Bitcoin Forum

Is it safe create a a peper wallet from bitcoin-qt n dumpprivatekey?

if I sweep one private all other ones that I have in cold storage will be vunerable because they are derived some way from the one spent?

Regards,
Slave

Yes. (Modern versions are called "Bitcoin Core", not Bitcoin-Qt).


If your Bitcoin Core is running on a computer that was ever connected to the internet, then the paper wallets you create are not "cold storage", they are just paper wallets.


Then don't sweep that private key.  You have a few options...

• Sign your transaction offline so that the private key is not exposed.
• Generate a new Bitcoin Core wallet for each paper wallet that you create
• Sweep all private keys that were generated from the same Bitcoin Core wallet. Send any excess to a new paper wallet.

 
If you are asking if paper wallets are safe ways to move your balance, sure.  Over a long period they are technically fine too, but you have to care for that code and make sure it stays readable and something like a USB drive can take a good bit more abuse than a paper and remain useable.

It is hard to say what you are trying to do.  Move a balance across the office, store for a day or store for ten years.  Each of those has a best option.  For me, the only real reason for a paper wallet is to use it kind of like a gift certificate to present as a surprise, although there are other uses, I have never used the paper wallet option for more than that.