Cryptocat Blog

Hi, I'm the lead developer for Cryptocat.
I strongly urge you all to please read our blog post regarding this audit: https://blog.crypto.cat/2014/04/recent-audits-and-coming-improvements/

This audit document alone does not give enough context. This audit was commissioned by us and concerns a pre-release version of Cryptocat for iPhone. Many of the bugs it found are due to the fact that it was reviewing a prototype with debugging features (such as NSLog) turned on. While this audit definitely does find some vulnerabilities and room for improvement, none of the critical bugs in this audit ever made it to Cryptocat for iPhone's release.

It's very unfortunate that this audit is being taken out of context like this and used to attack our effort. I'd appreciate it if you could please upvote this comment and help me contextualize this audit. Again, please, read the blog post for context (and also for the results of another audit we comissioned in parallel.) We've done our best to address these issues and are working towards an open discussion on how to improve accessible encryption. https://blog.crypto.cat/2014/04/recent-audits-and-coming-improvements/

The blog post's last section ("On the Significance of Audits") discusses why it is that Cryptocat has seen more audits published about it than other encryption projects. Please, dare to discern. Read what we're doing to improve the security of accessible encryption and our reasoning for publishing these audits. I'll be grateful…

Thank you very much for that comment.

I believe that we've been truly open source, transparent and accountable for our code since day one. There are other projects who are currently similarly open and transparent (I respect TextSecure for this,) but I can't say this is the standard in this field.

We've always solicited and compensated feedback from security enthusiasts, hobbyists and world-famous cryptographers alike. Over the past year, we've had the opportunity to grow into a product that examined what is fundamentally responsibly possible in the browser, and we've even landed ourselves as a primary use-case for the W3C's Web Cryptography working group. We've produced a true, responsible alternative for people who just don't know how to use anything more complicated than Facebook Chat, and we've made it clear that we are not trying to replace PGP or other iron-clad 30-year old solutions. We're trying to help mom and pop users.

Regarding our past vulnerabilities, I can't think of a fuller disclosure than dedicating an entire talk to detailing every single one of them: https://blog.crypto.cat/2013/11/documenting-and-presenting-vulnerabilities-in-cryptocat/

We also carried out a study to verify whether users were indeed clicking on the security warnings on our website: https://blog.crypto.cat/2013/11/yes-cryptocat-users-are-reading-our-warnings/

We want to do things right. We are truly open source, truly honest, transparent and we take immediate steps for mitigation…

https://blog.crypto.cat/2012/12/lebanese-government-asking-for-facebook-passwords-cryptocat-statement/

vvvvvv quote begins vvvvvv

(هذا المقال مترجم إلى اللغة العربية فالأسفل) – Arabic Translation follows

We’d like to talk about today’s news in Lebanon concerning the Lebanese Internal Security Forces demanding access to Facebook passwords from the Minister of Telecommunications. This notion is unacceptable, and the Cryptocat Project is moving forward on proposing solutions for Lebanese people on how to protect themselves against this sort of seizure, should it happen.

What Cryptocat can do for you

We would like to suggest to Lebanese citizens to use Cryptocat instead of Facebook chat to communicate. You can download Cryptocat here (it’s available in Arabic) — to the best of our ability, we have attempted to make Cryptocat a private, useful and open platform for easy to use IM. We want to offer it as an alternative in this time of potential legislative abuse. Cryptocat cannot promise you perfect privacy — at best, we are promising a slightly better alternative to Facebook chat.

What Cryptocat can’t do for you

Here we must repeat the warning from our project website: Cryptocat is not yet ready to be used in extreme situations. Don’t rely on Cryptocat if your life is threatened — it’s experimental software. But that doesn’t mean that Cryptocat can’t provide reliable, useful privacy for many individuals. Use Cryptocat if you are in Lebanon and want to talk with your…

There's something to be said about encouraging people to use crypto software that might not be well-written, though. To me, it's fine to write whatever you want in any language you want, but if you write an application and market it as "communicate securely and anonymously", or any kind of software that could put people's lives at risk, really--like Tor--you should be confident it is secure, i.e. that you know how to get it right. You are literally putting people's lives at risk, not just writing software that might be buggy, or which some people might not find useful.

IMO, the "lol, look at this, pathetic" for using node.js is inexcusable (regardless of what your opinion about node.js, and for the record, mine isn't favorable), but "X application has serious security holes in their software that could put you at risk. Don't use it" is not. For example, I don't consider this "bullying": http://www.schneier.com/blog/archives/2012/08/cryptocat.html

All this being said, I'm glad you powered through (https://blog.crypto.cat/2012/08/moving-to-a-browser-app-model/) and solved the issues. OTR is awesome, and most of the critics have come around, AFAICT. Many others don't listen to this kind of feedback, and so deserve the critique all the more.

I was really hoping Nadim would be successful with CryptoCat, but at least in my eyes, this bug is the failure of the project — especially because his response is, "Cryptocat is not any different from any of the other notable privacy, encryption and security projects, in which vulnerabilities get pointed out on a regular basis and are fixed. Bugs will continue to happen in Cryptocat, and they will continue to happen in other projects as well. This is how open source security works." <http://blog.crypto.cat/2013/07/new-critical-vulnerability-in-cryptocat-details/>

No. This is how open-source "security" fails. GnuPG has not had a security bug since 2008, and I don't think it's ever had a security bug that left your encrypted messages open to interception. You can't start with insecure cryptographic software and bugfix it until it's secure. You'll just bugfix it until only the bad guys know where the new holes are. How long has the Russian equivalent of the NSA (or, if you're Russian, the NSA) known about Lucky Thirteen, for example? How long did they know about the Million Message Attack?

(That, and the array of "15-bit" single-digit integers.)

I for one think that Nadim and the Open Tech Fund are to be applauded for opening up their review to the public. I have to wonder how many other commercial and non-profit organisations would ever consider doing this? (Especially those which are in the field of communications and are relied on by people for their lives).

Many people on HN seem to be reading the review without actually looking at Nadim's response on the Cryptocat blog - which I urge everyone to read first before commenting.

https://blog.crypto.cat/2014/04/recent-audits-and-coming-improvements/

As far as I understand the username for Nadim (Kaeporan) was also blocked from HN last night so probably he isn't able to continue responding to the comments up here.