Threat Modeling
Five-zone method for agentic AI. STRIDE/PASTA where they still fit.
STRIDE, PASTA, attack trees. The classical tooling still works for classical systems. For agentic AI, those frameworks miss most of what matters. The methodology I work from is a five-zone map of every place external data enters an agent's context: input, reasoning, action, state, coordination. Attack scenarios then get traced as chains across zones, not enumerated as events at boundaries.
Most of the writing on this site builds on this work. The STRIDE-breaks post is the clearest statement of the method.