TIU Consulting’s Post

Designing Secure Financial Apps: Why We’re Leaning Toward BFF + HMAC based security model. [Backend for FrontEnd + Hashbased Message Auth] 🏦 We’re currently in the architecture & threat-modeling phase for a new financial app. Standard session-based auth looks shaky for our needs, so we’re evaluating a Backend for Frontend (BFF) pattern paired with HMAC-based request signing, that looks very interesting and unique. Why Not Simple Session Tokens? Early analysis suggests traditional session + role ID has gaps: 🔓 Higher exposure to session hijacking 🧩 Awkward scaling across microservices ⚠️ CSRF protections that rely heavily on careful front-end handling 📉 Weaker, harder-to-trace audit signals for compliance 🧩 No protection against replays What We’re Exploring (BFF + HMAC) A BFF mediates client traffic and centralizes auth concerns; HMAC adds per-request integrity and authenticity. Targeted benefits: ✅ Stronger integrity with cryptographic signing ✅ Service-friendly, no shared session state needed ✅ Compliance-ready with verifiable request data ✅ Better CSRF protection ✅ Stateless at the edge for scalability In this design BFF would: Issue short-lived tokens with user/permission context Require HMAC-signed headers on each API call Enforce nonce/timestamp checks for anti-replay Delegate role/permission checks to services The Trade-Offs and the “Fort Knox” Argument The real strength of combining BFF + HMAC + Role-Based Auth lies in layering protections at every step. The BFF ensures the UI layer never directly touches the orchestrator (like n8n) or backend databases, cleanly segregating responsibilities and reducing attack surfaces. HMAC guarantees each request is cryptographically signed and time-bound, making replay or tampering infeasible. Role-based authorization enforces the “principle of least privilege,” ensuring users and services can do only what they’re explicitly permitted to do. This is is Zero-Trust security at its best! This isn’t just another “better than sessions” play—it’s designing for highest level security 🏰. Traditional session tokens often collapse under the weight of microservice sprawl, compliance demands, and modern threat models. In contrast, the BFF + HMAC + Role-based approach offers scalability, airtight security, immutable audit trails, and zero-trust enforcement across every layer. 💡 Question for you: 👉 What security models have you used in your applications? 👉 If you haven’t tried BFF + HMAC yet, do you see potential in adopting it for sensitive or financial use cases? (Do give it a try) 📚 References: The Backend For Frontend Pattern (Sam Newman, ThoughtWorks) https://lnkd.in/gWe7pSme Understanding HMAC Authentication (Okta Developer Blog) https://lnkd.in/gx69jV_b #FinTech #Security #Authentication #BFF #HMAC #Cybersecurity #SoftwareArchitecture #BackendDevelopment #ZeroTrust