this post was submitted on 28 Aug 2024
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Privacy
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Signal does not collect metadata.
https://signal.org/blog/sealed-sender/
that amounts to trust me bro since nobody actually knows what the server does with the data
You don't have to trust the server and shouldn't have to trust the server if the client is doing proper E2E because you know the maximum amount of metadata it's got.
Your phone number is the metadata that's not encrypted, that's literally the whole problem here. Signal server is able to harvest graphs of phone numbers that interact with one another.
With 'sealed sender' your phone number, or any other identifying information, is not included in the metadata on the envelope, only the recipient's id is visible, and it's up to the recipient's client to validate the sender information that is inside the encrypted envelope. It looks like a step in the right direction, though I don't use signal enough to have looked into auditing it myself.
Again, this is a trust based system because you don't know what the server is actually doing. The fact is that the server does collect enough information to trivially make the connection between phone numbers and the connections on the network. If trust me bro from Moxie is good enough for you, that's of course your prerogative.
You're correct that if you use the system the way it used to work they can trivially build that connection, but (and I know this is a big assumption) if it does now work the way they say it does, they do not have the information to do that any more as the client doesn't actually authenticate to the server to send a message. Yes, with some network tracing they could probably still work out that you're the same client that did login to read messages, and that's a certainly a concern. I would prefer to see a messaging app that uses cryptographic keys as the only identifiers, and uses different keys for different contact pairs, but given their general architecture it seems they've tried to deal with the issue.
Assuming that you want to use a publicly accessible messaging app, do you have any ideas about how it should be architected? The biggest issue I see is that the client runs on your phone, and unless you've compiled it yourself, you can't know what it's actually doing.
Again, everything you say is based purely on faith. As you acknowledge, the design of the system is such that people operating the server can trivially build out graphs of user connections. All the same arguments people apply to no trusting server side encryption equally apply to metadata.
Meanwhile, there are plenty of examples of messaging apps that don't require phone numbers. Matrix, Wire, SimpleX chat, are just a few examples. Being able to build your own client is also important, and there is a concept of reproducible builds which allows people to be reasonably sure that a binary being shipped is compiled from the source that's published. These are solved problems, and there is no technical reason for Signal to do what it's doing.
I agree that them having users' phone numbers isn't ideal. There are other identifiers they could use that would work just as well. However, both the client and server are open source, so you can build, at least the client, yourself. If you can content yourself that it does not leak your ID when sending messages, then you don't need to trust the server as it does not have the information to build a graph of your contacts. Sealed sender seems to have been announced in 2018, so it's had time to be tested.
Don't get me wrong, the fact they require a phone number at all is a huge concern, and the reason I don't really use it much, but the concern you initially stated was addressed years ago and you can build the client yourself to validate that.
Except that Signal won't allow third party clients to talk to their server, and the server doesn't federate. So, Signal being open source is completely meaningless in practice. If you want to use their network then you have to use the client they ship against the server they run, and only people operating this server actually know what it's doing.
I'm talking about the information the server has. The encrypted envelope has nothing to do with that. Your register with the server using your phone number, that's a unique identifier for your account. When you send messages to other people via the server it knows what accounts you're talking to and what their phone numbers are.
Whilst I absolutely agree it's correct to be skeptical about it, the 'sealed sender' process means they don't actually know which account sent the message, just which account it should be delivered to. Your client doesn't even authenticate to send the message.
Now, I'm just going on what they've published on the system, so either I could be completely wrong, or they could be being misleading, but it does look like they've tried to address the very issue you've been pointing out. Obviously it'd be better if they didn't have your phone number at all, but this does seem to decouple it in a way that means they can't build a connection graph.
The problem is that there is no way to verify any of this. You're just putting trust into people operating this service. That's not how security is supposed to work.
the protocol is secure, but privacy is this issue
I'd argue that this is part of the overall protocol design. The e2e encryption aspect of the protocol seems sound, but the system as implemented overall is problematic.
Strictly you're having to trust the build of the client rather than the people running the server. If the client doesn't send/leak the information to the server, the people running the server can't do anything with it. It's definitely still a concern, and, if I'm going to use a hosted messaging app, I'd much rather see the client built and published by a different group, and ideally compile it myself. Apart from that I'm not sure there's any way to satisfy your concerns without building and running the server and client yourself.
The problem is that a phone number is required to make an account, and that's a unique identifier for each person using Signal.
The government can then know you use Signal. This may be problematic in heavily autocratic regimes, but besides those, what threat scenario are you arguing for here? The Sealed Sender concept disallows building a social graph. However, you can utilize a VPN to mask your point of origin or, if necessary, even use a burner number. Under the worst case scenario that the US gov takes over the whole AWS infrastructure and tries to correlate connections to users, there's still very high information entropy. At that point, we're talking about the US gov as a targeting threat actor. If that's your opponent, you shouldn't use everyday customer electronics or applications anyway. That's some spy shit, even domestic activists won't fall under that much scrutiny.
The government can know you use Signal, and know who your contacts are, and can correlate all the data they have on your and your contacts to see if any of it makes your whole group of contacts of interest. So, yeah it's pretty concerning for people living in autocratic regimes like the US. Meanwhile, the sealed sender concept is just trust me bro because nobody aside from people who are actually operating the server know what it's doing. The fact that people in this thread have so much trouble understanding that any data that gets leaked has to be assumed to be in the hands of a bad actor is phenomenal. Signal is proof that vast majority of people don't understand the basics of privacy and security, and they don't actually care. It's just pure ideology for them.
first comment to provide a decent counterpoint.
Looks like signal and email use both. but it still does not answer
AI said:
'Sealed sender' seems to avoid this by not actually requiring the client to authenticate to the server at all, and relying on the recipient to validate that it's signed by the sender they expect from the encrypted data in the envelope. As I mentioned in another reply, I’m just going on what they’ve published on the system, so either I could be completely wrong, or they could be being misleading, but it does look like they’ve tried to address this issue.
same here overall. thank you for responding.
The identifier is unavoidable for push notifications to work. It needs to know which phone to send it after all, even if it doesn't use Google's services, it would still need a way to know which device has new messages when it checks in. If it's not a phone number it's gonna be some other kind of ID. Messages need a recipient.
Also, Signal's goal is protecting conversations for the normies, not be bulletproof to run the next Silk Road at the cost of usability. Signal wants to upgrade people's SMS messaging and make encryption the norm, you have to make some sacrifices for that. Phone numbers were a deliberate decision so that people can just install Signal and start using E2E texting immediately.
If you want something really private you should be using Tor or I2P based solutions because it's the only system that can reasonably hide both source and destination completely. Signal have your phone number and IP address after all. They could track your every movements.
Most people don't need protection against who they talk to, they want privacy of their conversations and their content. Solutions with perfect anonymity between users are hard to understand and use for the average person who's the target audience of Signal.
The identifier absolutely does not need to be your phone number, and plenty of other apps are able to do push notifications without harvesting personal information from the users.
Meanwhile, normies don't need Signal in the first place since e2ee primarily protects you from things like government agencies snooping on your data.
Just a side note but both Simplex Chat and Briar are free of unique identifiable IDs.
For Simplex Chat it uses hash tables. It still has a centralized server (which you can self host) but you can use the built in Tor functionality to hide your IP.
For Briar it is totally decentralized. All messages go directly over Tor but it also can use WiFi and Bluetooth. It supports group content types such as Forms and blogs. The downside is that you need a connected device. You can also use Briar Mailboxes on a old phone to receive messages more reliably.
Signal has been forced by court to provide all the information they have for specific phone numbers [0][1]. The only data they can provide is the date/time a profile was created and the last date (not time) a client pinged their server. That's it, because that's all the data they collect.
Feel free to browse the evidence below, they worked with the ACLU to ensure they could publish the documents as they were served a gag order to not talk about the request publicly [2].
[0] https://signal.org/bigbrother/
[1] https://www.aclu.org/news/national-security/new-documents-reveal-government-effort-impose-secrecy-encryption
[2] https://www.aclu.org/sites/default/files/field_document/open_whisper_documents_0.pdf#page=8
Once again, even if this is the way things worked back in 2016 there is no guarantee they still work like that today. This is the whole problem with a trust based system. You are trusting that people operating the server. It's absolutely shocking to me that people have such a hard time accepting this basic fact.
You have to trust someone. You're not building all your software and reading every line yourself are you?
While there's no guarantees, Signal continues to produce evidence that they don't collect data. Latest publication August 8th, 2024: https://signal.org/bigbrother/santa-clara-county/
The code is open has had a few audits: https://community.signalusers.org/t/overview-of-third-party-security-audits/13243
Can you point me to a working trustless system? I'm not sure one exists. You might say peer-to-peer systems are trustless because there's no third party, but did you compile the code yourself? did you read every last line of code before you compiled and understood exactly what it was doing?
What's shocking to me is the lack of understanding that unless you're developing the entire platform yourself, you have to trust someone at some point and Signal continues to post subpoenas to prove they collect no data, has an open source client/server, provides reproducible builds and continues to be the golden standard recommended by cryptographers.
I would recommend to anyone reading this to rely on the experts and people who are being open and honest vs those who try to push you to less secure platforms.
No, you don't have to trust anyone. That's literally the point of having secure protocols that don't leak your personal data. 🤦
Signal made an intentional choice to harvest people's phone numbers. The rationale for doing that is very thin, and plenty of other messengers avoid doing this. The fact that Signal insists on doing that is a huge red flag all of its own.
Only people who are actually operating the server know what's running on it. The fact that Signal aggressively prevents use of third party clients and refuses to implement federation that would allow other servers to run is again very suspect.
SimpleX, Matrix, Briar, and plenty of other chat systems do not collect personal data.
The discussion in this thread is specifically about Signal harvesting phone numbers. Something Signal has no technical reason to do.
Kind of ironic that you've exposed yourself as being utterly clueless on the subject while accusing me of lack of understanding.
I would recommend anyone reading this to rely on rational thinking and ignore trolls who tell you to just trust Signal. Privacy and security are not based on trust, and if you ask any actual expert in the field they will tell you that.
Unless you're reading all the code, understand the protocols, and compiling yourself you are placing your trust in someone else to do it for you. There's no way around this fact.
You suggest SimpleX, Matrix, and Briar (which I believe are great projects btw, I've used them all and continue to use SimpleX and Matrix) but have you read the code, understand the underlying protocols, and compiled the clients yourself or are you placing your trust in a third party to do it for you? Be honest.
I will agree though, if you absolutely do not trust Signal, you should use Briar or SimpleX, but neither are ready for "every day" users. Briar doesn't support iPhones so its basically dead in the water unless you can convince family/friends to switch their entire platform. SimpleX is almost there but it still continues to fail to notify me of messages, continues to crash, and the UX needs significant improvement before people are willing to put up with it.
Let me give you a history lesson, since you seem to have no clue about where Signal started and why they use phone numbers. Signal started as an encryption layer over standard text/SMS named TextSecure. They required phone numbers because that's how encrypted messages were being sent. In 2014, TextSecure migrated to using the internet as a data channel to allow them to obscure additional metadata from cell phone providers, as well as provide additional features like encrypted group chats. Signal continued to use phone numbers because it was a text message replacement which allowed people to install the app and see all their contacts and immediately start talking to them without having to take additional action - this helps with onboarding of less technical users. Fast forward to today and Signal is only using phone numbers as a spam mitigation filter and to create your initial profile that is no longer being shared with anyone unless you opt into it.
Now, you can say they're collecting phone numbers for other nefarious purposes but they publish evidence that they don't. Will they ever get rid of phone numbers? Unlikely unless they figure out a good alternative to block spam accounts.
You're 100% right. If you read the code, understand the protocols, and build the clients from source, you don't have to trust anyone 😊
That's why you have a lot of eyes on the code and security experts who dedicate their research to finding flaws and breaking algorithms. It's certainly a very different scenario from simply trusting people who run a server. The fact that this even needs to be said is frankly phenomenal. There's also a concept of reproducible builds, so even if you're not compiling everything yourself you can be reasonably sure that what's package in the binary was in fact compiled from the source. Again, these are solved problems.
If people genuinely care about privacy then it's important to promote apps that actually care about privacy by design and invest in improving these apps instead of just perpetuating the problem by recommending Signal. Even Matrix is far better in terms of privacy and it's plenty mature at this point.
I'm well aware of the history, and the justifications. The fact remains is that I simply do not trust Signal knowing where it originates.
The correct statement is that Signal claims to do this, there is no way for an outside party to verify that this is actually the case, hence why it comes down to you taking what people operating Signal say on faith.
Trusting countless researchers an security experts to read the code, understand the protocols, and provide reproducible builds, is a lot better than trusting a sketchy US company that was started by the CIA and NED. I guess that's a concept that's difficult for some to wrap their head around though.
I would disagree, this guy's been finding issues and reporting them to Matrix for a while now and appears to find them every time he glances at the project. I LOVE Matrix. I would recommend it over Discord, Telegram etc, but I would not recommend Matrix over Signal.
This is fair. No critique against this stance.
I agree! Trust the countless researchers, security and cryptography experts.
You're gonna have to cite your sources.
Issues being found with technology is perfectly normal, and in fact contradicts your whole previous argument. People do find flaws, and then these flaws get fixed, and things get more secure in the process. That's how things work. However, the key difference is that Matrix doesn't harvest metadata like phone numbers by design while Signal does. That's not a problem that has been identified but cannot be fixed because Signal is central server that's controlled by a US company.
I love how I've addressed this numerous times but you're still unable to understand the difference. Trusting that the protocol works correctly is different from trusting people operating a server. Clearly this is a concept that is beyond your comprehension.
Maybe go read up on where Signal comes from instead of spending your time trolling here. http://surveillancevalley.com/blog/internet-privacy-funded-by-spies-cia
You're right, Matrix doesn't ask for a phone number but it damn sure leaks metadata like a sieve. Unless things have significantly changed in the last year, here's a list of things Matrix can see about you in an encrypted room, that an app like Signal cannot:
I clearly understand the difference, what you fail to address is that at the end of the day you are placing your trust in a third party, whether its the code, the protocols or a back-end server. Matrix removes the server if you host your own and never interact with other instances, but otherwise, you're still trusting the code and the protocols and that - as I've pointed out above - that what you're recommending isn't already leaking tons of data. And don't get it twisted, I'm ROOTING for Matrix, it just has a long way to go to address issues that Signal clearly identified early on would hold back the platform (federation + third party clients).
I know what you're talking about but you don't want to bring it up because its all tinfoil hat wearing flat-earth conspiracy theory web of poorly connected dots. Your response is the MAGA equivalent of "do your research". I've done my research. The onus is on you to bring forth the evidence. To quote Carl Sagan, "Extraordinary claims require extraordinary evidence". Don't try and connect dots that don't back up your claim and stand proud behind what's at best poorly thought out misinformation.
None of the thing you listed are personally identifying information. I have to ask at this point, do you even understand what personally identifiable information is?
If you can't understand the fundamental difference between trusting that an algorithm is provably safe mathematically vs putting trust into some random people then it's clear that a rational discussion is not possible with you.
Imagine saying that without a hint of irony after Snowden revelations. Either you're a troll or the most gullible person to have ever walked this planet.
I'm going to stop replying to you here because I've said all there is to say on the issue and we're just going in circles. I think that you understand the problems with Signal perfectly well, as will anybody reading this thread. It's pretty clear that you're intentionally trolling, and there's no point continuing to engage with you. People can make their own mind whether they want to put their trust into a CIA outfit or not.
Funny enough, "Edward Snowden has reiterated his faith in the Signal app by saying that he uses it every day." - published 2021.
Same here, lets end this amicably and find common ground. I think we're both pushing for what we believe is best in attempts to guide people towards a secure platform, can we both at least agree that SimpleX is superior under more threat models compared to other messengers, even if it does have a few UX issues it needs fix?
I do think we can agree that SimpleX approach is the way to go long term. Cheers.
True but I find the opposite end of the spectrum hard to believe. Extraordinary claims require extraordinary proof.
What is known is that government agents from countries like Iran, China and Russia actively are spreading misinformation. Not to say that you are a government agent but you should doubt the argument on both sides. For instance, using Signal is way better than not using an audited encrypted messager. Often times I see people jump to worse platforms. I think it is important to understand the problems with Signal.
It's well known that the US and other western countries actively spread misinformation. It's also known thanks to Snowden that the US regime harvests personal data aggressively. Anybody who puts blind faith into a US based security company is frankly an imbecile.
@yogthos @possiblylinux127
Sad but true. It's definitely concerning.
True, however your claim lacks evidence. They have your phone number and a few time stamps. That isn't going help much.
My claim is that privacy should not be based on trust. This appears to be a very difficult concept for people in this thread to understand.
You always will have to trust something at some level.
Yeah, you trust that the encryption algorithm is designed correctly and that it doesn't leak data because many people have audited it and nobody found a flaw in it. You absolutely will not have to trust people operating servers however. If you can figure out why e2ee is important then I'm sure you'll be able to extrapolate from that why metadata shouldn't be seen by the server either.
I'm not very tech-savvy, and that article looks very nice, but it's kind of old and it's true that they haven't been as transparent (and frequently audited) as other services and they still require a phone number to set up an account, even if you can switch to only using a username later. Also, they removed encrypted database, and Molly brings that back which is the main reason I use it. Another thing I don't like about Signal is how ferociously they've tried to shut down forks in the past, and how they don't say that you need Google Play Services for it to work properly. Sadly it's the only "privacy-conscious" service I've managed to make most of my family and friends use, after trying for years.
They only shut down forks that violate Signal branding. Mozilla does the same thing with Firefox.
It is libre so if you fork it there is nothing they can do. Also if they were really hostile they would of used a non libre license or made it entirely proprietary.