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The biggest drawback with Signal for protesters is that it exposes the user's phone number to everyone else in groups (just like WhatsApp does). There is no way

by AnonC 6y ago

The biggest drawback with Signal for protesters is that it exposes the user's phone number to everyone else in groups (just like WhatsApp does). There is no way to even hide the fact that you have an account on Signal. I can add phone numbers by enumeration into my contacts and Signal will show who among my contacts is on it. If the authorities don't use tactics like they did in Hong Kong, the protesters may be safe from being spied on (or worse).

hjek 6y ago
Signal is not only used by protesters[0][1] so discovering that a phone number is connected to a Signal account by no means implies that the phone is used by a protester. [0]: https://www.militarytimes.com/flashpoints/2020/01/23/deployed-82nd-airborne-unit-told-to-use-these-encrypted-messaging-apps-on-government-cellphones/ https://www.militarytimes.com/flashpoints/2020/01/23/deploye... [1]: https://www.theguardian.com/politics/2019/dec/17/tories-switch-to-messaging-app-signal-to-curb-whatsapp-leaks https://www.theguardian.com/politics/2019/dec/17/tories-swit...
- m12k 6y ago
  Yeah, if you're ever asked why you're on Signal, just say you wanted to stay in touch with a programmer friend who's not on Facebook/WhatsApp, and they suggested Signal (that is now literally true as well - I suggest you try Signal, friend)
  - pwdisswordfish2 6y ago
    Couldn't you just say "I really like the user interface." Or "The logo looks cool." Or "It had 4 stars." Of "It had lots of good reviews."
    - Blaiz0r 6y ago
      no one would believe you...
      - mkup 6y ago
        How does that matter? You have the right to install any apps you want, and wacky questions deserve wacky answers.
        filleduchaos 6y ago
        How does that matter? Perhaps due to the potential scenario in question being interrogation by law enforcement that doesn't have your best interests at heart, not "who has the better witty retort to score points online?".
    - Hamuko 6y ago
      I mean, I don't get why it has to get any more complicated than "I have friends that use it". That's the main reason for having any messaging app.
    - izacus 6y ago
      And the cop will say "I don't believe you you terrorist" and lock you up until you say something else. This has happened time and time again, including in the latest Hong Kong protests, on American border interrogations and it will happen in these US protests as well. Once you're on the list of suspects from someone elses Signal chat, you're not going to persuade a suspicious official by bullshitting.
      - computerfriend 6y ago
        Do you have a source for the claim that this has happened at protests in Hong Kong? I haven't heard of anyone being arrested here on the basis that they had Signal installed.
        izacus 6y ago
        They got arrested by association. Signal chat group is such an association, just like other chat groups are. Except that Signal guarantees to give out your phone number (and by extension location and personal address) to every single person in a chat group. There have been lynchings in India based on this kind of data leaked by WhatsApp which resulted in them finally allowing joining groups anonymously.
        deadwing0 6y ago
        Do you have a source for this?
    - thinkingemote 6y ago
      Rubbing ones hands together to stave off the chilling effect.
    - pwdisswordfish2 6y ago
      How about "I searched for the term "private messaging" in Google Play Store database and Signal was the top result." https://play.google.com/store/search?q=private+messaging https://play.google.com/store/search?q=private+messaging
  - kilroy_jones 6y ago
    No need to say anything really.
  - Silhouette 6y ago
    FWIW, many of my friends actually could say this, for I am a programmer who's not on Facebook/WhatsApp and recommends Signal. It definitely needs to be more reliable, though. The last time I tried to call someone with Signal instead of just using it for messaging, I got a ringing indication but they heard nothing and then after a few seconds the call showed up as missed, and the same happened the other way around with them calling me. There seem to have been about 500 updates to the iOS app in the past 5 minutes via the app store, though, so many whatever caused that was a short-lived glitch.
    - sadfklsjlkjwt 6y ago
      This is not unique to Signal though. I've had this happen with WhatsApp about 1-2% of the times I've tried to place a call in the last few months
    - spockz 6y ago
      I’ve had this happen with normal carrier phone calls as well so it appears till be nothing special. Maybe there should be a different tone for “finding device(s) to ring” and “ringing device”.
  - jrochkind1 6y ago
    If the law enforcement is talking to you in the U.S., the only right answer is "I'd prefer to have a laywer here." Not a joke, for real. They are experts at getting you to talk to them even if you know this. They are experts at getting you to say things that incriminate you or your friends -- that you or your friends have done nothing wrong (in your opinion/as far as you know) will not protect you. The only answers you should be rehearsing or thinking of in advance are "I would like a lawyer" and "I would like to remain silent." They are rehearsing how to get you to say incriminating things, a lot. Rehearsing or thinking up any other answers only plays into their strengths. Even knowing this, I've been tricked into talking to them, to my detriment. They are really good at it.
    - vincentmarle 6y ago
      I’ve heard this before but here’s my practical problem: I don’t know any lawyers. I have literally no idea who to call in such a situation. Do I have to go find and retain a lawyer beforehand just in case I might need one later?
      - dfxm12 6y ago
        In the case you get arrested, you'll be made aware that if you don't have a lawyer, one will be appointed to you. If you're not arrested, you should be able to just leave the interrogation (emphasis on should, of course).
      - Loughla 6y ago
        It's not a bad idea to have a relationship with a lawyer. Talk to family/friends/co-workers. Somebody will have a name for you. We made a relationship with one I found through family via estate planning (not his specialty) and land deals (not his specialty). Now I have a name to say out loud when I interact with police. This has happened twice. The OP is right, they'll do everything they can to get you to talk, but understand that if a police officer is talking to you, they're digging for information to incriminate you. In my case, I was a witness to something, and they cuffed me and made me sit on the curb. No possible way I could've needed to be cuffed and questioned. And that was the approach my lawyer took when he came. Best $100 I ever spent.
  - lozf 6y ago
    Thanks! Just gonna need your phone number (for plausible deinabality) ;) ... And just hope there are no records that I've been using it since the days when it was 2 apps,- Red Phone & TextSecure, before becoming Signal.
  - ssully 6y ago
    I got a group of friends to use Signal because of the following: 1. Sharing videos/pictures/memes is terrible in an SMS group chat 2. One person in the group has bad cell service, so we needed something that would send messages over Wifi 3. Half the people are on Android, so no iMessage 4. 1/4 of the people aren't on Facebook, so no messenger I was the one who suggested Signal. I did so because I like the end to end encryption, but that was not a selling point for anyone else. They just cared that it solved the problems above.
  - antisocial 6y ago
    I want to emphasize that DeleteWhatsapp, DeleteInstagram should trend equally with DeleteFacebook.
- Vinnl 6y ago
  In fact, that's the main reason I'm using it, and the main counter-argument to 'I've got nothing to hide', IMHO. Sure I don't, but there are plenty of people who justifiably do.
  - moksly 6y ago
    I have nothing to hide, but I have nothing I want you to see either.
    - nix23 6y ago
      I have something to hide...it's called privacy.
- soziawa 6y ago
  The point made by the parent commenter was that you can join any group (if you get someone to invite you) related to a certain topic and get the phone numbers of everyone in that group. I am not sure about the situation in the US, but in Europe almost all phone numbers are directly linked to a certain person and address by the provider.
  - hjek 6y ago
    > The point One of the points which, yes, I agree with, but I mainly responded to this: > I can add phone numbers by enumeration into my contacts and Signal will show who among my contacts is on it.\ > I am not sure about the situation in the US, but in Europe almost all phone numbers are directly linked to a certain person and address by the provider. Or you can go to a corner shop and buy a Lyca or Lebara SIM with cash. No need to give them your address. You can buy top ups in cash as well. At least in Western Europe this is available everywhere, pretty much. (I'd still prefer if Signal didn't require phone number to sign up though.)
    - sadfklsjlkjwt 6y ago
      > Or you can go to a corner shop and buy a Lyca or Lebara SIM with cash. No need to give them your address. You can buy top ups in cash as well. At least in Western Europe this is available everywhere, pretty much. This is not legal in Norway.
      - jhauris 6y ago
        There are many countries it isn't legal in, which is a shame. The ability to get an anonymous phone ought to be something people care about preserving.
        ubercow13 6y ago
        It's illegal in the vast majority of countries [1] including Germany, France. Attempting to build a safe secure communication system around phone numbers that is suitable for situations like this, relying on them as being somehow anonymous, is just a complete non-starter. Even if you don't have to register the phone number, the cell provider will still know your location history. I think it just shows how America-centric Signal is. [1] https://privacyinternational.org/long-read/3018/timeline-sim-card-registration-laws https://privacyinternational.org/long-read/3018/timeline-sim...
- unicornporn 6y ago
  That doesn't change the fact that all phone numbers are visible to all group members. All it takes is one rogue participant to reveal the identities of all members. If that actor has access to triangulation data they now have identity, location history, words and possibly images/video.
  - m12k 6y ago
    Yeah, it's optimized for communication between trusted parties (e.g. Snowden and a journalist) - as such the focus is on verifying the identity of the other person, not hiding it. It'd be cool if they figured out a group chat setting that was optimized for groups like protesters trying to coordinate - show your identity only to users you are directly connected with/have verified/whitelisted, but hide your identity to everyone else.
    - cyphar 6y ago
      Except the whole point of OTR-like messaging was that you can communicate with someone who you can't be entirely sure you trust in perpetuity (that's why messages in Signal and similar systems don't have non-repudiation -- neither party can prove to a third party that a message really was sent by the other party). Now, obviously the metadata worry is separate to how the message cryptography is implemented but it does seem odd to have a threat model which is somewhat confused on this question.
      - nix23 6y ago
        But with signal you can verify that person, its like the opposite of otr. https://signal.org/blog/safety-number-updates/ https://signal.org/blog/safety-number-updates/
        cyphar 6y ago
        OTR also allows you to do key verification -- all encrypted chat systems support that. The point isn't that you cannot be sure who you're talking to, the point is that the communication transcript cannot be provided to a third party as evidence that either party in the conversation said something. This is fairly simply implemented in OTR. Rather than signing the message with an asymmetric keypair (as you would with PGP), you sign it with a HMAC. Thus both the sender and recipient could create a valid message from the sender (giving you the property that only the two people in the conversation can be sure what was actually said by the other party, without being able to prove it to a third party cryptographically).
- sorenjan 6y ago
  The issue isn't somebody proving you have a Signal account, the issue is somebody identifying members in a specific group used to communicate about a protest. That way a state actor can find the phone number of a key organizer, persuade their phone provider to share their location, and take them out. Here's a description of how it worked in Telegram before they added a setting to disable it last year: https://medium.com/adamant-im/telegrams-anonymity-hole-how-to-get-any-user-s-phone-number-88062b4fb94b https://medium.com/adamant-im/telegrams-anonymity-hole-how-t...
fossuser 6y ago
This tradeoff is arguably a good thing. By using phone numbers as IDs signal can rely on your phone's local contacts (meaning they don't have to send your social graph to their servers). This way they can keep very little metadata on you. There's pretty much nothing for them to turn over except the fact that your phone number has the signal app. Most of the other secure apps could turn over your entire contact list (which could be damaging for people in a protest that are being targeted). Confirming a single phone number has the app is not nearly as big of a deal (I'd argue it doesn't matter at all).
- Legogris 6y ago
  I've lost track of the number of times I've had this conversation but here we go: There's nothing inherent in phone numbers here. Both iOS and Android also allows you to add e-mail addresses (and other identifiers) to your local contacts. I'm yet to hear an argument as to why e-mail addresses or other identifiers can't be used in addition to phone numbers, or why it would be a complicating factor.
  - fossuser 6y ago
    My guess would be that phone numbers are guaranteed to be unique IDs that (almost) every phone will have which simplifies things and reduces the risk of someone impersonating someone else. I think they are working on non-phone number IDs though (Moxie was in an earlier signal thread on HN recently and mentioned it).
    - mikekchar 6y ago
      There is an issue on Github that is collating the problems they are working through. I've lost track of it, though, unfortunately. I've been pretty cynical about it in the past, but the last time I looked at the issue, it does look more complex than I first imagined. I wish it were higher priority, though. Hopefully somebody will remember the issue and post it here (it was from an HN post that I found it originally). Unfortunately, I'm not even sure what project it's under and there are many projects.
    - 6y ago
GlitchMr 6y ago
If that helps, there is a rate limit for checking whether a number is in Signal: with a single account, you can only check 4320 phone numbers a day. This makes mass user enumeration attacks somewhat less practical.
- ves 6y ago
  isn’t getting your hands on lots of sims/phone numbers, and thus Signal accounts, pretty trivial, though?
  - numpad0 6y ago
    Trivial as ordering a 2U 16 blade GSM modem array from AliExpress, sure
znpy 6y ago
Eh, you can't have everything. Still, having a signal account doesn't make you a chargeable protester more than owning a gun makes you a chargeable assassin.
- DyslexicAtheist 6y ago
  > Eh, you can't have everything. why not? Wire[1] doesn't tie your identity to your phone number. OpenWhisper devs too are aware of Signal's limitation (it was even discussed here on HN recently). [1] https://github.com/wireapp https://github.com/wireapp
kabacha 6y ago
Using phone number as ID has been proven idiotic since forever now. As much as I like Signal this is such a design flaw that it makes their software not only untrustable but often unusable too. What's wrong with email logins?
- siberianbear 6y ago
  I'm no expert on the subject, but probably the use of phone numbers (and confirmation by SMS) is helpful to limit the number of bots.
  - maxerickson 6y ago
    Phone numbers are used for contact discovery. https://signal.org/blog/private-contact-discovery/ https://signal.org/blog/private-contact-discovery/
  - noir_lord 6y ago
    Signal could still validate the phone number via SMS and immediately discard it afterwards. Personally I liked the way ICQ did it back in the day, they used a uniq ID just for their service decoupling it from a phone number. If Signal wanted to avoid long numbers, they could use a CorrectBatteryHorseStaple approach which is what Xbox does for their usernames if you don't pick one. Easier to remember,
sorenjan 6y ago
This was allegedly used by the authorities in Hong Kong during protests there in 2019, but using Telegram. Telegram responded by introducing a new setting that hides your number from people that aren't in your own contacts. https://telegram.org/blog/scheduled-reminders-themes#new-privacy-settings https://telegram.org/blog/scheduled-reminders-themes#new-pri...
- romanr 6y ago
  Telegram indeed have better UX and same level of e2e security. Why Signal is getting all the publicity?
  - nix23 6y ago
    Telegram is not opensource, Signal is...and yes you can setup your own server with Signal. Why trust a Closed-source-Software? Do you even know that it is encrypted?
    - fsflover 6y ago
      You can setup your own server with Signal, but you will not participate in the same network, so this is not really relevant.
      - nix23 6y ago
        For Country's or big-business it is relevant
    - sorenjan 6y ago
      https://github.com/DrKLO/Telegram https://github.com/DrKLO/Telegram https://github.com/telegramdesktop/tdesktop https://github.com/telegramdesktop/tdesktop
      - nix23 6y ago
        THAT is not the server, its like saying Firefox is opensource so Facebook is too, thanks and no thanks for the link's.
josefresco 6y ago
Step 1: Get a virtual phone number. Step 2: Get Signal and register using virtual phone number. Step 3: Protest!
- app4soft 6y ago
  Step 0: Use off-the-grid network. [0] https://apt.izzysoft.de/fdroid/index/apk/tk.giesecke.disaster_radio?repo=main https://apt.izzysoft.de/fdroid/index/apk/tk.giesecke.disaste...
lobster45 6y ago
What about Telegram?
md8 6y ago
Session is built to fix this problem https://getsession.org/ https://getsession.org/ It does not require a number to setup an account and communicate.
deleted 6y ago
[deleted]
Sami_Lehtinen 6y ago
Late post, but I'm just wondering why nobody has mentioned Briar Project. I think it's designed to remedy some of the issues mentioned here: https://briarproject.org/ https://briarproject.org/

by AnonC 6y ago

hjek 6y ago

Signal is not only used by protesters[0][1] so discovering that a phone number is connected to a Signal account by no means implies that the phone is used by a protester. [0]: https://www.militarytimes.com/flashpoints/2020/01/23/deployed-82nd-airborne-unit-told-to-use-these-encrypted-messaging-apps-on-government-cellphones/ https://www.militarytimes.com/flashpoints/2020/01/23/deploye... [1]: https://www.theguardian.com/politics/2019/dec/17/tories-switch-to-messaging-app-signal-to-curb-whatsapp-leaks https://www.theguardian.com/politics/2019/dec/17/tories-swit...

m12k 6y ago
Yeah, if you're ever asked why you're on Signal, just say you wanted to stay in touch with a programmer friend who's not on Facebook/WhatsApp, and they suggested Signal (that is now literally true as well - I suggest you try Signal, friend)
- pwdisswordfish2 6y ago
  Couldn't you just say "I really like the user interface." Or "The logo looks cool." Or "It had 4 stars." Of "It had lots of good reviews."
  - Blaiz0r 6y ago
    no one would believe you...
    - mkup 6y ago
      How does that matter? You have the right to install any apps you want, and wacky questions deserve wacky answers.
      - filleduchaos 6y ago
        How does that matter? Perhaps due to the potential scenario in question being interrogation by law enforcement that doesn't have your best interests at heart, not "who has the better witty retort to score points online?".
  - Hamuko 6y ago
    I mean, I don't get why it has to get any more complicated than "I have friends that use it". That's the main reason for having any messaging app.
  - izacus 6y ago
    And the cop will say "I don't believe you you terrorist" and lock you up until you say something else. This has happened time and time again, including in the latest Hong Kong protests, on American border interrogations and it will happen in these US protests as well. Once you're on the list of suspects from someone elses Signal chat, you're not going to persuade a suspicious official by bullshitting.
    - computerfriend 6y ago
      Do you have a source for the claim that this has happened at protests in Hong Kong? I haven't heard of anyone being arrested here on the basis that they had Signal installed.
      - izacus 6y ago
        They got arrested by association. Signal chat group is such an association, just like other chat groups are. Except that Signal guarantees to give out your phone number (and by extension location and personal address) to every single person in a chat group. There have been lynchings in India based on this kind of data leaked by WhatsApp which resulted in them finally allowing joining groups anonymously.
        deadwing0 6y ago
        Do you have a source for this?
  - thinkingemote 6y ago
    Rubbing ones hands together to stave off the chilling effect.
  - pwdisswordfish2 6y ago
    How about "I searched for the term "private messaging" in Google Play Store database and Signal was the top result." https://play.google.com/store/search?q=private+messaging https://play.google.com/store/search?q=private+messaging
- kilroy_jones 6y ago
  No need to say anything really.
- Silhouette 6y ago
  FWIW, many of my friends actually could say this, for I am a programmer who's not on Facebook/WhatsApp and recommends Signal. It definitely needs to be more reliable, though. The last time I tried to call someone with Signal instead of just using it for messaging, I got a ringing indication but they heard nothing and then after a few seconds the call showed up as missed, and the same happened the other way around with them calling me. There seem to have been about 500 updates to the iOS app in the past 5 minutes via the app store, though, so many whatever caused that was a short-lived glitch.
  - sadfklsjlkjwt 6y ago
    This is not unique to Signal though. I've had this happen with WhatsApp about 1-2% of the times I've tried to place a call in the last few months
  - spockz 6y ago
    I’ve had this happen with normal carrier phone calls as well so it appears till be nothing special. Maybe there should be a different tone for “finding device(s) to ring” and “ringing device”.
- jrochkind1 6y ago
  If the law enforcement is talking to you in the U.S., the only right answer is "I'd prefer to have a laywer here." Not a joke, for real. They are experts at getting you to talk to them even if you know this. They are experts at getting you to say things that incriminate you or your friends -- that you or your friends have done nothing wrong (in your opinion/as far as you know) will not protect you. The only answers you should be rehearsing or thinking of in advance are "I would like a lawyer" and "I would like to remain silent." They are rehearsing how to get you to say incriminating things, a lot. Rehearsing or thinking up any other answers only plays into their strengths. Even knowing this, I've been tricked into talking to them, to my detriment. They are really good at it.
  - vincentmarle 6y ago
    I’ve heard this before but here’s my practical problem: I don’t know any lawyers. I have literally no idea who to call in such a situation. Do I have to go find and retain a lawyer beforehand just in case I might need one later?
    - dfxm12 6y ago
      In the case you get arrested, you'll be made aware that if you don't have a lawyer, one will be appointed to you. If you're not arrested, you should be able to just leave the interrogation (emphasis on should, of course).
    - Loughla 6y ago
      It's not a bad idea to have a relationship with a lawyer. Talk to family/friends/co-workers. Somebody will have a name for you. We made a relationship with one I found through family via estate planning (not his specialty) and land deals (not his specialty). Now I have a name to say out loud when I interact with police. This has happened twice. The OP is right, they'll do everything they can to get you to talk, but understand that if a police officer is talking to you, they're digging for information to incriminate you. In my case, I was a witness to something, and they cuffed me and made me sit on the curb. No possible way I could've needed to be cuffed and questioned. And that was the approach my lawyer took when he came. Best $100 I ever spent.
- lozf 6y ago
  Thanks! Just gonna need your phone number (for plausible deinabality) ;) ... And just hope there are no records that I've been using it since the days when it was 2 apps,- Red Phone & TextSecure, before becoming Signal.
- ssully 6y ago
  I got a group of friends to use Signal because of the following: 1. Sharing videos/pictures/memes is terrible in an SMS group chat 2. One person in the group has bad cell service, so we needed something that would send messages over Wifi 3. Half the people are on Android, so no iMessage 4. 1/4 of the people aren't on Facebook, so no messenger I was the one who suggested Signal. I did so because I like the end to end encryption, but that was not a selling point for anyone else. They just cared that it solved the problems above.
- antisocial 6y ago
  I want to emphasize that DeleteWhatsapp, DeleteInstagram should trend equally with DeleteFacebook.
Vinnl 6y ago
In fact, that's the main reason I'm using it, and the main counter-argument to 'I've got nothing to hide', IMHO. Sure I don't, but there are plenty of people who justifiably do.
- moksly 6y ago
  I have nothing to hide, but I have nothing I want you to see either.
  - nix23 6y ago
    I have something to hide...it's called privacy.
soziawa 6y ago
The point made by the parent commenter was that you can join any group (if you get someone to invite you) related to a certain topic and get the phone numbers of everyone in that group. I am not sure about the situation in the US, but in Europe almost all phone numbers are directly linked to a certain person and address by the provider.
- hjek 6y ago
  > The point One of the points which, yes, I agree with, but I mainly responded to this: > I can add phone numbers by enumeration into my contacts and Signal will show who among my contacts is on it.\ > I am not sure about the situation in the US, but in Europe almost all phone numbers are directly linked to a certain person and address by the provider. Or you can go to a corner shop and buy a Lyca or Lebara SIM with cash. No need to give them your address. You can buy top ups in cash as well. At least in Western Europe this is available everywhere, pretty much. (I'd still prefer if Signal didn't require phone number to sign up though.)
  - sadfklsjlkjwt 6y ago
    > Or you can go to a corner shop and buy a Lyca or Lebara SIM with cash. No need to give them your address. You can buy top ups in cash as well. At least in Western Europe this is available everywhere, pretty much. This is not legal in Norway.
    - jhauris 6y ago
      There are many countries it isn't legal in, which is a shame. The ability to get an anonymous phone ought to be something people care about preserving.
      - ubercow13 6y ago
        It's illegal in the vast majority of countries [1] including Germany, France. Attempting to build a safe secure communication system around phone numbers that is suitable for situations like this, relying on them as being somehow anonymous, is just a complete non-starter. Even if you don't have to register the phone number, the cell provider will still know your location history. I think it just shows how America-centric Signal is. [1] https://privacyinternational.org/long-read/3018/timeline-sim-card-registration-laws https://privacyinternational.org/long-read/3018/timeline-sim...
unicornporn 6y ago
That doesn't change the fact that all phone numbers are visible to all group members. All it takes is one rogue participant to reveal the identities of all members. If that actor has access to triangulation data they now have identity, location history, words and possibly images/video.
- m12k 6y ago
  Yeah, it's optimized for communication between trusted parties (e.g. Snowden and a journalist) - as such the focus is on verifying the identity of the other person, not hiding it. It'd be cool if they figured out a group chat setting that was optimized for groups like protesters trying to coordinate - show your identity only to users you are directly connected with/have verified/whitelisted, but hide your identity to everyone else.
  - cyphar 6y ago
    Except the whole point of OTR-like messaging was that you can communicate with someone who you can't be entirely sure you trust in perpetuity (that's why messages in Signal and similar systems don't have non-repudiation -- neither party can prove to a third party that a message really was sent by the other party). Now, obviously the metadata worry is separate to how the message cryptography is implemented but it does seem odd to have a threat model which is somewhat confused on this question.
    - nix23 6y ago
      But with signal you can verify that person, its like the opposite of otr. https://signal.org/blog/safety-number-updates/ https://signal.org/blog/safety-number-updates/
      - cyphar 6y ago
        OTR also allows you to do key verification -- all encrypted chat systems support that. The point isn't that you cannot be sure who you're talking to, the point is that the communication transcript cannot be provided to a third party as evidence that either party in the conversation said something. This is fairly simply implemented in OTR. Rather than signing the message with an asymmetric keypair (as you would with PGP), you sign it with a HMAC. Thus both the sender and recipient could create a valid message from the sender (giving you the property that only the two people in the conversation can be sure what was actually said by the other party, without being able to prove it to a third party cryptographically).
sorenjan 6y ago
The issue isn't somebody proving you have a Signal account, the issue is somebody identifying members in a specific group used to communicate about a protest. That way a state actor can find the phone number of a key organizer, persuade their phone provider to share their location, and take them out. Here's a description of how it worked in Telegram before they added a setting to disable it last year: https://medium.com/adamant-im/telegrams-anonymity-hole-how-to-get-any-user-s-phone-number-88062b4fb94b https://medium.com/adamant-im/telegrams-anonymity-hole-how-t...

fossuser 6y ago

This tradeoff is arguably a good thing. By using phone numbers as IDs signal can rely on your phone's local contacts (meaning they don't have to send your social graph to their servers). This way they can keep very little metadata on you. There's pretty much nothing for them to turn over except the fact that your phone number has the signal app. Most of the other secure apps could turn over your entire contact list (which could be damaging for people in a protest that are being targeted). Confirming a single phone number has the app is not nearly as big of a deal (I'd argue it doesn't matter at all).

Legogris 6y ago
I've lost track of the number of times I've had this conversation but here we go: There's nothing inherent in phone numbers here. Both iOS and Android also allows you to add e-mail addresses (and other identifiers) to your local contacts. I'm yet to hear an argument as to why e-mail addresses or other identifiers can't be used in addition to phone numbers, or why it would be a complicating factor.
- fossuser 6y ago
  My guess would be that phone numbers are guaranteed to be unique IDs that (almost) every phone will have which simplifies things and reduces the risk of someone impersonating someone else. I think they are working on non-phone number IDs though (Moxie was in an earlier signal thread on HN recently and mentioned it).
  - mikekchar 6y ago
    There is an issue on Github that is collating the problems they are working through. I've lost track of it, though, unfortunately. I've been pretty cynical about it in the past, but the last time I looked at the issue, it does look more complex than I first imagined. I wish it were higher priority, though. Hopefully somebody will remember the issue and post it here (it was from an HN post that I found it originally). Unfortunately, I'm not even sure what project it's under and there are many projects.
  - 6y ago

GlitchMr 6y ago

If that helps, there is a rate limit for checking whether a number is in Signal: with a single account, you can only check 4320 phone numbers a day. This makes mass user enumeration attacks somewhat less practical.

ves 6y ago
isn’t getting your hands on lots of sims/phone numbers, and thus Signal accounts, pretty trivial, though?
- numpad0 6y ago
  Trivial as ordering a 2U 16 blade GSM modem array from AliExpress, sure

znpy 6y ago

Eh, you can't have everything. Still, having a signal account doesn't make you a chargeable protester more than owning a gun makes you a chargeable assassin.

DyslexicAtheist 6y ago
> Eh, you can't have everything. why not? Wire[1] doesn't tie your identity to your phone number. OpenWhisper devs too are aware of Signal's limitation (it was even discussed here on HN recently). [1] https://github.com/wireapp https://github.com/wireapp

kabacha 6y ago

Using phone number as ID has been proven idiotic since forever now. As much as I like Signal this is such a design flaw that it makes their software not only untrustable but often unusable too. What's wrong with email logins?

siberianbear 6y ago
I'm no expert on the subject, but probably the use of phone numbers (and confirmation by SMS) is helpful to limit the number of bots.
- maxerickson 6y ago
  Phone numbers are used for contact discovery. https://signal.org/blog/private-contact-discovery/ https://signal.org/blog/private-contact-discovery/
- noir_lord 6y ago
  Signal could still validate the phone number via SMS and immediately discard it afterwards. Personally I liked the way ICQ did it back in the day, they used a uniq ID just for their service decoupling it from a phone number. If Signal wanted to avoid long numbers, they could use a CorrectBatteryHorseStaple approach which is what Xbox does for their usernames if you don't pick one. Easier to remember,

sorenjan 6y ago

This was allegedly used by the authorities in Hong Kong during protests there in 2019, but using Telegram. Telegram responded by introducing a new setting that hides your number from people that aren't in your own contacts. https://telegram.org/blog/scheduled-reminders-themes#new-privacy-settings https://telegram.org/blog/scheduled-reminders-themes#new-pri...

romanr 6y ago
Telegram indeed have better UX and same level of e2e security. Why Signal is getting all the publicity?
- nix23 6y ago
  Telegram is not opensource, Signal is...and yes you can setup your own server with Signal. Why trust a Closed-source-Software? Do you even know that it is encrypted?
  - fsflover 6y ago
    You can setup your own server with Signal, but you will not participate in the same network, so this is not really relevant.
    - nix23 6y ago
      For Country's or big-business it is relevant
  - sorenjan 6y ago
    https://github.com/DrKLO/Telegram https://github.com/DrKLO/Telegram https://github.com/telegramdesktop/tdesktop https://github.com/telegramdesktop/tdesktop
    - nix23 6y ago
      THAT is not the server, its like saying Firefox is opensource so Facebook is too, thanks and no thanks for the link's.

josefresco 6y ago

Step 1: Get a virtual phone number. Step 2: Get Signal and register using virtual phone number. Step 3: Protest!

app4soft 6y ago
Step 0: Use off-the-grid network. [0] https://apt.izzysoft.de/fdroid/index/apk/tk.giesecke.disaster_radio?repo=main https://apt.izzysoft.de/fdroid/index/apk/tk.giesecke.disaste...

lobster45 6y ago

What about Telegram?

md8 6y ago

Session is built to fix this problem https://getsession.org/ https://getsession.org/ It does not require a number to setup an account and communicate.

deleted 6y ago

[deleted]

Sami_Lehtinen 6y ago

Late post, but I'm just wondering why nobody has mentioned Briar Project. I think it's designed to remedy some of the issues mentioned here: https://briarproject.org/ https://briarproject.org/