Convertibility is the ease with which a technology can be repurposed for a different use case. In cybersecurity, it describes how quickly a model, chip, platform, or research result can shift from benign use to a sensitive or harmful one. High convertibility makes a capability harder to classify and govern, because the same tool can support productivity, surveillance, intrusion, or military use depending on who controls it and how it is deployed.
This matters for defense and risk analysis because attackers often exploit general-purpose systems rather than purpose-built malware. A cloud service, AI model, or cryptographic tool may be adapted for phishing, automation, reconnaissance, or defense bypass if access controls are weak. For defenders, measuring convertibility helps prioritize safeguards such as usage restrictions, monitoring, supply-chain review, and export or research controls. In practice, the lower the convertibility, the easier it is to keep a technology within its intended security boundary.