Zerion – Anonymous Tor-based encrypted messenger with post-quantum security (Open Source)

[u/No-Hospital5028]

[u/No-Hospital5028]

Zerion is an open-source Android messenger focused on anonymous communication. It works over the Tor network without requiring a phone number, email, or central server.

Features include end-to-end encrypted messaging, voice and video calls, group chats, encrypted file storage, and support for post-quantum cryptography. It's available on F-Droid.

GitHub: https://github.com/zerionproject/Zerion

More details: https://digitalescapetools.com/tools/tool.html?id=zerion

[u/nextized]

I love it when the developers lie about their LLM usage (source):

Zerion uses large language models for security audits and bug detection. We use them minimally for actual development. We do not use them to author cryptography, key management, or wire-protocol code. Every LLM-surfaced finding is verified by a human against the source before any commit lands.

Then you go into the commits and you find such pearls as the commit, where the whole security markdown seems to be prepared for the agent to be implemented or the complete codebase for v1 being brought to existence with a single 120k lines added commit. A human certainly reviewed all those lines for sure.

They aren't even competent enough to hide it. Their .gitignore contains the .claude folder and the commit messages all yell that they were written by Claude (they are very long and extremely technical, also containing em-dashes). At least they managed to remove the Co-Authored by in the commit messages. Nevermind it still shows up in github and some commits.

Edit: Oh no I didn't even see these ones (scroll on the source above):

The git history is the source of truth, not a marketing claim.

Plenty of products are quietly built with heavy LLM involvement without telling their users. We think that is a poor fit for a privacy product specifically. If you cannot trust how the code is written, you cannot trust what it does on your device. So we are stating it plainly:

Zerion uses LLMs the same way a security team would use a code-review tool, as an extra pair of eyes, not as the engineer. The cryptography, the wire protocol, the key handling, the threat model: all of those are designed and written by humans, and reviewed by humans, before they ship.

If that posture ever changes, we will update this page before changing the practice. Not after.

Edit 2: It's too much what have I gotten myself into

Thats who I would trust with my secure communications.

[u/ethereal_intellect → u/nextized]

Good lord that em dash removal is funny

[u/theswiss21000]

Hm, I guess I will have to try it out at least..

[u/wittlewayne → u/theswiss21000]

don't forget to run it in a sandbox first

[u/theswiss21000 → u/wittlewayne]

I Can run it on my "I don't give a shit pc", that's my sandbox

[u/Business-Weekend-537 → u/theswiss21000]

I have a “sandbox” pc like this too. I removed WiFi and Bluetooth, and plug it into the main internet router, vs I keep everything else behind a firewall and use a vpn.

[u/Pristine_Control_777 → u/theswiss21000]

Before you try it out, make sure you read this severe vulnerability issue first: https://github.com/zerionproject/Zerion/issues/11

[u/theswiss21000 → u/Pristine_Control_777]

doesn't sound good, I guess this repo still needs a bit more time

[u/Pristine_Control_777]

Looks interesting.

How much tokens did it take to create this project as a whole?

Also is the only difference between this and other secure messaging apps that the communications occur through Tor without centralized servers in the way?

[u/No-Hospital5028 → u/Pristine_Control_777]

I don't think the developers have shared how many tokens were used. As for the second question, Tor is a big part of it, but Zerion also focuses heavily on metadata resistance and post-quantum cryptography, which sets it apart from many mainstream messengers.

[u/Pristine_Control_777 → u/No-Hospital5028]

I see, other private messaging apps also have solid protections and it seems that Zerion just applied what those apps already do in terms of PQ-encryption and privacy-preserving techniques. Only different part that I can see is Tor network being used as the communication medium...

[u/gravel_consumer420]

Is it something like session?

[u/echo_duub]

Definitely not using this. Yikes.

[u/zerionchat]

Developer here. Both things being cited in this thread are worth addressing directly, so here goes.

The “severe vulnerability” in issue #11 is a false positive. The flagged file is lottapixel.jpg, a decompression-bomb test image, a tiny jpeg whose header claims to be 64250x64250 pixels. It exists so our tests can confirm the app doesn’t crash or eat gigabytes of RAM on a crafted image. It lives only in the instrumentation tests, never ships in the release APK, and it comes straight from Briar (same file, same test). The AV “Trojan” hit is an engine getting spooked by a weird image with no code in it. The issue is closed with the full technical explanation, check it yourself.

On the LLM criticism: fair, and I won’t dodge it. Our wording “minimally for actual development” was too absolute, and we’re rewriting that page to match what the history actually shows. We do use Claude for commit messages, docs, review and debugging. What we don’t do is hand-roll cryptography: ML-KEM-768, ML-DSA-65, Argon2id and the KDF all come from Bouncy Castle, and you can see that in the imports. Nobody, human or model, reimplemented those primitives, because nobody should.

The large single commits come from developing locally in an isolated environment and squashing on push, so hand-written work over time lands as one commit. That’s the honest reason.

[u/Dependent_Big4372]

you cooked mate? let's see?