CipherRAG – Enterprise Privacy & Security Gateway for RAG Systems

Technologies: C#, .NET 10, Clean Architecture, Python, ArabBERT, Microsoft Presidio, EF Core, SQL Server, REST APIs

• Architected a .NET 10 Minimal API security gateway that intercepts, audits, and anonymizes user prompts before

they reach LLM/RAG vector stores.

• Built a hybrid PII/PHI detection engine (ArabBERT Python microservice + Presidio masking) to sanitize

Arabic/English sensitive data — National IDs, phone numbers, emails, credit cards, IBANs, and names — with zero

false positives.

• Enforced RBAC/ABAC via Cookie Authentication and ASP.NET Core Policies for department isolation and 5-level

clinical clearance security.

• Designed EF Core/SQL Server schemas with tamper-evident, cryptographically chained audit logging

(RowHash/PrevRowHash), plus in-memory caching, response compression, and rate limiting to optimize

throughput.