Locksmithing began as the science and art of making and defeating locks. A lock is a mechanism that secures buildings, rooms, cabinets, objects, or other storage facilities. A key is often used to open a lock. Means of opening a lock often include what you know (a combination), what you have (a key or keycard) or what you are (biometrics).
Locksmithing is one of the earliest forms of security engineering.Lock picking was one of the first methods of cracking security systems. The oldest known lock was approximately 4000 years old and was of Egyptian make. It was found in the ruins of the Emperor Sargon II's palace in Khorsabad. It used the same pin tumbler principle employed by many modern locks.