This offline bitcoin could work. I talked about it before.
Like with SAFEcoin you can also mint bitcoins, you simply send them to a new address and extract the privatekey. The problem is once you have the privatekey, you could just simply copy the privatekey and spend the coins. This problem can be solved, because with bitcoins you can also have a password. So entering a password would prevent the previous user to spend the coin. But this still means that you need an app, to communicate a new password to the bitcoin network. Changing the password is for free, so there would be no costs only a message to the bitcoin network to change the password. With every new owner of the bitcoin you would only have to change the password.
When you mint coins, it’s like coinage.
If some one could print out the privatekey, it could be scanned and a new password could be send to the Bitcoin network, then you have a trustworthy offline bitcoin.
It seems like they depend on the previous owner to immediately delete the privatekey.Well this doesn’t help. The only solution is to change the passphrase of the privatekey, that way only the new user knows the passphrase and the previous can’t spend the bitcoin, because a privatekey alone won’t grant you access to the bitcoins.
I really wonder if SAFEcoins will have a passphrase or even multisigs from the get go? Will it even be possible to mint SAFEcoins now that the Transaction manager is removed?