Tools / Microsoft Threat Modeling Tool (TMT) Interview questions
Why is a bidirectional data flow treated differently than unidirectional in TMT?
A bidirectional flow really represents two logical channels layered onto one arrow - a request going one way and a response coming back the other - and each direction can independently be tampered with, spoofed, or intercepted.
Because of that, the rule engine evaluates threat conditions for both directions rather than treating the arrow as a single one-way conduit, which in practice roughly doubles the relevant threat instances for that connection compared to a strictly unidirectional flow carrying the same trust-boundary and endpoint properties. Marking a flow bidirectional only because it's convenient, when the interaction is really fire-and-forget one-way, will inflate your report with threats that don't reflect the actual interaction.
More Related questions...