Does anyone keep an updated blockchain on his airgapped laptop?

[takuma sato]

Most people would have 2 laptops using linux with a distro of choice. The laptop that signs transactions (cold wallet) wouldn't even have wifi card, bluetooth or anything wireless installed. This laptop does not have an updated blockchain. If you use Bitcoin Core I asume you would just install Bitcoin Core, open it, and basically leave it as if it wast trying to synch, but since there is no internet, it never synchs, and you just generate PSBT file and put it on the other Bitcoin Core laptop that has a watch only wallet with a synched blockchain, then broadcast it into the network.

Thing is, I always thought he hot wallet laptop looks kinda "ugly" or offputing, it just looks like you have 0 funds, and its trying to synch, but since there is no internet, it's just there doing nothing.

What if you save the blockchain files from the hot laptop and put them into the airgapped laptop? this way you would see your funds in your airgapped laptop too, it would be cooler than seeing 0 BTC. I know this is just all mental because what matters is that the hot laptop shows the correct funds, but if you have a lot of free space doing nothing, I thought maybe i would just put in there the blockchain files again, and you would have a backup of it just in case. The problem of this would be, how to send the blockchain files safely to the airgapped laptop's drive. An USB stick may be infected. There are some alternatives, like optical disks. There are some huge capacity disks available that may be a good idea to have for backups. Last time I checked, you would be able to write to these disks without closing the lesion, so you could just update them with newer blockchain files from time to time, and copy them on your airgapped device. This way you would have 3 backups of the blockchain, and being able to see your actual funds on the airgapped machine safely which is cool. And I say safely because I doubt you can put a virus on an optical disk from doing this.

Anyway let me know your views on this specially those that use 2 Bitcoin Core instances for this (one for airgap and other for broadcasting)

[Yamane_Keto]

Transferring blockchain files will always force you to do this every time you want to spend, but why do you need to do that when you can import your MPK to full node/ SPV wallet?

Instead of using flash memory, CD or USB disks, you need to install a camera in the airgapped, sign the message, show the QR-code, broadcast the transaction, and  you will be 100% guaranteed that there are no viruses or weak spots in the airgapped system.

There is a case in which you do not need to synchronize, which is if you use the Send All feature.

[joniboini]

Thing is, I always thought he hot wallet laptop looks kinda "ugly" or offputing, it just looks like you have 0 funds, and its trying to synch, but since there is no internet, it's just there doing nothing.

Isn't that the point of using an air-gapped device? You're not supposed to daily drive it and make it work on something every day. I honestly think there's nothing wrong with that, as offputting as it is for you. The priority is the security of your wallet, which is why I don't think most people would recommend you buy a $1000 laptop just for that. If you don't have the funds to buy a separate device, what about using a live OS to manage your funds? You'll need a USB stick too, after wiping it and installing an OS of your choice. I don't think it is as secure as an air-gapped device though, CMIIW.

[pooya87]

Your question is a paradox in 2 places.

First is obviously the fact that when you say "cold storage" and "airgap" it means absolutely no connection to the outside world. Be it an internet connection or you connecting a USB disk, putting in a CD and regularly transfer files to that system, in which case it stops being "airgapped".

Second paradox is that when you say "cold storage" you are talking about a key storage not a "coin" storage. Which means it is only supposed to store your private keys and not your coins to know the balance. In fact I'd argue that the client should not even show a balance box in UI. Instead it should show you the number of private keys/addresses that the wallet holds.

[BlackHatCoiner]

First is obviously the fact that when you say "cold storage" and "airgap" it means absolutely no connection to the outside world.

"No connection to the outside world" sounds a bit of an absolute. If there is no connection to the outside world, then how can you make and transfer transactions with it?

Instead, I'd rather say "being airgapped means incapable to connecting to any network". Having a wireless network adapter, even if disabled from your operating system, does not make a machine airgapped. However, being able to transfer text in the form of QR codes, does not connect my machine to any network, nor does it allow the network connected computer to infect it in some manner.

Plugging USB sticks back and fourth is quite hard to decide if it passes the test, because it does not connect the computer to a network, but it might be able to infect it somehow if the network connected one injects a malware. Maybe a security expert can clears this out.

[Charles-Tim]

What if you save the blockchain files from the hot laptop and put them into the airgapped laptop? this way you would see your funds in your airgapped laptop too, it would be cooler than seeing 0 BTC.

The function of a airgapped device is to store your keys which can be used to sign your transaction. If you do what I quote, your airgapped wallet is no more airgapped as long as you do not see 0 BTC anymore. If you have a wallet on an airgapped device, you will have a watch-only wallet on another device which you will use to track your coins. It is also worth knowing that your coins are not stored on your wallet but rather on blockchain.

[satscraper]

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Cold wallet on airgapped laptop doesn't need any blockchain data, actual or past, to function in accordance with its assignment which is to sign raw transaction created by hot (watch-only) wallet and send it back to online device. The latter pushes  signed transaction alone. Thus the copy of actual blockchain would "contaminate" the airgapped  machine with unnecessary (and might be dangerous)  data.

[LoyceV]

I always thought he hot wallet laptop looks kinda "ugly" or offputing, it just looks like you have 0 funds

It's a feature, not a bug. If you want to have a secure air gapped system, you'll have to put your mind over such tiny inconveniences.

[ABCbits]

Plugging USB sticks back and fourth is quite hard to decide if it passes the test, because it does not connect the computer to a network, but it might be able to infect it somehow if the network connected one injects a malware. Maybe a security expert can clears this out.

On Linux, you could explicitt disable autorun when you plug USB drive and use noexec flag when mount the drive to partially prevent binary on that drive being run[1].

[1] https://superuser.com/a/1276936