PureCipher Prompt Firewall

Intercepts browser-to-LLM handoffs, sanitizes prompt-injection content, and guards AI prompt submission flows.

PureCipher Prompt Firewall adds a browser-side trust boundary when webpage content moves toward supported AI services. Core protections: - detects hidden or low-visibility prompt-injection patterns in webpage content - sanitizes suspicious text before copy, paste, handoff, or prompt submission - pauses risky page-to-service controls after hidden prompt-like content is found - provides Open Safe Handoff and Open Safe Summary review flows - shows recent interventions without keeping raw page text in long-lived history Current product boundary: - works on regular http:// and https:// webpages - protects webpage controls and prompt submission on supported AI websites - supports browser AI APIs that are exposed to webpage JavaScript - does not claim control over browser-owned native surfaces outside webpage content Privacy: - core page and prompt processing occurs locally in the browser - raw page text, raw prompt text, and clipboard contents are not uploaded to PureCipher by default - privacy-preserving reports and structured learning batches are local, opt-in, and user-initiated - structured learning signals are off by default