Tinfoil Chat – Onion-routed, endpoint secure messaging system

Transmitter Program encrypts and signs plaintext data and relays the ciphertexts from Source Computer to her Networked Computer through a serial interface and a hardware data diode. Relay Program on Alice’s Networked Computer relays commands and copies of outgoing messages to her Destination Computer via the serial interface and data diode. The web client of Bob’s Relay Program fetches the ciphertext from Alice’s Onion Service and forwards it to his Destination Computer (again through a serial interface and data diode).

Source: github.com