Multi-signature cold storage?

[ArcCsch]

I am considering to buy bitcoin in tangible am mounts, (more than the couple of mBTC I made at a faucet) andneed a way to store them, I have access to 3 computers (and 1 printer) and my scheme goes as follows:

Generate 3 independent long strings (50 rolls each) key strings using dice.

On each computer, go offline, generate a key-pair (prferably use different software for each), encrypt the private key with one of the strings, go online, and print the result.

Combine the addresses into a 3/3 multi-signature address.

Place the 3 private keys, with their respective key strings, in an envelope.

To receive coins, have them sent to the multi-signature address.

To spend coins, decrypt one key (offline, preferably on the same computer that generated it), sign the transaction, delete the decrypted key, send it to the second computer, go offline, decrypt the key, sign it, delete the decrypted key, repeat this for the third computer, and broadcast the transaction.


Is this a good way to store coins?
I am not clear on some details, how do I preform this procedure?
Is it a good idea to test the set-up with pocket change and reuse the same keys for large amounts?

[thejaytiesto]

Seems like a good idea, but im not too keen on multi signature to be honest. You have to think that it adds an added layer of stress by having to keep safe a couple different papers and if you miss X amount you might lose access to the coins.

I think it's better to simply make BIP38 encrypted wallet, print several backups and that's it. Generate it offline and so on.

[NeuroticFish]

From what I know normal paper wallets (normal keys) are safer (more future proof) than multisig.
If you want to keep your money safe for long time, why don't you just make a safe, offline PC (pen drive linux?) where you generate (offline) a ton of paper wallets (address+private key pairs) and print them.
You can keep the addresses at hand (save them anywhere, another stick for now?), wipe that temporary system and get the addresses back to the live computer.
Now you have some list of private keys on paper (as many copies as you want, maybe some laminated too) which are safe from hackers and you can fill those wallets with the amounts you want.

When you want to spend, import one private key and that wallet goes live (hence the idea of having more wallets with smaller amounts).
This is OK if you don't spend often, of course.

[unamis76]

You idea seems well constructed but I think it's an overkill. At least for me, it would be. Unless you don't value ease of use and practicality and only value safety. I'd rather a cold storage system with one software that I know how to work with. Makes things simpler for spending when needed. Your idea is maybe more secure, but a robust cold storage should be one you're comfortable using and it is easy to use. If you feel it's easy enough for you to deal with your scheme, feel free to ignore my comment...

[U2]

Place the 3 private keys, with their respective key strings, in an envelope.

This kills your idea. If all 3 private keys are in the same place then you might as well just have 1 private key. My suggestion would be to store them in different spots. Even if it's one in your attic, one buried in the backyard and one in a picture frame. I would never keep all of the private keys together. At least one of them should be somewhere extremely secure (eg. safety deposit box) IMO, but if that's not economical then hiding them in different spots is the next best thing.

[Red-Apple]

this sounds like a pretty good idea and if you feel safer this way then go for it. but remember that your way of storing the private keys (in an envelope so i am assuming it is printed on a paper) is not a permanent way and paper deteriorates over time.

i personally prefer a simple cold storage with a simple (1) bitcoin address but on a live linux.