A lightweight C implementation of the EFPIX protocol, a zero-trust, encrypted flood protocol designed for privacy, resilience, and metadata protection in hostile network environments.

• Four Packet Types: Supports unicast (signed/anonymous) and broadcast (signed/anonymous) messages.
• Modern Cryptographic Suite:
  • Ed25519 signatures for message authenticity.
  • X25519 key exchange for deriving shared secrets.
  • Perfect Forward Secrecy through the use of ephemeral keys for each message.
  • ChaCha20-Poly1305 AEAD for fast, secure, and tamper-proof authenticated encryption.
  • BLAKE2b for high-speed hashing and message identification.
• Minimalist Design: Written in C with a single dependency.

See src/example.c for usage and tests

• Monocypher 4.0.1+: A single-file, audited, public-domain crypto library. Place all 4 monocypher .c and .h files in the lib/ directory, or use the automatic fetch feature in nct.

• POSIX-compliant system: Requires getrandom() syscall for secure random number generation.

Run make for a standard build. Alternatively, if you have NCT installed, you can use nct build.

This implementation is experimental and has not undergone a formal security audit. It may be vulnerable to side-channel attacks. Use in production at your own risk.