Not to mention that when quantum computers become a reality, they'll be able to unencrypt all transactions in that blockchain, leaving your past open for anyone to see.
maybe that doesn't matter anymore by then?
Quantum computers can't break SHA256 and RIPEMD160 (or at least they shouldn't be able to) so you're fine as long as you've never spent any money from your bitcoin address (so your pub key is still unknown). Once your public key becomes known (i.e. you've spent money), then a quantum computer could trivially break the ECC encryption that protects your private key.
Remember, your address is NOT your public key. Your address is a double hash (SHA256 + RIPEMD160) of your private key. If you use bitcoin as intended, every time you spend, your remaining funds are sent to a new change address whose pubkey is unknown to the network.
Known pubkey >> break ECC >> private key...trivial when using Shor's Algorithm in polynomial time
Unknown pubkey >> break SHA256 & RIPEMD160 >> private key...currently not believed to be possible even with Shor's Algorithm
I'm learning so much lurking around you clever mofo's...
Keep up the brilliant technical debates lads...