Bitcoin Forum

I am confused about how to store bitcoins offline,



1. I downloaded the bitcoin core client

2. I went to settings>Encrypt Wallet and made a password.

3. i transferred my bitcoins into the wallet.

4. I went to File>Backup Wallet

5. Now i have a file called money.dat on my desktop


What do i do now?  Do i delete my bitcoin core client?  install a fresh one with 0 bitcoins

and then put the money.dat into a usb key?   and later when i want to get my money just load the money.dat into the wallet

And to get into the money.dat file is to remember my encrypt password that i made up?



I'm a little confused

You install the wallet into an offline computer, then generate an address and done.

Full guide for making a one time paper wallet to store large amounts of BTC offline;
https://blockchain.info/wallet/paper-tutorial

What if i don't have an extra computer? 

Then you can't use an offline wallet. Offline wallets require that you have two computers. You can buy a raspberry pi for $35 and use that as an offline wallet.

Use the guide i told you. The safest way to generate it offline with a online computer would be to use a virtual machine that has no networking. Make the paper wallet then wipe the VM.

Can't i just keep the money.dat file in a usb key, and keep it in storage until i need it?

Yes but that would not be offline or cold storage. It exposes your wallet to an online system so there is the potential for something to steal that wallet and password and thus your Bitcoin.

How it would it be exposed?  I wouldn't have a wallet

I plan to put the usb key locked inside a box under by bed.  And i will uninstall and delete the bitcoin core client on my desktop.



Then in a few years when i need the bitcoins, i will install bitcoin core client and upload the money.dat file, and i should be back in business?

For example you connect it into the pc, and there is a virus that would steal it from usb and send it online, so yeah it's not offline.

Use paper wallets, but remember when you sweep them take the whole amount, or the change will go to the network as reward.

When you generate the paper wallet, do it from a bootable linux live CD, and save the html page, cut off the internet, generate, print and don't go online again with that image, just restart and you will end up with a nice paper wallet, that's too much for storing 5 bucks worth of BTC tho so you might just use multi-bit hd as well in that case.

If your computer is online when the wallet was created, then some virus on your computer logs your wallet password and sends the wallet file to someone else who can now spend your money.

Say the computer was online (you had to be to download Bitcoin Core) so it got a virus. You make it offline but the virus is still there. When you make the wallet, it records your password and copies the file. Then when you go back online it sends it to an attacker and he just stole your Bitcoin.

It doesn't matter whether Bitcoin Core is presently installed or not, as long as the attacker has the wallet file and your password, the money is gone. To be fully secure, you need to create the wallet and any cold storage wallet for that matter on an offline computer that has never been online in the past. This includes virtual machines since a virtual machine running on a compromised host is just as bad as using Bitcoin on a compromised computer.

Yes you have to do it with a computer that never or never again will touch the internet. So a disposable VM or a linux booted is indeed ideal.

If at any point during or after the wallet creation the computer is connected to the internet, the priv key is never guaranteed to be cold storage.

ok wow!

that's all way to complicated for me at the moment,


For now i will just keep the wallet.dat file on a usb stick,  I'm pretty sure i don't have any viruses.  Im careful to click on things.


And i've had my wallet.dat file on my desktop for several days now and and my bitcoin core still says i have the same balance.

I'm new to bitcoin so i am unable to do the paper wallet.


I will read more about it and try to make a paper wallet when i am more advanced, and have more money in my wallet,

at the moment i don't have more than 1 bitcoin, so i think i should be ok


thanks for the info everyone!!

Users above are more than paranoid ;), you explained everything right in your first post of this topic.
You can delete bitcoin core now, you have backup with your private key (which allows you to spend your bitcoins) in money.dat on USB stick.
Password is additional security.

Good luck in bitcoin world!

Yes but remind him to have 2 USB sticks because if one can get damaged the guy don't know his private keys, he should print those too! security is number 1.

XD

What i was trying to say is. Doing that does not give any more security than just leaving the wallet there. There is no point after generating a hot wallet, to uninstall the wallet and put the wallet on a USB key.

It add 0 security.

Having a backup on a USB key is only for redundancy in case your HDD break.

I understand now, btw generating a vanity address on your server was like 0.8 and I can't afford it so please cancel that order, I will think of a shorter name and try again.

Hopefully its OP that will understand as well. Otherwise he'll go through loops that does not give any protection. The best thing he can do is secure his wallet environment as much as possible.

And the beginner way to do it very securely is using a VM.

private keys???     oh no!!!

I didn't get the private keys,  Is it too late?  I already uninstalled the bitcore client


Where are these bitcore private keys?  Why do i need these,  I thought all i needed was  the wallet.dat & Passphrase

I wasn't aware about these private keys


I saved my passphrase in a textfile inside the usb key along with the wallet.dat


is it too late?? did i do it wrong?? did i lose my money??

No, you are fine. The private keys are stored in the wallet.dat. They are protected by your passphrase. As long as you don't lose that file and no one is able to get it from you, then your Bitcoin is safe.

(@OP: You are confusing holding/keeping the BTC with SECURING the BTC, what you are doing is not security, it is only adding liability.)

He is not. From what he said, he did a hot wallet, which means uninstalling the client and putting it on a USB key still leave the priv key possibly exposed, since he did not have a secure, offline environment when he generated the priv key.

This is not cold storage.

TLDR: Uninstalling the client and putting the dat on a USB key add 0 security whatsoever.

I agree, there is a chance of 0.1% it could be already logged somewhere waiting for pickup, when dealing with money that's really is a big chance.

If you can lose 1 satoshi same apply for 1 btc.

Only offline storage would be trezor, paper wallet, deck wallet, some form of live cd on a disconnected pc, encrypted VM.

I will let this go just not to confuse the OP as he is new, but he will find the way sooner or later.

The key phrase to my response was no one is able to get it from you, which in this case, he is making it easy (relatively) for someone to steal the Bitcoin from him. However as long as he has the wallet.dat file, then he has the private keys and he will be able to spend any Bitcoin associated with the addresses associated with those private keys. Whether the Bitcoin remains there is up to his security, but he will continue to possess the private keys necessary to spend what is left as long as he has the wallet.dat and it remains uncorrupted.

I said he is not (fine). Because what he did just weakened his security/increased the chance of losing his BTC. Hopefully he at least *did* encrypt the wallet.

I do not use memory sticks at all, due to the vulnerabilities with the BadUsb exploits targeting the USB firmware. I would rather download the whole bitaddress.org website and transfer it to a offline computer and generate the paper wallets there. Print it and keep it safe and never go online with the old computer you used to generate it.

It has worked for me for years, and I have not lost any coins since I used this method. The printer buffer should also be cleared {hard rebooted} if you going to use it again in a online environment.

too much hassles for an offline way, you can store online and be 100% safe anymore

you just need to do a secure erase, if you are paranoid about a possible bios virus, then buy a new motherboard altogether

then simply do a backup on your usb

Why are you trying to generate vanity addresses? Just use bitaddress.org and download it offline to generate an address.

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OP, it would be an easier solution to use Electrum offline and copy the seeds down. There is a nice interface for generating raw TX and signing raw TX offline. It is easier than managing an USB which can get corrupted easily. If possible, just get a raspberry pi and install electrum offline there.

Btw, uninstalling Bitcoin Core does not delete the data directory which allows attacker to gain access to your wallet.dat. You have to manually delete the data directory.

To control bitcoins you only need a private key, which is a combination of characters thats about 32 long. All bitcoins are inside the blockchain and cannot be taken out. By owning a private key you can make a transaction on the network.

To make an offline storage, simply export your private key and store your public key together in a safe place.  :)

You do  not want to wipe your client and start a new one.  There is no need to do this.  Once you download a new client, and use your backup, you are basically making it into the same client you had before.  This is what I did to protect myself;  I bought a removable hard drive and installed my client on to that hard drive.  When I need it, I connect it through my USB.  When I do not, it is offline and no one can touch it.

Wanted to make a cool address like 1anonxsakdjksajdaksjd ut anyway I compiled vanity and in my CPU did't take long :D

When you connect it to your PC, it's just as vulnerable as anything else. As such, this is NOT protecting it at all.

google a paper wallet they work great