[HN Gopher] Improving Signal's Sealed Sender (2021)
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       Improving Signal's Sealed Sender (2021)
        
       Author : ementally
       Score  : 50 points
       Date   : 2023-03-07 18:02 UTC (4 hours ago)
        
 (HTM) web link (www.ndss-symposium.org)
 (TXT) w3m dump (www.ndss-symposium.org)
        
       | ShrimpHawk wrote:
       | from 2021
        
       | [deleted]
        
         | [deleted]
        
           | [deleted]
        
       | palata wrote:
       | Interesting analysis! Showing (once again) that anonymity is
       | difficult to achieve.
        
       | godelski wrote:
       | FYI I don't think Signal cares much about anonymity (sadly). I've
       | seen several discussions on their forums where admins have even
       | been hostile to people asking for it. I love Signal, but its
       | community is toxic and I really wish the devs would move a bit
       | faster. I know it is a tall order, but that's what Moxie argued
       | in his "The Ecosystem is Moving" talk (we can't have
       | decentralized because you have to move fast and adapt). There's a
       | lot of low hanging fruit that Signal just seems to ignore.
        
         | tptacek wrote:
         | However much they care or don't care about it, the salience of
         | this NDSS paper is that Signal has a relatively complex
         | anonymity feature that no other mainstream messenger has (the
         | ability to cryptographically authenticate a message that can be
         | delivered via the service without the client authenticating to
         | the server), and it's susceptible to some straightforward
         | network timing analyses.
         | 
         | There may be any number of other reasons to believe that Signal
         | doesn't care enough about anonymity, but with respect to this
         | paper, the most you can say is that they don't get full credit
         | for an extra credit anonymity project they did.
        
       | phneutral26 wrote:
       | Consider adding 2021 to the post title, for clarity. Anyhow,
       | interesting article. Thanks for sharing.
        
       | tandr wrote:
       | Did Signal fix the protocol, or at least responded with
       | something?
        
         | ementally wrote:
         | Nope, according to https://community.signalusers.org/t/sealed-
         | sender-still-brok...
        
           | wkat4242 wrote:
           | That's pretty bad 2 years later..
        
             | tptacek wrote:
             | I guess? This is an anonymity feature no other mainstream
             | messenger has in the first place. The idea behind sealed
             | sender is that clients can send messages through Signal's
             | service without authenticating directly to the server. It's
             | not, like, part of the core E2E mechanic of Signal; I'm not
             | even sure it was ever out of beta.
        
             | upofadown wrote:
             | The suggested fix was pretty complicated and had some
             | drawbacks (see section VII-B). Signal probably did not
             | agree that it was worth it. It's a hard problem and it just
             | might be the case that no one has of yet come up with a
             | workable solution.
        
       | autoexec wrote:
       | My impression is that since around 2020 Signal devs have been
       | trying as quietly as possible to tell people that the service can
       | no longer be trusted and everyone should switch to something
       | else. First they started keeping sensitive user data in the cloud
       | which upset and alienated a bunch of users, they've also refused
       | to update their privacy policy to reflect that fact, then they
       | added the weird crypto thing which upset more users, and killing
       | off the ability to handle SMS/MMS as well as secure
       | communications, one of their best features, seems like yet
       | another attempt drive away users. Maybe going years without
       | fixing important features with known vulnerabilities is just
       | another hint being left to ward off anyone who really needs their
       | communications secure.
       | 
       | I loved signal and recommended it to many people over the years,
       | but I ditched it after they started collecting and insecurely
       | storing user data in the cloud, and I'm still disappointed in
       | what it has turned into. The folks behind Signal had a great
       | project once and I hope someone outside of the US steps up to
       | give us a real replacement one of these days.
        
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       (page generated 2023-03-07 23:00 UTC)