Confused. How to store bitcoins offline - page 2.

VirosaGITS

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Quote from: achow101 on December 07, 2015, 07:53:38 PM

Quote from: joe101 on December 07, 2015, 07:39:31 PM

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?

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.

achow101

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Quote from: joe101 on December 07, 2015, 07:39:31 PM

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?

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.

anonymousx

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Quote from: joe101 on December 07, 2015, 07:39:31 PM

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.

joe101

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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?

achow101

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Just writing some code

Quote from: joe101 on December 07, 2015, 07:28:59 PM

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.

joe101

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

VirosaGITS

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Quote from: joe101 on December 07, 2015, 06:21:21 PM

What if i don't have an extra computer?

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.

achow101

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Quote from: joe101 on December 07, 2015, 06:21:21 PM

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.

joe101

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What if i don't have an extra computer?

VirosaGITS

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Quote from: joe101 on December 07, 2015, 06:05:52 PM

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

joe101

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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

Topic: Confused. How to store bitcoins offline - page 2. (Read 1601 times)