Divon's Blood Lock

You touch a closed door, window, gate, chest, or other entryway, and it becomes locked for the duration. Touching a written message while casting this spell causes the message to disappear until a drop of blood is touched on the message's surface. You and creatures that share the same bloodline or blood type with you when you cast this spell can open the object normally or read the secret message. You can also set a password that, when spoken within 5 feet of the object, suppresses this spell for 1 minute. Otherwise, it is impassable until it is broken or the spell is dispelled. 

While affected by this spell the object is impossible to open by any nonmagical means.