ETERNAL: Encrypted Transmission With an Error-correcting, Real-time, Noise-resilient Apparatus on Lightweight Devices

Abstract

In this work, we describe the design and implementation of a private-key voice encryption system that is designed to encrypt and decrypt voice communications between two people using lightweight computational devices (such as a Raspberry Pi) that sits between the headset and the communication platform (computer, phone, etc.). The key challenge in this work is designing lightweight encryption algorithms in such a way that even before voice enters the phone/computer platform, voice is encrypted, yet such that modern audio communication channels such as popular VoIP applications (such as Skype, Google Voice, etc.), or mobile communications (GSM, etc.) or other (Radio, etc.) do not filter encrypted voice out as "noise" and voice quality is preserved. Thus, two people with two such devices can communicate securely even if their smart phones and/or computers are compromised. Unlike previous solutions, our proposed work does not rely on special-purpose hardware, nor does it rely on trusting the communication device. It is a standalone solution that can be readily deployed on lightweight commodity hardware. We have tested our solution on two Raspberry Pi models and over a variety of communication channels, where we were able to carry a real-time voice conversation.