DIB stands for Defense Industrial Base: the network of contractors, subcontractors, and suppliers that build, maintain, and support defense systems and services. This includes organizations that handle sensitive government data, produce hardware or software, and provide logistics or engineering support for defense programs.
DIB matters because it sits inside a high-value supply chain. Attackers target DIB companies to steal controlled information, disrupt delivery, or use one vendor as a stepping stone into a larger program. Defenders focus on access control, logging, segmentation, and supplier oversight because a weak link in the chain can affect many others. In practice, DIB organizations are often measured against requirements such as CMMC and NIST SP 800-171 to prove they can protect sensitive data and remain contract-ready.