Bitcoin Forum

Greetings,

I have a couple of BTC in cold storage on an offline computer.  I want to do a complete new reinstall of the OS on my online computer, which entails reinstalling the Armory wallet.  However, I want to leave the offline computer untouched.

Is this possible or do I have to reinstall the same new armory wallet on the offline computer as well?

If someone could outline the coarse steps / key things to watch for, or could just point me to the right thread.

Pardon the noob question but I don't want to mess it up.

Thanks.

wait wait. I am not an armory cold storage expert, but just reinstall OS on online computer and install whatever you want.

Do not touch offline cold storage one and thats it. BTW arent you afraid of HDD fails? Cold storage should be made on some durable device.

You dont need to change anything on the offline computer. You'll need a watching only copy of your wallet on the online computer, once you're done setting it up.

Your situation boils down to Armory version mismatch with the offline signing scheme. While upgrading Armory on your offline machine will provide you with new features (like fragmented backups), you can use version of Armory as old as 0.7 on your offline signer with the current version of Armory. In general, the version of Armory you have created your wallet with will be able to sign offline transactions emitted by newer versions of Armory.

OK, that makes sense.  Great.  Thanks.

By durable, do you mean besides digital and paper backup.  My impression was that those are sufficient for recovering from HDD failure.

Those are sufficient indeed.  You also need the offline computer if you actually want to access your stored bitcoins.  So your setup is sound and perfectly normal:

• Online computer with newest Armory, and a watch-only wallet.
• Offline computer with some old version of Armory (was new when installed, but that was long ago!), and the full wallet.
• Digital (probably encrypted) backup on one or more USB sticks, CDs etc, stored safely.  If properly encrypted, even storing on Dropbox is an option.
• Paper backup (not encrypted) in a safe e.g. in the bank; or better yet: An N-of-M paper backup stored multiple reasonably safe places.
  

Ok, great explanation, very useful.

Couple related items:

1) Regarding the N of M approach that you mention, is the easiest way just to have say five sheets, each with a fifth of the code sequence/keys that shows up on the paper backup or is there a better way.

2) Also, any recommendations/resources for creating bomb-proof, yet easy to remember pass phrases.

Thanks

We all hope everything will be OK :) and just do what was told and sleep well.


Cheers!

The newest Armory has an N of M paper backup.  If you make a 3 of 5 backup, then you print five sheets of paper, each with a code on it.  You can restore the wallet from any three of these.  If a thief gets two of them, he has no information at all about the wallet.  If you lose one or two of them (fire?), then you can still recover your funds, as long as you have three pieces left.

It is using Shamir Secret Sharing, http://en.wikipedia.org/wiki/Shamir%27s_Secret_Sharing


Any passphrase that is easy to remember will be insecure.  Any passphrase that is secure will be forgotten :)

Seriously, you could use a sentence that is partly nonsense but still meaningful to you.  Or a sentence that is meaningful to you, but only use the first three letters of each word. 

OK, great.  Will have to implement that.