Use Stolen Private Key? If only my private key were stolen, could it be used? 

Without knowledge of the corresponding public key or address, can one spend BTC with only the private key?

I know you can derive the public key from a private key, but if an address has never been spent from  and change is never returned to the same public key, the public key will remain unknown, thus how could one exploit knowledge of a private key alone?

EDIT:  yes, i now realize this is a pretty bad question.  i now know that with just a private key, an attacker can calculate the public key and Bitcoin address and thus spend any stored coins.
Yes.


The private key is used to send from an address.
The public key is used to send to an address.
The public key is generated from the private key.


So if you have the private key you have full control over an address.