4 ms·

Just don't re-use addresses. Bitcoin does not expose your public key until you spend from it.

• nannal 5y ago
  > Bitcoin does not expose your public key until you spend from it. Are you sure, what about when someone sends to it?
  • DennisP 5y ago
    They're correct. The blockchain just records that the funds were sent to your address. To spend the funds you have to show the public key which hashes to that address, in another transaction signed by the private key. If the sender wanted to send you a private message, they would need your public key, but that's not what transactions do.
    • nannal 5y ago
      Fair enough, thank you.
  • shoghicp 5y ago
    Sending to an address means sending it to a "hash" of a public key (or a more complex script) on all modern formats. Then such script and data is revealed on spend.
• DennisP 5y ago
  If the QC can crack your private key within a few minutes, it would still have a decent chance to steal your money.