Bitcoin Forum

Hey guys!

I have been using exodus for a while, but with exodus I cannot confirm if my keys are stored on their server for my bitcoin wallet. I have also been wanting to put my keys in a cold storage. Do you think that electrum wallet would be the best for this?

Electrum is open-source and you can be sure that you are the only one who has control over the keys.

If you want your wallet to be 100% secure, you should generate the wallet on an air-gapped device. This means that you should use a device which has never connected to internet and will remain offline forever.
Note that your keys shouldn't touch the internet even when you want to make a transaction. You should create an unsigned transaction in a watch-only wallet, sign it on the air-gapped device and broadcast it using an online device. 

When comparing a closed source wallet (eg. Exodus) with an open source wallet (ie. Electrum) it is obvious that the open source wallet is superior. It is so much better that Electrum also has reproducible builds so you have be more confident that the binaries you download should be compiled from the same source you see not a different modified one.
Considering that Electrum is also one of the oldest wallets around (I believe it started in 2011) that gives it a higher score.

Just make sure you download it from the actual website/repository and verify signature if you download the binaries instead of building it from source. Here is a guide: https://bitcointalk.org/index.php?topic=5240594.0

For the record: that's impossible with you existing keys from any hot wallet. You'll need to create new cold private keys.

And if buying new device (which never connected to internet) feels too expensive/unnecessary for you, you could create bootable linux (such as Tails) on your USB drive. But the downside are you need to manually unplug Ethernet cable and don't plug the USB drive on computer which already booted.

If you have an extra laptop lying around, you can do a complete wipe to it and never connect it to the internet. There, you can do the advice from hosseinimr93. It's better to create new keys when doing this and do not import your old ones.

Maybe you can find the time to checkout hardware wallets as well, such as Ledger and Trezor. This could be useful if you don't have an extra device to use for the air-gapped device.

Sorry, I worded that weird, I ment that I wanted to generate keys on an air-gaped device, then moving my coins to the cold storage wallet, thanks for the advice!

Not the best but its feature comes with cold-storage support.
Follow this article for the procedure: https://electrum.readthedocs.io/en/latest/coldstorage.html (https://electrum.readthedocs.io/en/latest/coldstorage.html)
(screenshots are outdated but the steps are still good, except you won't use "save" but "export" to save the Raw Transaction to disk.)

For Cold-storage, there's also Armory if your want to have more privacy, but it requires the full blockchain and other database (400GB+) to work.
Website: https://btcarmory.com/ (https://btcarmory.com/) | Bitcointalk Board: https://bitcointalk.org/index.php?board=97.0 (https://bitcointalk.org/index.php?board=97.0)

Be aware that Electrum can be both a hot wallet or a cold wallet, depending on how you use it.

If you have a spare old computer or laptop (or are willing to buy a cheap one) which you can format, unplug all connectivity hardware such as WiFi cards and Ethernet cables, install a clean Linux OS, and use for nothing else except loading your Electrum wallet, then that is a good choice.

If you don't have a spare device, then rather than dual booting or loading from a live OS USB on your main computer, I would opt for simply buying a good hardware wallet, as it is far easier to use and far harder to make a critical mistake which leaks your private keys over the "non-airgapped" side of your computer.

It's not enough to just not connect to the internet. There should no longer be a possibility to do it. You need to make sure that you don't have the required hardware to ever establish such a connection. That entails the Ethernet and WIFI card.

If you do that and import keys that were once used with a hot wallet, they will remain as keys that were associated with a hot wallet. You are just using them in a safer environment now, but they are not secure, and remain potentially vulnerable depending on the software they were generated in.

I never thought about that before when I tried it the first time. I just input in the wallpaper and a bunch of words that say "Do not connect to the internet" if there's someone accessing my air-gapped laptop. That's a better way of doing it, making sure no connection. Well, I just opt for a hardware wallet when I had the chance before, never regretted it.

It's better to be safe than sorry. Paying for the transaction fee is better than paying with your whole wallet.

I was thinking of removing the wifi card. I think it's kind of replaceable, depending on the laptop of course but de-soldering is easy, you just need a soldering iron though lol. Maybe you can search for your laptop on the internet and see a Wi-Fi hardware upgrade and then find it just to remove there. Better take the hardware wallet route lol.

Not everyone even knows what a soldering iron is and they might think it's for clothes lol. Anyway, almost anyone can do a video search and see how it's being done. It just keeps on getting complicated.

That's if they are experienced with Linux.  :o.

Run this two lines I guess for Windows

I will most likely run a cold wallet on an Ubuntu machine, thats never been connected to the internet before, Ill open it up and take the wifi card out of it.