Currently you'd backup the private keys themselves - though adding a backup/restore feature to the wallet would also be an awesome feature. I opened a github issue for it :)
I have my private keys backed up on multiple USB drives at multiple physical locations - all encrypted with a very long password. If I lost my desktop + laptop, my backups, and my entire house burnt down, I'd be able to retrieve my keys from one of those USB drives, decrypt it, and import them to a brand new wallet.
Ok, so your crypto isn't tied specifically to any hardware. It's all still registered on the blockchain(?) so as long as you can produce the keys you can claim it?
It makes me wonder about those stories of that guy who lost about $70million worth of bitcoin when he accidentally threw out his hard drive. If he still had his keys, could he still have claimed them?
Yup, as long as you have the keys, you can use those keys on any wallet to access your funds.
The guys who lost 70m worth of bitcoin in a landfill is because those hard drives had the wallet files on them - and they didn't create backups of the keys.
This actually happened to me, though not nearly as much. I mined bitcoin in 2010 after discovering talks of it on a phpBB forum (no idea which one). I mined for about 2 weeks, and after that time, how much ever I had (I don't remember) wasn't much, so I stopped. BTC was like $0.06 back then, so maybe I had found a handful of blocks? I didn't really get back into crypto again for about 4 years. By that time, after a cross country move, I had trashed the PC that I did mining on. I didn't have backups, it was literally something I threw away because it was a gaming machine and I didn't really think about what bitcoins future was.
So those bitcoin are likely lost forever, unless someone found my HD in a dump or something and managed to decrypted the wallet I had on there. If I had backups of those keys - I'd be able to access those funds today.
Keys are everything - and the only way you actually own your crypto is if you control the keys.
Also, what happens if someone steals your computer with your desktop wallet on it... can they bruteforce the password and then have access to all your crypto?
If you had a shitty password - yes they could try. With a strong password, it'd likely take them more time to brute force it than it would take you to use a backup to alter the keys, rendering what they stole invalid (once they get it cracked).