different monitoring approaches fit into the Zero Trust framework:
| Approach | Proof | Ideal For |
|---|---|---|
| Device Certificates | Cryptographic device identity | Connected medical devices and gateways [4] |
| Firmware Attestation | Approved, untampered software state | High-risk or regulated device fleets [4] |
| Continuous Posture Monitoring | Ongoing trust status in real time | Hospital-at-home and distributed IoMT programs [4] |
Monitoring should be scaled based on clinical risk. For example, life-support devices demand stricter certificate rotations and more robust attestation compared to low-risk sensors [4]. Automated alerts should flag issues like certificate drift, unauthorized firmware changes, or devices operating outside approved areas or times [4]. When a device is decommissioned, its credentials must be fully revoked to prevent creating new vulnerabilities [4].
A Phased Zero Trust Rollout for Healthcare Organizations
Zero Trust Implementation Roadmap for Medical Device Security
Implementing Zero Trust within a healthcare setting, such as a hospital or health system, requires a deliberate, step-by-step plan. As the TMC Insight Team aptly notes, "Zero Trust is a journey, not a flip of a switch. Incremental wins matter." [9] This phased approach ensures your organization can enhance security while integrating these efforts into broader risk management practices. By taking it step by step, your team can build confidence, identify potential issues early, and, most importantly, maintain uninterrupted patient care.
Step 1: Baseline Assessment and Planning
Before making any changes to policies or firewalls, it’s crucial to understand what you’re protecting. This involves creating a detailed inventory of all devices, user accounts, applications, and data flows within your environment. Additionally, define your organization’s risk tolerance and set clinical safety boundaries from the start. For instance, systems like life-support equipment and electronic health records (EHRs) require higher levels of protection compared to administrative workstations, and your policies should reflect these priorities.
Skipping this foundational step can lead to significant problems, such as disrupted clinical workflows or access issues that are costly and time-consuming to resolve.
Step 2: Pilot Deployment and Testing
Begin with a small-scale rollout. Focus initial efforts on administrative and non-clinical staff by introducing phishing-resistant multi-factor authentication (MFA), single sign-on (SSO), and privileged access management (PAM). This measured approach allows your IT team to fine-tune policies without risking disruptions to patient care.
For example, one Integrated Delivery Network (IDN) successfully implemented identity hardening and PAM within 90 days. They then applied those lessons to micro-segment their EHR and imaging systems. As a result, lateral movement attempts were automatically contained, while clinicians retained access through monitored emergency "break-glass" protocols. Allow time during each phase for adjustments to address any issues that arise, ensuring patient care remains unaffected.
Step 3: Expanding Controls Across Systems
Once the pilot phase proves stable, extend Zero Trust measures to critical systems such as EHR platforms, PACS (Picture Archiving and Communication Systems), lab networks, and vendor remote access points. At this stage, micro-segmentation becomes essential to isolate systems and prevent lateral movement from compromised devices.
Vendor and telehealth partner access should transition to per-session authorizations instead of persistent connections. Additionally, legacy interfaces, like HL7 v2 running over plaintext TCP, should be upgraded to TLS-encrypted channels. For older devices with limited authentication capabilities, tailor policies to address their specific needs.
Step 4: Ongoing Policy Review and Updates
Zero Trust isn’t a one-and-done implementation. As your device inventory changes, workflows evolve, and new vulnerabilities emerge, policies must be continuously updated. Automate policy enforcement using SIEM (Security Information and Event Management) and SOAR (Security Orchestration, Automation, and Response) tools to quickly quarantine suspicious devices and revoke compromised credentials.
The importance of staying updated is clear: organizations with mature Zero Trust systems can identify and contain breaches in 162 days on average, compared to 277 days for those without such measures [8]. Regularly reviewing policies - at least once every quarter - helps catch issues like configuration drift, expired certificates, and outdated access rules.
By following these phases, healthcare organizations can protect medical devices while strengthening overall network resilience. This structured approach also supports better governance, risk management, and vendor oversight.
| Implementation Phase | Duration | Key Deliverables |
|---|---|---|
| Phase 0: Baseline | Weeks 0–4 | Asset/identity inventory, risk definition, clinical guardrails |
| Phase 1: Foundations | Days 0–90 | Phishing-resistant MFA, SSO, PAM, EDR enrollment, IoMT registration |
| Phase 2: Segmentation | Days 90–180 | Micro-segmentation for EHR/PACS, PHI classification, vendor access management |
| Phase 3: Scale | Days 180–365 | SIEM/SOAR automation, policy-as-code, cloud/edge integration |
Governance, Risk Management, and Vendor Oversight
Zero Trust isn’t just about securing devices - it’s about creating a system of accountability. By verifying every access request and logging every connection, enforcing governance becomes much more straightforward. For healthcare organizations, this means being able to show regulators, auditors, and boards exactly who accessed what, when, and why. But beyond internal controls, managing third-party access and handling risk exceptions are critical components of this framework.
Managing Third-Party and Vendor Access
Vendors often represent some of the biggest access risks in healthcare environments. From clinical equipment manufacturers to biomedical engineers and remote support teams, these parties frequently need access to sensitive systems. The problem? This access is often left open longer than necessary.
Zero Trust changes the game by turning vendor access into secure, time-limited sessions. Each session is restricted to a set duration, provides only the minimum permissions needed, and is fully logged. This applies to both on-site technicians and remote vendors using secure channels.
Another critical area is supply chain risk. A compromised software update from a device manufacturer can be just as dangerous as a direct network breach. Using Zero Trust principles like software composition analysis and environment-aware threat modeling can help identify and mitigate these risks before they impact production systems.
Risk Assessments and Handling Policy Exceptions
Not every device in a healthcare setting can meet all Zero Trust controls. For example, legacy infusion pumps or older imaging systems often rely on outdated software with no available updates. Ignoring these vulnerabilities isn’t an option, but taking essential equipment offline isn’t practical either.
The solution? Implement a documented, time-limited exception process. If a device can’t support a specific control, such as certificate-based authentication, document the associated risk, apply compensating measures - like tighter network segmentation or enhanced monitoring - and set a review date. This approach ensures exceptions don’t turn into permanent blind spots.
Regulators are taking note of these challenges. The FDA’s updated Compliance Program Manual (#7382.850), effective February 2, 2026, includes specific cybersecurity guidance for quality management system (QMSR) inspections [2]. This reflects the expectation for continuous, documented risk management rather than one-off assessments during procurement. As Exponent highlights:
"Safety and security for devices should be assessed within the context of the larger systems in which they operate, whether that is hospitals, homes, or networks." [2]
This means risk assessments must consider the broader environment. For instance, the risk profile of a cardiac monitor changes depending on whether it’s connected to a segmented VLAN, an unmanaged Wi-Fi network, or a third-party remote support tool.
How Censinet Supports Medical Device Risk Management
While technical controls are vital, governance and vendor oversight play an equally important role in making Zero Trust work for healthcare. Managing risk assessments, vendor relationships, and policy exceptions manually isn’t realistic. That’s where Censinet steps in with its Censinet RiskOps™ platform, designed specifically for healthcare organizations navigating complex risk landscapes.
Censinet RiskOps™ simplifies third-party and enterprise risk assessments, covering areas like medical devices, clinical applications, and supply chains. Its Censinet AI™ feature speeds up the process by allowing vendors to quickly complete security questionnaires, automatically summarizing evidence, and generating risk reports. This automation handles high volumes efficiently, enabling your team to focus on critical decisions.
For healthcare organizations juggling dozens or even hundreds of vendor relationships, this structured approach makes implementing Zero Trust governance achievable and effective.
Conclusion: Using Zero Trust to Secure Medical Devices in Healthcare
Securing medical devices isn't just about technology - it’s directly tied to patient safety. Zero Trust offers a solid approach to minimize risks, using methods like device discovery, network segmentation, robust identity controls, encryption, and ongoing monitoring. As Phil Englert, Director of Medical Device Security at Health-ISAC, explains:
"We've seen the real impact on patient safety and availability to deliver care. It's about device availability and access to the data those devices generate." [1]
Regulations are catching up with the need for stronger security. The FDA's updated Compliance Program Manual (#7382.850), effective February 2026 [2], integrates cybersecurity into every phase of the medical device lifecycle. This shift means security can no longer be treated as a one-time task during procurement - it’s now an ongoing responsibility.
Rather than attempting a rapid overhaul, healthcare organizations can adopt a phased approach. Start with a baseline security assessment, then implement a controlled pilot program, and gradually expand efforts. Even older devices can be managed effectively through documented exceptions and compensating controls, keeping risks visible and manageable.
Governance and vendor oversight play a crucial role in this process. Tools like Censinet RiskOps™ are tailored for healthcare, helping organizations streamline risk assessments, manage vendor relationships, and maintain the necessary documentation for audits and compliance.
Zero Trust isn’t an endpoint - it’s a continuous journey. Adopting this mindset means committing to ongoing security improvements. By doing so, healthcare organizations can better protect their patients, secure sensitive data, and ensure uninterrupted care delivery.
FAQs
How does Zero Trust secure devices that can’t run security agents?
Zero Trust protects devices without relying on security agents by constantly verifying their identity and behavior through tools like digital certificates and PKI (Public Key Infrastructure). This approach allows for automated authentication directly at the network layer, cutting out the need for any user involvement.
What’s the safest way to micro-segment clinical networks without disrupting care?
Creating secure zones within clinical networks starts with a clear strategy. Divide the network into zones based on clinical risk and functionality. For instance, keep life-sustaining devices, imaging systems, and administrative networks in separate zones. This separation minimizes risks and ensures each category operates independently.
To enforce these boundaries, rely on tools like VLANs and Layer 3 firewalls. These tools ensure that communication is limited to what's absolutely necessary, reducing the risk of interference or breaches.
Collaboration is key. By working closely with clinical staff and using passive discovery methods, you can map out the network without causing disruptions. A phased approach, combined with thorough testing, helps maintain both patient safety and operational continuity throughout the process.
How should hospitals handle Zero Trust exceptions for unpatchable legacy devices?
Hospitals dealing with unpatchable legacy devices should take steps to manage these risks effectively. One approach is network segmentation, which isolates these devices to limit their exposure. Adding compensating controls, such as strict access restrictions and continuous monitoring, can further protect these vulnerable systems. Keeping detailed audit logs is also essential for tracking activity and identifying potential issues.
To address long-term risks, hospitals should develop plans for either replacing these devices or securely decommissioning them when the time comes. This proactive strategy ensures that risks are minimized over time.
