The Hidden Difficulties of Redacting PDF Documents
PDFs leak redacted text in unexpected ways: invisible text layers, embedded files, and metadata. Why PDF redaction is harder than it looks, with Philter's fix.
Prompt Engineering for Privacy: Practical Patterns for Not Leaking PII
Every prompt sent to an LLM is a data egress point. Six concrete patterns for structuring prompts, redacting inputs, and scanning outputs so PII doesn't leak.
Building a Privacy-Aware RAG System
RAG pipelines have two distinct PII leak vectors: ingestion and inference. A defense-in-depth blueprint with code, using Philter and the Philter AI Proxy.
Why API-Based Redaction is a Security Antipattern
Sending sensitive data to a third-party redaction API opens the security holes you are trying to close. Why data sovereignty needs a self-hosted engine.
Deploying Philter in Air-Gapped Environments
Deploy Philter and the full Philterd toolkit into completely offline VPCs and disconnected cloud regions. No phone-home, no telemetry, no external dependencies.