Bitcoin Forum

For clients such as bittorrent-qt and Electrum, how do I back up my wallets so that even if each software was no longer supported in the future (eg dead servers), I could still access my BTC balance by entering the info into future, functional clients? I think this means I need to get the raw private keys, as opposed to just backing up app-specific files such as wallet.dat in bittorrent-qt, or the seed in Electrum, which seem like they wouldn't work outside of the app.

Export the private keys.
Also, bit torrent has nothing to do with bitcoin. It is bitcoin-qt, not bittorrent.

data from wallet.dat is data of private keys.
It will be always possible to recover.

As you can see you can already import private keys from one to another wallet apps.

Just make sure your backups are safe and you will be able to import always.

The wallet.dat can get corrupt, you can forget its password if you encrypt it, your hard drive can burn itself, etc.
Paper Wallet = Safer.

Every time you create a new address in Bitcoin-Qt, the wallet creates a new private key that is not yet on your paper wallet.

Every time you send a bitcoin transaction from Bitcoin-Qt, the wallet creates a new private key that is not yet on your paper wallet.

Unless you remember to create a new paper wallet EVERY TIME you create a new address OR send a transaction, Paper Wallet IS NOT Safer.

With default settings, the wallet.dat stores the next 100 private keys that the wallet will use.  Therefore, as long as you make a new backup of wallet.dat on a frequent enough regularly scheduled basis, you are protected.

It is safer with cold storage.
In his case, it does not matter.

He does not say anything about cold storage or long term storage without use anywhere in his post.  It is dangerous to give advice based on assumptions.  If you assume incorrectly, you can suggest options that will result in increasing risk of loss.

quick question about Bitcoin Core:
When you encrypt an old bitcoin-qt wallet(that was never encrypted) it says:

"Important: Any previous backups you made of your wallet file should be replaced with the newly generated, encrypted wallet file.  For security reasons, previous backups of the unencrypted wallet file will become useless as soon as you start using the new, encrypted wallet."

So it renders useless all of the old wallet backups, just because they were unencrypted?

How is that possible?

I thought the old unencrypted wallet backups still have the exact same private keys, and that is all that matters??

What happens is that the 100 (depending upon config settings) addresses that exist in the "key pool" which you haven't used are "discarded" to be replaced by new ones that are encrypted (otherwise your new encrypted wallet would be unsafe if someone found your old unencrypted backup).

So the problem is as soon as you create a new tx to either receive BTC or make an outgoing tx that needs a *change* address (and most of the time it will even though you might not realise it) then now your "old backup" cannot see these addresses (as they are completely *new*).

So - keep your old backup - encrypt your wallet and then make a *new* backup (before doing any txs).

Then only after you have checked that your new wallet backup *works* do new transactions - hope that helps clarify things (and yes your old backup is not very useful after you have made any new txs).

As far as electrum goes, you don't need their servers to be working to export your private keys.  So just keep your seed safe and a backup copy of electrum somewhere.