8 ms·
>As such, the cybercriminals managed to pull off the attack by impersonating the victim of the attack for roughly 13 hours. If Registration Lock had been enable
by throwaway0x7E6 4y ago
>As such, the cybercriminals managed to pull off the attack by impersonating the victim of the attack for roughly 13 hours. If Registration Lock had been enabled, they could not have logged in to the app knowing only the phone number and verification code.
and if Signal did not require a phone number, this wouldn't have happened at all
- dorfsmay 4y agoThat's my biggest issue with signal.
- tptacek 4y agoMaybe not, but Signal would be vulnerable to a much bigger problem: its server would, like other secure messengers, end up keeping an effectively plaintext database of every pair of users that communicates.
- verdverm 4y agoOr they could create a phone number like id that you then share with others, like a phone number. They would not need to store this
- tptacek 4y agoThat only works if you don't care whether anyone actually uses your messenger. In the real world, people will only adopt a messenger that remembers their contact list across multiple devices.
- palata 4y agoThey thought about that, but it's harder than you think. They even explain why on their blog.
- paranoidrobot 4y agoI don't see how that would follow? Lets assume that today that Signal is able to deliver messages securely between users, without maintaining a plaintext association between sender and receiver's phone numbers. Why would switching identifiers from phone numbers to some other identifier require that they change how that works? (Other than the obvious 'substitute out a phone number for some other identifier' thing)
- tptacek 4y agoPhone numbers are already attached to fairly complete contact databases for users. "Signal Usernames" aren't.
- woojoo666 4y agoCouldn't this plaintext contacts database be encrypted on the server and only decrypted on the client?
- tptacek 4y agoNow you're building Matrix. Look how that worked out: https://nebuchadnezzar-megolm.github.io/ https://nebuchadnezzar-megolm.github.io/
- woojoo666 4y agoSo it's possible, it just takes work, which Matrix is doing right now. Is Signal also working on this?
- tptacek 4y agoThis protocol was deployed for years before anyone even thought to check whether group messaging was secure (we just found out now that it isn't). Is Signal working on secure group messaging? Well, they won the Levchin Prize at RWC for the work they're doing on it.
- woojoo666 4y ago> Is Signal working on secure group messaging? Well, they won the Levchin Prize at RWC for the work they're doing on it. I perhaps should have clarified but I was talking about group messaging without phone numbers attached
- 4y ago
- remram 4y agoWhat happens if you do have a registration lock when your number gets transferred away? The new owner can't use Signal? Do they complain with their mobile company about getting a "broken number" or with Signal?
- tass 4y agoThe registration lock is active for 7 days after the last time signal was used by that account at which point it is removed. The edge case would be someone that continued to use signal with their old phone number, effectively blocking its new registration.
- remram 4y agoThere is no way to get that number unless the person who no longer owns it accepts to relinquish it?
- tass 4y agoWhen they eventually move to use a new phone, they’ll need to know the code sent via text. It’s basically a dumb idea to use the account while someone else owns the number, eventually you’ll lose access to it
- AtNightWeCode 4y agoIn some countries a phone number is a sacred and private thing and in other countries phone numbers are like umbrellas. Over time there is no connection between the user and the owner. Where I live phone numbers are not safe to use for identification. In a neighboring country a phone number is more or less equal to a SSN.
- Marsymars 4y ago> and if Signal did not require a phone number, this wouldn't have happened at all I’d change “require” to “allow”. If, for example, Signal operated like it did now, but optionally let you sign up without a phone number, with a warning to users that not using a phone number would result in not being able to receive messages to their phone number, I bet most users would still use a phone number.