5 ms·
Signal knows who you're talking to (2023)
- defraudbah 11mo agopeople often confuse privacy with anonymity, like in this article. the question was if signal is secure and private, and the answer is about anonymity is it secure and private - it is, is it anonymous - it's not, or at least, to some degree
- deleted 11mo ago[deleted]
- jijijijij 11mo agoHm. I think, you are confusing general privacy with confidentiality. Observing who I am talking to definitely falls into the privacy domain. Eg. you are talking to an HIV medical specialist. This inherently has privacy implications, if observable. Likewise, you wouldn't say DNS has no privacy implications. Anonymity rather means, you don't/can't know who exactly you are talking to.
- dist-epoch 11mo agoSome definitions of "private" also include "not knowing who I talk to".
- fmajid 11mo ago"We kill people based on metadata" General Michael Hayden, Director, NSA
- My_Name 11mo agoYou can't have end to end encryption without ends. That said, I have managed to write encrypted end to end communication, using wireguard no less, that doesn't tell a third party server who is talking, or what they are saying. This is single user talking to single user, though. I know it gets more complex when you have more users than that.
- zoobab 11mo agoFirst question after Moxie Marlinspike talk at the CCC conference was: "When will Signal not base itself on a mobile phone number, I am an activist from Iran" https://media.ccc.de/v/36c3-11086-the_ecosystem_is_moving https://media.ccc.de/v/36c3-11086-the_ecosystem_is_moving
- udev4096 11mo ago"Never"
- guytv 11mo agowhat was his answer?
- input_sh 11mo agoThat was not the first question, the first question was about post-quantum security. Care to time stamp it or do we have to sit through all of the Q&A to find your claim?
- jotaen 11mo agoNot OP, but I’ve referenced the time stamps in my sibling comment. Also, “Be kind. Don't be snarky.” (https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html)
- input_sh 11mo agoI saw your comment and just finished listening to it, to those that can't be bothered to, he boils it down to: they don't want you to lose all of your social network if you lose your device. Imagine having to re-discover every user you've communicated with because you no longer have their identifiers, which I think is a fair argument to make. Also, now that we know the timestamp, we know this user spread two pieces of misinformation in 28 words: Iran was never mentioned and it was not the first question in the QA. I think some snark is well justified here.
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- sturza 11mo agoThe critique of metadata being hard is fair, the claim that sealed sender is “totally useless” is not. It’s a small, incremental hardening step in a very messy design space, not a magic invisibility cloak, and judging it as the latter sets the bar unrealistically high for anything that still wants to be a drop-in WhatsApp replacement.
- sandblast 11mo agoIt's useless in the sense that it makes an anonymity promise to users that it cannot fulfill.
- halJordan 11mo agoBut it doesn't make the claims OP says are broken. Op makes several logical leaps and because each leap is a reasonable leap, he assumes it must be THE leap. Which isnt true and it's simple to come up with counterfactuals, and it's a common pitfall in analysis (he's confirming his bias)
- sliken 11mo agoJust because it's not perfect, does not mean it useless. A central signal message service receives millions of messages, I've seen claims of 40M active users a month. If each user sends 25 messages a day, that's 12,000 ish a second. Drawing conclusions about who is talking to each other out of a 12,000 message per second stream is far from trivial since both signal users are just sending and receiving encrypted packets to a central service. Much depends on how much you believe about how signal handles things on the server size. Not sure federation or pure p2p would improve things, especially since some fraction of the service could be malicious.
- HelloUsername 11mo agoI thought you can register Signal with a virtual number, then in settings simply hide the phone number, and create new chats with your username? Also, what about Briar/Berty as alternative? https://play.google.com/store/apps/details?id=org.briarproject.briar.android https://play.google.com/store/apps/details?id=org.briarproje... https://apps.apple.com/app/id1535500412 https://apps.apple.com/app/id1535500412
- Arnt 11mo agoI'm curious. What happens if you do that and immediately send messages to lots of people? Will all if the messages be delivered promptly, or will most be delayed until the first few recipients have either replied or have reported your new account as spam? I don't know, I'm curious. Signal appears to have the necessary information to compute spam prevalence per virtual number provider.
- sandblast 11mo agoSince a lot of people might not reach the conclusion at the bottom of the post: Just use SimpleX.
- w1nt3rmut3 11mo agoSimplex is developed by a person who has a rather difficult view of the world. I would not recommend using it as long as this person is responsible for it.
- sandblast 11mo agoI don't know what you're mentioning, but let's not forget that whatever view he might have, it changes nothing in the technology he creates. It's open source, it's auditable, and the code does not have worldviews of its own. Your comment promotes cancel-culture, and as filthy as it is in general, it's even more so in the technology world. Don't do it. Please.
- jijijijij 11mo agoAs long as you are not auditing every bit of code you run yourself AND are sufficiently knowledgeable to detect even obfuscated malicious code, you need some basis of trust. Evident world views far off reason, reality, compassion and pragmatic self-regulation, don't speak for a stable, predictable and reasonable personality. If a person thinks some humans deserve less rights than others, how could you trust any update to not reflect this world view? Additionally you may be becoming technologically dependent on a person whose actions may be detrimental to your safety or wellbeing in other parts of your life. You may also just don't like to promote this person's work. It's fair to inform others about the person behind the software they are running. Everybody can make their own informed choices.
- sandblast 11mo agoAnd the appropriate basis of trust in the technology world would be source code audits, not scraping some individual's Twitter posts. If the users' communications are encrypted — which they are — there is no way for the creator to "reflect his world view", whatever it might be, in the form of undermining the security or privacy for some part of the user base.
- bjoli 11mo agoI always thought sealed sender was something they implemented for their own sake. The less metadata they can see is better. As a user that means you have to trust them in what they say regarding the data they keep anyway. Regarding sealed sender I don't think they ever fixed the statistical method of identifying sealed senders described in the "improving sealed sender" paper from 2019 (?), meaning it is pretty useless anyway if signal decided they wanted to identify senders.
- upofadown 11mo agoThe paper: Improving Signal's Sealed Sender https://www.ndss-symposium.org/ndss-paper/improving-signals-sealed-sender/ https://www.ndss-symposium.org/ndss-paper/improving-signals-...
- jwr 11mo agoSignal is in an impossible position. On one hand, it needs to appeal to the crowds currently using WhatsApp and happily syncing their entire contact list to Facebook/Meta, so that they can be profiled and a social graph can be built. That crowd needs it to be super simple and "just work". If it doesn't do that, people will criticize it for being difficult to use. On the other hand, it needs to provide ultimate security, even though there is always a compromise between security and convenience. If it doesn't, geeks will criticize it for not being secure enough.
- hacker_homie 11mo agoI mean you could always see where a letter was addressed, so knowing who your talking too seems like a reasonable compromise. Sealed sender feels like a get out subpoena feature.
- dist-epoch 11mo agoSounds like 2 apps to me, maybe they should split it into Signal and SignalUltraSafeTM, for the paranoid, but more inconvenient, with some interoperability between them.
- CrossVR 11mo agoWhat if people on SignalUltraSafeTM want to talk to people on regular Signal? Telegram solved this already though, they allow users to register using either their phone number or a unique username. But Telegram has a huge spam problem. Which is likely the real reason Signal requires a phone number.
- nalekberov 11mo ago> But Telegram has a huge spam problem. Which is likely the real reason Signal requires a phone number. I was able to register with fake number I got for free on the internet. That clearly doesn't solve SPAM problem. If I know that, Signal certainly knows that.
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- vedmed 11mo agoI like the way SimpleXChat works. Good luck getting anyone to switch to it though. https://simplex.chat/ https://simplex.chat/
- sschueller 11mo agoIf they fix the android battery issue (due to how notifications work) it would be a lot easier to get people to switch. I hope the PR gets merged soon.
- sandblast 11mo agoI don't claim that the problem does not exist, but I haven't really felt it during my daily usage with relatives.
- sschueller 11mo agoI do notice it but then again my phone is quite old at this point.
- newscracker 11mo agoI read through this. I don't think Proton Mail is a good replacement for Signal (it's worse because Proton does log and share IP addresses of users with a court order). One thing I dislike about Signal on its privacy posture is that the moment you register, anyone who already has Signal and has your phone number in their contacts list will get a message saying you're on Signal. This is a good way for others with bad intentions to know about your presence on the platform. The options to hide your phone number are available only after registering on Signal (after this broadcast has already happened) and when the user figures out that this is possible somewhere deep in the settings. On registration Signal could ask whether to inform all random people who happen to have your number. But since unused/discarded phone numbers are recycled by carriers to other customers within a matter of weeks or months or years (depending on where you are), your presence on Signal may be sent to someone you've never ever known or has known you. Signal ought to remove this broadcast on registration. Telegram (and I guess WhatsApp) also suffer from the same issue.
- udev4096 11mo agoThat's false. You can set your phone number discovery to None and even your contacts cannot find you unless you explicitly message them or share your username
- shevy-java 11mo agoNSA will know.
- baxuz 11mo agoWhy do you even need a phone number in the first place?
- sourraspberry 11mo agoSignal is the only WhatsApp/Messenger alternative I've managed to get friends and family to actually move to. I suppose this Sealed Sender issue is problematic for some people, but it's not enough for me to seriously consider jumping ship.
- ezst 11mo ago> Signal is the only WhatsApp/Messenger alternative I've managed to get friends and family to actually move to. And what good did that achieve, practically? In effect, your friends and family: - still use a centralised service with Signal (subject to enshittification/changing the deal overnight/acting as a single point of control and failure) - still use WhatsApp because they really have no choice: that's where everyone else is (and so, there is no avoiding Meta's data collection on them and indirectly, on you) - gained nothing compared to WhatsApp+E2EE (being centralised, both Signal and Meta can infer your social graph, the nature and volume of exchanges you have with your contacts, and hence the nature of your relationships, Signal only "pinky swears" it's not looking at it, and that's a very lame "guarantee").
- kamranjon 11mo agoWhat do you mean signal “pinky swears” it’s not looking at it? It’s E2E encrypted and the code is open source - am I missing something? How would they possibly look at it?
- fragmede 11mo agoezst is referring to the metadata — who you're talking to, not the contents of the message
- ezst 11mo agoPrecisely. The metadata and some basic packets analysis suffices to reveal if you are at home or at work, sending text or images, traveling/from approximately where to where or still, on the toilet or working, etc, all without breaking the glamorous post quantum ratchet encryption.
- flaburgan 11mo agoI'm sorry but I don't think this guy did his homework correctly. You don't need a phone number anymore to use Signal. You still need one to register, but not to communicate with anyone. You can simply share your username for that. So you can just buy a prepaid card with cash, register, and then throw it away, and it will never be linked to your real identity. Signal is not perfect, but it's still the best we have.
- whisht 11mo agoYou would need to throw the phone away too, and use it only for the prepaid SIM, otherwise its IMEI will be linked to anyone who can observe which are associated with which SIM registrations.
- vedmed 11mo agoIIRC there's like three developed countries in the world where one can buy a phone# without providing ID. In the US one can buy a prepaid card wearing a mask and paying with cash. Also I came across this service which purports to be anonymous: https://www.cape.co/ https://www.cape.co/ but has a ridiculous monthly fee.
- viktorcode 11mo ago> You still need one to register Case in point: recently, some Russian mobile service providers started blocking registration SMS for popular messengers, Signal included. In earlier years there were also cases of mobile number spoofing in the country, where the control over the number was given to law enforcement who then use it as second factor authentication to break into different accounts. That's how easy it is. The word "secure" and "mobile phone number" are the opposites of each other.
- Beretta_Vexee 11mo agoThe article confuses confidentiality with anonymity/pseudonymity. Signal has always aimed to ensure confidentiality in the simplest way possible. People forget that there are anonymous systems or systems that do not require a telephone number but they are incredibly painful to set up. You either have to go through physical checks with QR code exchanges to validate participants or have some kind of web of trust (no one has fond memories of PGP key signing parties). The same goes for decentralization. On paper, everyone wants decentralization. But when it comes to interconnecting hundreds of servers with different rules, moderation and legislation, and protocol versions, it becomes hell and no one wants to have to manage it (e.g. Mastodon). There are objective reasons why these systems are not popular. The other problem is that the very use of this type of software becomes a marker. I am convinced that the majority of Olvid users work for the French government, for example. Iranian activists who are checked at the border or elsewhere with any uncommon communication application have already lost, regardless of the security of the application. Crypto-punks are a niche group that can accept this type of usage constraint. My grandmother cannot, but she can use Signal and she will be one user among millions.
- noduerme 11mo agoPrecisely. It's a bit like the browser fingerprinting dilemma. The greater lengths to which you go to hide your fingerprint, the more unusual your total profile becomes. May I humbly suggest the thing I've done for 25 years, when I need to pass sensitive data like a slate of passwords or API keys or confidential business logic... I just PGP encrypt a zip file and attach it to a normal email. This does nothing to address the anonymity issue, as you point out. But I'm really not sure that any set of measures I could take would truly keep me anonymous at this point in the race between governments and the well-funded organizations trying to evade them. I assume that no matter what I do to hide my identity, someone with enough money and motivation would be able to unmask it. To believe otherwise would be foolish.
- tchalla 11mo agoThe amount of times I have Signal dunked on for confusing confidentiality versus anonymity is just too high.
- dist-epoch 11mo agoLet's not forget one way Ross Ulbricht was caught was by correlating traffic from his home through Tor to posts appearing on SilkRoad.
- input_sh 11mo agoThat's not how they caught him. They caught him because he posted a StackOverflow question under his real name that contained a snippet of the code that was found in SilkRoad's source code.
- dist-epoch 11mo agoThat was another mistake. > The server running Silk Road was imaged and forensically examined in late July. This was done surreptitiously by the hosting provider at the request of the FBI via local authorities and the Mutual Legal Assistance Treaty. They used the server’s ssh config to find the VPN server Ulbricht was logging in from and the VPN server’s last login record of IP addresses to locate a cafe near his home. The FBI was able to correlate the location based on Google’s records of the email account that was previously used to solicit users and help on the Bitcoin Talk forums, which he accessed from home the same day he logged into the VPN server. https://www.comparitech.com/blog/vpn-privacy/staying-anonymous-online-silk-road-founder-mistakes/ https://www.comparitech.com/blog/vpn-privacy/staying-anonymo...
- shmichael 11mo agoIt is, as far as I know, an unsolved problem how to implement full metadata transparency on a mobile device. For example, Aztec, a privacy focused blockchain, requires recipients to download the entire block to determine if any private message is addressed to them (and BTW use techniques resembling Signal's double ratcheting in creating these identifiers) [1] This is infeasible on mobile devices. At best, it allows the user to select a proxy server they trust to identify messages intended for them and forward a notification. 1 - https://www.taurushq.com/blog/enhancing-token-transaction-privacy-on-public-blockchains-while-ensuring-compliance/ https://www.taurushq.com/blog/enhancing-token-transaction-pr... (search for "synchronizer")
- shevy-java 11mo agoThese are all spy-apps anyway. To me it always looked as if the US government is just a thin fake-coat over this operation. There is a reason they dislike people having secrets. No spy agency wants people to have secrets. Cops asking for an ID without a probable cause is another reason that then ties into the legal system. I feel that most governments overreach what they can do in general; they have a tendency to grow in what they claim is their concern when it really is not.
- paranoidrobot 11mo ago> These are all spy-apps anyway. Do you have any evidence to back this claim? Specifically as it relates to Signal.
- BlackLotus89 11mo ago(2023) missing in title
- 89297288 11mo agoIt doesn't sound like SimpleX solves this either [0]: > There is still a risk that a server maliciously records all queues and messages (even though encrypted) sent via the same transport connection to gain a partial knowledge of the user’s communications graph and other meta-data. [0]: https://github.com/simplex-chat/simplexmq/blob/master/protocol/overview-tjr.md#trust-in-servers https://github.com/simplex-chat/simplexmq/blob/master/protoc...
- sandblast 11mo ago> SimpleX supports measures (managed transparently to the user at the agent level) to mitigate the trust placed in servers. These include rotating the queues in use between users, noise traffic, supporting overlay networks such as Tor, and isolating traffic to different queues to different transport connections (and Tor circuits, if Tor is used). Also, most often the two parties use different receiving servers, and this aligns us more with the physicals letters analogy from the submitted article, except that each receiving server is more like a central post warehouse in a big city and not a small district branch.
- baxuz 11mo agoI absolutely agree with the article. Using phone numbers as IDs or a verification method is a horrible practice, not to mention that it forces you to use a phone in the first place.
- skylerwiernik 11mo ago> this feature is very technically complex, and totally useless Now, to break your confidentiality, Signal would have to have a relatively complex system setup for trying to match up messages and deanonymize people. You could imagine many scenarios where a bad actor (agency) attempts to trick Signal into logging metadata. This now requires a lot more information, and if nothing else would give you a level of deniability.
- jmakov 11mo agoAll you need is metadata. Once you know your targets, install spyware (on one of them) and enjoy access to Signal's unencrypted msgs on the phone. Almost feels like another CryptoAG with Snowden recommending it so much when he knows that metadata is enough.
- pogue 11mo agoThe Molly fork of Signal solves some of these problems. https://molly.im/ https://molly.im/ How does Signal make money to be able to afford their AWS subscription? Do corporate clients pay for it or something? That MySudo service he mentions in the article sounds quite interesting as well. Has anyone given it a try?
- evolve2k 11mo agoIf one person uses Molly but the other uses standard Signal. Do we have the same problem or is security still somewhat improved with regards to who’s communicating w who?
- pogue 11mo agoI think the primary concern addressed in the article is it's ability to connect directly through TOR, so the person using Molly would potentially have less metadata available for analysis. So, as with all things privacy related, it depends on your level of paranoia, I suppose ;)
- INTPenis 11mo agoBriar is also an alternative.
- perryizgr8 11mo agoFundamentally any centralised message relay system will have enough metadata to know something about participants and maybe even things like message frequency. If you truly want anonymous communication it has to be p2p.
- upofadown 11mo agoThis is ultimately a usability issue. The Signal app has a feature called sealed sender. The assumption is that a feature actually does what it is intended to do. Signal makes no effort to inform the user about the limitations of this feature. My experience is that almost all Signal users that actually know about sealed sender think that it actually provides some practical benefit. Users that do not know the limitation of a tool are unlikely to use that tool properly. This sort of thing is depressingly common in the world of encrypted messaging. It is really common for a user to not know about the requirement to do identity verification with E2EE for example.
- deleted 11mo ago[deleted]
- penguin_booze 11mo agoWhom you're talking to.