Trying to get my head around her royal Bitcoin here...
I understand that blocks of transactions are broadcast to the network, and that miners verify that the BC is 'spendable' by trawling the blockchain and following the wallet address's transaction history (or at least I assume that's how it works).
But how does one actually verify that the BC transaction has been signed by it's owner when the miners don't have access to the private key? To put it simpler, how can verification take place without processing both the public and private keys?
I'm probably misunderstanding PKI encryption, but (say) with SSH, the private key would be on a trusted server and verification would take place on that server. How can that possibly work in a distributed network?