3 ms·

I solved this problem (and more) by switching to Matrix.

tptacek 3y ago
Records of precisely who you talk to are being kept serverside because of that decision. Maybe that's totally fine for you! Most people have pretty unserious secure messaging threat models (I don't mean that as a value judgement).
- greyface- 3y ago
  The same is likely true of Signal, no? Traffic analysis on AWS' edge would tell you precisely who is talking to who, and user identities are tied to legal identities via phone numbers. Maybe Signal doesn't store this data serverside, but there are entities with both the capability and motivation to obtain it. I bet there are Signal XKEYSCORE selectors.
  - tptacek 3y ago
    No, it's not. Traffic analysis is potent, but it is not a literal SQL database of who has talked to who when.
    - fsflover 3y ago
      So the problem is the same: trusting the server. At least small Matrix servers aren't huge targets for attacks, since they don't serve so many users. Also on Matrix you can run your own server.
      - stavros 3y ago
        Signal doesn't know who's talking to you, it's called sealed sender: https://signal.org/blog/sealed-sender/ https://signal.org/blog/sealed-sender/
        fsflover 3y ago
        Which is irrelevant when Amazon has all IP addresses.
        akerl_ 3y ago
        So the two things we're comparing are: 1. Signal, where an attacker with granular access to AWS's global network logs could perform traffic analysis to match timings between sender and recipient IP addresses, which would work for some portion, and narrow things down for some other portion. The attacker would then need to combine that with data from mobile networks and other ISPs to link the sender/recipient IPs at a given timestamp with a subscriber. 2. Other messaging platforms, including Matrix, where they can just check the server's database to get a table of what user messaged what other user at a given time.
        Arathorn 3y ago
        On Matrix, that assumes the attacker knows where the server is or that it even exists. Whereas on Signal it’s pretty obvious where the server is, given there’s only one logical server.
        wkat4242 3y ago
        Yeah matrix is pretty great. The only thing I find is that it's such a moving target. I was trying Element X last week which is now meant to be the new client to be. But I wasn't able to set up the encryption with my recovery key, there was only the online validation which I couldn't use because I was on the go and didn't have access to my desktop. It's supposed to be better but still lacks such basic things (also seems to still lack TOFU for my private server) The same with the homeservers, there's synapse and dendrite is supposed to take over at some point but that point is forever far in the future. And then there's conduit, so which one is it? I understand this is a fully open multi-server multi-client platform but I kinda expect the "stock" ones to be clear in their strategy :) The strategy doesn't really feel well thought out in that sense. I really like Matrix and am rooting for it but such things undermine my confidence in recommending it to others. I'm sure the questions I ask are crystal clear to the matrix in-crowd but to me they're not. In that sense it feels a bit like recommmending arch Linux to a beginner, the first thing they have to do is choose a partition scheme, a network management stack, a desktop environment etc etc. This just doesn't work for those that aren't already deeply in the know :)
    - stavros 3y ago
      Signal's "sealed sender" feature means it doesn't even know who sent you the message (all they can see is an IP address): https://signal.org/blog/sealed-sender/ https://signal.org/blog/sealed-sender/
      - hobobaggins 3y ago
        > all they can see is an IP address That is precisely the, ahem, signal metadata.
        antisocialist 3y ago
        Yep, whoever gets hold of those records can cross-reference logs from the same time to narrow down or even outright identify Signal chat participants.
      - gojomo 3y ago
        Signal or any surveillor surrounding their servers (with or without Signal's cooperation) almost certainly has enough timing/traffic-shape info to reconstruct who-to-who logs. "Sealed sender" (and some of Signal's other tactics) just demonstrate: Signal's main & disclosed codepaths aren't stockpiling the canonical metadata via the same blatant & undenied mechanisms of other services. Sufficiently sophisticated outside attackers, or insider threats, can construct nearly-equivalent logs via other means. (And: Signal seems reluctant to make choices, like truly ditching phone numbers as account IDs, that could limit these 'shadow' leaks.)
Erratic6576 3y ago
The amount of problems remains stable, as a universal constant . Problems are neither solved nor created, only transformed. By switching from Telegram to Matrix, new problems arose. By switching from Matrix to Session, by switching to Signal, where we are now, fewer problems arose

Records of precisely who you talk to are being kept serverside because of that decision. Maybe that's totally fine for you! Most people have pretty unserious secure messaging threat models (I don't mean that as a value judgement).

greyface- 3y ago
The same is likely true of Signal, no? Traffic analysis on AWS' edge would tell you precisely who is talking to who, and user identities are tied to legal identities via phone numbers. Maybe Signal doesn't store this data serverside, but there are entities with both the capability and motivation to obtain it. I bet there are Signal XKEYSCORE selectors.
- tptacek 3y ago
  No, it's not. Traffic analysis is potent, but it is not a literal SQL database of who has talked to who when.
  - fsflover 3y ago
    So the problem is the same: trusting the server. At least small Matrix servers aren't huge targets for attacks, since they don't serve so many users. Also on Matrix you can run your own server.
    - stavros 3y ago
      Signal doesn't know who's talking to you, it's called sealed sender: https://signal.org/blog/sealed-sender/ https://signal.org/blog/sealed-sender/
      - fsflover 3y ago
        Which is irrelevant when Amazon has all IP addresses.
        akerl_ 3y ago
        So the two things we're comparing are: 1. Signal, where an attacker with granular access to AWS's global network logs could perform traffic analysis to match timings between sender and recipient IP addresses, which would work for some portion, and narrow things down for some other portion. The attacker would then need to combine that with data from mobile networks and other ISPs to link the sender/recipient IPs at a given timestamp with a subscriber. 2. Other messaging platforms, including Matrix, where they can just check the server's database to get a table of what user messaged what other user at a given time.
        Arathorn 3y ago
        On Matrix, that assumes the attacker knows where the server is or that it even exists. Whereas on Signal it’s pretty obvious where the server is, given there’s only one logical server.
        wkat4242 3y ago
        Yeah matrix is pretty great. The only thing I find is that it's such a moving target. I was trying Element X last week which is now meant to be the new client to be. But I wasn't able to set up the encryption with my recovery key, there was only the online validation which I couldn't use because I was on the go and didn't have access to my desktop. It's supposed to be better but still lacks such basic things (also seems to still lack TOFU for my private server) The same with the homeservers, there's synapse and dendrite is supposed to take over at some point but that point is forever far in the future. And then there's conduit, so which one is it? I understand this is a fully open multi-server multi-client platform but I kinda expect the "stock" ones to be clear in their strategy :) The strategy doesn't really feel well thought out in that sense. I really like Matrix and am rooting for it but such things undermine my confidence in recommending it to others. I'm sure the questions I ask are crystal clear to the matrix in-crowd but to me they're not. In that sense it feels a bit like recommmending arch Linux to a beginner, the first thing they have to do is choose a partition scheme, a network management stack, a desktop environment etc etc. This just doesn't work for those that aren't already deeply in the know :)
  - stavros 3y ago
    Signal's "sealed sender" feature means it doesn't even know who sent you the message (all they can see is an IP address): https://signal.org/blog/sealed-sender/ https://signal.org/blog/sealed-sender/
    - hobobaggins 3y ago
      > all they can see is an IP address That is precisely the, ahem, signal metadata.
      - antisocialist 3y ago
        Yep, whoever gets hold of those records can cross-reference logs from the same time to narrow down or even outright identify Signal chat participants.
    - gojomo 3y ago
      Signal or any surveillor surrounding their servers (with or without Signal's cooperation) almost certainly has enough timing/traffic-shape info to reconstruct who-to-who logs. "Sealed sender" (and some of Signal's other tactics) just demonstrate: Signal's main & disclosed codepaths aren't stockpiling the canonical metadata via the same blatant & undenied mechanisms of other services. Sufficiently sophisticated outside attackers, or insider threats, can construct nearly-equivalent logs via other means. (And: Signal seems reluctant to make choices, like truly ditching phone numbers as account IDs, that could limit these 'shadow' leaks.)

Erratic6576 3y ago

The amount of problems remains stable, as a universal constant . Problems are neither solved nor created, only transformed. By switching from Telegram to Matrix, new problems arose. By switching from Matrix to Session, by switching to Signal, where we are now, fewer problems arose