I don't know if what it's promising is actually possible. Ultimately you need to trust that the machine/node which claims to be running your code is in fact running it as-is and not running some hacked version of it which behaves the same superficially but is actually collecting all your user passwords behind the scenes.

The node can always lie by perfectly adhering to the protocol but doing something completely different behind the scenes. You can hash, sign or encrypt the code as much as you like but that has nothing to do with verifying that the hardware is actually running that code.

Maybe with homomorphic encryption this will be possible but AFAIK this technology is not even close to ready for such use cases.