I'm using the standard Mac Bitcoin client and I added a passphrase. I'd like to remove that passphrase. Is that possible?
The Bitcoin.org client does not yet have the feature to remove encryption from a wallet. You can use a single space as the encryption key but there no way to get it to no longer use encryption.
That is expected to be implemented in a future release.
In the meantime, those that want this will create a new wallet and leave it unencrypted, and send their coins from the encrypted wallet to it.
You can dump your old wallet to a backup file, restart the program to generate a new wallet and import your old wallet into it.
Assuming you are in the directory where your wallet file is located, using the command line that would look like this:
bitcoind walletpassphrase "xxx" 60 bitcoind dumpwallet "wallet.dat.backup" bitcoind stop mv wallet.dat wallet.dat.old bitcoind -daemon bitcoind importwallet wallet.dat.backup
I would be interested in a less dirty way, if anybody knows one.
Yes. It is possible.
Either the UI supports it or it does not. You are better equipped to find out than I am but I suspect it does not (yet).
If it does not you can either:
- Export the keys, move the wallet files (rather than deleting it, so you can move it back if things to wrong, on Mac the wallet files are here: ~/Library/Application Support/Bitcoin/), import the keys.
- implement it yourself / pay someone to implement if for you
- find an alternative client to do it for you (Armory might have it, a list is here)
- find an alternative client to open it and export the private keys, so you can import them into a new unencrypted wallet.
- when all else fails: transact your Bitcoin towards a new unencrypted wallet and ditch the old, encrypted, wallet. Be sure to tell people you've migrated, your old addresses are still in your encrypted wallet.