Let me add to this: NO NO NO! You can mess up your change address if you don't know what you're doing, so just swipe the entire balance (and pay a transaction fee for this) instead of importing the private key.
I like using Mycelium Android wallet, it's very easy to import from the QR-code.
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swipe so when swiping (it gets the whole balance of the wallet) I don't need to import private keys .... That would work for a donation address right? , use that address (fix) just swipe it every time the balance got higher... [private key never touches the internet]
but how do i swipe a paper wallet in that way? (only way to spend coins is thru private keys right?, then still touches the internet)..
Address A hat 1 BTC.
I import it to my Wallte. Then my Wallet just adds adress a to my Wallet.
If i sweep adress A, then all the funds of adress A will be send to address B and a transaction fee will be necessary.
With importing you have the private keys in two places now and can spend from two wallets. With sweeping it is just on the new one.
Also private key touching the internet as you call it is something you should research more. you just use your private key to sign the transaction and can do this offline. then the keys get encrypted again and send to the internet. this is quite safe.
