14 ms·

Telegram publishes users' locations online

488 points by Nullslash 6y ago

gotem 6y ago
It’s a good first step but not enough. I was scammed a while back on Telegram and wish I had been able to also see the persons real identity to recover my money. Location is not enough to go on. Perhaps TG should publish an API to allow people to see any users government ID if they are scammed.
- 2Gkashmiri 6y ago
  How can telegram give you government issued ID if it doesn't collect it ?
  - Hnrobert42 6y ago
    I think they are being sarcastic.
    - gotem 6y ago
      Nope. I think they should probably ask for one at signup. Would also reduce their server load if people only used 1 account instead of making 2+
      - 2Gkashmiri 6y ago
        Yeah. Where I live people are already getting picked up for being in a WhatsApp group, for sharing something on WhatsApp or even being a WhatsApp group admin. Do you know how they are caught? Their phone number is kyc compliant so its a cake walk. While I use telegram, I use it to only communicate essential stuff with family. Same for signal and other stuff. Matrix is interesting as it does not require a phone number... To think a government ID card would be needed to talk to family....shudders
- hombre_fatal 6y ago
  This is like choosing to deal with cash and then complaining that you can't do a chargeback. You didn't learn your lesson. The lesson wasn't that Telegram should require a government ID (then nobody would use it much less the scammer who scammed you). The lesson was that you need to consider the impact of being scammed when you're open to using a channel with no recourse.
KingMachiavelli 6y ago
Telegram has so many anti features and dark patterns that I really wish it was less popular. I honestly use WhatsApp over Telegram because at least I know WhatsApp is insecure while people sometimes act like Telegram is a secure platform.
- Hnrobert42 6y ago
  I’ve heard other folks say WhatsApp is insecure. Do you (or anyone else) have specific examples or concerns?
  - deleted 6y ago
    [deleted]
  - marta_morena_9 6y ago
    Like... Facebook can read all your messages? The encryption only protects you from entities that are not Facebook. With that out of the door, it's not really worth it to even consider other angles of attack, since you now depend on the goodwill of a billion dollar company whose sole purpose and reason for existence is to extract and monetize your data. WhatsApp is a nice chat tool, but it's nothing you should ever use for secure communication. Sending a letter via mail is more safe.
    - srockets 6y ago
      If they can, then either Facebook boldly lied about implementing end-to-end encryption[0], or found significant attack against the Signal protocol, which is considered quite safe. They do have access to the metadata, i.e. whom you messaged and when. -- [0] https://techcrunch.com/2016/04/05/whatsapp-completes-end-to-end-encryption-rollout/ https://techcrunch.com/2016/04/05/whatsapp-completes-end-to-...
    - kolmogorov 6y ago
      that's incorrect. WhatsApp is end to end encrypted using the signal technology as confirmed by moxie. are you suggesting Facebook tricked the signal team into believing that WhatsApp is using end to end encryption when it isn't? a source: https://signal.org/blog/there-is-no-whatsapp-backdoor/ https://signal.org/blog/there-is-no-whatsapp-backdoor/
kop316 6y ago
Hmm...So I have Telegram installed via F-Droid (so presumably without Google Play Services). I do NOT have the "People Nearby" feature. I am curious if that means my location is not published?
- lynndotpy 6y ago
  It's under Hamburger Menu > Contacts > Find People Nearby. You do not need give access to Contacts, but you do need to give access to Location. Barring no exploits, you have to press "Make Myself Visible" and then confirm with a popup in order to share your location.
- whomst 6y ago
  I have Telegram on iOS and I can't find any People Nearby feature. It doesn't request the location permission according to Settings either.
  - vengefulduck 6y ago
    It took me a while to find it on iOS, it’s under the contacts tab called “find people near by”. It doesn’t seem to work without location enabled so hopefully that would keep you safe.
    - dawnerd 6y ago
      Also doesn't work unless you share contacts - which .... why would you anyways?
      - TedDoesntTalk 6y ago
        People do that so they do not have to type by hand all their friends using the app. Granted, most people probably don’t have a lot of friends using Telegram... but that’s not what Telegram is hoping.
    - crispyambulance 6y ago
      Wow Telegram ¯_(ツ)_/¯ Most folks would be inclined to look under "Settings" rather than "Contacts" for something like this. How strange!
gruez 6y ago
>[Line] fixed it by adding a random number to the user's destination This is a imperfect solution. There's two possibilities: the offset (aka "random number") is dynamic, or it's fixed. If it's the former all you have to do is sample enough times to get through the noise. If it's the latter, it's not vulnerable to the previous attack, but if you have a known point of reference (so you can deduce what the offset is), then you can still stalk them (forever?). IMO the only way to do is "properly" is to quantize people into map cells, like how apple does it with their coarse location feature[1]. [1] "Apple doesn't reduce the accuracy of location fixes by adding noise. Instead, they've carved up the world into regions, allowing approximate locations to preserve the user's current city when possible." https://radar.io/blog/understanding-approximate-location-in-ios-14 https://radar.io/blog/understanding-approximate-location-in-...
- kibwen 6y ago
  > If it's the latter, it's not vulnerable to the previous attack, but if you have a known point of reference (so you can deduce what the offset is) It sounds like this approach could be prevented by having a random fixed offset for each user, so that you have no point of reference unless you already know where that specific user is. [Removed bit about regenerating this offset infrequently.] EDIT: You could even do this in conjunction with the quantization mitigation, which sounds like it would shore up the slight weaknesses with that approach (where being on a quantization boundary makes it obvious where you are in that dimension) for the best of both worlds, as long as you're okay with further decreasing accuracy.
  - algesten 6y ago
    With enough data points you'd easily figure out that offset. Just overlay each data point with map data and decide whether the location makes sense. (i.e. you're unlikely to most of the time be in the middle of a lake, farm field etc)
    - deleted 6y ago
      [deleted]
    - 6y ago
arthurcolle 6y ago
It's a shame that people still use Telegram when Signal is so much better, and has better credentials all around.
- est 6y ago
  signal the protocol is (maybe) better, but the app is inferior. People like Telegram for their usability and security is just a bonus.
  - blackfawn 6y ago
    I definitely agree with this. Getting people to use Telegram instead of SMS or other random chat apps can be difficult but getting them to switch to Signal is basically a "not going to happen" until Signal ups their usability. Even people I've gotten to try out Signal all abandoned it. At least with Telegram, they stuck with it and still use it to this day. It'd honestly probably be easier to get Telegram to adopt Signal's protocol than it would be to get users to adopt [current] Signal.
    - j-james 6y ago
      Telegram's protocol itself isn't necessarily a weakness - recently, a paper was published claiming to have proved the MTProto 2.0 protocol correct. Perhaps because of how recent this was, it doesn't seem to have garnered any discussion or review anywhere. https://arxiv.org/abs/2012.03141 https://arxiv.org/abs/2012.03141
      - blackfawn 6y ago
        My above post was more of a complaint of the Signal UX rather than a critique of either protocol but thanks for the link! I would be interested to hear whether people still perceive MTProto to have weakness... but that likely won't change with how much people seem to complain about it, seemingly without much/any rationale. Either way I'll probably still be using Telegram since that's where the users are :)
- 6y ago
ve55 6y ago
The ability to find user locations via triangulation is overlooked in a lot of products - it's easy to not think twice when showing a user the distance between themselves and someone else. In my own products I fix this by aggressively rounding/adding noise before the distance calculation is performed, and then rounding again afterwards, or quantizing into ranges (e.g. '0-10 miles'). Other solutions can be storing locations imprecisely to begin with, using pre-defined geobuckets, and so on, although remember that randomness by itself can be bypassed with enough queries since it will average out. It's rare that you need to know exactly how far away someone is from you rather than a rough approximation. Telegram is definitely not the only product with this issue, but hopefully they fix it even so.
- ROARosen 6y ago
  Doesn't this triangulation assume the other user is in one location the entire time of manually going to these places to triangulate them?
  - peteretep 6y ago
    You don’t need to go to a location to tell an app you’re in that location and want to know the distance to your target.
  - hombre_fatal 6y ago
    It's not much of an assumption. People go the same places every day (work, cafe) and then go to the same home to sleep in the same bed.
  - taneq 6y ago
    It does, but you can keep trying until you get an accurate location. In the simplest version you can just watch the distance and play warmer/colder until you physically track them down.
- dheera 6y ago
  Quantizing is much safer. Adding random noise is useless because one can just average multiple samples. If you want to be extra safe, quantize the user's lat/lon before computing the distance, and then quantize the distance again. (Quantizing only the distance can theoretically allow an attacker to travel in one direction until they see the transition from one bucket to the other which would tell them exactly when they are precisely 10 miles from the target.)
zeronine 6y ago
> If this feature is enabled on your phone, you're publishing your home address online. Depending on your definition of 'online' this is true of any app you use. Telegram could at least take a similar approach to Tinder, who have already learnt from a similar mistake.
- j-james 6y ago
  Here's an overview of the system Tinder currently uses, after their 2014 privacy fiascos: https://robertheaton.com/2018/07/09/how-tinder-keeps-your-location-a-bit-private/ https://robertheaton.com/2018/07/09/how-tinder-keeps-your-lo...
kelt 6y ago
After going into the 'People nearby' I do not see any option to disable. I do see 'Make myself visible' option and a list of nearby users. (on iPhone) I wonder if this will be sufficient?
- Nullslash 6y ago
  Your location will be shared on the map if you make yourself visible. Otherwise, you're safe. Disable location sharing for the whole app.
mercora 6y ago
so i know some people around me who are using telegram and very likely most of them did not change anything about their privacy settings as usual. However, i do not see any of them in the list and it even shows me users some 10km away. When viewing this list on the top it has a button to make yourself visible so i assume if you don't do it voluntarily its not broadcasted at all which appears to be a non issue then, like he was already told.
- dawnerd 6y ago
  Yeah its very much opt in so Im not sure what the real issue is apart from being somewhat granular. How granular telegram makes it is the question. From the article the way they asked didn't sound like it was "do you live at 123 something st" but instead are you by, which even if you were a few blocks off someone might say yes. For all we know Telegram is doing some rounding. Gonna need to test some more to see I guess.
  - meowface 6y ago
    If they don't want to fix this issue (maybe they find it's advantageous to let benign users find each other precisely), some kind of warning when you opt-in like "Warning: By enabling this setting, anyone around the world may be able to determine your location, such as your home address, even if they live in a different region or country." would be nice. Not sure of the best way to word it, but making it clear that someone in a different continent may be able to see your location and address would at least make the full implications clear. Most users probably assume the risk is limited to people in their city (or a smaller area within it) seeing their location, and also may not necessarily be thinking about the address disclosure (even if that's arguably already obvious to some).
gaudat 6y ago
On the "People Nearby" page in the Telegram app it specifically says Quickly add people nearby who are also viewing this section ... If a user is not specifically on that page, they are not listed in the section. The user most likely wants the world (or strangers) to know his position. This case shows precise localization can be a double-edge sword. But instead of fuzzing the returned location, we should educate the people on privacy implications of showing their position to the public.
- rkoten 6y ago
  > If a user is not specifically on that page, they are not listed in the section. I'm consistently seeing some of the people nearby across multiple times opening the page, some of which weeks apart.
3PercentMan 6y ago
So in the article, the author was able to find the x- and y- coordinates of the other user. What if the target user lives in a high rise building, is there any technique you can get the height of the said user? Makes me wonder how the law enforcement is able to tri-angulate the suspect's exact location.
- rkoten 6y ago
  My somewhat educated guess would be that, firstly, cell tower triangulation includes altitude by necessity of measuring directly the reach of electromagnetic waves, whereas Telegram advertises the subset of users' GPS data that they choose to advertise, which is likely just lat-long. Secondly, law enforcement also likely has the cooperation of the administration of said high-rise building.
  - swiley 6y ago
    That's going to be pretty distorted (likely uselessly so) in a highrise unless you're connecting to the "femto cells" (I think?)
- Nullslash 6y ago
  Author here. No, that is called z-coordinate. It's not possible to get z-coordinate by just finding the distance between me and the user.
- taneq 6y ago
  You can certainly triangulate in three dimensions, IF the distance displayed is the 3-dimensional distance rather than just the distance between two lat/long locations. You just need to sample an additional point that's not collinear with the first two.
nnx 6y ago
iOS recently introduced per-app “Precise Location” toggle in Settings. Turning this toggle off is a great mitigation for apps who haven’t fixed or clarified how they handle such triangulation attacks.
shp0ngle 6y ago
I used the "people nearby" feature once, and I kept getting random messages from random people 2 months later. I could not figure out how the hell to turn it off.
- nguyenkien 6y ago
  Android: Go back to people nearby, click "Stop showing me"
  - shp0ngle 6y ago
    ...oh. OK.
isodev 6y ago
A user does not show up in “People nearby” unless they enable the function. Doing so triggers a warning from Telegram informing you your location is about to be published and it may lead to undesired attention so it really can’t happen by accident. I’m also using the app on iOS, the operating system asks periodically if I want to continue sharing location in the background (in case I forget to turn it off) or I can just choose to enable it while using the app (which is what I usually do).
- taneq 6y ago
  Yeah, it seems pretty explicit that you're making your location public when you press this button. I'd say the 'bug' is in people not realising that pushing their location to a 'show users near me' function inherently reveals their location to some degree of accuracy.
  - eznzt 6y ago
    This is the exact message: https://i.imgur.com/PDnMmQV.png https://i.imgur.com/PDnMmQV.png -- Additionally, iOS allows you to make your location imprecise on purpose. This is a non-issue, this guy "Ahmed" is just fishing for attention with an incendiary title.
    - justcool393 6y ago
      yeah, I would definitely say that that's fine. like, if it were some dark pattern or unknown or something then whatever, but it's pretty explicit
- Nullslash 6y ago
  it's a privacy issue. Users who enable the feature don't understand that are basically publishing thier latitude longitude online. Which can be resolved into a home address.
  - krbzsq 6y ago
    Blanket stating that users don't understand is pretty dismissive and frankly quite patronising. I'm a big privacy advocate, so I don't personally like volunteering location info, but personally know lots of people who will happily do so for all sorts of reasons (e.g. seeing each other on snapchat maps), they understand what they're doing. Simple fact is, plenty of people just _don't care_ and that is their right to do so.
aportnoy 6y ago
You might want to change the title to something not as clickbaity and misleading.
ShakataGaNai 6y ago
More systems need to truncate location data. It is relatively "easy" to solve this particular issue by just not returning highly specific data. Instead of saying "896m", return "<1km" or "1km-3km" etc. Can you still abuse the data to some extent? Yes in theory, but it's significantly harder and takes a lot more work to get anything reasonable. You can also truncate the data you have on users. 2 digits of Decimal_degrees precision is +/- 1KM. If you're doing an Uber-like service, knowing where a user is down to a few feet makes a different (which side of the street). But if you're just concerned with "Hey people nearby you are using this app too" (which is all too common).. Do you really need to know/save/keep where a user is beyond 1 sq km? No, you don't. Yes, Apple has a coarse data that does something like this, but take it that one step farther. Don't need the info? Don't collect it (your app doesn't need to send it) and don't store it.
- enw 6y ago
  > Instead of saying "896m", return "<1km" or "1km-3km" etc. Can you still abuse the data to some extent? Wouldn't eventually samples of arbitrary precision have their "range donuts" overlap heavily at the user's location? This could probably be automated to track in real-time someone's position.
  - KingMachiavelli 6y ago
    Yes, you just have to spoof locations near the boundaries of the quanta. If they are less than 1km then test locations until they are in the 1km-3km group but you will know they are actually 1km away. Repeat between 3 and a dozen times at different angles and you can still determine a location.
tzs 6y ago
Maybe this would be a little to confusing for users, but perhaps apps that have an option to publish your location should have an option to automatically disable location publishing when you are near home, or even better when you are near any location on a user-specified list of locations.
luxuryballs 6y ago
So wait by showing your location on the map you show your location on the map? Scandal.
solarkraft 6y ago
- Clickbait headline - Of course this shouldn't be possible, what is up with Telegram? At last make publishing your precise location optional (within that feature) with a good warning!
- EVa5I7bHFq9mnYK 6y ago
  But it is optional (you must press a button to enable it) and comes with a warning ...
nerdbaggy 6y ago
Triangulation is often used incorrectly instead of trilateration as in this article. Since the author is dealing with distances and not angles it’s trilateration. https://gis.stackexchange.com/questions/17344/differences-between-triangulation-and-trilateration https://gis.stackexchange.com/questions/17344/differences-be...
- sbodyiused2no 6y ago
  Exactly, it should be trilateration. This problem is a very old and known in many location-based apps, which has been reported years ago. https://www.wired.com/2016/05/grindr-promises-privacy-still-leaks-exact-location/ https://www.wired.com/2016/05/grindr-promises-privacy-still-... Gay Dating Apps Promise Privacy, But Leak Your Exact Location
RMPR 6y ago
Oddly enough, I don't see that feature in Telegram FOSS from F-Droid
- TheChaplain 6y ago
  Wild guess is because it could depend on Google Play services.
m2f2 6y ago
I've asked family to switch to Telegram because I didn't want Facebook to read my data. What shall I do then? Revert to WhatsApp, which I still have for those who can't be bothered by choosing a different tool?
- pdimitar 6y ago
  The described Telegram feature is strictly opt-in and it comes with a big warning before you enable it. It's a really low-quality article, pay no attention. The author is basically complaining that GPS works.
Donckele 6y ago
“Users in the People Nearby section” Is that everyone on telegram or just your “friends”?
- punnerud 6y ago
  Everyone on Telegram
  - ComodoHacker 6y ago
    Who have also opened People Nearby section and shared their location.
johnisgood 6y ago
Now that my phone supports it, I just installed Wire. I wish their desktop version had more options regarding appearance, for one. Honestly, it would not take much to implement giving us, users the choice to change a couple of things. I hate it how I cannot make the left bar less wide, for example, and there are a couple of more complains, all of which have been reported a long time ago. They are easy to add/fix! I also wish the desktop version supported sending audio messages just like the Android version does, similarly to WhatsApp. No need for these fancy audio filters, just let me record and send an audio message from the desktop version!
aaron695 6y ago
I can confirm on Android it does not warn you people will/could know your precise location in anyway. It implies it's only 'nearby' with a warning about people you don't know messaging you. Claims the app warns you or the user should know are either everything wrong with IT, or perhaps iOS is different.
diimdeep 6y ago
Please change title so that it reflects that shared location is only for those who explicitly enabled feature to do so and not implicitly that all users location is shared.
- capableweb 6y ago
  "Telegram publishes users' locations online only for those who explicitly enabled feature to do so and not implicitly that all users location is shared" is a bit long for a title. While you're right, the title is accurate although it comes with bunch of caveats of course, some of them outlined in the article. That's why we read the full article instead of just titles. More caveats are that they are using a smartphone, has GPS location on, are using Telegram, have allowed the app to access the location and finally shared their location in Telegram.
  - ffpip 6y ago
    "Telegram publishes users' locations online only for those who explicitly enabled feature " Why add more?
ffpip 6y ago
Clickbait. User explicitly shares location to all people nearby, discovers it is accessible to all people. Feature is disabled by default, and user must find this and enable it. They are not even prompted to enable it unless they seek it.
- deleted 6y ago
  [deleted]
- dafoex 6y ago
  They also say you need root to software spoof your location, but I thought you could do this without root using Mock Locations in developer options. I'm not sure if that's just an oversight, but it makes me think they aren't exactly familiar with Android as a whole.
  - budafish 6y ago
    Correct, spoofing can be done with the "FakeGPS Free" app and developer options. Or via an emulator.
    - maple3142 6y ago
      If you just want to spoof location, you only need to use the setting in developer options, but this is detectable by apps. For example, Ingress or Pokemon GO will refuse to work when it is enabled, so to actually spoof location on some apps, root is needed.
- koonsolo 6y ago
  Most users will not conclude from "sharing how nearby" people are, that someone could pinpoint exactly where they live by triangulating. Unless Telegram does some extra steps to prevent exact locations (see other threads here), they should name it "share my location" instead of "show nearby users".
  - wruza 6y ago
    Apparently that's what they do, at least on iOS: People nearby. Quickly add people nearby who are also viewing this section and discover local group chats. Please allow on location access to enable this feature. "Allow in settings" (a button) Then you see a system location access dialog. iOS allows to choose between (always, when in use, nope) and optionally to turn off "high precision" setting (not sure how much, but it covers entire city when off). Then you may tap another button named "Make myself visible". I didn't, but a list of nearby users/groups was populated regardless.
KLexpat 6y ago
This is less of an issue in highly dense urban areas, such as typical east-asian metropolises. If you live in a building with 2000 other people, it becomes less concerning. It seems like it would be rather easy to create an automated tool for triangulating users locations; by spoofing the GPS location of ones phone say 33 times, it should be very easy to triangulate every single person in the 'nearby' section.
tpoacher 6y ago
I discovered a bug too. If you ask a user to give you their location, this can be used to find out where they are!
spacemanmatt 6y ago
Signal puts your safety first because of the organization behind it. Telegram will continue to expose its most sensitive users over novel features while they try to capitalize on use of the Signal protocol. The profit motivation predicted this. Don't trust Telegram.
- anoncake 6y ago
  Telegram uses the Signal protocol? How do you propose Telegram give their users the ability to expose their location to other people without exposing their location to them?
  - spacemanmatt 6y ago
    How do you propose that users trust in their secure messaging app, when safety is the priority? Nothing stops you from putting your location into Telegram to send it. The issue is code that does it for you.
    - anoncake 6y ago
      The code is not an issue. Users shouldn't trust that their messaging app does not share their location when they ordered their messaging app to share their location, that makes no sense.
      - spacemanmatt 6y ago
        That completely misses the point that there are users for whom location sharing is a strict no-go. Having the feature exist to pose a risk of accidental enabling or default enabling could result in death.
        anoncake 6y ago
        That is not a reason to cripple the default client. Fortunately, unlike Signal and WhatsApp Telegram is not a walled garden and you can use a different client. There is no problem with location sharing being enabled by default because location sharing is not enabled by default.
sbodyiused2no 6y ago
This reminds me of a study done more than 5 years ago on this exact problem. https://www.wired.com/2016/05/grindr-promises-privacy-still-leaks-exact-location/ https://www.wired.com/2016/05/grindr-promises-privacy-still-... Gay Dating Apps Promise Privacy, But Leak Your Exact Location Researchers in Kyoto demonstrate for WIRED how they can precisely track the locations of people using Grindr, Hornet, and Jack'd despite features meant to hide them. The mentioned research paper is here: https://arxiv.org/pdf/1604.08235.pdf https://arxiv.org/pdf/1604.08235.pdf

488 points by Nullslash 6y ago

It’s a good first step but not enough. I was scammed a while back on Telegram and wish I had been able to also see the persons real identity to recover my money. Location is not enough to go on. Perhaps TG should publish an API to allow people to see any users government ID if they are scammed.

2Gkashmiri 6y ago
How can telegram give you government issued ID if it doesn't collect it ?
- Hnrobert42 6y ago
  I think they are being sarcastic.
  - gotem 6y ago
    Nope. I think they should probably ask for one at signup. Would also reduce their server load if people only used 1 account instead of making 2+
    - 2Gkashmiri 6y ago
      Yeah. Where I live people are already getting picked up for being in a WhatsApp group, for sharing something on WhatsApp or even being a WhatsApp group admin. Do you know how they are caught? Their phone number is kyc compliant so its a cake walk. While I use telegram, I use it to only communicate essential stuff with family. Same for signal and other stuff. Matrix is interesting as it does not require a phone number... To think a government ID card would be needed to talk to family....shudders
hombre_fatal 6y ago
This is like choosing to deal with cash and then complaining that you can't do a chargeback. You didn't learn your lesson. The lesson wasn't that Telegram should require a government ID (then nobody would use it much less the scammer who scammed you). The lesson was that you need to consider the impact of being scammed when you're open to using a channel with no recourse.

KingMachiavelli 6y ago

Telegram has so many anti features and dark patterns that I really wish it was less popular. I honestly use WhatsApp over Telegram because at least I know WhatsApp is insecure while people sometimes act like Telegram is a secure platform.

Hnrobert42 6y ago
I’ve heard other folks say WhatsApp is insecure. Do you (or anyone else) have specific examples or concerns?
- deleted 6y ago
  [deleted]
- marta_morena_9 6y ago
  Like... Facebook can read all your messages? The encryption only protects you from entities that are not Facebook. With that out of the door, it's not really worth it to even consider other angles of attack, since you now depend on the goodwill of a billion dollar company whose sole purpose and reason for existence is to extract and monetize your data. WhatsApp is a nice chat tool, but it's nothing you should ever use for secure communication. Sending a letter via mail is more safe.
  - srockets 6y ago
    If they can, then either Facebook boldly lied about implementing end-to-end encryption[0], or found significant attack against the Signal protocol, which is considered quite safe. They do have access to the metadata, i.e. whom you messaged and when. -- [0] https://techcrunch.com/2016/04/05/whatsapp-completes-end-to-end-encryption-rollout/ https://techcrunch.com/2016/04/05/whatsapp-completes-end-to-...
  - kolmogorov 6y ago
    that's incorrect. WhatsApp is end to end encrypted using the signal technology as confirmed by moxie. are you suggesting Facebook tricked the signal team into believing that WhatsApp is using end to end encryption when it isn't? a source: https://signal.org/blog/there-is-no-whatsapp-backdoor/ https://signal.org/blog/there-is-no-whatsapp-backdoor/

kop316 6y ago

Hmm...So I have Telegram installed via F-Droid (so presumably without Google Play Services). I do NOT have the "People Nearby" feature. I am curious if that means my location is not published?

lynndotpy 6y ago
It's under Hamburger Menu > Contacts > Find People Nearby. You do not need give access to Contacts, but you do need to give access to Location. Barring no exploits, you have to press "Make Myself Visible" and then confirm with a popup in order to share your location.
whomst 6y ago
I have Telegram on iOS and I can't find any People Nearby feature. It doesn't request the location permission according to Settings either.
- vengefulduck 6y ago
  It took me a while to find it on iOS, it’s under the contacts tab called “find people near by”. It doesn’t seem to work without location enabled so hopefully that would keep you safe.
  - dawnerd 6y ago
    Also doesn't work unless you share contacts - which .... why would you anyways?
    - TedDoesntTalk 6y ago
      People do that so they do not have to type by hand all their friends using the app. Granted, most people probably don’t have a lot of friends using Telegram... but that’s not what Telegram is hoping.
  - crispyambulance 6y ago
    Wow Telegram ¯_(ツ)_/¯ Most folks would be inclined to look under "Settings" rather than "Contacts" for something like this. How strange!

gruez 6y ago

>[Line] fixed it by adding a random number to the user's destination This is a imperfect solution. There's two possibilities: the offset (aka "random number") is dynamic, or it's fixed. If it's the former all you have to do is sample enough times to get through the noise. If it's the latter, it's not vulnerable to the previous attack, but if you have a known point of reference (so you can deduce what the offset is), then you can still stalk them (forever?). IMO the only way to do is "properly" is to quantize people into map cells, like how apple does it with their coarse location feature[1]. [1] "Apple doesn't reduce the accuracy of location fixes by adding noise. Instead, they've carved up the world into regions, allowing approximate locations to preserve the user's current city when possible." https://radar.io/blog/understanding-approximate-location-in-ios-14 https://radar.io/blog/understanding-approximate-location-in-...

kibwen 6y ago
> If it's the latter, it's not vulnerable to the previous attack, but if you have a known point of reference (so you can deduce what the offset is) It sounds like this approach could be prevented by having a random fixed offset for each user, so that you have no point of reference unless you already know where that specific user is. [Removed bit about regenerating this offset infrequently.] EDIT: You could even do this in conjunction with the quantization mitigation, which sounds like it would shore up the slight weaknesses with that approach (where being on a quantization boundary makes it obvious where you are in that dimension) for the best of both worlds, as long as you're okay with further decreasing accuracy.
- algesten 6y ago
  With enough data points you'd easily figure out that offset. Just overlay each data point with map data and decide whether the location makes sense. (i.e. you're unlikely to most of the time be in the middle of a lake, farm field etc)
  - deleted 6y ago
    [deleted]
  - 6y ago

arthurcolle 6y ago

It's a shame that people still use Telegram when Signal is so much better, and has better credentials all around.

est 6y ago
signal the protocol is (maybe) better, but the app is inferior. People like Telegram for their usability and security is just a bonus.
- blackfawn 6y ago
  I definitely agree with this. Getting people to use Telegram instead of SMS or other random chat apps can be difficult but getting them to switch to Signal is basically a "not going to happen" until Signal ups their usability. Even people I've gotten to try out Signal all abandoned it. At least with Telegram, they stuck with it and still use it to this day. It'd honestly probably be easier to get Telegram to adopt Signal's protocol than it would be to get users to adopt [current] Signal.
  - j-james 6y ago
    Telegram's protocol itself isn't necessarily a weakness - recently, a paper was published claiming to have proved the MTProto 2.0 protocol correct. Perhaps because of how recent this was, it doesn't seem to have garnered any discussion or review anywhere. https://arxiv.org/abs/2012.03141 https://arxiv.org/abs/2012.03141
    - blackfawn 6y ago
      My above post was more of a complaint of the Signal UX rather than a critique of either protocol but thanks for the link! I would be interested to hear whether people still perceive MTProto to have weakness... but that likely won't change with how much people seem to complain about it, seemingly without much/any rationale. Either way I'll probably still be using Telegram since that's where the users are :)
6y ago

ve55 6y ago

The ability to find user locations via triangulation is overlooked in a lot of products - it's easy to not think twice when showing a user the distance between themselves and someone else. In my own products I fix this by aggressively rounding/adding noise before the distance calculation is performed, and then rounding again afterwards, or quantizing into ranges (e.g. '0-10 miles'). Other solutions can be storing locations imprecisely to begin with, using pre-defined geobuckets, and so on, although remember that randomness by itself can be bypassed with enough queries since it will average out. It's rare that you need to know exactly how far away someone is from you rather than a rough approximation. Telegram is definitely not the only product with this issue, but hopefully they fix it even so.

ROARosen 6y ago
Doesn't this triangulation assume the other user is in one location the entire time of manually going to these places to triangulate them?
- peteretep 6y ago
  You don’t need to go to a location to tell an app you’re in that location and want to know the distance to your target.
- hombre_fatal 6y ago
  It's not much of an assumption. People go the same places every day (work, cafe) and then go to the same home to sleep in the same bed.
- taneq 6y ago
  It does, but you can keep trying until you get an accurate location. In the simplest version you can just watch the distance and play warmer/colder until you physically track them down.
dheera 6y ago
Quantizing is much safer. Adding random noise is useless because one can just average multiple samples. If you want to be extra safe, quantize the user's lat/lon before computing the distance, and then quantize the distance again. (Quantizing only the distance can theoretically allow an attacker to travel in one direction until they see the transition from one bucket to the other which would tell them exactly when they are precisely 10 miles from the target.)

zeronine 6y ago

> If this feature is enabled on your phone, you're publishing your home address online. Depending on your definition of 'online' this is true of any app you use. Telegram could at least take a similar approach to Tinder, who have already learnt from a similar mistake.

j-james 6y ago
Here's an overview of the system Tinder currently uses, after their 2014 privacy fiascos: https://robertheaton.com/2018/07/09/how-tinder-keeps-your-location-a-bit-private/ https://robertheaton.com/2018/07/09/how-tinder-keeps-your-lo...

kelt 6y ago

After going into the 'People nearby' I do not see any option to disable. I do see 'Make myself visible' option and a list of nearby users. (on iPhone) I wonder if this will be sufficient?

Nullslash 6y ago
Your location will be shared on the map if you make yourself visible. Otherwise, you're safe. Disable location sharing for the whole app.

mercora 6y ago

so i know some people around me who are using telegram and very likely most of them did not change anything about their privacy settings as usual. However, i do not see any of them in the list and it even shows me users some 10km away. When viewing this list on the top it has a button to make yourself visible so i assume if you don't do it voluntarily its not broadcasted at all which appears to be a non issue then, like he was already told.

dawnerd 6y ago
Yeah its very much opt in so Im not sure what the real issue is apart from being somewhat granular. How granular telegram makes it is the question. From the article the way they asked didn't sound like it was "do you live at 123 something st" but instead are you by, which even if you were a few blocks off someone might say yes. For all we know Telegram is doing some rounding. Gonna need to test some more to see I guess.
- meowface 6y ago
  If they don't want to fix this issue (maybe they find it's advantageous to let benign users find each other precisely), some kind of warning when you opt-in like "Warning: By enabling this setting, anyone around the world may be able to determine your location, such as your home address, even if they live in a different region or country." would be nice. Not sure of the best way to word it, but making it clear that someone in a different continent may be able to see your location and address would at least make the full implications clear. Most users probably assume the risk is limited to people in their city (or a smaller area within it) seeing their location, and also may not necessarily be thinking about the address disclosure (even if that's arguably already obvious to some).

gaudat 6y ago

On the "People Nearby" page in the Telegram app it specifically says Quickly add people nearby who are also viewing this section ... If a user is not specifically on that page, they are not listed in the section. The user most likely wants the world (or strangers) to know his position. This case shows precise localization can be a double-edge sword. But instead of fuzzing the returned location, we should educate the people on privacy implications of showing their position to the public.

rkoten 6y ago
> If a user is not specifically on that page, they are not listed in the section. I'm consistently seeing some of the people nearby across multiple times opening the page, some of which weeks apart.

3PercentMan 6y ago

So in the article, the author was able to find the x- and y- coordinates of the other user. What if the target user lives in a high rise building, is there any technique you can get the height of the said user? Makes me wonder how the law enforcement is able to tri-angulate the suspect's exact location.

rkoten 6y ago
My somewhat educated guess would be that, firstly, cell tower triangulation includes altitude by necessity of measuring directly the reach of electromagnetic waves, whereas Telegram advertises the subset of users' GPS data that they choose to advertise, which is likely just lat-long. Secondly, law enforcement also likely has the cooperation of the administration of said high-rise building.
- swiley 6y ago
  That's going to be pretty distorted (likely uselessly so) in a highrise unless you're connecting to the "femto cells" (I think?)
Nullslash 6y ago
Author here. No, that is called z-coordinate. It's not possible to get z-coordinate by just finding the distance between me and the user.
taneq 6y ago
You can certainly triangulate in three dimensions, IF the distance displayed is the 3-dimensional distance rather than just the distance between two lat/long locations. You just need to sample an additional point that's not collinear with the first two.

nnx 6y ago

iOS recently introduced per-app “Precise Location” toggle in Settings. Turning this toggle off is a great mitigation for apps who haven’t fixed or clarified how they handle such triangulation attacks.

shp0ngle 6y ago

I used the "people nearby" feature once, and I kept getting random messages from random people 2 months later. I could not figure out how the hell to turn it off.

nguyenkien 6y ago
Android: Go back to people nearby, click "Stop showing me"
- shp0ngle 6y ago
  ...oh. OK.

isodev 6y ago

A user does not show up in “People nearby” unless they enable the function. Doing so triggers a warning from Telegram informing you your location is about to be published and it may lead to undesired attention so it really can’t happen by accident. I’m also using the app on iOS, the operating system asks periodically if I want to continue sharing location in the background (in case I forget to turn it off) or I can just choose to enable it while using the app (which is what I usually do).

taneq 6y ago
Yeah, it seems pretty explicit that you're making your location public when you press this button. I'd say the 'bug' is in people not realising that pushing their location to a 'show users near me' function inherently reveals their location to some degree of accuracy.
- eznzt 6y ago
  This is the exact message: https://i.imgur.com/PDnMmQV.png https://i.imgur.com/PDnMmQV.png -- Additionally, iOS allows you to make your location imprecise on purpose. This is a non-issue, this guy "Ahmed" is just fishing for attention with an incendiary title.
  - justcool393 6y ago
    yeah, I would definitely say that that's fine. like, if it were some dark pattern or unknown or something then whatever, but it's pretty explicit
Nullslash 6y ago
it's a privacy issue. Users who enable the feature don't understand that are basically publishing thier latitude longitude online. Which can be resolved into a home address.
- krbzsq 6y ago
  Blanket stating that users don't understand is pretty dismissive and frankly quite patronising. I'm a big privacy advocate, so I don't personally like volunteering location info, but personally know lots of people who will happily do so for all sorts of reasons (e.g. seeing each other on snapchat maps), they understand what they're doing. Simple fact is, plenty of people just _don't care_ and that is their right to do so.

aportnoy 6y ago

You might want to change the title to something not as clickbaity and misleading.

ShakataGaNai 6y ago

More systems need to truncate location data. It is relatively "easy" to solve this particular issue by just not returning highly specific data. Instead of saying "896m", return "<1km" or "1km-3km" etc. Can you still abuse the data to some extent? Yes in theory, but it's significantly harder and takes a lot more work to get anything reasonable. You can also truncate the data you have on users. 2 digits of Decimal_degrees precision is +/- 1KM. If you're doing an Uber-like service, knowing where a user is down to a few feet makes a different (which side of the street). But if you're just concerned with "Hey people nearby you are using this app too" (which is all too common).. Do you really need to know/save/keep where a user is beyond 1 sq km? No, you don't. Yes, Apple has a coarse data that does something like this, but take it that one step farther. Don't need the info? Don't collect it (your app doesn't need to send it) and don't store it.

enw 6y ago
> Instead of saying "896m", return "<1km" or "1km-3km" etc. Can you still abuse the data to some extent? Wouldn't eventually samples of arbitrary precision have their "range donuts" overlap heavily at the user's location? This could probably be automated to track in real-time someone's position.
- KingMachiavelli 6y ago
  Yes, you just have to spoof locations near the boundaries of the quanta. If they are less than 1km then test locations until they are in the 1km-3km group but you will know they are actually 1km away. Repeat between 3 and a dozen times at different angles and you can still determine a location.

tzs 6y ago

Maybe this would be a little to confusing for users, but perhaps apps that have an option to publish your location should have an option to automatically disable location publishing when you are near home, or even better when you are near any location on a user-specified list of locations.

luxuryballs 6y ago

So wait by showing your location on the map you show your location on the map? Scandal.

solarkraft 6y ago

- Clickbait headline - Of course this shouldn't be possible, what is up with Telegram? At last make publishing your precise location optional (within that feature) with a good warning!

EVa5I7bHFq9mnYK 6y ago
But it is optional (you must press a button to enable it) and comes with a warning ...

nerdbaggy 6y ago

Triangulation is often used incorrectly instead of trilateration as in this article. Since the author is dealing with distances and not angles it’s trilateration. https://gis.stackexchange.com/questions/17344/differences-between-triangulation-and-trilateration https://gis.stackexchange.com/questions/17344/differences-be...

sbodyiused2no 6y ago
Exactly, it should be trilateration. This problem is a very old and known in many location-based apps, which has been reported years ago. https://www.wired.com/2016/05/grindr-promises-privacy-still-leaks-exact-location/ https://www.wired.com/2016/05/grindr-promises-privacy-still-... Gay Dating Apps Promise Privacy, But Leak Your Exact Location

RMPR 6y ago

Oddly enough, I don't see that feature in Telegram FOSS from F-Droid

TheChaplain 6y ago
Wild guess is because it could depend on Google Play services.

m2f2 6y ago

I've asked family to switch to Telegram because I didn't want Facebook to read my data. What shall I do then? Revert to WhatsApp, which I still have for those who can't be bothered by choosing a different tool?

pdimitar 6y ago
The described Telegram feature is strictly opt-in and it comes with a big warning before you enable it. It's a really low-quality article, pay no attention. The author is basically complaining that GPS works.

Donckele 6y ago

“Users in the People Nearby section” Is that everyone on telegram or just your “friends”?

punnerud 6y ago
Everyone on Telegram
- ComodoHacker 6y ago
  Who have also opened People Nearby section and shared their location.

johnisgood 6y ago

Now that my phone supports it, I just installed Wire. I wish their desktop version had more options regarding appearance, for one. Honestly, it would not take much to implement giving us, users the choice to change a couple of things. I hate it how I cannot make the left bar less wide, for example, and there are a couple of more complains, all of which have been reported a long time ago. They are easy to add/fix! I also wish the desktop version supported sending audio messages just like the Android version does, similarly to WhatsApp. No need for these fancy audio filters, just let me record and send an audio message from the desktop version!

aaron695 6y ago

I can confirm on Android it does not warn you people will/could know your precise location in anyway. It implies it's only 'nearby' with a warning about people you don't know messaging you. Claims the app warns you or the user should know are either everything wrong with IT, or perhaps iOS is different.

diimdeep 6y ago

Please change title so that it reflects that shared location is only for those who explicitly enabled feature to do so and not implicitly that all users location is shared.

capableweb 6y ago
"Telegram publishes users' locations online only for those who explicitly enabled feature to do so and not implicitly that all users location is shared" is a bit long for a title. While you're right, the title is accurate although it comes with bunch of caveats of course, some of them outlined in the article. That's why we read the full article instead of just titles. More caveats are that they are using a smartphone, has GPS location on, are using Telegram, have allowed the app to access the location and finally shared their location in Telegram.
- ffpip 6y ago
  "Telegram publishes users' locations online only for those who explicitly enabled feature " Why add more?

ffpip 6y ago

Clickbait. User explicitly shares location to all people nearby, discovers it is accessible to all people. Feature is disabled by default, and user must find this and enable it. They are not even prompted to enable it unless they seek it.

deleted 6y ago
[deleted]
dafoex 6y ago
They also say you need root to software spoof your location, but I thought you could do this without root using Mock Locations in developer options. I'm not sure if that's just an oversight, but it makes me think they aren't exactly familiar with Android as a whole.
- budafish 6y ago
  Correct, spoofing can be done with the "FakeGPS Free" app and developer options. Or via an emulator.
  - maple3142 6y ago
    If you just want to spoof location, you only need to use the setting in developer options, but this is detectable by apps. For example, Ingress or Pokemon GO will refuse to work when it is enabled, so to actually spoof location on some apps, root is needed.
koonsolo 6y ago
Most users will not conclude from "sharing how nearby" people are, that someone could pinpoint exactly where they live by triangulating. Unless Telegram does some extra steps to prevent exact locations (see other threads here), they should name it "share my location" instead of "show nearby users".
- wruza 6y ago
  Apparently that's what they do, at least on iOS: People nearby. Quickly add people nearby who are also viewing this section and discover local group chats. Please allow on location access to enable this feature. "Allow in settings" (a button) Then you see a system location access dialog. iOS allows to choose between (always, when in use, nope) and optionally to turn off "high precision" setting (not sure how much, but it covers entire city when off). Then you may tap another button named "Make myself visible". I didn't, but a list of nearby users/groups was populated regardless.

KLexpat 6y ago

This is less of an issue in highly dense urban areas, such as typical east-asian metropolises. If you live in a building with 2000 other people, it becomes less concerning. It seems like it would be rather easy to create an automated tool for triangulating users locations; by spoofing the GPS location of ones phone say 33 times, it should be very easy to triangulate every single person in the 'nearby' section.

tpoacher 6y ago

I discovered a bug too. If you ask a user to give you their location, this can be used to find out where they are!

spacemanmatt 6y ago

Signal puts your safety first because of the organization behind it. Telegram will continue to expose its most sensitive users over novel features while they try to capitalize on use of the Signal protocol. The profit motivation predicted this. Don't trust Telegram.

anoncake 6y ago
Telegram uses the Signal protocol? How do you propose Telegram give their users the ability to expose their location to other people without exposing their location to them?
- spacemanmatt 6y ago
  How do you propose that users trust in their secure messaging app, when safety is the priority? Nothing stops you from putting your location into Telegram to send it. The issue is code that does it for you.
  - anoncake 6y ago
    The code is not an issue. Users shouldn't trust that their messaging app does not share their location when they ordered their messaging app to share their location, that makes no sense.
    - spacemanmatt 6y ago
      That completely misses the point that there are users for whom location sharing is a strict no-go. Having the feature exist to pose a risk of accidental enabling or default enabling could result in death.
      - anoncake 6y ago
        That is not a reason to cripple the default client. Fortunately, unlike Signal and WhatsApp Telegram is not a walled garden and you can use a different client. There is no problem with location sharing being enabled by default because location sharing is not enabled by default.

sbodyiused2no 6y ago

This reminds me of a study done more than 5 years ago on this exact problem. https://www.wired.com/2016/05/grindr-promises-privacy-still-leaks-exact-location/ https://www.wired.com/2016/05/grindr-promises-privacy-still-... Gay Dating Apps Promise Privacy, But Leak Your Exact Location Researchers in Kyoto demonstrate for WIRED how they can precisely track the locations of people using Grindr, Hornet, and Jack'd despite features meant to hide them. The mentioned research paper is here: https://arxiv.org/pdf/1604.08235.pdf https://arxiv.org/pdf/1604.08235.pdf