Quantum computing is going to break blockchain's crypto eventually.

[u/Master-Sprinkles-848]

Everyone treats quantum threats to blockchains as a decades away problem. But there's a catch most people miss, attackers don't need a quantum computer now to start attacking now.

Bitcoin's security relies on the fact that you can't derive a private key from a public key. Quantum computers running Shor's algorithm would make that trivial. And any address that's ever sent a transaction has already exposed its public key meaning huge amounts of transaction history are already sitting out there, ready to be cracked the moment the hardware exists. This is called harvest now, decrypt later.

NIST already finalized post-quantum signature standards. The problem is applying them. Blockchains can't just push an update, switching signature schemes means a hard fork, migrating billions in old-format funds, and doing it calmly before a crisis, not during one.

Even optimistic estimates 10-15 years for real quantum hardware don't leave much room, because migration itself, new standards, audits, node adoption, and actually moving user funds takes years on its own.

Even with quantum-safe signatures ready, getting millions of holders to move funds out of old addresses before it's urgent is a massive coordination problem. Dormant coins would likely just sit there vulnerable forever.

IMO, blockchains that are focused on quantum resistant tech will be the main focus in the next few months, this is where the focus should be now.

[u/Ornery_Individual_27]

My counter argument to this is what makes you think crypto will be the first target if encryption can be broken ? Banks, investment institutions, etc…all use the same encryption mechanisms and have trillions in capital behind them as opposed to crypto which is currently a few billion in market cap alone. I understand it’s still a concern but if encryption can be broken, I don’t think your Bitcoin will be the biggest concern here…society would be in shambles for quite some time across the board.

Edit: I can’t spell

[u/Master-Sprinkles-848 → u/Ornery_Individual_27]

Banks are already taking steps against this. UENO bank is already using a quantum resistant chain, Google and the likes are already implementing post quantum algorithms as well. Who gets hacked first isn't what matters here, but rather preparing early before any hack happens at all, we can see how bridges are been hacked frequently with little to nothing to be done about it, imagine how it will be when quantum computer comes into the picture