“super Secure” Messaging App Leaks Everyone's Phone Number

I think the comment you're responding to just means monetizing high-visibility creators in general as a systemic practice, not deliberately facilitating deception.

Yes that feature was long overdue

Because people that don't think will believe the shown location is accurate, instead of whatever the corrupt jack-ass running the site wants it to show. Any account that praises him will be a "verified human US citizen"

That's a fair point, I appreciate being taught something new.

Well, no - as long as someone you trust is able to do that verification, that's good enough.

SimpleX front page lied by omission about it having no identifiers. The fine print threat model did not mention the server has access to your IP addresses, and the mitigation to create "decentralized" system of users talking via separate servers ran into the problem of there being two VPS companies hosting the entire public server infrastructure. These issues were major as SimpleX advertised itself as an improvement over Cwtch, which should've meant superset of metadata had been protected. But that obviously wasn't the case.

The CEO vanished from the discussion (again) so my proposals to improve ease of use of Tor never reached them. You can catch up on the discussion at https://discuss.privacyguides.net/t/simplex-vs-cwtch-who-is-...

Check out the developer/owner's social media, the chats they're in, and their responses to others and you'll see. They're much more interesting in crypto and politics than they are acting professional in public and towards others while representing their project and company.

It's not hard to do so, so if they're having difficulty doing that, what other simple things are they having difficulty with? Why would anyone hinge their safety and well being on the whims of such a person?

I say this as a person who bought into the initial concept, and who has used it myself.

No. https://delta.chat/en/help#pfs

That's cool that there are phonenumbers without SIMs, my concern was more about SIM swap takeover. (Signal only guards this with a 4 digit PIN iirc)

So buy a number from a different country.

Can you buy a phone number from a different country? (genuinely curious, I live somewhere I can buy a sim card with cash, and saw some in the impulse-purchase section of a store earlier today)

yes before.

discoverability does default to "on", but there is an opportunity to disable it during registration, which prevents those notifications.

>So we can make registration or adding contacts paid (in cryptocurrency) and the problem is gone.

The majority of the user base would be gone, too.

I had a hard enough time convincing my friend group to use Signal as is. If they had to pay (especially if it had to be via cryptocurrency) none of them would have ever even considered it.

  > What's wrong with account generation?

Your comment *literally* explains one issue...

Ah yes, and convincing friends/family/partners to use Signal instead of Whatsapp clearly what will convince them is that they need to setup, acquire, and use cryptocurrency to register or connect with me on the encrypted messaging service. "No thanks, I just use Whatsapp/iMessage. I heard they're actually e2e encrypted too, so what's the problem?"

>What's wrong with account generation?

What's right with it? Accounts being generated (i.e. many inauthentic accounts controlled by few people) are always used to send spam, there are no exceptions. The perpetrators should be in prison.

  > That doesn't answer the GP question:

It does.

They asked

   >>> Does Signal protect from the scheme when the government sends discovery requests for all existing phone numbers (< 1B) and gets a full mapping between user id and phone number?

Which yes, this does protect that. There is no mapping between a user id and phone number. Go look at the reports. They only show that the phone number has a registered account but they do not show what the user id is. Signal doesn't have that information to give.

  > Can they connect a number to a username?

From Signal

  Usernames in Signal are protected using a custom Ristretto 25519 hashing algorithm and zero-knowledge proofs. Signal can’t easily see or produce the username if given the phone number of a Signal account. Note that if provided with the plaintext of a username known to be in use, Signal can connect that username to the Signal account that the username is currently associated with. However, once a username has been changed or deleted, it can no longer be associated with a Signal account. 

This is in the details on[0] right above the section "Set it, share it, change it"

So Signal cannot use phone numbers to identify usernames BUT Signal can use usernames to identify phone numbers IF AND ONLY IF that username is in active use. (Note that the usernames is not the Signal ID)

If you are worried about this issue I'd either disable usernames or continually rotate them. If the username is not connected with your account at the time the request is being made then no connection can be made by Signal. So this is pretty easy to thwart, though I wish Signal included a way to automate this (perhaps Molly has a way or someone can add it?) Either rotating after every use or on a timer would almost guarantee that this happens given that it takes time to get a search warrant and time for Signal to process them. You can see from the BigBrother link that Signal is not very quick to respond...

[0] https://signal.org/blog/phone-number-privacy-usernames/

Or a small payment in cryptocurrency.

> you'd use a proof-of-work scheme

I thought the general belief (e.g., '“Proof-of-Work” Proves Not to Work') was that proof-of-work isn't very good anti-spam.

> or a Captcha

Aren't bots better at those than humans by now?

> or an invite-code system like lobste.rs or early Gmail.

That's not a long-term option if you want to make something mainstream.

>proof-of-work scheme using a memory-hard hash function like scrypt

So who's doing the computation? The spammer can't afford to run 3 second key derivation time per spam device? Or how long do you think normal user will wait while you burn their battery power before saying "Screw it, I'll just use WA"? Or is this something the server should be doing?

>Captcha

LLMs are getting quite good at getting around captchas.

>invite-code system

That works in lobste.rs when everyone can talk together, and recruit interesting people to join the public conversation. Try doing that with limited invites to recruit your peers to build a useful local network of peers and relatives. "I'm sorry Adam, I'm out of invites can you invite my mom's step-cousin, my mom needs to talk to them?"

>Signal's architects already knew that when they started designng it.

I think they really did, and they did what the industry had already established as the best practice for a hard problem.

The only reasonable alternative would've been email with heavy temp-mail hardening, or looking into the opposite end of Zooko's triangle and having long, random, hard-to-enumerate usernames like Cwtch and other Tor-based messengers do. But even that's not removing the spam-list problem of any publicly listed address ending up in a list that gets spammed with contact requests or opening messages with spam.

If privacy wasn't their objective they would just have a database of all the phone numbers.

Perfect privacy would mean not sending any messages at all, because you can never prove the message is going to the intended recipient. Any actual system is going to have tradeoffs, calling Signal anti-privacy is not serious, especially when you're suggesting cryptocurrency as a solution.

A ZKP system where you make a public record of your zero-knowledge proof sounds anti-privacy to me. Even if you're using something obfuscated like Monero, it's still public. I see where you're coming from, but I think I would prefer Signal just keep a database of all their users and promise to try and keep it safe rather than rely on something like Monero.

Your first formulation I agree with:

> privacy was not their objective. Only secure communications was.

> Signal is demonstrably anti-privacy by design.

But your second is uncharitable and misses Signal's historical context.

The value of a phone number for spam prevention has been mentioned, but that's not the original reason why phone numbers were central to Signal. People forget that Signal was initially designed around using SMS as transport, as with Twitter.

Signal began as an SMS client for Android that transparently applied encryption on top of SMS messages when communicating with other Signal users. They added servers and IP backhaul as it grew. Then it got an iOS app, where 3rd party SMS clients aren't allowed. The two clients coexisted awkwardly for years, with Signal iOS as a pure modern messenger and Signal Android as a hybrid SMS client. Finally they ripped out SMS support. Still later they added usernames and communicating without exposing phone numbers to the other party.

You can reasonably disdain still having to expose a phone number to Signal, but calling it "anti-privacy by design" elides the origins of that design. It took a lot of refactoring to get out from under the initial design, just like Twitter in transcending the 140-character limit.

It's also possible that a lot of the criticism for Signal setting a practical/realistic level of what security they will try to provide, is from people who would rather that people either

1. were unable to communicate effectively, or

2. used no security at all.

Do you really use a communication system where you have all exchanged private keys in person and where even the fact that you use it is hidden from your government and phone operator?

> Those people already had your contact info, probably.

What leaked was that I was a signal user, and that the person on the other side was a signal user. The security implications are obvious, and by itself, that's already enough to get someone who really needs to care about privacy killed.

> Also, I think there is a setting in Signal to prevent that

False. It happened without my permission as soon as the app was installed, and there was no way to opt out. Maybe they changed it since then, but the fact remains they obviously cared more about network-effects and user-counts than user privacy.

Sigh, there's just no need for this kind of apologism. You could just admit that a) it's bad behavior, b) they did it on purpose, and c) it's not possible to trust someone who does something like this. I'm aware they are nonprofit, so I don't know why it's like this, but the answer is probably somewhere in the list of donors.

[delayed]