WhatsApp's Signal Protocol integration is now complete • Hacker News Board

Re: WhatsApp's Signal Protocol integration is now complete

#261

Post by Ar-Curunir » Tue, Apr 05, 2016, 9:48 PM UTC

bad_user wrote: post #223

hollander wrote: post #215

Earlier quoted context omitted.

> - Does WhatsApp Auto Backup encrypt messages before sending them to Google Drive or iCloud? So you make a backup and loose the phone. What about the key? Is that gone too? Without it, encrypted backup is useless. How do you backup the key? You and me maybe will manage to do this, but what about grandma and all those people without anybody close who knows about this?

The decryption key you're talking about can be a simple password. For symmetric encryption (e.g. AES-256) even a simple password would be secure enough, while something like a 24 chars password would be unbreakable.

No, not really. Passwords are terribly low entropy, and so having a common password is not a solution, at least without using some sort of KDF or such.

Re: WhatsApp's Signal Protocol integration is now complete

#262

Post by DigitalJack » Tue, Apr 05, 2016, 9:52 PM UTC

tptacek wrote: post #154

aw3c2 wrote: post #131

Earlier quoted context omitted.

Why? "Axolotl" at least has seriously pronunciation issues so I am glad it is not used "user-side".

For my part: because "Axolotl" is one of the most widely name-dropped terms in hipster cryptography, and because it's been adopted by other projects, and because it's distinctive, and because they basically own the term. In a stroke, everyone doing secure key ratchets would have been using their product . It's also just a cool name.

I thought it was a misspelling of axlotl from dune, so I had to google it. Frank Herbert must have taken his inspiration from the salamander as well, given what the axlotl tanks were for.

Re: WhatsApp's Signal Protocol integration is now complete

#263

Post by kobayashi » Tue, Apr 05, 2016, 9:53 PM UTC

mike_hearn wrote: post #14

This is really excellent. A few thoughts: 1) They seem to have replaced TLS/SSL between client and server with "Noise Pipes". Based on a couple of minutes Googling this seems to be a brand new one-man protocol from Trevor Perrin (the same guy who did Axoltl on which Signal is based). At least, I'd never heard of it. I wonder if this is the first inkling of a post-TLS future? http://noiseprotocol.org/noise.html 2) It'…

Why on Earth would someone from a liberal democracy want to partner with a security firm based in Iran?

Re: WhatsApp's Signal Protocol integration is now complete

#264

Post by BozeWolf » Tue, Apr 05, 2016, 9:54 PM UTC

giancarlostoro wrote: post #239

lauritz wrote: post #229

Okay, first off: This is great. The most popular messaging app finally gets the security it needed. And we've just rolled out E2E to 1b 'monthly active users'. However, I have always wondered one thing about WhatsApp: How does it generate any kind of meaningful revenue? Apparently they've ditched the old $1 subscription model [0], and even that was so loosely enforced that I have never paid a single cent for WhatsApp…

I figure this isn't the question others want to discuss, but I too wonder the same. I think I used WhatsApp for a short period of time, until the point they asked me for money. Since then I haven't looked back. Now I am left wondering where their revenue comes from.

It probably doesnt need to generate any revenue (in dollars, perhaps when measured power it does). Facebook does not really want it to be profitable, at least not as long as the communication is c2c. Facebook is only profitable because of its b2c parts!

Re: WhatsApp's Signal Protocol integration is now complete

#265

Post by feld » Tue, Apr 05, 2016, 10:09 PM UTC

jamesdwilson wrote: post #107

tptacek wrote: post #92

Earlier quoted context omitted.

You keep saying "source is a must" but you have yet to explain why that is the case.

fair enough! https://www.schneier.com/blog/archives/2016/03/possible_gove... i think this is why source is a must. if a user compiled and installed the app themselves, and hypothetically had the entire stack above it be similarly open, then it would prevent the kind of attack mentioned. do you agree? if the source is closed anywhere in the stack, or pushed out in a walled garden as it is currently, then it allows the…

iOS is not completely open source, so how do you know that Apple isn't scraping your screen or the iOS keyboard isn't sending your characters?

Also, Apple's push messaging subsystem gets a copy of (most) of the message too so Apple could be doing evil things there too!

OH NOES!

Re: WhatsApp's Signal Protocol integration is now complete

#266

Post by stelonix » Tue, Apr 05, 2016, 10:14 PM UTC

kobayashi wrote: post #263

mike_hearn wrote: post #14

This is really excellent. A few thoughts: 1) They seem to have replaced TLS/SSL between client and server with "Noise Pipes". Based on a couple of minutes Googling this seems to be a brand new one-man protocol from Trevor Perrin (the same guy who did Axoltl on which Signal is based). At least, I'd never heard of it. I wonder if this is the first inkling of a post-TLS future? http://noiseprotocol.org/noise.html 2) It'…

Why on Earth would someone from a liberal democracy want to partner with a security firm based in Iran?

Perhaps because said liberal democracies are known to spy on that someone more than Iran, North Korea and China combined.

Re: WhatsApp's Signal Protocol integration is now complete

#267

Post by ianmiers » Tue, Apr 05, 2016, 10:18 PM UTC

pa7ch wrote: post #170

ianmiers wrote: post #128

Earlier quoted context omitted.

I'm hoping they deploy some from of key transparency. E.g. CONIKS or CONAME, the version Yahoo and Google are working on for e2e that already has a productionish grade sever and client[0]. Either that or give the community a practical reason why it can't be used as is, and then we can start working on alternatives. [0] https://github.com/yahoo/conam

I think he already made a strong point why CONIKS style transparency isn't all that great for end-users. See this mailing list thread that includes the author of CONIKS talking about it with moxie before CONIKS was published: https://moderncrypto.org/mail-archive/messaging/2014/000226.... https://moderncrypto.org/mail-archive/messaging/2014/000234.... Basically, users change their identity key in practice so often th…

So I think CONAME solves 90% of this. It's set up in such a way that third party verifiers only have to check that the update counter for each key is monotonic. Users can check just that, for the current epoch, the write counter is correct and their key is there. So only a user themselves should see a warning. (and warning cans be disabled by default ... as long as the attacker doesn't know if the user has them on or not, it's an issue)

In contrast, in CONIKS, a user had to check every single epoch. Which was impractical and meant you relied on third party auditors.

This doesn't deal with the restore from backup issue. I think given the FBI apple phone issue though, maybe it's worth reevaluating the risk vs. reword here. Especially if user visible warnings are opt in.

Re: WhatsApp's Signal Protocol integration is now complete

#268

Post by dvdplm » Tue, Apr 05, 2016, 10:19 PM UTC

kobayashi wrote: post #263

mike_hearn wrote: post #14

This is really excellent. A few thoughts: 1) They seem to have replaced TLS/SSL between client and server with "Noise Pipes". Based on a couple of minutes Googling this seems to be a brand new one-man protocol from Trevor Perrin (the same guy who did Axoltl on which Signal is based). At least, I'd never heard of it. I wonder if this is the first inkling of a post-TLS future? http://noiseprotocol.org/noise.html 2) It'…

Why on Earth would someone from a liberal democracy want to partner with a security firm based in Iran?

To keep said liberal democracy honest?

Re: WhatsApp's Signal Protocol integration is now complete

#269

Post by nxzero » Tue, Apr 05, 2016, 10:21 PM UTC

nickik wrote: post #211

tuyguntn wrote: post #173

Earlier quoted context omitted.

Does this mean Whatsapp do peer-to-peer message transfer or messages still pass through whatsapp servers?

Their is no mobile message app that does peer-to-peer as far as I know. Whatsapp, Telegram, Signal, Actor, Threema all go over a server.

Why?

Re: WhatsApp's Signal Protocol integration is now complete

#270

Post by danjoc » Tue, Apr 05, 2016, 10:44 PM UTC

tptacek wrote: post #71

jamesdwilson wrote: post #66

Earlier quoted context omitted.

do you know even with source, backdoors can be hidden? open source is a must to even begin to work to verify any claims of security.

Your comment here is incoherent. I agree: source can easily lie. How does that make it the gold standard for verification? The reverse-engineering of the actual shipped binary (for instance, the ARM code lifted to LLVM) seems like a safer analysis target. But, what do I know.

>The reverse-engineering of the actual shipped binary (for instance, the ARM code lifted to LLVM) seems like a safer analysis target.

Reverse engineering binaries is only permitted under the DMCA for the purpose of interoperability, AFAIK.[1] If so, that would make reverse engineering to verify stated security claims illegal in the United States. I'll just assume I'm wrong here for the sake of argument though.

Reverse engineering sounds much less friendly than providing actual source code. It's much easier for me to compare changes from version to version with source control, commit comments, and diffs. Then all I need is a reproducible build to verify that the output matches the binary being shipped.

Do you have some reverse engineering tools you would suggest? Obviously the one's I'm familiar with are not as good as yours. Links to those would be greatly appreciated.

[1]https://www.eff.org/issues/coders/reverse-engineering-faq