A data flow map is a diagram or written model that shows how information moves through a system. It identifies where data is created, transmitted, processed, stored, accessed, logged, and deleted, along with the systems and users that touch it. In security work, this is essential for understanding trust boundaries, because the risk is often not only the data itself, but every place it can be exposed along the way.
Data flow maps matter in cyber security because attackers often target weak points in the path: overly broad permissions, insecure APIs, exposed logs, or forgotten retention stores. Defenders use them to spot unnecessary data collection, limit access, define segmentation, and verify that sensitive material stays inside approved boundaries. In AI-assisted tools, a data flow map helps confirm whether source code, prompts, findings, and remediation notes remain contained, who can read them, and how long they persist. It is a practical control for auditing, privacy, and incident response.