Quote from: crofrihosl on September 23, 2019, 05:58:41 PM

i have this question when exactly the year and month we start using 2^256?

the year that we succeed at optimizing the algorithm for nested hash function {RIPEMD160(SHA256)} and find a collision. nobody can predict when that can happen, estimating it would be at least another 50 years.

Quote from: crofrihosl on September 23, 2019, 08:01:32 PM

~
am i understand you correctly!
all bitcoin addresses use 2^160 160bits and the only exception 2009 and 2010 that use 2^256 Embarrassed

an address is the hash of the public key where as those outputs from first year(s) were the public key itself.

Quote from: ETFbitcoin on September 23, 2019, 07:08:26 PM

There's no change of "bitcoin version 1", assuming you're talking about Bitcoin address which have prefix 1.

Bech32 address format have more character count, but according to https://bitcoin.stackexchange.com/a/69554 it also uses RIPEMD-160 which means current address space is still 2^160, but only with different format/encoding. CMIIW.

P2WPKH scripts are using the same RIPEMD160(SHA256(pubkey)) digests so they are the same 20 bytes (160 bits). P2WSH scripts use SHA256(script) digest so they are 32 bytes (256 bits) and both of them use Bech32 encoding to represent the corresponding "address".