So I have 5 monero, but if nobody else can see my balance, how can I prove that these coins are in my posession, and that they have not been spent yet.
I just fail to see how Monero can ensure that without the ability to view either a list of transactions or balances.
If I understand correctly, I can see my received transactions with my viewkey, and my sent transactions with my spendkey, but how can I prove that the coins have not been spent before if I don't disclose my spendkey?
I understand most of Bitcoin transactions and I have a more than basic understanding of encryption and how public and private keys work.
Also, please link easy-to-understand posts about the security of monero.