Bitcoin 101 - Quindecillions & The Amazing Math Of Bitcoin's Private Keys
Why Bitcoin Stack Exchange recommends it
Bitcoin Stack Exchange users link it when explaining why brute-forcing private keys or address collisions is not a realistic threat, since it gives an intuitive sense of the key space's size.
Recommended by 4 people across 4 different months, 2014 to 2017.
What it is
A 2014 blackboard-style explainer from James D'Angelo, part of a Bitcoin 101 series, about how enormous Bitcoin's private key space is. He uses an analogy of drawers and pirates to show why guessing private keys is infeasible even with all the world's computers.
What people said
Recommends drewmikb · 2014-11 · Bitcoin Stack Exchange · on “Why I don't need to specify public key to import paper wallet”
Unlike email accounts and passwords, in Bitcoin no two public keys can share the same private key because the public key is derived from the private key mathematically. It's true you could generate private keys at random and check their corresponding public addresses for unspent bitcoins. And if you found any, you could spend them since you'd have the private key. If it was at all feasible to find and spend other users' bitcoins this way, the Bitcoin ledger would be useless. So the set of possible keys was made intentionally enormous as to make such random searching infeasible and pointless even if extremely powerful computers were used to perform these searches for centuries. Here's a great
Recommends Murch · 2015-03 · Bitcoin Stack Exchange · on “Is it possible to brute force bitcoin address creation in order to steal money?”
James D'Angelo has created a video to visualize the magnitude of Bitcoin's private key space: Bitcoin 101 - Quindecillions & The Amazing Math of Bitcoin's Private Keys [this video]
Recommends Jestin · 2016-04 · Bitcoin Stack Exchange · on “How does Bitcoin handle address collisions?”
In elliptic curve cryptography, public keys are derived from private keys, with seemingly random distribution. You are correct that two different private keys could produce two different public keys that just so happen to hash to the same Bitcoin address. A SCRIPT_SIG of the transaction that spends from that address would need to provide: A public key that hashes to that address A signature of the transaction produced from a private key that matches the given public key Since two different key pairs could both meet this criteria, either one of them could spend the bitcoins. However, this is very unlikely. So much so, that it's not even worth considering as a possibility. The best metaphor I'
Recommends Dan Bolser · 2017-08 · Bitcoin Stack Exchange · on “what if someone tries to finish public keys by non-stop creating”
This is technically impossible and economically illogical. If you could check this many addresses, you could also mine bitcoins. Here are a couple of fun vids: Bitcoin 101 - Quindecillions & The Amazing Math Of Bitcoin's Private Keys [this video] Ever wonder how Bitcoin (and other cryptocurrencies) actually work? [LINK] Both discuss the 'size' of the bitcoin address space.