Bitcoin Forum

So I grabbed a few BTC and I want to put them into cold storage for a while. I have been browsing and I think that a wallet that gives me a 12 word seed phrase would be best. I am thinking about Electrum. Would you guys agree or do you have any better (if possible free) alternatives?

Thank you!

Whether or not electrum is for you depends on your needs. If you are just looking for cold storrage electrum should be fine. It does not require much in terms of hardware and is quickly installed and ready to use. I would suggest you use electrum 2.x.x (currently 2.5.1(2) AFAIK), which works with 13+ words as seed.

Electrum is good to go.I would also write down the keys somewhere and hide it safe.It is better to have 2-3 different methods of saving your coins in cold storage. I also recommend to safe the wallet.dat at least two times if you use usb or external hard disk drives.

Great, thank you!



Thank you for the tip. But why should I save the wallet.dat? Wouldn't the seed phrase bring back my coins?

Its just an extra layer of security. If your seed is lost for some reason and your offline system is no longer working, but you still have your password and a backup wallet file you can still access your coins.

Why dont you try paper wallet.They are more secure unless you live in a disaster prone area.
You can create one at blockchain for free.

I was reading about paper wallets but what seems to be the problem here is losing change. Am I right? How does one avoid it?

To avoid issues with change you send the change to a fresh paper wallet. Either directly with the transaction you issue or you 1st swipe the private key (thus transfering the funds to a different address of the wallet you use), create the TX and afterwards send the rest to your new paperwallet. The last approach requires 3 transactions, the 1st only one. I would prefer the 1st approach, but it might be a bit tricky to get the correct amount with fees depending on the wallet you use that leaves no rest.

A little of topic but you should seriously consider a hardware wallet like Trezor.

When I started out I also made paper wallets and had Electrum as my 'daily' wallet. Things became a bit complicated or rather a bit of a hassle when I needed extra coins so had to use some of the paper wallets and also the storage of all the details of each wallet etc...

I eventually invested in a Trezor and its the best thing I could have done. I now just have one wallet that does it all. Its a daily 'hot wallet' but also a 'cold storage' wallet at the same time. You also have the ability to create multiple wallets on the trezor so you can easily have say 5 bitcoin wallets, 5 litecoin wallets etc. without any problems and all of them are recoverable from a single seed so no need to store tons of wallet details, just the one seed.

If you have an Android phone then things are even better as you can make use of MyCelium that interfaces with the Trezor so you can access your Trezor while you are on the go, no need to wait until you are back at your pc. And if you are already familiar with Electrum you can use that to manage your Trezor wallets on your pc, if you want. Electrum picks up all the accounts so it will show you all the wallets on the Trezor in a watch-only mode until such time as you plug your Trezor in and enter your pin.

I'm not saying that paper wallets and the like do not have their place, just that life is so more hassle free with a hardware wallet. It is really the best of both worlds and in my opinion well worth the cost.

the best tip is to hide your paper wallet if you will use it as a cold storage in a place where no one could find it and steal your money

What i use for cold storage is this:
1. Put your bitcoins into blockchain.info.
2. Generate a paper wallet for your address which contains your bitcoins.
3. Get a print of the paper wallet.
4. Delete the address from blockchain and again put the address online as watch only.
5. Keep the paper wallet safe and use it to retrieve the bitcoins when you need it.

It defeats the purpose of an offline wallet to use a third party who can know your private key.
I strongly recommend against using this method.

Blockchain.info stores your private key encrypted on their server. You aren't supposed to let any third party know about your private key, whether encrypted or not. I would go for bitaddress.org instead.

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I would go for Electrum on a offline computer if I want full security and broadcast transaction on another computer separately.

I see people recommending Electrum for a cold storage. Electrum is not a cold storage. Electrum is a lite weight, hot wallet.

You have two options for a real cold storage! These are paper wallets or one of the hardware wallets. For the hardware wallets, I suggest Trezor, the best one in my opinion. It is a bit expensive, but it's well worth of investment if you have a but more coins, I would say 10+ coins.

Of course there are other hardware wallets as well. There is a list somewhere with all of them listed and presented.

But after you delete the address from you wallet they delete the encrypted private keys too(that's what i know, correct me if i am wrong).

They may. I'm not too sure about that. Even though the code is opensourced, they could easily change the server such that it doesn't completely erase the private key. Still, you would not be able to securely generate your keys since they can easily capture it. There was once a vulnerability which affected the RNG and costed user lots of BTC(Update was pushed without acknowledgement of users). I wouldn't take the chance.

the only tip i would give is to hide it in a safe place i think

You might want to go with a secure physical storage as well. I like to place an un-encrypted copy of my cold wallet on a thumb drive then place it in a safe deposit box at the bank. It's one of the few services banks sill have to offer me.

Just dropped a support request to blockchain.info regarding this thing(don't know if they will reply or not). Also, to my knowledge the returned back the users what they had lost.

Yes they did. It happened to android wallet recently too. Do you think its acceptable? No for me. Refunding the losses is one thing, not learning from their mistakes is another. Furthermore, both of the incidents could have been prevented easily.

Electrum is a very recommended wallet.

But just the cold wallet is not enough.

You should think about backup, antivirus protection, firewall...

Remember to set your cold wallet as "only read" when you connect it to internet for updating...

You dont connect to the internet for updates with a cold wallet. The point is that its offline, you dont need updates on an offline system.

Paper wallets are as bout as cold as it gets. You set up one print it off from a safe printer, and make it on a computer that is for sure clean and has no malware/virus problems.

You put this away in a safe, or safty deposit box.  Something very secure to hold it, also have a few copies in case as you don't want one copy incase something happens to it.

But then use a phone app, or blockchain to view your address without having access to your account.  it is nice since you can watch it hopefully grow and not have to worry about connecting to internet and becoming a hot wallet each time you want to see how much you have.

Recently I set up cold storage for my funds. What I did was I set up a spare Raspberry Pi and I installed Electrum onto it which acted as the storage its self.
Since I have the addresses on my main PC to send the funds to, I don't intend to turn on that Raspberry Pi until I need the funds out of that wallet.

a hardware wallet is good too:

https://bitcointalk.org/index.php?topic=899253.0

hardware wallet would be the best but if you cant afford it you can use armory on your computer or something like that i think

If you have your own spare computer you can use that as a cold hardware wallet too. Basically run Armory on a 100% offline computer and us it to sign transaction in the rare case you need to.

Cold storage is pretty much for storing BTC for a long period of time so you could even do this on a VM, for the same level of security.

Actual hardware wallets are good when you move a lot of BTC often. So i see them more useful for hot wallets than cold storage.

You dont need pass phrases, its not vanilla bitcoin. Plain and simple paper wallet is good enough, laminated tho to not beign easily, damaged :)

One thing to keep in mind is to not keep your eggs in one basket. Diversify your funds in different cold storage methods.

I think hardware wallets are only a waste of money.
Instead I suggest to use Electrum in its portable version. Just put the wallet in an USB and keep this device in a safe place.
For better security you should write your seed in 3 or 4 different places ( for example a sheet, a file on another USB and of course your brain too  ;) ) .
Imho acting this way your coins will stay very safe.

First of all you should pick what software will you use to generate the cold wallet Keys.

Second and most important: you should create your cold wallet keys offline.

You might wanna use ARMORY

I fail to see how it would help. A malware can still infect your computer and capture whatever information needed. Or in theory could damage the randomness of signing of your transaction. (It's in theory, not sure if possible)
There isn't a need to connect it to the internet unless there are protocol changes on the signing of the transactions. You can download the transaction from an online computer and sign it on the offline computer then broadcast it on the online computer.

And if that even happen you can update the software offline anyways, pretty much the same way you plug your usb key from one computer to the other to sign the transaction.

All in all Armory is indeed very handy. Which is the one i would use to do this.

+1 for Electrum

You can easily take your wallet.dat file and save it on a USB somewhere and then delete it from your computer

Agree to that. Saving your paper wallet in a truly safe place is essential to ensure your Bitcoins security. Hackers and thieves are adapting to the latest technologies. Any place off-grid seems more secure than the traditional ones online.

hardware wallets are an option but i would not go for these if i were you, if you want to store for long time the of course not they are good flash drives but still  flash drive which can be currepted and after all its an electronic device it can fail, paper wallet is they way to go

If you're going to store Bitcoins for long term, you need multiple copies of it with layers of protection to prevent any damage to it. IMO, hardware wallets are great for frequent use as it is hard to get infected compared to spending from a paper wallet.

I had one paper wallet created as an offline wallet. I know how to import it on blockchain.info. Can anyone tell me that how can i import that address, along with private key to bitcoind on Ubuntu using command line?

Is there somewhere in the forum like this for all the different wallet types. I thought I had a pretty good understanding about how to set-up a paper wallet, but after reading this I'm not so sure. Basically what I would be looking for is these are all your options for a hardware/hot/cold/etc wallet. These are the pro's and cons. These are the recommended options. This is one example of how to set up your hardware/hot/cold/etc wallet. Maybe something like this is a bitcoin wallet best practice procedure. Or does everyone differ too much to have a best practice bitcoin wallet system?

there are some good paper to use and good printer still multiple copies are more efficient its all depend on what are you storing how much it is ofcourse if you are storing 100 BTC then spending 0.5 BTC for it will not hurt anything

If your wallet has a password, use this to unlock it.
Next, to import the key, you have to use this.

You have to unfortunately type the entire private key word by word, it must also be case sensitive.

Don't I have to type in the address somewhere along with the private key? Or the address automatically gets imported.
Thanks for all the info though.

You don't have to do that. I don't know any wallet that requires you to do that either. Address is easily retrievable from the private key.

Public keys are easily calculated from private keys.  Private keys are nearly impossible to calculate with the public key (brute force very large key space required).  One of the great reasons Bitcoin works!

Just for clarity, a bitcoin address is not the same as a public key.

The best option and most secure is a paper wallet.

You can make one via many websites, eg blockchain.info

Cheers
LondonTrader

If you make the paper wallet from blockchain it kinda defeats the purpose.  Blockchain is a hot wallet.... so getting the wallet there for the cold wallet is not the best idea.

There are much better way's to get paper wallets.   Do not get them from a hot wallet or you still have all the security risks of the hot wallet you got the private key from (in your suggestion this would be blockchain).

Blockchain.info stores your private key on their server and hence isn't secure. Encrypted or not.

Instead, try downloading bitaddress.org. They offer userfriendly UI and secure generation. The paper wallets also have a Qr code on it. It is more convenient when using it with mobile wallets.

nah it is not the best, there is the well known problem with the printer and their memory

i find usb much more secure, if you buy many of them, and much faster

and i would avoid webwallet like the plague, for anything really...

I thought a seed was a paper wallet, no?

You can easily place backups at different locations and laminate all of them for waterproofing.  It is a cheap option to secure your Bitcoin. USB thumbdrives are likely more vulnerable to water damage though. Trezor is water resistent but not waterproof. It's very expensive too.
Technically yes. But some seeds are only used by a specific wallet client for generation and isn't universal. Arguably, private keys are accepted by all the Bitcoin wallets.

Technically the Trezor really depends on how many coins you hold.  For a wallet of 1 or 2 yes very high.  But if a decent sized holder it really is not horrible.

And I would get the private key.  With the private key you can put it in most any wallet.  And really paper wallets even if laminated do not withstand fires, so I would not just keep copies in home as if something bad happens... it could burn with the home which would be horrible ontop of horrible.  If you have a safety deposit box at a bank that is best spot for paper wallet.

I think they stopped producing them but they are still available via Amazon etc...
Mycelium had a USB stick on the market that generates images of paper wallets when inserted in the USB slot of a printer.
The printer sees it as a regular USB stick that has the image of the wallet on it, with QR codes etc... Should be totally cold that way.

https://mycelium.com/entropy

Paper wallet has always been my best bet.

Hardware wallets really are kinda taking over in some aspects.  They will never take over paper wallets completely, but a hardware wallet that can send even if using on compromised computer like Trezor and still be secure... is impressive.

Paper wallets are great long term storage but when you load a  paper wallet into a wallet and use it, is when you have some possible security risks.

A lot of replies here, let me give you the best option, for a large quantity of coins forget the trouble of paper wallets, cold offline storage, I am sure you can buy a hardware wallet, I recommend trezor , but if you want  a cheap one even Ledger Nano does the job for just 20 USD. If I had large quantity of coins over 10-15 I would buy one.