LLM Guard vs Purfect Shield: architecture matters.
Both detect secrets. The difference is where they sit — in your code or on your wire. Structural decisions compound across every LLM call your organization makes.
Architecture is destiny. An SDK can only protect what it wraps. A proxy protects everything that transits.
Real threats. Real-time response.
Three common AI security scenarios and exactly how Shield handles each one — at the proxy layer, before the model sees anything.
Shield detects the AWS access key pattern before the request leaves your machine. The key is replaced with a stable placeholder — the model never sees it. Claude Code operates normally, receiving the tokenized prompt. Responses are rehydrated transparently.
PII patterns (names, DOBs, MRNs) are caught at the proxy layer. Patient identifiers are swapped for deterministic placeholders. The LLM processes de-identified data. Results are rehydrated with original values before the engineer sees them.
Canary fingerprints embedded in every request detect tampering. If an attacker tries to strip or modify tokenized placeholders, the canary breaks. Shield blocks the request, logs the attempt, and alerts your security team via the audit sidecar.
Every redaction is cryptographically linked to its predecessor.
Shield writes every tokenization event to an append-only JSONL log. Each record includes the hash of the previous record. Modify or delete any entry and the chain breaks — immediately and verifiably.
Records can only be added, never modified or deleted. The log is an immutable sequence of events from Shield's first boot.
Each record carries the SHA-256 hash of its predecessor. Breaking the chain requires breaking SHA-256 — computationally infeasible.
Export the JSONL log for auditors. Every redaction is timestamped, attributable, and cryptographically linked. Satisfies PCI-DSS, SOC 2, and HIPAA evidence requirements.
The audit sidecar runs on your infrastructure alongside Shield. No audit data ever leaves your network. You control retention, rotation, and access.
See it live on your workflow
We'll deploy Shield in front of your AI tools and walk through real scenarios — paste an API key, inject PII, attempt a prompt injection — and watch Shield detect, tokenize, and log every event in real time. No slides. No promises. Just the proxy running on your machine.
Don't take our word for it. Verify it.
Purfect Shield ships with a verifiable hash chain from its first boot. Every claim on this page is backed by cryptographic evidence your auditors can validate independently. Let us show you on your own infrastructure.
Fixed-price engagement · Source code at handoff · No subscription