Top CRYPTOGRAPHY GitHub Repositories & Tools (2026)

Tiny post-quantum encryption for sensitive data. Write-only by design. ML-KEM-768 + X25519 + AES-256-GCM. Please break it.

Cryptomator for Windows, macOS, and Linux: Secure client-side encryption for your cloud storage, ensuring privacy and control over your data.

Bitcoin Core integration/staging tree

RSA attack tool (mainly for ctf) - retrieve private key from weak public key and/or uncipher data

A Decentralized Operating System for ZK Applications

🛡 I2P: End-to-End encrypted and anonymous Internet

Cryptography Toolkit

BouncyCastle.NET Cryptography Library (Mirror)

The simplest and most extensible zkVM. Fast and fully open source from a16z crypto and friends. ⚡

Unsafely fast hashing algorithm 📈

🔑 Free Offline-first Password Manager

Homomorphic Encryption library and applications in Swift

End-to-end encrypted notes, tasks, files, passwords, journal and bookmarks. Keyed by a 12-word BIP-39 phrase: no email, no password, no account to leak. The full client source for web, desktop and mobile is published, along with the encryption (XChaCha20-Poly1305, HKDF-SHA256, Ed25519) and the threat model, so the privacy claims are falsifiable.

Don't Roll Your Own Crypto: fast, type-safe, pure-Rust cryptography with post-quantum support

Easy file sharing with server-side encryption, curl/httpie/wget compliant

A Friend-to-Friend, decentralized and secure application for communication and sharing

Quantova's client core for JavaScript and WebAssembly. Post quantum signing and Q1 addresses, generated over the Rust core.

A Python library for 'bitcoin cryptography'

Lowkey Vault is a small test double for Azure Key Vault. Developer feedback needed, please vote here: https://github.com/nagyesta/lowkey-vault/discussions/272

A Messaging Layer Security (RFC 9420, MLS) implementation in TypeScript