WhatsApp Just Switched on Encryption for a Billion People • Hacker News Board

Re: WhatsApp Just Switched on Encryption for a Billion People

#51

Post by aorth » Tue, Apr 05, 2016, 6:25 PM UTC

x1798DE wrote: post #40

aorth wrote: post #39

So now WhatsApp is finally on par with iMessage and Signal, and shares the same weakness: public key distribution. Key distribution is controlled by a centralized server that could, for malicious or other reasons, send you new fake keys for people you communicate with. For iMessage, this is explained in this 2015 post by Matthew Green: http://blog.cryptographyengineering.com/2015/09/lets-talk-ab... At least with Sign…

Is there no UI notifying you that a user's keys have changed in Signal? If so, the central server would need to send compromised keys on day 1, which would be detectable when you check the key signature.

There is a UI. It doesn't even show (decrypt) the new messages until you add the new key.

Re: WhatsApp Just Switched on Encryption for a Billion People

#52

Post by SteveNuts » Tue, Apr 05, 2016, 6:32 PM UTC

jonny_eh wrote: post #44

> WhatsApp has no way of complying with a court order demanding access to the content of any message, phone call, photo, or video traveling through its service Unless the NSA/FBI/CIA secretly orders WhatApp to release compromised app update with a backdoor.

It's only a matter of time

Re: WhatsApp Just Switched on Encryption for a Billion People

#53

Post by raulk » Tue, Apr 05, 2016, 6:46 PM UTC

wcummings wrote: post #13

raulk wrote: post #11

The article says: "With end-to-end encryption in place, not even WhatsApp’s employees can read the data that’s sent across its network." But according to the diagram: http://www.wired.com/wp-content/uploads/2016/04/Whatsapp_Enc... ... A's message is encrypted with Whatsapp's public key, which means that Whatsapp's private key can (and has to) decrypt it on the server side to encrypt it in turn with B's public key. If…

What in the diagram gives you the impression the public key belongs to WhatsApp? Presumably WhatsApp is handling PKI.

"Public key from server" is an ambiguous phrase. I took "from" to denote possession, not source.

After reading the other sources of information, it's clear it is a secure protocol. More so when designed by the Snowden-approved Open Whisper Systems team.

Re: WhatsApp Just Switched on Encryption for a Billion People

#54

Post by ThrustVectoring » Tue, Apr 05, 2016, 6:53 PM UTC

visarga wrote: post #20

> The encryption genie is out of the bottle > There was a middle period where the government had a broad ability to surveil, but if you look at human history in total, people evolved and civilizations evolved with private conversations and private speech. If anything, we’re bringing that back to individuals. I think on the contrary, the surveillance demon is out of the bottle. It's too hard to hide metadata such as i…

Social network graphs are also a huge surveillance leak. If you use an otherwise anonymous way to talk to all your friends, and someone knows who those friends are, they have a pretty good idea who owns that "anonymous" communication channel.

This is tragic, since the most interesting and private uses of the internet are in interacting with friends, family, and loved ones.

Re: WhatsApp Just Switched on Encryption for a Billion People

#55

Post by SAI_Peregrinus » Tue, Apr 05, 2016, 7:00 PM UTC

dogma1138 wrote: post #31

M4v3R wrote: post #28

Earlier quoted context omitted.

That's true, but they provide means to verify the fingerprint of the other party, so you can verify that your app is encrypting messages using legitimate public key and that there's no MITM going on.

Yeah but again there are quite a few questions here (not an WA user). How foolproof is the verification system, how susceptible is it to downgrade attacks (while E2EE isn't not universally deployed) is there are 3d party verification of signatures, is there a community trust signing, can whats app disable E2EE in it's application without a noticeable UX change to either party, how does this work with multi user messa…

Downgrade attacks should be difficult. As the article mentions once a client has communicated with another once using encryption all future communications to that client will be encrypted. So a downgrade attack would require either spoofing a new client for a user (eg a phone they didn't have before) which is likely noticeable.

The whitepaper (https://www.whatsapp.com/security/WhatsApp-Security-Whitepap...) goes into more detail.

That said, they could push out an update that changes the UI to disable E2EE without notifying the user, and that would be difficult to notice since the app is closed source. For this reason Signal is more secure, despite using the exact same protocol.

Re: WhatsApp Just Switched on Encryption for a Billion People

#56

Post by d0ugie » Tue, Apr 05, 2016, 7:14 PM UTC

Did they roll this out to their Mainland Chinese users?

Re: WhatsApp Just Switched on Encryption for a Billion People

#57

Post by throw7 » Tue, Apr 05, 2016, 7:14 PM UTC

raulk wrote: post #11

The article says: "With end-to-end encryption in place, not even WhatsApp’s employees can read the data that’s sent across its network." But according to the diagram: http://www.wired.com/wp-content/uploads/2016/04/Whatsapp_Enc... ... A's message is encrypted with Whatsapp's public key, which means that Whatsapp's private key can (and has to) decrypt it on the server side to encrypt it in turn with B's public key. If…

Actually, it's the private key that needs to be kept secret... I'm not sure how that's guaranteed or how we can actually verify that the private key is secure. Knowing that whatsapp is built by spying and uploading all your contacts and phone numbers to their servers, well, do you trust them to not upload the private key also?

Re: WhatsApp Just Switched on Encryption for a Billion People

#58

Post by distances » Tue, Apr 05, 2016, 7:18 PM UTC

neerdowell wrote: post #7

Whisper System's announcement of this: https://whispersystems.org/blog/whatsapp-complete/

> This includes chats, group chats, attachments, voice notes, and voice calls across Android, iPhone, Windows Phone, Nokia S40, Nokia S60, Blackberry, and BB10.

Wow. I'm genuinely impressed. The Nokia app store closed over two years ago, and they still implemented this for those old, trusty devices. That's some dedication for serving the users!

Re: WhatsApp Just Switched on Encryption for a Billion People

#59

Post by techthroway443 » Tue, Apr 05, 2016, 7:31 PM UTC

sickbeard wrote: post #47

techthroway443 wrote: post #41

Earlier quoted context omitted.

Are you implying WhatsApp designed an insecure encryption?

how do you know it's secure other than what you read from the press release?

I have no idea how secure it is, I was asking for clarification.

Side note, I noticed your account is still green and 13 days old. Are new accounts green only for two weeks?

Re: WhatsApp Just Switched on Encryption for a Billion People

#60

Post by alias240 » Tue, Apr 05, 2016, 7:50 PM UTC

Nekit1234007 wrote: post #50

sidcool wrote: post #46

Earlier quoted context omitted.

Really? How so? I can understand from scale perspective, but is it more secure than Telegram?

Telegram received quite a backlash from crypto community for rolling out nonsensical throw-a-bunch-of-crypto-algorithms-together homebrew protocol that was designed by Math PhD™ students and having an audacity of conducting a contest to break it. This OTOH uses peer reviewed, strong, modern crypto that was designed by people who know how to do these things.

The crypto might be superior, but we do not know for sure that Whatsapp/Facebook is not covertly decrypting the messages and funneling through some Prism v2 NSA surveillance operation.