Possibility of Creating Same Bitcoin Address & Safeguards

[NameBaby]

Hi All,

Is it possible that two or more people create the same bitcoin address as this process is decentralized?
If that happen, what are the safeguards to protect your Bitcoin?

[1715210295]

1715210295

[1715210295]

1715210295

[ranochigo]

It is possible. But it is incredibly unlikely. The total number of addresses are 2^160 due to the nature of RIPEMD160 for P2PKH while the total number of (possible) private keys would be 2^256 (a little less than that). This makes it such that there would be 2^96 private keys that corresponds to an address.

To find a specific address, you'll need to generate about 2^160 keys before you can find it. The safeguard is the math behind this; it is simply not feasible for anyone to generate even half of the sufficient keys within any remotely feasible amount of time (thousands of years). That is provided that the keys are generated unpredictably.

[BlackHatCoiner]

Hi. Theoretically it is possible, but more important is how probable it is, because you have no idea how small are the chances. Let's start by taking the numbers. Once you create an address your computer generates a 256-bit private key like:

Code:

152067ed867d0d11bcb785e337aa6b3861d4202464a26a257aebb460c5ddc9d5

Then it encodes it to wallet import format (WIF), but right now it doesn't matter. Based on the elliptic curve that bitcoin follows (Secp256k1) we have around 2²⁵⁶ different private key combinations. An address is an encoded RIPEMD-160 hash, which means that cannot exceed the 2¹⁶⁰ range. Thus, all possible combinations of an address are 2¹⁶⁰. If you believe that this isn't a big one, you should see its decimal format:

1,461,501,637,330,902,918,203,684,832,716,283,019,655,932,542,976

Since private keys have more combinations than the addresses, we conclude that every address has most likely around 2⁹⁶ different private keys. Even with all these private keys, it's considered impossible for a human to find another private key that satisfies the conditions.

If that happen, what are the safeguards to protect your Bitcoin?

You won't know it if that ever happens and no, there won't be any ways to protect your bitcoin. It's like giving someone your private key.