5 ms·

The sad part is, that's what's keeping Signal safe from spam. Also, average Joe is not using proxy to hide the IP-address of their device so they leak their id

by maqp 10mo ago

The sad part is, that's what's keeping Signal safe from spam. Also, average Joe is not using proxy to hide the IP-address of their device so they leak their identity to the server anyway. Signal is not keeping those logs so that helps. Messaging apps cater to different needs, sometimes you need only content-privacy. It's not a secret you're married to your partner and you talk daily, but the topics of the conversation aren't public information. When you need to hide who you are and who you talk to (say Russian dissident group, or sexual minorities in fundamentalist countries), you might want to use Tor-exclusive messaging tools like Cwtch. But that comes at a near-unavoidable issue of no offline-messaging, meaning you'll have to have a schedule when to meet online. Signal's centralized architecture has upsides and downsides, but what matters ultimately is, (a) are you doing what you can in the architectural limitations of the platform (strong privacy-by-design provides more features at same security level), and (b), are you communicating the threat model to the users so they can make informed decision whether the applications fits their threat model.

kragen 10mo ago
If you wanted to keep it safe from spam, you'd use a proof-of-work scheme using a memory-hard hash function like scrypt, or a Captcha, or an invite-code system like lobste.rs or early Gmail. Signal's architects already knew that when they started designng it.
- codedokode 10mo ago
  Or a small payment in cryptocurrency.
  - kragen 10mo ago
    Yes, that would also work, but you should probably offer alternatives.
- creata 10mo ago
  > 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? And making people do captchas in an instant messenger is a great way to make people not use that instant messenger. > 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.
  - kragen 10mo ago
    There are people who believe that proof-of-work isn't very effective, but none of them have succeeded in spamming the Bitcoin network with blocks they've mined, driving the other miners out of business, nor (for the last several years) with spamming the Bitcoin network with dust transactions they've signed, so I don't think we should take their opinions very seriously. Bots may be better than humans at Captchas now, although I'm not certain of that, but they certainly weren't when Signal was designed. I don't see why invite codes would be a problem for mainstream use.
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    - Ieghaehia9 10mo ago
      > There are people who believe that proof-of-work isn't very effective, but none of them have succeeded in spamming the Bitcoin network with blocks they've mined, driving the other miners out of business, nor (for the last several years) with spamming the Bitcoin network with dust transactions they've signed, so I don't think we should take their opinions very seriously. Different system. The parent and GP are talking about proof-of-work being used directly for account creation. If a chat service required mining-levels of PoW (and hence any prospective new users to have an ASIC), it would not be very popular. Nor would it be very popular if it used a relative difficulty system and the spammers used dedicated servers while the legitimate users had to compete using only their phones.
    - creata 10mo ago
      > none of them have succeeded in spamming the Bitcoin network with blocks they've mined I'm not saying you're wrong, but I have no idea what you're getting at, because the sentence sounds kind of absurd. As a result, I'm not sure if it addresses your point, but just to throw it out there: Bitcoin and anti-spam are different applications of proof of work. Anti-spam has to strike a compromise between being cheap for the user (who is often on relatively low-powered mobile hardware), and yet annoying enough to deter the spammer. It's not unreasonable to believe that such a compromise does not exist. > Bots may be better than humans at Captchas now, although I'm not certain of that, but they certainly weren't when Signal was designed. Fair point, but again, even in 2014, an instant messenger with captchas would have much more friction than every other messenger. And captchas aren't just bad because they introduce enough friction to drive away pretty much everybody: they also make users feel like they're being treated as potential criminals. > I don't see why invite codes would be a problem for mainstream use. Can you elaborate? Invite codes blocking access to the service itself "like lobste.rs" mean that no one can use your service unless they've been transitively blessed by you. That's obviously going to limit its reach...
- maqp 10mo ago
  >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.
  - kragen 10mo ago
    Those are reasonable questions, but they suggest that you don't understand the landscape very well. The user's device has to do the computation for it to be effective. How long does it normally take to sign up for a new messaging service like WhatsApp? Five minutes? You should burn the user's cellphone battery for about half that long, 150 seconds, 50 times more than you were thinking. Plus another half-minute every time you add a new contact. Times two for every time someone blocks you, up to a limit of 150 seconds. Minus one second for each day you've been signed up. Or something like that. The value of signing up for Signal is much higher to a real user than it is to a spammer, so you just have to put the signup cost somewhere in the wide range in between. LLMs didn't exist when Signal was designed, and Captchas still seem to be getting a lot of use today. Invite codes worked fine for Gmail, and would work even better for any kind of closed messaging system like Signal; people who don't know any users of a particular messaging system almost never try to use it. The diameter of the world's social graph is maybe ten or twelve, so invite codes can cover the world's social graph with only small, transitory "out of invites" problems. The "industry" had "established" that they "should" gather as much PII as possible in order to sell ads and get investments from In-Q-Tel.
- deleted 10mo ago
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coppsilgold 10mo ago
If you intend to use SMS (phone numbers) as a resource constraint (sign up requires 'locking up' a resource that is worth at least a few cents) then at least you can offer a ZKP system where the 'consumed' phone number is not tied to an account. You could also offer to accept cryptocurrency for this function - call it a donation. That Signal did none of those things implies that privacy was not their objective. Only secure communications was. It's possible that the reason behind their anti-privacy stand is strategic, to discourage criminal use which could be used as a vector of attack against them. Doesn't change the fact that Signal is demonstrably anti-privacy by design.
- lukeschlather 10mo ago
  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.
  - coppsilgold 10mo ago
    > have a database of all the phone numbers They have exactly that. They rely on TPMs for "privacy" which is not serious. > Perfect privacy would mean not sending any messages at all Not sending messages is incompatible with secure messaging which is the subject of the discussion... > ZKP system where you make a public record of your zero-knowledge proof sounds anti-privacy to me. A zero-knowledge proof provably contains zero information. Even if you use a type of ZKP vulnerable to a potential CRQC it's still zero information and can never be cracked to reveal information (a CRQC could forge proofs however). > especially when you're suggesting cryptocurrency as a solution Would you elaborate on why cryptocurrencies are not a solution? Especially if combined with ZKPs to sever the connection between the payment and the account. When combined with ZKPs, they could even accept Paypal for donations in exchange for private accounts.
wkat4242 10mo ago
I get lots of spam on WhatsApp which also requires a number. And some on signal too for that matter. Signal is just much smaller in terms of users so the potential value is lower.
rendaw 10mo ago
I get zero spam on Line... I don't allow people to add me by phone number. Line isn't known for their cryptography/security skills.

by maqp 10mo ago

kragen 10mo ago

If you wanted to keep it safe from spam, you'd use a proof-of-work scheme using a memory-hard hash function like scrypt, or a Captcha, or an invite-code system like lobste.rs or early Gmail. Signal's architects already knew that when they started designng it.

codedokode 10mo ago
Or a small payment in cryptocurrency.
- kragen 10mo ago
  Yes, that would also work, but you should probably offer alternatives.
creata 10mo ago
> 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? And making people do captchas in an instant messenger is a great way to make people not use that instant messenger. > 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.
- kragen 10mo ago
  There are people who believe that proof-of-work isn't very effective, but none of them have succeeded in spamming the Bitcoin network with blocks they've mined, driving the other miners out of business, nor (for the last several years) with spamming the Bitcoin network with dust transactions they've signed, so I don't think we should take their opinions very seriously. Bots may be better than humans at Captchas now, although I'm not certain of that, but they certainly weren't when Signal was designed. I don't see why invite codes would be a problem for mainstream use.
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  - Ieghaehia9 10mo ago
    > There are people who believe that proof-of-work isn't very effective, but none of them have succeeded in spamming the Bitcoin network with blocks they've mined, driving the other miners out of business, nor (for the last several years) with spamming the Bitcoin network with dust transactions they've signed, so I don't think we should take their opinions very seriously. Different system. The parent and GP are talking about proof-of-work being used directly for account creation. If a chat service required mining-levels of PoW (and hence any prospective new users to have an ASIC), it would not be very popular. Nor would it be very popular if it used a relative difficulty system and the spammers used dedicated servers while the legitimate users had to compete using only their phones.
  - creata 10mo ago
    > none of them have succeeded in spamming the Bitcoin network with blocks they've mined I'm not saying you're wrong, but I have no idea what you're getting at, because the sentence sounds kind of absurd. As a result, I'm not sure if it addresses your point, but just to throw it out there: Bitcoin and anti-spam are different applications of proof of work. Anti-spam has to strike a compromise between being cheap for the user (who is often on relatively low-powered mobile hardware), and yet annoying enough to deter the spammer. It's not unreasonable to believe that such a compromise does not exist. > Bots may be better than humans at Captchas now, although I'm not certain of that, but they certainly weren't when Signal was designed. Fair point, but again, even in 2014, an instant messenger with captchas would have much more friction than every other messenger. And captchas aren't just bad because they introduce enough friction to drive away pretty much everybody: they also make users feel like they're being treated as potential criminals. > I don't see why invite codes would be a problem for mainstream use. Can you elaborate? Invite codes blocking access to the service itself "like lobste.rs" mean that no one can use your service unless they've been transitively blessed by you. That's obviously going to limit its reach...
maqp 10mo ago
>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.
- kragen 10mo ago
  Those are reasonable questions, but they suggest that you don't understand the landscape very well. The user's device has to do the computation for it to be effective. How long does it normally take to sign up for a new messaging service like WhatsApp? Five minutes? You should burn the user's cellphone battery for about half that long, 150 seconds, 50 times more than you were thinking. Plus another half-minute every time you add a new contact. Times two for every time someone blocks you, up to a limit of 150 seconds. Minus one second for each day you've been signed up. Or something like that. The value of signing up for Signal is much higher to a real user than it is to a spammer, so you just have to put the signup cost somewhere in the wide range in between. LLMs didn't exist when Signal was designed, and Captchas still seem to be getting a lot of use today. Invite codes worked fine for Gmail, and would work even better for any kind of closed messaging system like Signal; people who don't know any users of a particular messaging system almost never try to use it. The diameter of the world's social graph is maybe ten or twelve, so invite codes can cover the world's social graph with only small, transitory "out of invites" problems. The "industry" had "established" that they "should" gather as much PII as possible in order to sell ads and get investments from In-Q-Tel.
deleted 10mo ago
[deleted]

coppsilgold 10mo ago

If you intend to use SMS (phone numbers) as a resource constraint (sign up requires 'locking up' a resource that is worth at least a few cents) then at least you can offer a ZKP system where the 'consumed' phone number is not tied to an account. You could also offer to accept cryptocurrency for this function - call it a donation. That Signal did none of those things implies that privacy was not their objective. Only secure communications was. It's possible that the reason behind their anti-privacy stand is strategic, to discourage criminal use which could be used as a vector of attack against them. Doesn't change the fact that Signal is demonstrably anti-privacy by design.

lukeschlather 10mo ago
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.
- coppsilgold 10mo ago
  > have a database of all the phone numbers They have exactly that. They rely on TPMs for "privacy" which is not serious. > Perfect privacy would mean not sending any messages at all Not sending messages is incompatible with secure messaging which is the subject of the discussion... > ZKP system where you make a public record of your zero-knowledge proof sounds anti-privacy to me. A zero-knowledge proof provably contains zero information. Even if you use a type of ZKP vulnerable to a potential CRQC it's still zero information and can never be cracked to reveal information (a CRQC could forge proofs however). > especially when you're suggesting cryptocurrency as a solution Would you elaborate on why cryptocurrencies are not a solution? Especially if combined with ZKPs to sever the connection between the payment and the account. When combined with ZKPs, they could even accept Paypal for donations in exchange for private accounts.

wkat4242 10mo ago

I get lots of spam on WhatsApp which also requires a number. And some on signal too for that matter. Signal is just much smaller in terms of users so the potential value is lower.

rendaw 10mo ago

I get zero spam on Line... I don't allow people to add me by phone number. Line isn't known for their cryptography/security skills.