This is a topic for years and everyone's making a claim that they will crack down sha-256 but until now, it's still secure and here's a good explanation:
Google Willow Quantum vs Bitcoin Encryption
Today, Google announced that Willow has reached 105 qubits with improved error rates. Should Bitcoiners worry?
🚫 Short Answer: No.
🔒 Bitcoin relies on two types of encryption:
1️⃣ ECDSA 256: Vulnerable to "Shors algorithm," but cracking it would require over 1,000,000 qubits. Willows 105 isnt even close.
2️⃣ SHA-256: Even tougherrequires a different approach (Grovers algorithm) and millions of physical qubits to pose a real threat.
Bitcoins cryptography remains SAFU... for now.
SHA-256 is very strong. It's not like the incremental step from MD5 to SHA1. It can last several decades unless there's some massive breakthrough attack.
If SHA-256 became completely broken, I think we could come to some agreement about what the honest block chain was before the trouble started, lock that in and continue from there with a new hash function.
If the hash breakdown came gradually, we could transition to a new hash in an orderly way. The software would be programmed to start using a new hash after a certain block number. Everyone would have to upgrade by that time. The software could save the new hash of all the old blocks to make sure a different block with the same old hash can't be used.
Quantum computers are real in theory, but the way people talk about them feels like we're already living in a sci-fi movie.
And besides, the most advanced nations likely already know when quantum capabilities will become possible, they're quietly developing and concealing it, preserving the advantage for moments of strategic necessity, like war or global leverage so if countries like US making a move such as owning 5% supply of BTC then it's probably secured. Nothing to worry about but still as a holder, we should still be aware of advanced tech., since we're investing on the tech too.
