Disappearing messages for Signal

https://whispersystems.org/blog/disappearing-messages/

by iddqd • 10 years ago

290 177 10 years ago

libeclipse• 10 years ago

I'm not sure that this is a benefit. It gives users a false sense of security. Screenshots or pictures can always be taken on the other end.

Didn't signal used to be explicitly against this feature.

uph14• 10 years ago

"Disappearing messages are a way for you and your friends to keep your message history tidy. They are a collaborative feature for conversations where all participants want to automate minimalist data hygiene, not for situations where your contact is your adversary — after all, if someone who receives a disappearing message really wants a record of it, they can always use another camera to take a photo of the screen before the message disappears."

subway• 10 years ago

This should be strictly a recipient controlled option, only affecting the recipient's view then. Anything else is still a misleading UX for the sender, and assumes people read the fine print. They don't.

oconnore• 10 years ago

If their sense is that -- after configuring 1 week self destruct, the people they're talking to likely won't be keeping months and months of chat logs on their phone anymore -- it's a very true sense of security.

kuschku9• 10 years ago

[deleted]

rorosaurus• 10 years ago

At least until the Jailbreak tweak is released with patches out this feature, allowing people to retain everything they want.

I don't disagree that it works for the average user, but I do agree with the sentiment that it is a false sense of security.

Unless maybe you cryptographically verify the deletion (is that possible?) and notify the other party of the successful deletion. But even then a copy could be made beforehand, on-device or with an external camera...

I think it's much better to maintain zero expectation of message destruction with all end users.

subliminalpanda7• 10 years ago

Signal keeps getting better with each release, great job at everyone from Whisper Systems.

MereKatMoves6• 10 years ago

I love using Signal and will continue to make modest donations, but I would really appreciate an improvement in audio call quality. I still use Silent Circle for calls because it is so tiring to talk when the bitrate is low.

subliminalpanda7• 10 years ago

Agreed. WhatsApp calls are near flawless when connections are good, I'm sure WS can reach audio quality parity.

I often get disconnected on Signal after 20 minutes or so on a voice call, but I suspect that's due to the other end being behind a VPN with awful latency.

kkl2• 10 years ago

My Signal phone audio issues went away after I upgraded hardware. Not a great solution (obviously) but something worth noting.

StavrosK7• 10 years ago

I still use Silent Circle for calls because it is so tiring to talk when the bitrate is low.

To be fair, that's a high bar. Our (SC) phone guys are masters at optimizing audio quality. I would be extremely surprised if any other app (encrypted or not) had significantly better audio quality than Silent Phone.

taejo• 10 years ago

I've never noticed a quality issue... because I've never had a call connect at all (to be fair, it's been a while since I accidentally clicked the "call" button and checked, since I've long given up on trying to use it deliberately).

Johnny_Brahms3• 10 years ago

I'd guess both SC and WhatsApp use opus, whereas Signal at the moment is using speex. There is an issue open at github, but it does not seem to be a priority.

I haven't read very much about it, but there seems to be concerns about opus leaking data about the call. I don't know how, but from android5.0 there is an opus encoder included that supports CBR mode.

jpt4• 10 years ago

With all due respect, Open Whisper Systems might ought first consider fixing Signal's multiplicate message problem, especially silent (to the sender) group chat spamming.

moosingin3space2• 10 years ago

As a Signal user, I've experienced this issue as well. I work around it by deleting the message, then re-sending it, but that's clunky.

avhon12• 10 years ago

I don't think that's the problem that jpt4 is talking about. I believe he is talking about how sometimes a group message will be received 20 times or more, and yet the sender will still see "message not sent" for some recipients.

soared• 10 years ago

multiplicate

I'd never heard this word so I looked it up. Google didn't have a definition but merriam-webster was the first result. They showed me an extra concise definition and then this message...

Wait, there’s more! This word doesn't usually appear in our free dictionary, but we’ve shared just a bit of the information that appears in our premium Unabridged Dictionary. There’s more definition detail there. Start your FREE Trial Now!

Umm.. Fuck you Merriam-Webster?

schoen2• 10 years ago

There's something weird about that marketing angle coming from a dictionary; it seems somehow at odds with the notion of completeness that we associate with reference materials. Like "there are secret words that only paying customers get to know about", or something?

dragonwriter• 10 years ago

More expensive unabridged dictionaries and less exepensive abridged veraions have been the norm for nearly as long as commercially published dictionaries have been a thing. That one of the cheaper abridged ones is now free on the web doesn't really change that.

thaumasiotes2• 10 years ago

To the best of my knowledge, I've never heard the word "multiplicate" either, and I wouldn't have been surprised if there were no dictionary entry for it at all.

If you know the word "duplicate", though, you should be able to figure this one out.

topkeks• 10 years ago

That's the only big complaint I've got about Signal.

newman3143• 10 years ago

Actually, my biggest "bug" is where the recipient uninstalls or switches to a new phone and Signal allows you to keep sending messages to what amounts to the ether before you finally realize that they aren't getting the messages.

mtgx• 10 years ago

Great. One of the most requested features is finally here. I think all that's left now is video calling (on the desktop, too).

subliminalpanda7• 10 years ago

I would like to be able to re-register a new number without having to de-activate the account thereby not losing all of my chats.

geomark2• 10 years ago

Is there a way to export chart history and then import it to the new account?

thomasville3• 10 years ago

Is there a way from preventing certain contacts from knowing I'm on Signal? Like, it is embarrassing that Jason from college knows I'm on Signal. I know you guys will disagree and say it is not embarrassing, but it seems that a privacy-focused app would respect this notion. Obviously being a member of certain apps (grindr) can be seen as negative. I think I should be able to Whitelist my contacts.

cbsmith• 10 years ago

SIgnal is basically getting the full feature set of TigerText.

mordant• 10 years ago

I don't understand why it still doesn't support landscape mode on iPhone.

uph14• 10 years ago

It's on the roadmap https://github.com/WhisperSystems/Signal-iOS/issues/937 The iOS version didn't have a dev for a while after Frederic Jacobs went to Apple, but Michael Kirk recently took over so things are happening again.

Canada3• 10 years ago

I've been receiving a bunch of "Bad encrypted message..." lately. Wonder what's up with that.

MichaelGG2• 10 years ago

Tons of those, plus repeats, and "random" delays. Sometimes it takes a few minutes for messages to go through (single check). Last week was really bad. I don't know how multiple messages can happen; shouldn't they have a unique ID?

uph14• 10 years ago

Last week was due to server issues https://whispersystems.discoursehosting.net/t/intermittent-m...

Canada3• 10 years ago

Yeah. My understanding is the message key used to decrypt first copy should be immediately deleted after decrypting it, so how can the second copy be decrypted successfully? Seems to fly in the face of forward secrecy unless it's purely a client side bug.

Bad encrypted message, if I recall correctly, means either the MAC check failed or the protobuf payload inside didn't deserialize correctly.

I don't know.. I'm not setup to debug it on my regular phone with a production signal apk installed.

newscracker4• 10 years ago

and "random" delays. Sometimes it takes a few minutes for messages to go through (single check).

This was the main reason I almost stopped using Signal several months ago and started trying out Wire (which is also slower when compared to Telegram). I find it disappointing that the problem still exists. I can't convince others in my circle to use it if basic message delivery is flakey and slow.

sigmar• 10 years ago

I had an idea a few days ago where you authenticate your identity (i.e. numeric fingerprint) on-demand by sending a pic of yourself where the QR code is overlayed as blacked-out pixels before being transmitted. Then the recipient can look at the photo to see it hasn't been manipulated, and use the app to verify the QR codes match.

I'm sure there are issues with this, but it seems like a nice feature for when secure out-of-band communication is not possible.

drudru112• 10 years ago

How do they make money?

subliminalpanda7• 10 years ago

From wikipedia:

"The group is funded by a combination of donations and grants, and all of its products are published as free and open-source software."

https://en.wikipedia.org/wiki/Open_Whisper_Systems

drudru112• 10 years ago

Why isn't this on their site? ... this is just thinking out loud, not directed at you.

baby• 10 years ago

If you want to implement the signal protocol for your own company (see WhatsApp, Messenger, Allo, ...) you will probably have to buy a license ($$$), and ask for their help ($$).

* https://whispersystems.org/blog/whatsapp-complete/

* https://whispersystems.org/blog/allo/

* https://whispersystems.org/blog/facebook-messenger/

cyphar2• 10 years ago

Cool feature, though it'd be nice if Signal fixed the message delay and message dropping problem. But Signal uses the proprietary GCM service (because "it's impossible to do message sending correctly, so let's force people to use proprietary software") so they probably can't fix it...

uph14• 10 years ago

No one is forcing you to use proprietary software. See this comment from moxie https://news.ycombinator.com/item?id=10665520

Using GCM is only a problem for people running a custom Android ROM without Google Play Services. Using GCM doesn't make Signal less private.

Google doesn't see any data via gcm, it's just a tickle. If you want push messages, you gotta use a push network.

https://twitter.com/whispersystems/status/695399112833761283

Feel free to help out with code https://github.com/LibreSignal/LibreSignal/issues/43 or money https://www.bountysource.com/issues/35722527-create-proper-p... if using Signal without GCM is important to you.

If the only thing that the remaining people here want out of LibreSignal is a websocket-only solution and gmscore isn't an option for whatever reason, I would consider a clean, well written, and well tested PR for websocket-only support in Signal. I expect it to have high battery consumption and an unreliable user experience, but would be fine with it if it comes with a warning and only runs in the absence of play services. However, I also realize that still won't help people that are trying to build a Google-free experience on Google's platform https://github.com/WhisperSystems/Signal-Android/issues/127 , since we still don't have the things we need https://github.com/WhisperSystems/Signal-Android/issues/127#... to be comfortable distributing software outside of Play.

https://github.com/LibreSignal/LibreSignal/issues/37#issueco...

Considering how a small minority complain about this everytime Signal is mentioned you'd think they'd do something about it, but take a look at that Bountysource link and you'll see 8 backers. Guess complaining is easier.

kuschku9• 10 years ago

Actually, Moxie has threatened to shut LibreSignal down if they allow LibreSignal users to message normal Signal users, and refused to even discuss alternative solutions.

He also uses the GCM library from Google, which pulls in several analytics libraries into the APK, so "Using GCM doesn't make Signal less private." is objectively false.

(And in addition to that, Moxie even refuses to allow any distribution that doesn’t come with full analytics, which is extremely user hostile.)

Guess complaining is easier.

No, it’s easier to use XMPP than to fix a system that’s broken by design like Signal.

EDIT: Seriously? Downvotes for criticising publicly documented user-hostile behaviour from Moxie? Fuck this, the discussion culture here really got worse than even Reddit.

cyphar2• 10 years ago

Using GCM is only a problem for people running a custom Android ROM without Google Play Services. Using GCM doesn't make Signal less private.

The issue is not privacy, it's the use of a proprietary service. Now, GsmCore from microG does solve the problem somewhat. But then you have to ask "where will you get the app from?". The answer is "not F-Droid because moxie doesn't like it". So you have three options for actually installing the app and keeping it up to date:

1. Use the Google Play Store (proprietary). 2. Build the app yourself and keep it up to date yourself (not fun and doesn't help anyone other than me). 3. Use an unofficial FDroid repo (or do step 2 and host the repo myself). This option means that you have some random administrator controlling updates. I actually agree with moxie that FDroid really should add developer signatures to packages (though IMO the desktop GNU/Linux model of package updates is actually fairly solid -- though you don't have the Open Build Service for android packages :P).

Overall, the choices are a shit-show. Now, I get that it isn't of concern to moxie what people like me have to do to get this to work with their phones. That's fine, I understand. But that doesn't mean that I'm not going to mention it if I get the chance -- because it does legitimately make things harder for me. I get that free software on phones isn't a big concern to many people, but it is to me.

Considering how a small minority complain about this everytime Signal is mentioned you'd think they'd do something about it, but take a look at that Bountysource link and you'll see 8 backers. Guess complaining is easier.

I contribute (both code and money, and also as part of my day job) to many free software projects, but I refuse to contribute to a project which actively encourages the use of proprietary software in order to use it properly. I get that it makes things easier for users, but that doesn't make it right. So maybe you shouldn't be so condescending?

lqdc133• 10 years ago

I love Signal and this seems to be a stab at Wickr since from what I've heard that is the reason people prefer it to Signal sometimes. Having said that, it has a couple of problems:

1. Images are downsampled without warning. There should be some sort of warning or mini info box for the times when the images are downsampled and there should be information about the changes in resolution.

2. If one uses it as the main messaging app, one has to search through history sometimes. But there is no chat search feature. I am forced to scroll all the way up and copy the message data to an editor. Even really basic case insensitive search would be great.

mahyarm2• 10 years ago

I know this is apple level 'file a radar', but you should also ping about this in the github issues page.

drew-y• 10 years ago

It'd also be nice if the iOS or Chrome client had a chat history backup feature like they have on android. This is one of my biggest complaint with messaging apps in general. I'd like to be able to preserve and archive my chat history with people close to me.

1024core• 10 years ago

What if the person you're chatting with does not want it archived? (I'm not questioning, but wondering what a protocol would be)

abysmallyideal• 10 years ago

Doesn't downsampling have the affect of preventing the use of more popular stego apps? Makes me wonder if there's something hidden in 25519. According to recent publications, it's easy to create backdoored primes fashioned to simplify search methods. Although those were for SNFS and DH, there are likely applications for searching the ECDH space.

secfirstmd2• 10 years ago

How to donate to Signal!

http://support.whispersystems.org/hc/en-us/articles/21294015...

AckSyn2• 10 years ago

Now if they would drop the ridiculous requirement of having a phone number and go with usernames and not require access to my contact list like most other services, you could actually be safer and not rely on _their word_ alone.

mahyarm2• 10 years ago

The app is open source and you could do something like a proxy or similar if you really want to be sure of what get sent from your client. The server is also open source too.

As moxie said, it's about raising the defaults of the world, not about making it secure for the crypto nerd.

throwaway7767• 10 years ago

As moxie said, it's about raising the defaults of the world, not about making it secure for the crypto nerd.

The thing is, the attacks in the "crypto-nerd paranoia" category tend to become everyday attacks over time. Pre-Snowden, most people would put a lot of the things the NSA is doing into the "crypto-nerd paranoia" bucket. Now we know they were wrong to do so.

Signal routes all conversation metadata through one infrastructure, which becomes a very tempting target. By also requiring phone numbers as identity, they make it very easy to tie that metadata to real people and perform graph analysis on it.

mifreewil2• 10 years ago

With the approach that Signal has taken, it doesn't require you to register a username. The app just registers you with the server as a Signal user using your already unique ID - your phone number. While not the most secure and privacy-protecting method, it allows anyone to just install it and start using it as a secure alternative to plaintext SMS.

lqdc133• 10 years ago

Regarding SMS - it's not always an alternative to SMS since it uses data. I know data is more popular than SMS in many countries, but when you hit your monthly limit, you want to disable all data.

Regarding the simplicity of using a phone number and how it would be very easy for all users - Wickr provides basically the same service, is more popular, but uses usernames instead of phone numbers.

The fact that something is open source isn't always a clear win. OpenSSL, for example, is open source and yet they seem to have many bugs.

For the record, I use Signal almost exclusively for communication. I just wish it was more protective of users' privacy without having to put in a ton of effort.

woah• 10 years ago

If you really want to be secure, get a disposable prepaid phone and use its phone number with signal.

MereKatMoves6• 10 years ago

That is increasingly hard to do these days. Verified addresses etc are now minimum requirements to get the handset.

Of course you can pay cash and make up an address

laretluval• 10 years ago

Indeed. It's not just crypto nerds would want to use the service without having to have a smartphone with a phone number.

The phone requirement is beyond ridiculous. How did Signal get the reputation it enjoys in the tech community anyway?

CoryG89• 10 years ago

How did Signal get the reputation it enjoys in the tech community anyway?

You can thank Edward Snowden for that. In fact, they have his picture and testimonial on their front page:

https://whispersystems.org

cgag• 10 years ago

What's a trustworthy alternative?

walterbell5• 10 years ago

Wire (http://wire.com) does not need a phone number (register with email on a desktop browser at http://app.wire.com, then login to mobile) and does not need a copy of your contacts. Supports text, image, files, audio, video. E2E encryption is based on Signal protocol. Funded by Skype founder.

mbenjaminsmith• 10 years ago

What's more bothersome: If you withdraw access (after they've already scanned your contacts) they'll disable the app. That's why I deleted the app and won't use it again.

If a privacy-focused app makes you nervous about privacy they've already lost the war, haven't they?

uph14• 10 years ago

Seems reasonable that an app that's used for messaging my contacts has access to my contacts. What exactly are you nervous about?

wtbob3• 10 years ago

They're relatively compact. Users compare 12 groups of 5 digits with each other, which is half the size of our previous hexadecimal format.

60 digits have 199 bits of security, so I suppose that's mostly okay, right? Does the birthday paradox apply here, reducing it to 98 bits?

StavrosK7• 10 years ago

No, since you presumably want to match a specific user's key, not just find two users with the same key.

lenish4• 10 years ago

It is a similar problem, however: https://en.wikipedia.org/wiki/Birthday_problem#Same_birthday...

lenish4• 10 years ago

reducing it to 98 bits?

Did you mean 198?

198 bits is entirely reasonable assuming a brute force attack is the only option. Were it not we'd be in a panic over AES-128 and AES-192. :)

wtbob3• 10 years ago

No, hashes generally require twice as many bits in order to avoid birthday attacks — that's why one uses SHA-256 for 128-bit security.

98 bits is still plenty, of course, but it's not 128 bits.

Zhenya2• 10 years ago

Everytime there is an update, I become more emboldened to continue to push my friends from whatsapp to Signal.

I just wish we had way to see what's going on in their server.

uph14• 10 years ago

https://www.whispersystems.org/bigbrother/

https://github.com/WhisperSystems/TextSecure-Server

mi100hael2• 10 years ago

The fact that their phone server isn't free makes me somewhat more concerned as time goes on. I used to think it was just because they were busy, then I thought maybe they just wanted more time to refine things, but now it's been nearly two years since they released the current re-vamped Signal 2.0 for iOS and over a year since releasing Signal for Android. At this point I'm running out of justifications for them for why their phone server is still proprietary & closed source.

newman3143• 10 years ago

I'm not sure I like the UX for the disappearing messages. Having a little hourglass after every message breaks the flow up. I'd rather see the message bubbles be black instead of blue.

It's also not intuitive to tap on a recipient's name to enable disappearing messages.

Lastly, maybe messaging should default to 1 week disappearing messages...

lettergram• 10 years ago

I was thinking that too.

I actually want my messages to just be deleted every month, but w.e. I'll take it.

countingteeth• 10 years ago

Hexadecimal isn't compatible with all alphabets, so it left a lot of people out.

Not ... really. Latin characters are available in every locale. Virtually anyone literate enough to use signal is going to distinguish the latin letters A through F. You reading this, I'm assuming you're not literate in Greek, but can you distinguish the letters α, β, γ, and δ, even if you cannot name them? Don't bring up CJK; virtually no one in this day and age is functionally literate in any CJK language that can't read the Latin alphabet.

Let's take the hypothetical person literate in another script who is completely unfamiliar with the letters ABCDEF. They don't use our arabic numerals either. If you need to localize arabic numerals, why on earth couldn't you localize hexadecimal, too?

Obviously, hexadecimal is not friendly to the layperson as a means of representing numeric quantities. But neither is comparing two 60 decimal digit numbers as a means of authentication. I don't think it's inherently easier for a layperson to match 60 decimal digits versus 50 hexadecimal digits.

antocv• 10 years ago

Signal is not anonymous.

Antox from the tox.im people is a better more secure and anonymous messaging application.

Ring.cx is also better.

lorenzhs7• 10 years ago

Signal does not claim to be anonymous, nor does it try to be. Your recommendation misses the point.

miguelrochefort• 10 years ago

Who exactly uses Signal? Why do you think it's secure?

uph14• 10 years ago

Edward Snowden, Bruce Schneier, Matt Green and a few more. I think it's secure because it's been audited, because I trust the experts who say that it is secure, because of http://support.whispersystems.org/hc/en-us/articles/21247776... and because of https://whispersystems.org/bigbrother/

Disappearing messages for Signal

Related Stories