Introduction

The UK’s transport networks are undergoing significant digital change. Passenger numbers are recovering, infrastructure modernisation is progressing, and operators are increasingly reliant on connected systems. With this shift comes a new cybersecurity challenge: ensuring that critical digital services can be trusted at all times.

Digital trust is now a fundamental requirement. Rail signalling systems, airport operations, highway control centres, and public transport ticketing all rely on secure communication, identity verification, and data protection. This is why Public Key Infrastructure (PKI) and Certificate Lifecycle Management (CLM) have become central to service reliability across the sector.

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Why Transport Now Depends on Digital Trust

Transport operations that were once mostly mechanical and isolated have become digital, distributed, and data-driven. Examples include:

• Rail control and signalling systems exchanging real-time commands across connected networks
• Airports securing radar communication, airside access, and control systems
• Highways deploying intelligent transport systems, including vehicle-to-infrastructure messaging
• Public transport operators delivering ticketing, journey planning, and payment services online and through mobile apps

In these environments, cybersecurity failures can lead to service disruption, financial cost, and potential safety concerns. PKI ensures devices and systems can trust one another and that data is encrypted and authenticated end to end.

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Where PKI Protects Critical Transport Systems

PKI provides trust across several areas of UK transport, including:

• Rail: securing signalling, trackside devices, and control infrastructure
• Aviation: enabling trusted access for airside systems, radar, and electronic flight information
• Highways: supporting connected infrastructure and roadside device integrity
• Public transport platforms: protecting ticketing APIs, mobile apps, and customer data

Without PKI, operators cannot verify system integrity or maintain secure operations.

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The Risk of Not Getting PKI and CLM Right

Many organisations still rely on spreadsheets, shared inboxes, or siloed teams to manage digital certificates. This approach leads to:

• Outages caused by expired or misconfigured certificates
• Difficulty locating certificates across legacy and cloud environments
• Delays in responding to certificate-related incidents
• Increased audit and compliance burden
• Limited preparation for post-quantum cryptography and encryption changes

Across critical infrastructure sectors, a high proportion of organisations indicate they would redesign their PKI if given the opportunity, reflecting growing complexity and operational risk.

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Why Certificate Lifecycle Management (CLM) is Now Essential

CLM enables organisations to manage certificates at scale, ensuring that only trusted, valid certificates are in use. Effective CLM supports:

• Visibility of certificates across IT, OT, cloud, and edge systems
• Automated issuance, renewal, revocation, and provisioning
• Reduced risk of service interruption linked to certificate failures
• Integration with DevOps pipelines and cloud-native workloads

For transport services that operate continuously, automated certificate management is critical to operational confidence.

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Strategic Benefits for UK Transport Operators

Mature PKI and CLM capabilities enable:

• Fewer service interruptions and stronger operational continuity
• Improved cybersecurity posture and reduced attack surface
• Compliance with NIS regulations, ISO 27001, and sector assurance frameworks
• Scalable adoption of IoT, connected vehicles, and smart infrastructure
• Long-term readiness for cryptographic change and post-quantum security

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The Role of Unsung Ltd

Unsung Ltd works with transport operators, infrastructure owners, and technology suppliers to modernise PKI and CLM. Support includes:

• Certificate discovery and inventory across complex environments
• Implementation and optimisation of CLM platforms and automation workflows
• PKI governance model design, policy frameworks, and operational processes
• Planning for crypto-agility and the transition to post-quantum encryption

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Conclusion

Transport is a critical national function. As infrastructure modernises and becomes more connected, trust in digital systems becomes an essential component of safety, reliability, and public confidence. PKI and Certificate Lifecycle Management provide the basis for that trust.

Organisations that invest in mature PKI and CLM capabilities are better prepared to secure their networks, prevent outages, support innovation, and ensure that the systems moving people and goods remain resilient.

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