Secure by Design in Defence – From Mission Assurance to Supply Chain Integrity

• by Anthony Orjally
• Advent IM Blog

The defence sector has always operated under conditions of heightened sensitivity. Information advantage and operational readiness depend on the confidentiality, integrity, and availability of systems that must remain resilient even under direct attack. For decades, however, security assurance was too often bolted on late in the lifecycle, treated as a gatekeeping activity that delayed capability introduction and introduced spiralling costs.

Secure by Design is changing that paradigm. By embedding security into the earliest phases of design, procurement, and integration, defence organisations are shifting towards continuous assurance.

Mission Assurance

Defence capabilities are increasingly software-driven: autonomous platforms, mission data systems, and AI-enabled decision tools. Secure by Design ensures these are architected with assurance baked in, aligning with MOD’s Secure by Design guidance and the Defence Digital Service’s mandate for secure development practices. This reduces the need for late-stage remediation that can compromise operational timelines.

Supply Chain Trust

Defence relies on an intricate supply ecosystem – from prime contractors to specialist SMEs providing niche capability. Secure by Design insists on a governance framework that propagates down the chain, ensuring third parties comply with baseline controls, testing, and assurance processes. This is vital for NIS2 compliance and to counter supply chain compromise (such as those seen in global aerospace incidents).

GRC Implications

• Governance: Security responsibilities are codified in contractual frameworks and supported by MOD’s Secure by Design procurement templates.
• Risk: Threat modelling is conducted at project inception, factoring in state-level actors and insider risk.
• Compliance: Defence systems must align not only with NIS2 but also with JSP 440, DEFCONs, and NATO standards.

Example in Practice

Recent naval platform procurements have adopted Secure by Design principles at the design authority level, mandating red-team style penetration testing at prototype stage. This reduces exposure windows and delivers higher assurance before operational deployment.

Defence stakeholders should view Secure by Design as more than a compliance requirement: it is a mechanism for mission assurance, competitive advantage, and sustaining trust with allies.

Written by Ellie Hurst, Commercial Director.