I have been reading about Account Extended Private Key and Account Extended Public Key that derives from the Master Private Key and Master Public Key, but I still have some question about their security.
I read that Account Extended Private Key should be kept private because if others got hold of it, they could sign the transaction with the key, effectively stealing your cryptocurrency. How does this work exactly? Is there an application that I can import other's Account Extended Private Key and send certain amount to my other wallet's address?
Also, I read that Account Extended Public Key should be kept private as well because exposing it to others allow them to go through the transactions. How does this work? Is there an application that I can import to view the transaction history?