Supply chain concentration is the clustering of critical production steps in a small number of regions, factories, or suppliers. In technology supply chains, that can mean a few companies make the key tools, a few plants do the fabrication, or one region controls advanced packaging. This matters in cyber security because concentration creates single points of failure: if one supplier is disrupted, many downstream products and services can be affected at once.
Attackers and defenders both care about this risk. Criminals may target concentrated suppliers to reach many victims through one compromise, while defenders worry about hidden exposure in hardware, firmware, and software dependencies several tiers deep. Concentration also makes provenance harder to verify, increasing the chance of tampering, counterfeit parts, or delayed detection of defects. Resilience improves when organizations map their dependencies, diversify suppliers where possible, and validate the integrity of components before deployment.