C

cryptography

Leonardus is an open source project. It is a minimalist, stack-based programming system designed as a flexible framework for implementing and exploring algorithms. The syntax and semantics of its scripting language, LeoScript, are inspired by PostScript and Forth. It is extended with a prototype-based, object-oriented paradigm, has seamless integration into JupyterLab and Docker, and provides a concise and expressive environment for learning and experimentation.

The project name is a nod to Leonardus Pisanus, who was named and became known as Fibonacci.

Consult the project's GitLab Pages for documentation.

QUIC-native TLS 1.3 implementation in Zig. RFC 8446/9001 compliant with zero external dependencies.

Zig Hardware Security Module library for PIV, CAC, and YubiKey tokens via PC/SC. Supports certificates, PIN management, signing, and decryption.

A Rust end-to-end encryption library (e2eel) for key management using a Directed Acyclic Graph (DAG) of encrypted keys

CryptoLyzer is a fast, flexible, and comprehensive server cryptographic protocol (TLS, SSL, SSH, DNSSEC) and related setting (HTTP headers, DNS records) analyzer and fingerprint (JA3, HASSH tag) generator with Python API and CLI.

Cryptographic protocol and security-related protocol piece parser.

Free repository of cryptography-related data.

A sponge-based secure hash function that uses AES-256 as its internal PRF.

Encryption & compression companion — inspired by Diophantus of Alexandria

Production-grade cryptographic keystore in Rust with ChaCha20-Poly1305 and Argon2 KDF

ProofShield is an open-source document authenticity and fraud prevention system designed to protect digital and physical documents from forgery, unauthorized alteration, and AI-generated manipulation. Using certified mirror images, cryptographic verification, AI detection, privacy-preserving validation, and hardware security integration, ProofShield creates a trusted verification layer that makes document authenticity provable and alterations visible. https://roxanneardary.com/proofshield/

VeritasVote is an open-source, tamper-evident in-person voting machine. Fully auditable, cryptographically verifiable, and backed by paper ballots, it provides transparent and secure elections. Hardware and software are fully open for inspection, ensuring every vote can be trusted. https://roxanneardary.com/veritasvote/

Hill cipher (matrix-based cryptography) in C, with worked encrypt/decrypt examples and step-by-step output.

Five classic ciphers (A1Z26, Caesar, Rail Fence, mixed-alphabet, ROT13) in C, with an interactive menu for each.

A package that handles key pair generation and encryption / decryption of secrets using keys

ItemShield is an open source specification for securely identifying, authenticating, tracking, and protecting physical products throughout their lifecycle. It enables cryptographically verifiable product identities, chain of custody, fraud detection, theft prevention, and consumer verification. https://roxanneardary.com/itemshield/

LightQuest is a real-world adventure game specification that combines surface and underground exploration with Shadow encounters, cooperative gameplay, persistent digital assets, federated worlds, and player-driven trading. It defines a persistent, interconnected adventure experience where exploration, combat, quests, and community-driven economies evolve together. https://roxanneardary.com/lightquest/

Bletchley is a collection of historical ciphers and cryptanalysis tools. Eventually, it is planned for Bletchley to become a suite capable of identifying and attacking historical ciphers automatically.

Cryptopals challenges https://cryptopals.com/