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It's always worth noting to newbies that airgapping is most ideal in Linux than in Windows, for obvious reasons, including avoiding a plethora of malware and other assorted threats.
Even if your computer is airgapped, and has never touched the internet since you installed the OS, you still can get a virus via USB, CD, etc, so dealing only with open source software will always reduce these possible exploits by a big %.
Look into Ubuntu or Lubuntu if your computer is very old. You can always use Xubuntu as a good balance between performance and aesthetics.
--snip--
You could set up a webcam for the offline pc and use that to load the tx rather than using a USB flash drive. A much more secure method this is, as you know for a fact that only the tx is being transferred.
--snip--
The only difference is that i have mentioned a CD which will be destroyed, but thats related to the whole (second) point of my post.
It is still worth to note that this also does NOT mean 100% security.
An attacker could foist you a malicious version of a QR code reader, which will modify the transactions on transmission.
This, of course, is a very unrealistic attack vector. But the possibility does still exist. Especially if people have access to your offline machine (assuming the machine is accessable and the private keys are encrypted).
You guys are all making excellent points, but i personally feel we're going into a paranoid level of semantics here. IMHO, the odds of a $5 wrench attack is significantly higher than the odds of running into somebody that tailored an attack against these attack vectors (i could be wrong tough, but that's my gut feeling).
I think the most important thing the OP and other newcomers should remember about this thread:
- web wallets => not good
- exchange wallets => not good
- mobile wallets => only for very small amounts (spending money: enough to buy a couple cups of coffee if you stumble upon a place that accepts BTC payments)
- TRUSTED, up-to-date desktop wallets on a CLEAN up-to-date pc => good for small amounts (think: a couple hundred bucks in FIAT value equivalent)
- properly generated paper wallets => good for large amounts
- airgapped wallets => good for large amounts
- hardware* wallets => good for large amounts
IF they're ever managing a BTC value whose FIAT equivalent they can't earn in a month, it *CAN* be a good idear to spread their funds over several trusted wallets
IF they're ever managing a BTC value whose FIAT equivalent they can't earn in a year, they should talk to a specialist that can walk them trough all kinds of paranoid scenario's they can protect themselfs against
* thanking bob123 for discovering my typo