Cards vs Keys: Why Physical Key Systems Still Dominate Critical Infrastructure

Cards vs Keys: Why Physical Key Systems Still Dominate Critical Infrastructure

When it comes to access management in critical infrastructure, the debate between card systems and intelligent key systems is more than a matter of technology preference, it’s about operational resilience, compliance, and safety in high-risk environments.

While digital transformation continues to push identity and access management (IAM) deeper into operational technology (OT), the reality on the ground is that physical security remains the final line of defence. The question is not which system is more modern, but which system is more resilient, auditable, and compliant under the CER Directive (EU 2022/2557)and NIS2.

The Promise and Pitfalls of Card Systems

Card-based access systems, whether RFID, NFC, or smartcards, have long been the default in office environments and data centres. They integrate well with IAM solutions like Entra ID, Okta, and SailPoint, providing convenience, scalability, and centralized management.

However, in the context of critical infrastructure, such as energy distribution, water management, rail transport, and telecom these systems face practical and operational challenges:

1. Connectivity dependency – Most card systems rely on online controllers and wired or wireless connectivity to function. In remote substations, tunnels, or pumping stations, network availability is often unreliable or deliberately air-gapped.

2. Tamper risk – Controllers, readers, and cabling represent physical attack surfaces. A single compromised node can invalidate the security of an entire segment.

3. Limited autonomy – When power or network fails, card systems revert to fail-open or fail-closed states. Both create operational risks.

4. Maintenance overhead – Firmware updates, network audits, and patch management across thousands of sites quickly become cost-intensive.

In short: card systems are designed for convenience, not for isolation or resilience.

The Case for Intelligent Key Systems

Modern electromechanical key systems, such as ASSA ABLOY CLIQ or iLOQ S5, offer a hybrid model that combines mechanical reliability with digital accountability. Every key and cylinder acts as a secure, autonomous access node, operating without permanent network connectivity.

Key advantages:

1. Offline operation – Each key carries its own access rights and audit trail, functioning in disconnected environments while still ensuring full traceability.

2. Strong cryptographic security – Keys and cylinders use end-to-end encryption and challenge-response authentication; no reader, no controller, no cables.

3. Simplified compliance – CER and NIS2 emphasize continuity, accountability, and supply-chain security. Intelligent key systems deliver provable control over who accessed which site, when, and why — even in isolated OT zones.

4. Operational flexibility – Access rights can be updated via mobile or desktop platforms, allowing time-limited or role-based permissions aligned with IAM policies.

5. Lower TCO – Without cabling, networking, or power infrastructure, lifecycle costs are lower, and deployment is faster.

The result: a distributed, cyber-resilient access ecosystem that aligns with OT security requirements and regulatory compliance.

Integrating IAM and Key Management: The Hybrid Future

The strongest security posture emerges when the physical and digital domains converge. By integrating IAM platforms with intelligent key management, organisations can enforce the same governance and role-based access controls (RBAC) across both IT and OT.

This is precisely what Key2XS enables:

• Synchronising key rights with IAM roles and policies.

• Automating provisioning and de-provisioning across systems.

• Delivering unified audit trails for compliance reporting.

• Enabling AI-driven recommendations for key plans and access segmentation.

In practice, this means a transformer substation engineer, a harbour technician, or a rail maintenance crew can receive just-in-time access based on identity attributes, without exposing the physical infrastructure to network-based vulnerabilities.

Conclusion: Cards for Offices, Keys for Operations

In controlled, connected environments, card systems make perfect sense. But for dispersed, unmanned, or high-security operational sites, intelligent keys remain unmatched in resilience and compliance.
The path forward is not replacement, but integration: combining the autonomy of physical key systems with the governance power of IAM.

In a world where regulatory frameworks such as CER and NIS2 are redefining accountability, this hybrid approach is not just a best practice, it’s a necessity for critical entities.
Key2XS bridges the gap between IAM and key management enabling secure, compliant, and automated control over every door, gate, and substation that matters.