'Keys' in the Bible

I will give you the keys (authority) of the kingdom of heaven; and whatever you bind [forbid, declare to be improper and unlawful] on earth will have [already] been bound in heaven, and whatever you loose [permit, declare lawful] on earth will have [already] been loosed in heaven.”

and the Ever-living One [living in and beyond all time and space]. I died, but see, I am alive forevermore, and I have the keys of [absolute control and victory over] death and of Hades (the realm of the dead).