Bitcoin Forum

Hi,
I've setup an offline wallet at home in a VM with no networkcards. I have a few bitcoins in that VM and when I'm at home I transfer an unsigned transaction to the VM, have it signed, and use that transaction. This is usually good for small transactions when buying pizza or stuff. A few weeks ago, the bitcoin price changed and while I was on the road, I actually had want to sell a few bitcoins, but this was impossible since my coins were very very safe at home.

So i'm wondering how you all use this in a practical way. I usually kept for like 100 US dollar bitcoin in an online wallet for small payments. But if there is a big price change, I would like to be able to respond faster and not rely on my very safe offline VM. And I of course don't want to store too much money in an online account.

Any tips?

Gabrie

This is not very elegant, but you could just keep a USB stick in your pocket with a wallet.dat file on it. Or even a QR code with private keys ready to load.   ???

Buy a Trezor and use it with Mycellium when on the road.

I second this.
Buy a cold storage device that is portable.
You can use Trezor or Ledger Wallet with Electrum at home and with MyCelium on your phone.

The VM is not such a good "cold storage" solution.
If your computer get's compromised the VM could too.

That is what I do, but when at home I sometimes prefer the MyTrezor.com site over Electrum.

Thank you all for your tips!

Bought the Unplugged Ledger Wallet, love it !!!
https://www.ledgerwallet.com/products/6-ledger-unplugged (https://www.ledgerwallet.com/products/6-ledger-unplugged)

Wow, that's a cool toy. I can't keep up with all the new stuff being developed anymore.  :)

VM's tend to be bad at generating randomness so if you sign a transaction with/in a VM, there is a greater chance that the "R" value will be weak/not random.

Although you did not explicitly say this, I somewhat assume that you generated the electrum seed within your VM, and due to the "bad" randomness (mentioned above), there is a chance that your seed may not have as much entropy as you might want.

Additionally, VM's are designed to keep "bad" things (eg malware) inside of the VM, but are not quite as good at keeping "bad" things out of the VM. So if your computer has malware, then such malware might be able to infect the VM as well

Why not keep an encrypted copy of the seed on an USB drive that you'll always take with you?

The moment you decrypt the seed it is compromised.
A cold wallet is much safer.