Post
Topic
Board Bitcoin Technical Support
Re: infinite number of private keys / finite number of public keys
by
shorena
on 30/04/2014, 08:29:16 UTC

So every adress contains 2^96 public keys and also 2^96 private keys?

Doesn't this reduce the difficulty to bruteforce an adress?

That's like saying if I tell you that a molecule of water is located in the pacific ocean, that reduces the difficulty of finding it.

Pacific ocean vs. 2^96... lets see

https://en.wikipedia.org/wiki/Pacific_Ocean#Water_characteristics

"The volume of the Pacific Ocean, representing about 50.1 percent of the world's oceanic water, has been estimated at some 714 million cubic kilometers."

714.000.000 km^3 water vs. 79.228.162.514.264.337.593.543.950.336 (since my OS is in german think of . as , and of , as .)

With ~3*10^25 water particles in 1 liter and 1 liter = 0,001 m^3

We have 714* 10^6 * 10^12 (km^3 to liter) * 3*10^25 = 714*3 * 10^(6+12+25) = 2.142 * 10^43 water molecules. While 2^96 = approx. 7,9 * 10^28.

Hmm if we take 1 liter... that would be 7,14 * 10^20.... so 1/10^8 th of a liter, thats 1/10^2 µl or 0,01 mm^3 thats a fraction of a drop of water (~ 1/20 ml). Still hard to find Wink

PS: If some of the calculations are wrong, sorry. I checked everything twice, but due to the nature of large numbers and switching units there might be slips of the keyboard Wink

Thank you for your calculations.

Do I understand correctly: it's as hard to find a private key as to find 0.01mm^3 of water in the world's ocean?

This would be the most precise comparison I've ever read


If the calculations and the data I researched are correct: its as hard to find a private key to a given address as its hard to find 0,01mm^3 of water in the pacific (!) ocean. Since its the biggest ocean I dont think throwing in the other 2 makes a big difference.
Lets see Smiley

Atlantic: "354,700,000 cubic kilometers" https://en.wikipedia.org/wiki/Atlantic_Ocean
indian:  "292,131,000 km³" https://en.wikipedia.org/wiki/Indian_Ocean
pacific: 714.000.000 km^3

Sooo: 714 + 292 + 355 (rounded to 100 million km^3) hmm 1,361 10^9 km^3... ~ 0,019mm^3, actually doubles it.

But I think the biggest problem with this comparission is that while you "know" how big the oceans are you dont know how small ~0,02mm^3 is. Well maybe someone else can find an everyday object that is ~0,02mm^3