Fiat money is currency whose value comes from government backing and public confidence, not from a physical commodity such as gold. Most modern national currencies are fiat money, which means their use depends on trusted institutions, payment infrastructure, and the stability of the financial system.
In cyber security, fiat money matters because attackers often try to convert stolen access, data, or crypto into spendable currency. That conversion can involve payment processors, bank transfers, cards, or money-mule networks, making fraud detection and transaction monitoring important defenses. When digital payments are disrupted by phishing, account takeover, ransomware, or service outages, the trust that supports fiat value is stressed. Security teams therefore protect identities, payment rails, and settlement systems to preserve integrity, availability, and confidence in the money flow.