Unfortunately, if you would like to use this mode to generate nice printed bank notes with an encrypted version of the private key of one of your existing cold-storage accounts, the BtcAddress app reference implementation does not support this - it only supports creating notes containing brand-new encrypted keys. The underlying code is already there, but the GUI does not support it.
Therefore, I have made enhancements to the BtcAddress app to provide GUI support for printing banknotes of encrypted keys generated using this mode.
Some links:
- Original Casascius utility: https://en.bitcoin.it/wiki/BIP_0038#Reference_implementation
- My fork: https://github.com/mikepfrank/Bitcoin-Address-Utility (see cleanmod branch for minimal diffs)
- Precompiled Windows executable: https://dl.dropboxusercontent.com/u/3133557/BtcAddress_mod.zip
Some screenshots:
(New menu item.)
(New dialog box.)
Caveat: The "compress public address" option does not work yet.
(Some data filled in.)
(Resulting encrypted key in collection.)
(Example of a bill that can then be printed - not the same example.)
Obviously, this capability ought really to be included in the master branch of the reference client for better trustability, and hopefully Mr. Caldwell will honor that pull request.
UPDATE 12/3/13: In the below branch, I have now cleaned up the diffs (reverted inconsequential changes) and submitted it as a pull request.
Comments/tips are welcome...