Group Chat Vulnerability Discovered in Cryptocat, Project Fixes and Apologizes

alphadogg writes "The founder of an eavesdropping-resistant instant messaging application called Cryptocat has apologized over a now-fixed bug that made some types of messages more vulnerable to snooping. Cryptocat, which runs inside a web browser, is an open-source application intended to provide users with a high degree of security by using encryption to scramble messages. But Cryptocat warns that users should still be very cautious with communications and not to trust their life with the application. The vulnerability affected group chats and not private conversations. The encryption keys used to encode those conversations were too short, which in theory made it easier for an attacker to decrypt and read conversations." The bug report/merge request, and an analysis of the bug (although, in light of the Cryptocat's gracious response, overly acerbic and dismissive of the project).

Comments

Nothing overly dismissive there

[Anonymous Coward]

This bug and the history of it point to the cryptocat people being utterly incompetent. It's perfectly possible that they did what they did with the best of intentions and that they reacted as well as they could - that does not change one iota about them being incompetent and that you better don't trust the work of incompetent engineers. It's nice that that civil engineer did not intend to kill anyone and that she helped in rescuing people, but still her incompetence is what caused the bridge to collapse and what makes it reasonable to be suspicious of the other bridges she's responsible for.

Re:Nothing overly dismissive there

[rtfa-troll]

Go blow it out your ass, you smug little prick. What have you contributed to cryptography that is so great and awesome?

Probably.. nothing. And that's exactly the point. By contributing nothing he has put nobody's life in danger. Crypto systems are essentially security and safety systems which have to work right. When they are done wrong people think they are safe and take risks they would not take otherwise.

Re:Nothing overly dismissive there

[Anonymous Coward]

It is a devastatingly simple and obvious bug that any code review would have spotted. It's laughably amateurish.

It's especially egregious after the rant the author (isn't there just one?) went on about Javascript cryptography. Couldn't have happened to a nicer guy.

After all, what's the single biggest challenge in JavaScript cryptography? Random number generation. So what's the FIRST thing you look at when reviewing? Random number generation for keys. And what, pray, is their excuse for not using window.crypto.getRandomValues() with a typed array of bytes, which is guaranteed to be available in every supported browser? What, in fact, is their excuse for not using Uint8Array for carrying keys wherever they go?

Re:Nothing overly dismissive there

[chihowa]

As it is designed, email is capable of peer-to-peer(ish, if people have their own domains) operation and if people used PGP the messages would be safe in transit. It's not totally decentralized, though, as you still depend on DNS.

More importantly, a shift away from centralized corporate mail servers toward individual (or at least family or co-op) mail servers can happen gradually without relying on the network effect to legitimize a new system.

Re:A mathematician's apology

[lxs]

I don't really want to live in a world where I have to actively hide shit from people or they'll try to take advantage of me

Neither do I, but such is the world we live in. All you can do is accept that the world is a mostly shitty place, deeply appreciate the moments of stunning beauty it offers as well and try to improve your little corner of it.