SSDF stands for the NIST Secure Software Development Framework. It is a set of practices that helps teams build security into software from planning and coding through testing, release, and maintenance. Instead of treating security as a final checklist, SSDF makes it part of the development lifecycle.
This matters because many attacks exploit weaknesses introduced long before software reaches users: insecure code, weak dependencies, unsafe build pipelines, or poor update controls. SSDF helps reduce that risk by promoting secure design, code review, vulnerability management, authentication of build and release artifacts, and continuous improvement. In real defenses, organizations use SSDF to harden development processes, support supplier assurance, and lower the chance that compromised upstream software can enter trusted environments. It is especially relevant in supply chain security, where verification and traceability are essential.