I think I understand the purpose of a blind oracle: to not have our encryption key stored in Jade so that an attacker can’t perform a physical key extraction by manipulating the hardware.
The oracle serves as a form of “secure element” and helps keep Jade fully open-source by being in an external server.
We can get the secret key to unlock the wallet using an Elliptic Curve Diffie-Hellman (ECDH) key exchange, which is only available after we set the PIN correctly.
However, I don’t understand how is the PIN itself secured.
Question:
Wouldn’t the PIN be subject to the type of key extraction the oracle is supposed to protect us from, since it is not stored in a secure element?
If yes, sounds like getting the PIN would be just an additional step, but once the attacker has it, he is capable of obtaining the secret key by performing the ECDH himself, which doesn’t sound much safer.
Can someone explain to me what I’m getting wrong here?
Thanks!
