1. What if miners start sabotaging block creation after 2140? Would introducing some coins that haven't moved since January 2009 help? (Similarly, in four years, in 2144, coins untouched since February 2009 could be put into circulation, and so on.)
Could you provide example of sabotage? Invalid block or transaction would be rejected by other node (whether it's owned by pool, exchange or somebody else), so sabotage option would be very limited and probably lead to economical losses.
2. Some say quantum computers could crack private keys of UTXOs created in Satoshi's time. By the time such computers exist, nobody will be using the old algorithms (the community will be forced to transition to something else). But would it be fair that the UTXOs from 2009 go to the quantum computer developer? Wouldn't it be better to change the consensus regarding UTXOs made with old algorithms when transitioning to new ones?
Consensus for such thing probably never achieved (as in majority agree to specific action) due to opinion difference.
2. Some say quantum computers could crack private keys of UTXOs created in Satoshi's time. By the time such computers exist, nobody will be using the old algorithms (the community will be forced to transition to something else). But would it be fair that the UTXOs from 2009 go to the quantum computer developer? Wouldn't it be better to change the consensus regarding UTXOs made with old algorithms when transitioning to new ones?
answer:
First of all, these mythical quantum computers. They are not and will not be useful for such tasks. All those fancy scientific studies are tainted with elaborate theories. Notice that so far, they can only confirm algorithms that have already been devised. The states of the so-called qubits as 0, 1, or unknown, don't really matter. If it were otherwise, why would people keep creating new supercomputers when they could have a super quantum computer for half the cost? Please stop scaring people with these quantum computers and what they cannot do. If you had experience with such computers (and I do), you would know that it's a fairy tale, like something from moss and ferns.
Quantum computer isn't myth. The reason people create supercomputer rather than "super" quantum computer is nobody have ability to build large scale quantum computer (have many qubits) and i expect it won't happen anytime soon. And i'll reiterate that ECDSA is vulnerable to quantum computer.
