Bitcoin Forum

I've recently moved my cold storage to a hot wallet for a purchase which never went through, I'm looking to make a new cold storage but a quick and easy efficent way. Which is 100% safe from online attacks. I have a spare computer which has been on the internet before and used for a short while but I'm going to be wiping it clean soon.

I don't want to use the Bitcoin core client as it takes me around 3 days to sync and I need to get my coins into cold storage as soon as possible. Whats the quickest, easiest and safest way to do this?

Trezor is out of the question as I see my Bitcoin worth too much to spend 0.2 on it, if I could pay in cash for it I would.

There was a site which allowed you to do it quickyl and easily but I'm not sure how safe it is. you can always use the blockchain.info method which seems pretty safe to me.

1. Go to blockchain.info.

2. Create a wallet.

3. Download the paper wallet in PDF format and print out. Write the password on it.

4. Send your coins to this address.

5. Remove all digital copies of your blockchain.info password and the PDF.

Bither wallet can meet your requirement.
https://bitcointalk.org/index.php?topic=606238.0

Not bad, but you can also find this feature on coinbase, can't you!?

Thanks, but this requires me to be online to be able to do it right? So wouldn't this be a flaw and if my computer is infected or is connected to the internet it could be a vunerbility? I have considered doing this but because of this flaw Its stopped me from doing it. I will be doing a clean reinstall of Linux Ubuntu to do this so it should remove all viruses but I'm still concerned about connected to the internet and doing this.

Safest is paper wallet
you won't find anything safest
download the paper wallet program in a safe computer and disconnect from internet
after that you can generate many wallets and just use one

If your offline computer has a webcam then you might consider using CIYAM Safe to do 100% "air-gapped" offline tx signing (https://susestudio.com/a/kp8B3G/ciyam-safe).

It is a SUSE distro and is not a "point and click" UI (sorry) but does have instructions and has been in use (by myself and at least a few others) for quite a long time (no bugs have been reported).

This is probably what you want.

https://bitcoinpaperwallet.com

The easy way to go about that then is to put Ubuntu on a USB.  To be extra safe about viruses or malware then unplug your hard drives (I don't think it is necessary though).  Boot Ubuntu from USB on startup, follow the instructions above.  Afterwards format the USB.  

I don't have a lot of bitcoins, but if I did, I would use blockchain and follow the above steps.  It is pretty easy and from start to finish could be done in under an hour.

On your computer that is not connected to the Internet load vanitygen.

Run it to get public and private addresses.

Save, encrypt the private keys.

Send bitcoins to the public addresses.

If using vanitygen then I'd advise that the "output" be encrypted immediately rather than "appear on the screen" (that could be fatal if there is a camera "over your shoulder").

the  quickest at the same time it is the most unsafe!

sorry, but ... after 3 months of study ... and 5 months of process : only the bitcoin core is able to work for cold storage without problem.

https://bitcointalk.org/index.php?topic=763970.msg8608715#msg8608715

because it don't depend from 1 and unique developper.

because, it's the only way that bitcoin network work ... from miners using the bitcoinj (in pool server) or nodes (like me) using a "always on" bitcoin core.

and compared to the hell of administration of a bank, dedicated PC running ON 24h/24 with a bitcoin core in "nodes" command is not a big deal (the 25go ... too).

you can run this bitcoin core on a 100 USD portable PC loosed is the WC if you want ... behind the rool paper  ;D

bitaddress.org is open source and has been reviewed by several developers.

You can download the webpage and then transfer it to your offline computer to generate as many addresses as you like.

Also note, if you are just using Bitcoin Core (bitcoin-qt) to generate cold storage addresses, then you don't need to wait for it to synchronize.  You can install it on an offline computer and leave it permanently disconnected from the internet.  You can then generate as many addresses and/or wallets with it as you like.  Just make sure you keep good backups.

I think Coinbase's new feature, the Vault, is as safe as it gets in terms of online storage services. The only thing is, it takes 48 hrs to withdraw your BTC so if you need to access your BTC urgently, it would be a problem. But then again this cold storage service is really meant for big amounts of Bitcoin. Why don't you just save your encrypted wallet.dat file on a pendrive? Instead of using the Bitcoin core client, you could use Multibit or something. That would be pretty safe.

I would never trust more in an online service that in a paper wallet under your control
would you store there 100 btc?

Go to localbitcoins.com (or coinbase or circle). Use your cash to buy 0.2 BTC. Buy a trezor.

Well an online service is the best option if you travel a lot and would like to have access to your Bitcoin anywhere. I mean you could carry your laptop around with you but that's just too much hassle for me, plus you'd still be at risk. Also Coinbase is actually insured against theft and hacking  :)

Absolutely this.
- Go to https://www.bitaddress.org
- Press [Ctrl] + [S ]
- Choose the "HTML only" option
- Save the file on a USB drive and copy it to your offline computer.

I checked out this website.  It looks really good.  A very nice and easy way to create pretty safe cold wallets.  If I get enough bitcoins, I will definitely use it. 

For right now I don't have hardly any and I keep them divided between Blockchain, Coinbase, and Circle.

next time , sign a offline transaction using your cold privkey , you dont need to move

Install core client on offline machine.  No long blockchain download required.  Export private keys as needed.

Why Ctrl+s?

I would download directly from github in zip format.
https://github.com/pointbiz/bitaddress.org   (download zip)

Then you can open this zip for the first time using your offline computer.

Try paperwal by deepceleron.
https://bitcointalk.org/index.php?topic=361092.0

An offline bitcoin paper wallet (android app): https://play.google.com/store/apps/details?id=ru.valle.btc

They said a floppy disk is the safest wallet.