Strong Customer Authentication (SCA)
Strong Customer Authentication (SCA) is a regulatory requirement under the second Payment Services Directive (PSD2) in the European Economic Area (EEA). It mandates that electronic payments require multi-factor authentication to enhance security.
SCA Requirements
SCA requires authentication based on at least two of the following three elements:
- Something You Know - Knowledge (e.g., password, PIN)
- Something You Have - Possession (e.g., phone, hardware token)
- Something You Are - Inherence (e.g., fingerprint, face recognition)
Exemptions
Certain transactions may be exempt from SCA requirements:
- Low-value transactions (under €30)
- Trusted beneficiaries (whitelisted merchants)
- Recurring transactions with the same merchant
- Transactions deemed low-risk by risk analysis
Implementation Challenges
Implementing SCA effectively while maintaining user experience involves:
- Balancing security with convenience
- Ensuring compatibility with existing systems
- Managing fallback mechanisms for failed authentication
- Complying with regional regulations beyond PSD2
Pros & Cons
- ✅ Significantly increases transaction security
- ✅ Reduces fraud and unauthorized transactions
- ✅ Complies with regulatory requirements
- ❌ Can impact user experience during checkout
- ❌ May increase transaction abandonment rates