The digital landscape is constantly shifting, as exemplified by the CA/Browser (CA/B) Forums recently approved change to reduce the maximum validity period for TLS certificates to 47 days by 2029. For those using public Certificate Authorities (CAs) for their medical devices, this isn’t just a minor IT hiccup — it’s a potential compliance and operational hurdle that requires serious consideration.

This change in policy is clearly intended to bolster the security of web browsers and public-facing services by limiting the lifespan of potentially compromised certificates. Shorter certificate lifespans reduce the window of opportunity for attackers to exploit stolen or compromised keys. For the general internet, this is a net positive enhancement to security.

Now, here’s a critical point: private CAs are exempt from this 47-day limitation.

In the vast majority of cases, medical devices should be leveraging private CAs.

Why? Because private CAs offer the flexibility and control required to address the challenges of medical devices operating in highly specialized, regulated, and often resource-constrained environments. This manifests in several key ways:

• Custom Certificate Lifetimes: With private CAs, you define certificate validity periods that align with device lifecycles, regulatory validation schedules, and expected maintenance intervals — rather than being constrained by one-size-fits-all rules.
• Controlled Trust Anchors: You decide which root certificates are trusted by your devices and backend systems, eliminating dependence on third-party browser root programs and avoiding unexpected trust chain changes.
• Deployment Flexibility: Private CAs allow the use of offline or pre-provisioned certificates, which is essential for air-gapped environments, surgical devices, or systems with limited or no internet access.
• Adaptable Revocation and Renewal Policies: You can design revocation strategies that reflect realistic threat models and operational capabilities — whether that’s CRLs, OCSP, or custom mechanisms suited for embedded devices.
• Consistent Identity Models: Private PKI enables you to define naming conventions and identity models that match your product architecture (e.g., per-device, per-subsystem, or batch-level identities) without relying on external CA constraints.
• Reduced Risk Surface: Avoiding public CAs minimizes your exposure to external compromise scenarios (e.g., public CA misissuance) and removes dependencies on internet-facing CA infrastructure for device operation.

Public CAs play a critical role in securing internet-facing services, but they are not designed for embedded systems with long lifespans, complex validation environments, and safety-critical constraints.

For those who do use public CAs to establish the identities of their medical devices, the prospect of renewing these certificates every 47 days could potentially lead to:

• Significant Operational Overload: Imagine the sheer scale of our installed base. Tracking, renewing, and deploying new certificates across all those devices every few weeks? The resource implications are staggering.
• Increased Risk of Service Disruption: Missing a 47-day renewal window could lead to devices losing connectivity, potentially impacting patient care. Non-compliant or unusable devices are a serious patient safety concern and a regulatory nightmare.
• Strain on Device Update Mechanisms: Our devices aren’t like smartphones with monthly updates. Many have infrequent or complex update processes. Forcing this rapid renewal cycle could overburden these systems, leading to update failures and a weakened security posture.
• Complex Validation and Compliance: Each certificate renewal could trigger the need for re-validation and re-certification. The cost and time burdens associated with this under our regulatory framework are substantial.
• Potential for System Instability: Frequent updates across diverse device models and healthcare IT infrastructure increase the risk of unforeseen compatibility issues and system instability.

So, what’s the takeaway? If your medical devices currently rely on public CAs for their identity, this new 47-day policy is a strong signal to review your certificate strategy. While not a cause for panic, it does highlight some practical challenges that are worth addressing now — before they become operational burdens later.

Here are some steps to consider as you think through the impact:

• Assess your current usage: Take inventory of where and how public TLS certificates are being used across your device fleet. Understanding these touchpoints is the first step to identifying where changes might be needed.
• Evaluate your update infrastructure: Look at whether your current certificate renewal and software update mechanisms could handle a faster renewal cadence. Some may already be well-suited — others might need attention.
• Explore private PKI options: If you’re not already using a private CA for device identity, now is a good time to consider whether it offers better long-term alignment with your operational model.
• Consider certificate embedding: Depending on your device design, embedding long-lived certificates at manufacturing time (or enabling secure provisioning) may reduce renewal complexity in the field.
• Look into automation: If continuing with public CAs is necessary for some use cases, investigate automated certificate management tooling.

Ultimately, this shift in the public certificate ecosystem is part of a broader trend toward tighter, more agile security. It’s a positive move — but one that assumes flexibility and infrastructure many medical devices weren’t designed around. By acting thoughtfully now, teams can stay ahead of that curve and build a stronger, more resilient foundation for the future.

Talk to the Medcrypt team today for a comprehensive discussion about your cryptographic strategy and how we can help you proactively address the implications of policies like the CA/B’s 47-day certificate renewal cycle. Let us help you build a resilient and compliant security posture for the long term.

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