CMIIW
Actually, bitcoin security --if your only concern is about someone's ability to steal your "balance"-- is not in the sha256, but it's in the secp256k1. Let's say someone could find the original message/phrase, then he could only get public keys from bitcoin addresses. He then has to crack the secp256k1 to get the private key.
However, bitcoin security --if we talk about mining and difficulty-- would greatly be impacted by the sha256 vulnerability. If we could predict what's the hash outcome, then, there is no such this as mining, and someone could rehash all blocks from the genesis block.
Hello, thank you for your answer
No, I'm not worried about the balance because for what I've seen, there are more letters than A-F in the bitcoin accounts and passwords
It worries me, about the consequences that would be in bitcoin, and also in the Internet world. As I see it, if sha256 is replaced by for example sha512 would be hard to mine, but what would happen in the transition?
I mean, it has to be really complicated to change both (bitcoin, and all the sensitive information with sha256 all over the Internet), so my question and what concerns me, is who would manage this change? who would organize the change between sha256 and the new secure hash algortihm?
