The part that scares me: If I plan to use it as a long term storage equipment, how I can be sure that the NAND flash will store the private key without loosing it as it could happen with a standard usb drive left in the drawer for a long time?
You can always unseal it and backup the private key.
I can also generate an offline seed and backup it on a uncompromised machine...
The point is: opendime, wonderful idea, but what about the long term security without exposing the private key?
You can't have both. It's either a never exposed private key or it has a backup.
Let me explain with a decent example. I don't know if you have already heard of the Ledger Nano. Basically in the setup process, the nano output once the seed to your computer (that is supposed to run a live distro), so you can have peace of mind even in the case that the nano is destroyed.
I know that the opendime is supposed to be a security token that you can pass to other users and cannot have this function, but the insecurity caused of random (and systematical in large production batches) malfunction is really a deal breaker to me.
However I wouldn't hide that the idea of testing one of them is really appealing, i like the concept!
