Advancing Zero Trust Maturity Assessment With a Quantitative Scoring System

Zero Trust (ZT) has become a cornerstone in modern cybersecurity architectures, emphasizing the principle of “never trust, always verify.” The Cybersecurity and Infrastructure Security Agency (CISA) introduced the Zero Trust Maturity Model (ZTMM) to guide organizations through four stages of maturity: Traditional, Initial, Advanced, and Optimal. While the CISA ZTMM provides high-level criteria for each stage, it lacks the granularity needed for organizations to quantitatively assess and strategically progress along the maturity path. This paper introduces a novel quantitative scoring system tailored for ZTMM, enabling organizations to self-evaluate their Zero Trust maturity with precision. The proposed system assigns weighted scores across multiple Zero Trust Maturity Pillars including Identity, Devices, Networks, Applications, Workloads, and Data. Each domain is assessed according to specific criteria established for the four maturity levels, enabling organizations to systematically identify deficiencies and prioritize initiatives. The scoring system's utility is demonstrated using two fictional organizations with contrasting cyber-security postures, illustrating how this model provides actionable insights for advancing Zero Trust implementations. Additionally, the paper underscores the global absence of standardized ZTMM scoring systems and highlights the benefits of adopting this approach, including improved planning, resource allocation, and alignment with strategic cybersecurity goals. This contribution aims to fill a critical gap in the Zero Trust ecosystem, equipping organizations with a practical framework to measure and achieve maturity in their Zero Trust journey.