Quote from: dsattler on July 22, 2015, 06:36:40 AM

Have a look at threema: https://threema.ch/en/

It's quite popular in western europe. Unfortunately no open-source, but AFAIR the code was security-reviewed by an independant expert.

Yeah, this one seems all right, a million downloads in the playstore, no data storage/mining by provider. But, like you said, it's not open-source, nor is it p2p, hence not 100% private. Independent experts and service providers can be bought/coerced into disclosing users' personal data. It's doubtful that anyone will bother right now, but when and if it grows, it can become a vulnerable target.

Another problem with it is that it's not free, which means that it won't enjoy a similar level of natural growth that free counterparts, like WhatsApp or Telegram do, and I can't just ask all my friends and colleagues use it. So it's either going to remain on this unpopular level, where I can't really use it, or it will grow and with it will grow the probability of gvt. agencies tapping into it.

What I think this shows is the fundamental problem that any messenger has to face: it's either going to rely on a financially- and/or technologically-intensive solution, which will make it less popular and thus less usable, or decrease the complexity of the underlying solution to attract a larger userbase, in exchange for fundamental flaws, which may ultimately lead to security leaks. I think, when someone finds out a way to integrate a p2p solution in a mobile app in a cheap and computationally efficient way, and markets it right, they will be golden. So far I've failed to find such an app.

Quote from: misterycoins on July 22, 2015, 12:00:44 PM

OTR
https://en.wikipedia.org/wiki/Off-the-Record_Messaging
Off-the-Record Messaging (OTR) is a cryptographic protocol that provides encryption for instant messaging conversations.

This is nice, never heard of it. Found a report about some security vulnerabilities found by the EFF and less-then-optimal battery usage by the Diffie-Hellman protocol, but overall it seems legit. Have you been using any of its mobile implementations yourself?

Quote from: The Bad Guy on July 22, 2015, 12:11:02 PM

What about ICQ , how save is it ?
For privacy I guess you could go with MEGA-CHAT which is made by Kim Dotcom (we all know his problems with NSA and their spying ) but it's still on BETA phase AFAIK

Look it up, man. I've just found several reports on ICQ's vulnerability, here's just one of them. Anyway, it's pretty apparent, since it uses proprietary software and servers, that it isn't and can't be secure.

I failed to find a mobile version for the MegaChat, is there one?