It depends what you want to do with it. If it’s just for storing files/backups then encrypt them before uploading and make sure the key never goes anywhere near the VPS. If it’s for serving up something like a simple website, you probably care more about data integrity than exfiltration, so make sure you have the security, including selinux or equivalent, locked down, and regularly run integrity checks. If it’s for running something interactive, or where data will be generated or downloaded to the machine, you’re out of luck, there’s no even theoretical way of securing that against an adversary with that much access.

I agree that them having users’ phone numbers isn’t ideal. There are other identifiers they could use that would work just as well. However, both the client and server are open source, so you can build, at least the client, yourself. If you can content yourself that it does not leak your ID when sending messages, then you don’t need to trust the server as it does not have the information to build a graph of your contacts. Sealed sender seems to have been announced in 2018, so it’s had time to be tested.

Don’t get me wrong, the fact they require a phone number at all is a huge concern, and the reason I don’t really use it much, but the concern you initially stated was addressed years ago and you can build the client yourself to validate that.

You’re correct that if you use the system the way it used to work they can trivially build that connection, but (and I know this is a big assumption) if it does now work the way they say it does, they do not have the information to do that any more as the client doesn’t actually authenticate to the server to send a message. Yes, with some network tracing they could probably still work out that you’re the same client that did login to read messages, and that’s a certainly a concern. I would prefer to see a messaging app that uses cryptographic keys as the only identifiers, and uses different keys for different contact pairs, but given their general architecture it seems they’ve tried to deal with the issue.

Assuming that you want to use a publicly accessible messaging app, do you have any ideas about how it should be architected? The biggest issue I see is that the client runs on your phone, and unless you’ve compiled it yourself, you can’t know what it’s actually doing.

Strictly you’re having to trust the build of the client rather than the people running the server. If the client doesn’t send/leak the information to the server, the people running the server can’t do anything with it. It’s definitely still a concern, and, if I’m going to use a hosted messaging app, I’d much rather see the client built and published by a different group, and ideally compile it myself. Apart from that I’m not sure there’s any way to satisfy your concerns without building and running the server and client yourself.

‘Sealed sender’ seems to avoid this by not actually requiring the client to authenticate to the server at all, and relying on the recipient to validate that it’s signed by the sender they expect from the encrypted data in the envelope. As I mentioned in another reply, I’m just going on what they’ve published on the system, so either I could be completely wrong, or they could be being misleading, but it does look like they’ve tried to address this issue.

Whilst I absolutely agree it’s correct to be skeptical about it, the ‘sealed sender’ process means they don’t actually know which account sent the message, just which account it should be delivered to. Your client doesn’t even authenticate to send the message.

Now, I’m just going on what they’ve published on the system, so either I could be completely wrong, or they could be being misleading, but it does look like they’ve tried to address the very issue you’ve been pointing out. Obviously it’d be better if they didn’t have your phone number at all, but this does seem to decouple it in a way that means they can’t build a connection graph.

With ‘sealed sender’ your phone number, or any other identifying information, is not included in the metadata on the envelope, only the recipient’s id is visible, and it’s up to the recipient’s client to validate the sender information that is inside the encrypted envelope. It looks like a step in the right direction, though I don’t use signal enough to have looked into auditing it myself.

First Lad of the United States.

NATO’s having a presence in a member state is protection. It reduces the chance of opportunists like Putin invading.

Putin tried to call NATO’s bluff, using Ukraine as a bargaining chip. NATO didn’t blink, and so he started a war. He doesn’t get to do the abuser thing of saying “see what you made me do”. This is on him, and him alone.

He can demand that NATO withdraw all he likes, and I’d have some sympathy for that if it didn’t involve invading another country as leverage. Note, I say some sympathy, not that NATO should actually do it, especially as Putin’s regieme has threatened other countries already.

So, you’re saying that Putin sent demands to NATO, saying they either bend to his will by removing their protection from a large portion of their member states or he’d start a war, and by not signing it NATO are responsible for starting the war? I just want to fully understand your position on this.

The movie “Brewster’s Millions” is based on that premis.

I like it, this is clearly very enterprisey and solution focused, but I would like to suggest a couple of amendments if I may?

• Namespaces We should make full use of namespaces. Make the structural tags be in a language specific namespace (to be referenced in every function spec, obviously) but change the in an out params to use the parameter name as the tag, namespaced to the function they’re for, with a type attribute.

• In memory message queues Have all function invocations be marshaled as xml documents posted to an in memory message queue. Said documents should use a schema that validates the structure and a function specific schema to validate the types of arguments being passed. Namespace everything.

I reckon we could power a medium sided country if we could generate energy from the programmers despair.