I am new to
securing my bitcoins in offline "cold storage". Do any of you more sophisticated users see any glaring security flaws with the following system?
To a USB thumb drive, I copied:
- The HTML/CSS/JavaScript of http://bitaddress.org ("Open Source JavaScript Client-Side Bitcoin Wallet Generator") on a USB drive
- The bitcoin 0.8.0 Linux binary
I then booted Ubuntu from a live disc. Keeping my computer completely offline, I opened the bitaddress.org page in Firefox on Ubuntu. I generated a few pages of public/private keypairs and printed them out on paper via a non-networked printer directly connected to my computer. (I want a bunch of keypairs so I can keep small bitcoin balances at each address rather than all my bitcoins at one address.)
Still disconnected from the internet, I opened the bitcoin client on Ubuntu. From the bitaddress.org page open in Firefox, I copied the private keys from each keypair into the bitcoin client using the "importprivkey" command from the Debug console. I then encrypted the wallet with a very long passphrase (10+ words and random characters, written on paper) and saved the encrypted wallet.dat file on the USB drive. I then shut down Ubuntu and powered off my machine.
I now have unencrypted copies of the public/private keypairs on paper, along with a long handwritten passphrase on paper, which I will put in the apocalypse-proof safe in my apocalypse-proof bunker. I also have an encrypted wallet.dat file containing the same keypairs on my USB drive, which I will put out in the cloud.
(The reason I want to keep offline, unencrypted paper keypairs is that it's so nice to just be able to scan that private key QR code when I need to access the funds again, rather than juggling various wallet.dat files around in my Bitcoin client to extract the private keys from my offline wallet. It's also nice to be able to scan the public address QR code into Blockchain.org so I can quickly create a "watch list" of all my cold storage addresses, which allows me to see my total savings balance in one place.)
Thoughts? Suggestions?
