PureCipher Prompt Defender by PureCipher Inc

PureCipher Prompt Defender is a browser extension designed to reduce prompt-injection risk before webpage content reaches an AI system.

The add-on processes webpage content locally to detect hidden prompt-like instructions, scrutinizes likely AI-bound handoffs, sanitizes suspicious prompt text in guarded workflows, and provides extension-owned safe fallback paths for review and summary flows.

What the current release does:

• scans hidden or low-visibility DOM content for prompt-injection patterns
• guards risky page-to-AI controls and destination-based AI handoffs
• sanitizes suspicious copy and paste into AI prompt surfaces
• protects prompt submission on supported AI web apps
• provides safe handoff and safe summary review flows

Platform status:

• Firefox desktop is runtime-verified
• Firefox for Android is included only after the same version passes the documented device or emulator test

What the current release does not claim:

• universal interception of every browser-native AI UI
• automatic cloud training from user browsing content
• default-on remote analytics or telemetry to PureCipher

Privacy:

This add-on processes webpage content locally in the browser for security purposes. It does not upload raw page text, raw prompt text, clipboard contents, URLs, or page titles to the developer by default.

Optional remote features are off by default and require Firefox permission before they can be enabled. If a user explicitly opts in and configures an HTTPS endpoint, the add-on can transmit aggregate browsing-provider, website-interaction, extension-usage, and technical metadata for federated learning or SecureMCP policy delivery. These payloads exclude raw page text, raw prompts, raw URLs, page titles, clipboard contents, cookies, and advertising identifiers.

Local redacted exports leave the device only if the user chooses to share them.