Implementing Strong Customer Authentication (SCA)

Strong Customer Authentication (SCA) is a regulatory requirement designed to make online payments more secure. It requires customers to verify their identity using at least two independent authentication factors.

• Knowledge: Something only the user knows (e.g., password, PIN).
• Possession: Something only the user possesses (e.g., phone, hardware token).
• Inherence: Something the user is (e.g., fingerprint, facial recognition).

These factors must be independent, meaning compromising one doesn't compromise the others.

SCA is a key component of the Revised Payment Services Directive (PSD2), an EU regulation. PSD2 aims to enhance consumer protection, promote innovation, and improve the security of payment services across the European Economic Area (EEA).

For developers, this means ensuring your payment flows can handle dynamic authentication challenges when required, especially for transactions involving European customers and banks.