tox_push_msg_app VS simplex-chat

It's not hard for IRC-style chats, but it gets harder if you want to handle:

* Asynchronous messaging: what if the two devices are not online at the same time, or on disjointed networks? Store the message on a server somewhere? Secure Scuttlebutt[1] relies on devices pulling encrypted data that does not belong to them.

* NAT or firewall hole-punching, though it can be remediated by leveraging other nodes. Some implementations use a DHT[2], but you're often relying on other servers of some sort.

* What you call contact discovery is also typically handled through a DHT of some kind. Yggdrasil-like (or hyperboria, cjdns, .onion) overlay networks are usually able to route to a public key, regardless of how it moves around on the network.

* Push notifications. Either you accept the use of an external server (like the Tox client TRIfA, which has an add-on[3])

[1] https://scuttlebutt.nz/docs/introduction/detailed-start/#mor...

[2] https://blog.ipfs.tech/2022-01-20-libp2p-hole-punching/

[3] https://github.com/zoff99/tox_push_msg_app

For messaging I'm currently on Olvid (E2E with physical key exchange) but since it still use their servers, I'm currently testing SimpleX where I can host my own servers.

Notice how SimpleX (https://simplex.chat/) has no push notifications by default because of this issue.

I've been using SimpleX [0] with a couple of friends recently. It appears to work as advertised.

[0] https://simplex.chat

If you have a mobile phone number, the domestic intelligence agency knows exactly where you are at all times and any LEO (without a warrant) can also find you. In addition, there have been numerous CCC presentations showing how insecure the global (excluding US) and (separately) US carriers are guilty of promiscuous metadata trafficking ($$) and insecure SS7 setups. As a consequence, for low $, you can go to any one of several shady websites and find the last location of almost any phone number (person unique ID) globally. There are additional varying exploitable vulnerabilities depending on the exact combination of {handset x carrier x country} to impersonate them, tap their line, reveal their exact location, and redirect their phone number through a third-party handset or even a PBX. These are more expensive and some capabilities are forbidden for all but a few selective intelligence uses.

Session (Signal fork) doesn't use phone numbers. It's pretty well-designed overall and uses an onion routing approach. It's already a superset of Signal except it doesn't use phone numbers. https://getsession.org

Also look interesting:

* (unproven) https://www.olvid.io/technology

* (unproven) https://simplex.chat

PS: Using regular TOR on home broadband or cloud servers is relatively risky and inefficient. Sybil attacks on it are common. And to network operators and security agencies it gives an easy "flow tag" of your uplink and exit node data traffic as automatically suspicious.

Why not open up a Feature request on https://github.com/simplex-chat/simplex-chat/issues