Best open-source Security projects

Self-hosted, cookie-free CAPTCHA alternative that uses proof-of-work to block spam and bots without visual puzzles.

A free, open source Android authenticator app that generates HOTP and TOTP two-factor codes and keeps them in an encrypted vault.

Open-source Android authenticator app from 2FAS that generates TOTP and HOTP one-time codes for two-factor login.

A CLI tool that extracts TLS/SSL certificates from servers and exports them as PEM, DER, or truststores.

Self-hosted home security camera system for Raspberry Pi with end-to-end encrypted live video, alerts and recordings on your phone.

A Python CLI that automatically locks your desktop when your paired Bluetooth phone or smartwatch moves out of range.

Chrome extension that detects which anti-bot systems, captchas and fingerprinting techniques a website uses, with confidence scores.

Forensic tool that mounts, analyzes and visualizes Google Chrome browser artifacts such as history, downloads, logins and cache.

An Android app that scans nearby Bluetooth Low Energy devices, tracks them over time, and alerts you to suspicious or following devices.

An MCP server that exposes Ghidra's reverse engineering functions so LLM clients can decompile and analyze binaries.

Open-source Rust firmware that turns a cheap Raspberry Pi RP2350 board into a USB passkey and security key for WebAuthn, ssh, gpg, PIV and TOTP.

A CLI that finds leaked credentials across Git, cloud storage, chats and other sources, then checks whether each one is still live.

Open-source Python SDK and service for detecting and anonymizing PII in text, images and structured data.

A Python command-line tool that decompiles Android APK files with jadx and scans them for URLs, endpoints and hardcoded secrets.

Converts untrusted PDFs, office documents and images into safe PDFs by rasterizing them inside a sandbox.

Self-hostable, open source service for sharing self-destructing encrypted notes and files, inspired by PrivNote, with a Rust backend and Svelte frontend.

A Python tool from Cisco that scans MCP servers, tools, prompts and source code for security threats using YARA rules, LLM analysis and Cisco AI Defense.

Android firewall that blocks per-app network access without using a VPN, driven by Shizuku, LibADB or root.

A self-hosted, email-first dead man's switch that delivers end-to-end encrypted messages to your loved ones if you stop checking in.

AI-powered OSINT tool that searches dark web engines through Tor, uses an LLM to refine queries and filter results, and writes an investigation summary.