How would you mitigate LLM06 (Sensitive Information Disclosure)?

Layered approach: (1) Pre-input PII redaction (Presidio, AWS Comprehend PII); (2) System prompt restrictions (explicit 'never repeat user data, system info'); (3) Output PII filters before return; (4) Training/fine-tuning data audit — remove PII before training; (5) RAG context filtering — strip PII from retrieved chunks; (6) Audit logs for prompt/response pairs (with PII redaction in logs); (7) Periodic data leakage testing using known sensitive prompts. No single layer is sufficient — defence in depth required.