Okay, thanks. So it is really improbable. I'm still a bit unseasy to have no edge against the "three times quickly" scenario, but I guess nothing is truly certain.
I guess that's just the human mind not being capable of understanding these odds... I mean, allmost nothing you've ever considered safe enough so you don't have to edge against it is 100% safe (and it's impossiblee to have an edge against everything and everyone you ever need/use/have/...).
Is your bank safe? Nope... Personally, i think the odds of losing fiat money in the banking system greatly outweighs the odds of somebody randomly bruteforcing your private key.
Is your country safe? Nope... No matter which country you live in, odds are probably bigger it dissapears before somebody bruteforces your private key.
Is gold safe? Nope... Just a piece of metal... If civilisation collapses, you can't eat gold and it might lose it's value.
Are we alone in the universe? No idear, but i would say odds are much bigger we are not than somebody bruteforcing your private key.
Normally, this is the point where i'd start calculating stuff to make you feel at ease, but chatgpt took over this part for me... I asked it to compare the odds of bruteforcing a private key using 1 million RTX 3090 GPUs for a full year, and compare it to the odds of an individual being struck by lightning AND winning a major lottery AND surviving a shark attack AND being elected as the prime minister of an EU country in the same year... Here's it's answer:
A Bitcoin private key is a 256-bit number, meaning there are 2²⁵⁶ (~10⁷⁷) possible private keys.
A high-end GPU (e.g., an NVIDIA RTX 3090) can compute around 10⁹ hashes per second in a brute-force attack.
Assuming the attacker uses 1 million RTX 3090 GPUs running for 1 year, the number of attempted keys would be:
109×106×60×60×24×365=3.15×1022
Comparing that to the total key space means the odds of guessing a Bitcoin private key within a year are about 1 in 1055
Now, let's compare this to a combination of rare events:
If we assume all these events must happen in the same year, the combined odds are:
106×3×108×3.75×106×2×107=2.25×1029
So, it's about 100.000.000.000.000.000.000.000.000 times more likely that you'll be struck by lightning, win a major lottery, survive a shark attack and be elected as prime minister of an EU country as it is to bruteforce a private key using 1 million RTX 3090 GPU's in one year.
I did not redo chatgpt's calculations, but they seem plausible to me...
Offcourse, as soon as there's a problem with the algorithm creating your private key, things might change drastically... I'm assuming a truely random private key