Hi, nice to see another project working on data-diode isolated TCBs.

The line 915 of audioReceiver.py shows you're using a hard-coded and thus predictable IV. This is not safe since you're using the X25519 shared key repeatedly. Please see the explanation here for more information.

Also, you're using per-session short authentication strings that are not very secure. Please strongly consider the best practice of generating long-term ed25519 identity keys instead to sign and verify the per-session X25519 public values, and generate a 256-bit fingerprint of the ed25519 public (signature verification) key that the users verify once and mark as verified. You can combine the public keys for a symmetric fingerprint by sorting them lexicographically and taking the BLAKE2 hash of them. My recommendation is to use base-10 encoding for representing the fingerprint as human languages have evolved to communicate digits in a distinguishable way for obvious reasons.

Is your feature request related to a problem? Please describe.
Laptop with Qubes OS

Describe the solution you'd like
An AC4QGP Template would be great

Describe alternatives you've considered
TinFoil Chat for text and recorded messages

Have you tried using this over Tor and Onion to Onion services?

Would be great if it works with low/no metadata environment.

cool project, but no way to contact the author available.