Comment by yardstick

Thanks for the reply, and glad to know it’s something you’re already thinking about!

That blog needs some inline padding for mobile view.

Mullvad is near the cutting edge on zero trust deployments; allowing user traffic to pass thru, with guaranteed no logging, assumption of compromise guiding system architecture, etc. Nobody can withstand a nation state, not even other nation states, so I feel like they're doing the best that can be reasonably expected of them

Timing attacks are notably not a part of Tor's threat model, i.e. they are a real concern: https://support.torproject.org/about/attacks-on-onion-routin...

(Carl from Obscura here)

> Does Mullvad have the budget and expertise to protect itself against determined, highly-resourced attackers?

I think Mullvad is actively working on [System Transparency](https://www.system-transparency.org/), which will help a lot.

> Finally, is it possible for a third party, intercepting traffic between Obscura and Mullvad, to identify the public key used to encrypt it? I don't think so - the only way to validate a signature is with both keys; that's kind of the point. But maybe there is an attack I'm unaware of?

I had asked this question a long time ago on either a noiseprotocol or wireguard IRC channel, and the answer is no, a third party intercepting traffic between Obscura and Mullvad, WON'T be able to identify the public key used to encrypt it.

Yeah my thinking is even if they don’t have the users IP, knowing and seeing all the traffic associated with a specific public key would allow them to build a profile of the user.

Eg based on the specific sites visited, payload sizes potentially, domains looked up, etc you’d be able to characterise the person. Especially so if anything they did was not encrypted, or they have their own vanity domain (for emails or anything else).

> Mullvad only needs to associate each decrypted IP packet against an assertion that the packet was paid for.

The idea of Obscura is by using two middlemen (them + Mullvad) that neither party can figure out who the end user is. So I’m looking at Mullvad from the perspective of: if they were evil, what about this solution are safeguard protecting the end users privacy. And my conclusion is they’d still be able to break the users privacy in the same way as knowing the users IP, just without the IP.