HIPAA-Compliant Patient Data Anonymization API Middleware

Design a Flask-based microservice that automatically anonymizes patient health records using advanced data masking techniques. Implement robust encryption for PHI (Protected Health Information) with support for HIPAA compliance. The middleware should handle RESTful API requests, use cryptographic hashing for patient identifiers, and provide granular access control with role-based authentication. Include comprehensive error handling for potential data leakage scenarios and generate detailed audit logs for each anonymization process.