What is the safest medium on which to store my wallet/private keys?

I avoid eWallets like the plague.

I have my wallet on my computer at the moment with the Bitcoin passphrase encryption and I have a few backups on different harddrives/USB drives.

But USB drives don't seem to be the most reliable thing to store wallets on, and I want to move my wallet off my computer for improved safety, so I was looking at paper wallets and they seem good apart from if they deteriorate over time, or from things like water damage etc.

CDs seem okay to use but they can also get scratched and can't be updated once burnt.

I'd also rather avoid cloud file services.

A plastic card that I could print my public/private keys on seemed like a good idea, but this would have to be printed by a third party as card printers are expensive, unless there's somewhere I can go to do it myself.

Any recommendations on the safest medium to store Bitcoins on?

Sean Chapman

Posted 2011-12-15T12:12:48.010

Reputation: 1 718

Answers

Print out your private keys to a Paper Wallet and print the keys on Archival Quality Paper. Those should last until the year 2211. They are however un-encrypted so you should store them in a bank safety-deposit-box or somewhere just as safe.

DougTanner

Posted 2011-12-15T12:12:48.010

Reputation: 106

Don't forget about deterministic wallet generators like Casascius' Bitcoin Address Utility. Instead of needing to physically store highly complex keys somewhere you could instead store (or even memorize) a passphrase which deterministically generates your keys.

– David Perry – 2011-12-15T17:00:23.310

One such paper wallet is

http://www.bitaddress.org

The addresses can be generated when offline (i.e., not connected to the internet) for even greater security. Use a LiveCD on a computer that has no internet connection and then loading the .html page from a thumb drive will give you a paper wallet that is as secure as you can get.

– Stephen Gornick – 2011-12-16T03:18:29.443

@DougTanner Can the archival paper be torn? – Pacerier – 2012-06-18T03:30:36.380

You probably should ask this question on other Stack Exchanges, like Super User, as the question is not specific to Bitcoins really.

Safest place to store your wallet key would be in your memory, if you are a type that can recall a long string of digits many years later. You could try using some mnemonic tricks, like encoding the numbers in a poem with number of letters in each word corresponding to a given number.

If you want something tangible, you should look into putting the key on some medium that does not deteriorate over a long period of time. You can try scratching it into a sheet of plastic, or using some soldering iron to melt it in. You could also go for carving it in stone or cement block, but that would start to get a bit excessive. You can always get a laminating device, print your wallet as a QR code and laminate it, should work well enough while not being too expensive.

It all boils down to how much time and money you want to spend securing your wallet and what hazards you want to protect it from.

ThePiachu

Posted 2011-12-15T12:12:48.010

Reputation: 41 594

Good idea. And unfortunately for me, my memory is one of the worst places to store any kind of important information =P

Also good ideas about the laminator, thanks. – Sean Chapman – 2011-12-15T14:20:29.447

The human body is much more likely to fail than a computer. If it is in fact stored in human memory, you will lose all your hard-earned cash with just a memory-impairment illness. Even with a perfectly healthy body, a small knock on the head will be all it takes to lose all your cash. – Pacerier – 2012-06-18T03:32:53.693

I used this tutorial to backup my Bitcoins for long-term storage. The basic steps are as follows:

Create a Linux LiveCD
Put a TrueCrypt installer on a USB key (or embed it in the above installation)
Boot the live CD and install TrueCrypt
Create two TrueCrypt volumes, one 4 GB with an easy password, another smaller one with a unique ultra-long password
Mount the large volume and install Bitcoin in it
Start Bitcoin and let the blockchain populate and the Wallet.dat be created
Copy down some of the public addresses
Close Bitcoin and move the wallet.dat into the smaller ultra-secure volume
Unmount both volumes, store the smaller volume in the cloud or on physical media

The advantages of this method are as follows:

With a static live-cd you are guaranteed an un-corrupted/virus-free operating system
Your un-encrypted Bitcoin wallet is never stored to physical media (that's just the way TrueCrypt volumes work)
You can backup the small volume containing your wallet anywhere you want because it's tiny and protected by an ultra-secure password
You can send Bitcoins to this backup wallet any time you want with the addresses you saved

To access the Bitcoins in the future:

Boot the live CD/install TruCrypt
Mount both volumes, and copy the Wallet.dat into the large volume
Start Bitcoin and then you have access to your Bitcoins
Remember to delete the Wallet.dat from the larger volume before shutting down

DougTanner

Posted 2011-12-15T12:12:48.010

Reputation: 106

1A USB flash drive has a much longer lifetime than a CD, around 10x. – zaph – 2014-01-01T22:20:49.983

Thanks for the info but I'd rather not store it on a USB drive. – Sean Chapman – 2011-12-15T14:23:26.040

The point is that you can store the TrueCrypt-encrypted volume with your wallet anywhere you want. You could remove it from the USB key and only copy it to the key as-needed. Or burn it to a CD and access it that way if you wanted. Just be careful to not create more than 100 addresses. – DougTanner – 2011-12-15T14:27:06.360

my personal choice to have a secure online bitcoin wallet is :

having a very secure dedicated server ( gentoo hardened, grsecurity kernel . . . )
having my wallet on a ssh account ( with a very secure password, lowercase, uppercase and numbers in the password ) on that secure dedicated server
having backups of my wallet on other dedicated servers
using ssh from everywhere ( now even martphones have ssh client apps ) to connect and use my wallet

neofutur

Posted 2011-12-15T12:12:48.010

Reputation: 1 495

IMO, as a complete beginner, paper wallet with 2-3 copies sounds best. All stored in secure places! I also like the thumb drives, but some of these answers seem ludicrous even to the geeky set, such as "using this tutorial" 2 posts above.

undeRGRound

Posted 2011-12-15T12:12:48.010

Reputation: 9

I don't understand why people overlook the simplest and cheapest option. I personally just hand-write the keys on paper, and for verification purpose, type the private key back into an offline wallet software to ensure the generated address matches.

uminatsu

Posted 2011-12-15T12:12:48.010

Reputation: 1 061

I found a SanDisk thumbdrive in my desk, that I had purchased a couple of years ago. It was on sale, and I never really used it. It has a password protected VAULT in the drive, and it can be (obviously) removed from the computer. I will explore this further... :D

undeRGRound

Posted 2011-12-15T12:12:48.010

Reputation: 9