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Show HN: A P2P messenger with dual network modes (Fast and Tor) (opens in new tab)

(github.com)

39 pointsRealman781mo ago23 comments

Hello HN,

I have been working on a desktop P2P messenger called Kiyeovo for the last ~8 months, and I just published its beta version.

Quick backstory: It started out as a CLI application for my Graduate Thesis, where I tried to make the most secure and private messenger application possible. Then, I transformed it into a desktop application, gave it "clearnet" support and added a bunch of features.

Short summary:

The app runs in 2 completely isolated modes:

- fast mode: relay/DCUtR -> lower latency, calls support

- anonymous mode: Tor message routing -> slower, anonymous

These modes use different protocol IDs, DHT namespaces, pubsub topics and storage scopes so there’s no data crossover between them.

Messaging works peer-to-peer when both parties are online, but falls back to DHT "offline buckets" when one of them is not. To ensure robustness, messages are ACK-ed and deleted after being read.

Group chats use GossipSub for realtime messaging. Group messages are also saved to offline buckets in order for offline users to be able to read them upon logging in. Kick/Join/Leave events are also propagated using the DHT. Group metadata and all offline data is of course encrypted.

Other features: Chats are E2E, file sharing is supported, 1:1 audio/video calls are supported (only in fast mode though, using WebRTC)

Tradeoffs: Tor has noticeable latency, offline delivery is not immediately guaranteed, but rather "eventually consistent"; beta version does not have group calls yet.

I’d appreciate feedback, that's why I posted this as a beta version

Repo: https://github.com/Realman78/Kiyeovo

23 comments

dostick1mo ago

Since Tor has become increasingly susceptible to state monitoring of exit nodes, making app rely on Tor is potentially compromising your future users. Look into i2p or other protocol that’s really anonymous.

Realman78OP1mo ago

Yes, I agree Tor is not the best anonymity service these days. I2P was my first choice, but the performance was just awful. I did not fully give up on the I2P idea, maybe it was just that day, so I will give it a second choice and mazbe add a third mode or fully replace tor. Not sure since a lot of people are familiar with tor, and not I2P

dostick1mo ago

Whom you want to please with TOR support.. You have advantage not being a commercial product driven by recognition, to be free to base it on the next and better thing.

kvisner1mo ago

So most messaging apps rely on a phone number or centralized server to provide a means of making atleast the initial connection. In a purely P2P messaging system, how do I, as a user, find the other person I might want to talk to?

Realman78OP1mo ago

Third party info exchange. I don't see that as an issue though. For example, for discord, you also 100% exchanged usernames via a third party system. I mean, even phone numbers are exchanged via third parties. Now that I think about it, the only place where you can search people somewhat reliably are social media sites

blamestross1mo ago

I'm a fan of "face to face mutual qr code key exchange." I should implement that someday.

Realman78OP1mo ago

QR code key exchange is convenient, but I did not plan phone support.

blamestross1mo ago

Nobody does "face to face" key exchange like I imagine. Just two phones facing each other spamming QR codes for the other to read.

What I REALLY want is an app that builds a big bank of nonces between you and your peers over short range radio or QR codes and then lets you use a 1-time pad.

Ultimately, I'm only offering criticism because I have spent a lot of time working on exactly this problem, but I am not in a position to actually implement it. This is awesome and you should be proud of it.

allenwest1mo ago

If the protocols and data are completely isolated, and features differ in many ways, why combine them in a single App? There's a chance a user might accidentally leak sensitive info over the anonymous mode.

Realman78OP1mo ago

The two modes are in one app for convenience, but they are separate systems. IMO, the risk is not data leaking between mode protocols/DHT, but rather the user linking their identity between the modes through their behavior - reusing usernames, same contacts... So in short, it's ease of use vs the risk of user error

blamestross1mo ago

I don't recommend DHTs with public participants being made from scratch. Use mainline bittorrent DHT instead. Small networks are really easy to eclipse and censor.

DHTs of trusted participants are great.

noman-land1mo ago

How does one find large DHTs? Is there anything connecting them all?

blamestross1mo ago

"Mainline DHT" is the primary one. It backs magnet links and has resisted censorship for over a decade. Largest most robust group of cooperating computers there is.

You can reliably use it to store arbitrary key-value pairs up to 1kb in in size.

https://en.wikipedia.org/wiki/Mainline_DHT

Realman78OP1mo ago

In theory, if only Kiyeovo nodes were handling Kiyeovo records, then yes, they could kind of behave like their own subnetwork. The problem is that in a public DHT, the nodes responsible for storing keys are those closes to that key, we cannot guarantee it would be a Kiyeovo node. So even if Kiyeovo clients all use the same validation rules locally, the actual nodes that get hit with the queries do not. The chances of the network converging to the same, correct answer are much slimmer this way

Realman78OP1mo ago

Good question. The 4 initial bootstrap nodes that I provided (in the README) are all connected to each other. If everyone connects to all of them, we are all basically on the same network instead of on "isolated islands"

youniverse1mo ago

Is this pronounced keovo/keyovo? Just thoughts for a shorter name. Cool project!

Realman78OP1mo ago

Haha, it's roughly pronounced as it's typed out. The name actually comes from a Croatian dialect. "Ki je ovo" translates to "who is this" -> and then when you connect the words and make it english compatible, you get kiyeovo.

If you go to google translate, select Croatian input "kijeovo" and click the speak button, you will hear how it is properly pronounced. Not that I care how people pronounce it, just wanted to share :)

kopitev1741mo ago

I worked on a p2p group chat app for a short time (no central server, same as this), but the group updates were a real problem. how do they get distributed?

Realman78OP1mo ago

The group creator distributes the updates to each group member individually (each pair of users has their own buckets). Of course, if the member is not online for a long time, the update does not just get lost, it gets republished and will continue to republish until the member has read the update. Did I answer your question?

neozmmv1mo ago

Cool project, I really like the separation between fast and anonymous mode, just starred it

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