Cryptagram

Privacy-preserving image encryption and steganography.

Modernized Cryptagram is a high-performance, cross-platform architecture for local-first photo privacy. It allows you to encrypt photos locally and embed them into images that survive social network transformations (JPEG recompression), revealing them in-place via a browser extension.

🚀 Modern Architecture (Phase 2 & 3)

The project has transitioned from a legacy Closure-based implementation to a modern, monorepo-based core:

• 📦 Shared Core (@cryptagram/core): TypeScript implementation of the Bacchant and Aesthete protocols with WebCrypto (AES-GCM).
• 🧩 Chrome Extension (MV3): A modern, Vite-based extension for real-time image decoding and reveal.
• 🦀 Rust Core: High-performance Wasm-ready core for edge and proxy integration.
• 🧪 Testing Harness: A rigorous Python-based suite for JPEG robustness and bit-parity verification.

🛠 Developer Onboarding

Please see DEVELOPER.md for detailed instructions on setup, building, and contributing to the modernized stack.

🧪 Quick Test

Ensure everything is passing with the baseline suite:

make test

📜 History & Vision

Cryptagram was originally developed at the NYU Media Research Lab. The goal remains the same: to give users control over their visual privacy on the web without relying on trusted third-party servers.

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© 2012-2026 Matt Tierney & Ian Spiro. BSD-3-Clause License.