Show HN: ZuccNet – Encrypted Facebook Messaging(github.com) |
Show HN: ZuccNet – Encrypted Facebook Messaging(github.com) |
Here's the technical whitepaper: https://about.fb.com/wp-content/uploads/2016/07/messenger-se...
Here's some of the academic work on messaging franking that it has driven: https://eprint.iacr.org/2017/664.pdf
Here's the instructions how to use it: https://www.facebook.com/help/messenger-app/1084673321594605
Of course, you need to trust that the client from the app store and no, the implementation is not open source.
This is not forward secure. It will also only work for messages under 256 bytes. I don't know what happens in this code if you exceed that message length.
You want to use ephemeral session keys here. Read the Secret Conversations whitepaper as an example.
I dislike this "ZuccNet" as the real goal should be abandoning facebook ecosystem but I still think that anything for naive people is better than nothing, so thumbs up.
Facebook does not have the key to decrypt messages sent with Secret Conversations. It is generated on-device. You can confirm that using simple reverse engineering tools on, say, the Android APK.
Yes, Facebook could subvert the binary by pushing an update. That is the risk you are accepting.
This is a baseless assertion.
> If you think a message you've received in a secret conversation goes against our Community Standards, you can report it. Learn more about what a secret conversation is. When you report a secret conversation, recent messages from that conversation will be decrypted and sent securely from your device to our Help Team for review. We won't tell the person you're talking to that you reported it.
Since Facebook's software is managing the keys, they have the ability to decrypt Secret Conversations. You have to trust Facebook not to snoop. Whereas w/ ZuccNet, the public keys can be exchanged via a separate channel from Facebook, thus rendering Facebook unable to snoop.
If we chat and then shortly there after you search for some fringe political group, it's pretty safe to see that as a strong indication that I'm involved with that group. Or if my geolocation places me at some political event and we chat during or just after it, you're implicated.
FB doesn't need the contents of messages, they need the metadata plus all the other user tracking.
https://github.com/tomquirk/zuccnet/blob/42e351e36b3b5dbaef0...
1. Try encrypting a message larger than 256 characters. Even if you somehow succeed, it will fail to decrypt. (My understanding of JS crypto is that it will throw an error if you try.)
2. It lacks forward secrecy.
A much better design would be to encrypt with an ephemeral (one-time) 256-bit AES key (using CBC+HMAC), then encrypt the key with RSA. (AES-GCM is probably easier, but if you're worried about message commitment, that's not recommended.)
(On sweis's comment about Secret Conversations: I don't trust closed source implementations--and neither do a lot of us on HN, so that's a non-starter. Tell the Facebook team to open source it, with reproducible builds, if you want it to be trusted.)
Recommended reading for the author: https://soatok.blog/2020/11/14/going-bark-a-furrys-guide-to-...
This doesn't address it; if you're willing to go to these lengths, just switch to another platform that encrypts E2E.
Still, it's a fun proof of concept tool.
For a little while it was possible to just use pidgin, and have OTR work with Google talk (also boycotting fédération), Facebook and general XMPP.
But now the silo walls have been reinforced.
Data mining is the price you pay to have those things for free. I'll leave it up to individuals to decide whether or not it's worth the cost.
Let me explain how this works in PR world. You publish (with all the bells and whistles) that you have end to end encryption and explain protocol that uses asymmetric cryptography (just for the sake of simplicity I will simplify - you have public and private key, you send public key to all chatters with you, they will encrypt randomly generated symmetric key with it (asymmetric crypto is slow, you don't want to use it directly) and send it back (where you decrypt it) and vice versa. Then you use symmetric key that you have safely exchanged for use in block cypher, lets say Rijndael 265635238 bits (as big numbers mean more safety(tm) /s).
You publish white papers of protocol, get all the cryptographers on your side. Fanboys are screaming, public is applauding, girls wants to sleep with you and president is thankful. What you don't tell is that you also encrypt symmetric key with YOUR public key that is embedded into application and send it along as a "status_check" field.
And everyone is happy forever after. /s
> Your speculation is not interesting to me.
This works in both directions. But bottom line, whitepaper is not the application (and even if it would be, have fun reading http://www.underhanded-c.org/ or https://en.wikipedia.org/wiki/Dual_EC_DRBG and who has more motive as the corporation that profits from spying on everyone and everything). It is just as the name says. Whitepaper.
"Timeo Danaos et dona ferentes"
or maybe you will like this one more:
"Trust is built in drops and lost in buckets"
And you dont trust someone as Facebook or Google any more. They have lost trust in ship containers not buckets.
That's exactly the kind of risk you should never accept when it comes to Facebook.
Do they offer this service in Australia? Yes. Then they have the keys.
[1]https://www.independent.co.uk/life-style/gadgets-and-tech/go...
If you want to go beyond generic concerns, there are plenty of academic papers that have looked at Facebook Secret Conversations, found actual issues, and helped get them fixed: https://link.springer.com/article/10.1007/s00145-020-09360-1 https://link.springer.com/chapter/10.1007/978-3-319-63697-9_... https://link.springer.com/chapter/10.1007/978-3-319-96884-1_...
This is Facebook, for pete's sake. The same company that conducted psychological experiments with zero clinical/ethical oversight by manipulating its users' feeds to see if it could cause depression/anxiety (or the opposite).
Facebook is evil and you should not trust them even a little bit.
So they either have the keys or a way to force the client to decrypt.