On the other hand, it needs to provide ultimate security, even though there is always a compromise between security and convenience. If it doesn't, geeks will criticize it for not being secure enough.

One thing I dislike about Signal on its privacy posture is that the moment you register, anyone who already has Signal and has your phone number in their contacts list will get a message saying you're on Signal. This is a good way for others with bad intentions to know about your presence on the platform. The options to hide your phone number are available only after registering on Signal (after this broadcast has already happened) and when the user figures out that this is possible somewhere deep in the settings.

On registration Signal could ask whether to inform all random people who happen to have your number. But since unused/discarded phone numbers are recycled by carriers to other customers within a matter of weeks or months or years (depending on where you are), your presence on Signal may be sent to someone you've never ever known or has known you. Signal ought to remove this broadcast on registration. Telegram (and I guess WhatsApp) also suffer from the same issue.

Signal has always aimed to ensure confidentiality in the simplest way possible. People forget that there are anonymous systems or systems that do not require a telephone number but they are incredibly painful to set up. You either have to go through physical checks with QR code exchanges to validate participants or have some kind of web of trust (no one has fond memories of PGP key signing parties).

The same goes for decentralization. On paper, everyone wants decentralization. But when it comes to interconnecting hundreds of servers with different rules, moderation and legislation, and protocol versions, it becomes hell and no one wants to have to manage it (e.g. Mastodon).

There are objective reasons why these systems are not popular.

The other problem is that the very use of this type of software becomes a marker. I am convinced that the majority of Olvid users work for the French government, for example.

Iranian activists who are checked at the border or elsewhere with any uncommon communication application have already lost, regardless of the security of the application.

Crypto-punks are a niche group that can accept this type of usage constraint. My grandmother cannot, but she can use Signal and she will be one user among millions.

Also, what about Briar/Berty as alternative?

https://play.google.com/store/apps/details?id=org.briarproje...

https://apps.apple.com/app/id1535500412

the question was if signal is secure and private, and the answer is about anonymity

is it secure and private - it is, is it anonymous - it's not, or at least, to some degree

Now, to break your confidentiality, Signal would have to have a relatively complex system setup for trying to match up messages and deanonymize people. You could imagine many scenarios where a bad actor (agency) attempts to trick Signal into logging metadata. This now requires a lot more information, and if nothing else would give you a level of deniability.

Regarding sealed sender I don't think they ever fixed the statistical method of identifying sealed senders described in the "improving sealed sender" paper from 2019 (?), meaning it is pretty useless anyway if signal decided they wanted to identify senders.

This is single user talking to single user, though. I know it gets more complex when you have more users than that.

I suppose this Sealed Sender issue is problematic for some people, but it's not enough for me to seriously consider jumping ship.

Just use SimpleX.

https://media.ccc.de/v/36c3-11086-the_ecosystem_is_moving

This sort of thing is depressingly common in the world of encrypted messaging. It is really common for a user to not know about the requirement to do identity verification with E2EE for example.

For example, Aztec, a privacy focused blockchain, requires recipients to download the entire block to determine if any private message is addressed to them (and BTW use techniques resembling Signal's double ratcheting in creating these identifiers) [1]

This is infeasible on mobile devices. At best, it allows the user to select a proxy server they trust to identify messages intended for them and forward a notification.

1 - https://www.taurushq.com/blog/enhancing-token-transaction-pr... (search for "synchronizer")

https://molly.im/

How does Signal make money to be able to afford their AWS subscription? Do corporate clients pay for it or something?

That MySudo service he mentions in the article sounds quite interesting as well. Has anyone given it a try?

Almost feels like another CryptoAG with Snowden recommending it so much when he knows that metadata is enough.

> There is still a risk that a server maliciously records all queues and messages (even though encrypted) sent via the same transport connection to gain a partial knowledge of the user’s communications graph and other meta-data.

[0]: https://github.com/simplex-chat/simplexmq/blob/master/protoc...

Using phone numbers as IDs or a verification method is a horrible practice, not to mention that it forces you to use a phone in the first place.