If I expose my public view key and public spend key, what can someone do with it?
Your public view and spend keys are already disclosed - they are parts of your standard, public address. All someone can do with your address is send you funds. Of course, anyone you disclose your address to will know you use Monero, they will not however be able to view any of your transactions.
Someone who gets your public view and spend keys can:
- send you money
Your public keys are basically your standard address, so you're giving them out when you hand someone your address.
- search for this address in any set they have
If someone obtained, say, a set of addresses used to withdrawn from an exchange, they can determine whether you ever withdrew from that exchange using that address. Using subadresses fixes this, since they're meant to be one off use.
Things they CANNOT do include:
- check a block explorer to see that address' balance
Nope noppety nope. With Monero, you keep your privacy. People you give your address to have no business knowing your balance nor your transaction history
- steal your money
It's public keys. If they have your secret spend key, that'd be another story.
- Determine your secret keys
Public keys are created using a one way function from the secret keys. You can't "go back" up the derivation.