Episode 13: Non-Repudiation and AAA (Authentication, Authorization, Accounting) (Domain 1)

Cybersecurity is not only about prevention—it’s also about proof, accountability, and enforcement. In this episode, we examine non-repudiation and the AAA model—Authentication, Authorization, and Accounting—as cornerstones of digital trust. Non-repudiation ensures that users cannot deny actions they’ve taken, supported by mechanisms such as digital signatures, system logging, and secure timestamps. Authentication verifies identity through usernames, passwords, biometrics, or tokens, while authorization determines what that identity is allowed to do based on roles or policies. Accounting (or auditing) captures activity logs, tracking actions for analysis, compliance, and incident response. Together, AAA creates a framework for managing access, enforcing accountability, and providing traceability in both user and system interactions. We break down each element using case scenarios from enterprise environments to illustrate how they’re implemented and monitored for effectiveness.