maybe I am overthink, but still there something I want to refer.
off course this is not very important, we can do it later.
1. we need 2 step to create a paper wallet, register account and transfer fund.this is not graceful.
2. this may waster many ID, if paper wallet is very popular ....
3. it's very hard to manage many paper wallet
if we implement paper wallet with a new transaction, the paper wallet is belong to origin account,
1. we can cancel paper wallet with account's key, even we lost paper wallet's key, we'll not lost fund.
2. we can get transaction history clear, paper wallet spend to who.
3. we can get something more powerful, like a paper wallet with several keys, every key can only use 1 time.
if I have a paper wallet with 100 USD, I can give it 100 key, I can pay 1 USD with a key, and I can still use left key.
this will very useful for small payment