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Integrating Encrypted Multi-Channel Communication into deltachat

Bachelor Thesis, Master Thesis

Motivation

While point-to-point encryption is widely solved by protocols like TLS, End-to-End Encryption (E2EE) still faces challenges. Existing E2EE solutions such as PGP and Signal suffer from problems such as low usability, small user bases, dependence on central providers, and risk of backdoors. These concerns are increasing with new US and EU surveillance proposals requiring chat monitoring

In [1|, we proposed Encrypted MultiChannel Communication (EMC2), a secret sharing-based E2EE system that splits messages into multiple shares and sends them over independent communication channels. As demonstrator, we developed a web-based prototype that allows users to manually send these shares via email, SMS, Signal, WhatsApp, etc (see code in [1]). While manual copy and paste improve transparency, automation can further enhance usability. One possible automation is to extend an email application so that, instead of sending a message directly, it secret shares the message and sends the shares via two different email accounts to two corresponding addresses of the recipient which we showed in [2].

Goal

The goal of this thesis is to integrate EMC2 with Delta Chat [3,4], an email-based chat application that provides a messenger-like user experience while remaining compatible with standard email (SMTP). This task requires adding core capabilities to secret sharing emails to Delta chat and enabling UI support for multi-email accounts.

Requirements

  • Experience in Web and Android development
  • Basic knowledge of Cryptography
  • High motivation + ability to work independently
  • Knowledge of the English language, Git, LaTeX, etc.

References

Supervisors