Offline machine & tools to store BTC

[MrVodnik]

Hi again!

I am going to buy a couple more of BTC, and invest in it on monthly basics. Until now, I am using Bitcoin Core on my local PC and some lightweight wallet on my smartphone, but as I would like to hold bigger amount of BTC for a longer period of time, I am concerned about safety.

My idea is to buy an old laptop, that will be completely offline (turned-off/unplugged LAN devices). I'd use it to keep my private key and sign transaction with. I would communicate with it only with USB stick to migrate signed transactions outside. Private key would be offcourse saved on a paper copy(ies) as well.

Questions:
1. Is this do-able? If so, how can I sign transaction on an offline machine? Which tools should I use?
2. Could I do it with a tablet as well? Do you knwo any tools?
3. Do you see any security issues with this approach?
4. Do you know any tricks, to make paper copy of PK more secure? Less readable?

And yes, I did consider Trezor, but I decided to do it the other way.

[Kprawn]

Using a USB stick, as you called it, does not make your strategy bullet proof. There is always the possibility that you might carry around some nasty exploit in the firmware of

the memory stick. See this for more details : http://arstechnica.com/security/2014/07/this-thumbdrive-hacks-computers-badusb-exploit-makes-devices-turn-evil/

I'd just use the old computer to create some BIP38 encrypted Paper wallets and keep all transfers from external media away from it. Just print you private keys on this "offline"

computer and you will be fine.  ..{Use a old printer too... and do not use it on a online computer... some traces might be left in the printer buffer or firmware}

[altcoinhosting]

cp1 is giving a proper tutorial here:

https://bitcointalk.org/index.php?topic=241730.msg2563355#msg2563355

If you follow it to the letter, you should be fine