I want to generate a vanity address with BIP-38 encryption for a cold storage paper wallet, how would I go about securely making one? From what I've found, generating a vanity address with Vanitygen does not allow me to encrypt the key. Or is a vanity address advisable at all for long-term cold storage?
Take a look at http://bippy.org.
The main potential issue I see with using a vanity address for cold storage is in spending from the address multiple times. If the wallet software you use isn't properly crafted (i.e., by using RFC 6979) there's a possibility that it will use the same
k value during ECDSA on the transaction, which will make it possible to recover your private key (see this). Note that this potential issue applies to any address for which there is more than one spend, not just vanity addresses. But I bring it up in particular here since the nature of a vanity address implies a reasonable likelihood of multiple spends from the address.
Would there be a possibility of Bippy causing this? I'd more than likely only be using it for very few spends, and more long-term storage and many deposits. Dec 18, 2014 at 2:46
Or could I just hypothetically use Vanitygen offline, and then encrypt it with Bippy? Vanitygen is tried and true, I'd assume it wouldn't have any glaring issues. Dec 18, 2014 at 3:33
This specific issue I mentioned is relevant at the time of spending, or that is to say, after the private key has been imported into wallet software in order to retrieve funds. It is not related to how the private key or address are generated. Dec 18, 2014 at 14:06
In summary -- when spending, know your wallet software. :-) Dec 18, 2014 at 14:08