"Oh good, a bunch of randoms have rolled their own crypto. I stopped reading at this point."
An ad-hominem attack. This is Hacker News and their work is open, how about making a statement after researching the actual code instead?
An ad-hominem attack. This is Hacker News and their work is open, how about making a statement after researching the actual code instead?
In our case, we needed something that is both secure and competitive in comparison to mass market solutions in terms of speed, working on weak connections and usability.
Disclaimer: I work for Telegram.
Usability, however, is a different beast. You must compromise security to make a chat application appeal to "regular" users. Still, this is a trade-off that can be clearly communicated to the user and to developers, and does not require a custom crypto protocol. You can achieve the same effects with using existing and tested libraries.
Edit: Disclaimer: I am the developer of the yaxim Android XMPP client and the operator of the public yax.im XMPP server (both available at http://yax.im).
Now that google is killing talk in favour of proprietary hangouts, I predict it'll be a while before I'm a serious xmpp user again.
Sadly it's very hard to push process changes when one are in the minority in a group... Thanks for the reminder though, it does look like it full-fills most of my needs (and fixes annoyances I've encountered with other android clients).
Knowing this, I hope you can appreciate why the burden of proof on your unproven team and approach is fairly high.
We know that writing crypto is hard and experienced crypto programmers make mistakes.
The possibility of a naive programmer creating a sturdy piece of crypto software with no previous experience is vanishingly small.
When you're rolling out a secure system + implementation you want to use algorithms that have been proven, tested and certified as correct. It's a delicate field that can't be approached like your standard software development field. Yes, being a "random" and developing your own encryption algorithm out of the box is bad. Never trust anything like that. Period.
We use well audited crypto primitives with formal proofs because they're known safe, or at least orders of magnitude safer than whatever these fools cooked up.
tl;dr provide proof or gtfo. We're not here to audit you.