Visa's global, secure network (VisaNet), employs multiple layers of security to protect cardholder data and maintain high levels of trust in the payment system. The instant a merchant processes your card, Visa goes to work preventing fraud.
We use a detection system to scan thousands of transactions per second, looking for subtle changes in spending patterns that could indicate fraud. If something's amiss – a mismatched address, an unusually large purchase, or transaction far from home – we're able to respond immediately.
Visa also applies standards such as PCI DSS (Payment Card Industry Data Security Standard) and encryption of transaction information between financial institutions and Visa's network. This helps protect against counterfeit card fraud. Visa's secure network can also help detect and stop large scale ATM 'cashout' to help minimize ATM fraud.