Quote from: Pmalek on Today at 06:59:40 AM

Quote from: ovcijisir on September 01, 2025, 07:59:11 PM

Thank you Pmalek for your initiative, it would be great to have it fixed if it is bug, or at least to have some information why it is needed if they make it like this on purpose. It would be great if you would share information when you get feedback from them

The Blockstream support team replied back to me and it's not a bug. They made it that way on purpose.

They say it's a security design. PIN-based logins take advantage of Blockstream's blind oracle security model. Essentially, it's a remote server. When you use PIN logins, the application communicates with the blind oracle that holds a piece of your wallet's encryption key and retrieves that piece of data. The combination of the two is needed to unlock your wallet. They say that this design prevents someone from accessing your wallet and stealing from your app by just knowing your PIN and having physical access to your phone.

But if you use biometric logins, then the encryption and decryption takes place in your device's operating system. It doesn't require access to the blind oracle to retrieve a part of the encryption key. Everything is done locally on the device. That's also why you can generate a seed when offline.

Thank you for your effort Pmalek. To be honest that security method doesn't makes sense to me, because of someone has physical acces to the phone and knows PIN, he can just enter PIN in app he will have access to the decrypted wallet just the same like if decryption without blund oracle wouldn't take place ...

I am not very educated in computers but it just isn't logical to me

But it is nice to know that they did that solution by design and not by accident.