UK updates cyber resilience guidance with CAF 4.0: A strategic tool for critical infrastructure protection

The UK’s National Cyber Security Centre (NCSC) has published Version 4.0 of its Cyber Assessment Framework (CAF), a structured guide designed to evaluate and strengthen the cybersecurity and resilience of organisations providing essential services. This includes sectors such as energy, transport, healthcare, and finance, where any cyber disruption could significantly impact daily life in the UK.

CAF 4.0 updates previous iterations with clearer guidance, more detailed Indicators of Good Practice (IGPs), and an expanded approach to sector-specific applications. It allows for both self-assessment and third-party evaluations, making it a flexible yet rigorous tool. The framework maintains its core design around four objectives: managing security risk, protecting against cyberattack, detecting cybersecurity events, and minimising the impact of incidents, broken down into 14 high-level principles and 41 contributing outcomes.

A key strength of CAF 4.0 is its shift away from checkbox compliance, instead emphasising outcome-based evaluations. This means organisations are judged on how well they achieve specific security objectives, not merely whether they follow prescribed procedures. The use of IGPs helps guide expert assessments without constraining them, allowing for adaptation based on the organisation’s context and threats faced.

The framework supports the creation of ‘CAF profiles,’ which are tailored targets set by regulatory or oversight bodies. These profiles help prioritise certain cybersecurity outcomes based on the nature of the essential services involved. They also allow regulators to define proportionate security expectations—something especially important given the increasing capabilities of threat actors targeting national infrastructure.

CAF 4.0 also recognises the importance of sector-specific adjustments, such as adapting IGPs or adding new contributing outcomes to reflect unique industry requirements. This makes it a dynamic tool that regulators and organisations can continue to shape collaboratively.

Why does it matter?

CAF 4.0 provides a practical yet thorough methodology for improving national resilience. By guiding organisations to identify risks, implement effective controls, and measure performance against meaningful outcomes, the framework plays a crucial role in safeguarding the UK’s critical infrastructure. Its emphasis on board-level engagement, supply chain security, and threat-informed decision-making reflects a modern understanding of the cyber landscape—making CAF 4.0 not just a compliance tool, but a strategic asset for public and private sectors alike.