A padlock includes a lock housing, a U-shaped lock hoop and a lock cylinder in order selectively to lock the lock hoop to the lock housing, wherein the lock cylinder has a cylinder axis and is secured to the lock housing by means of a securing element. When receiving a detection signal from the water sensor which indicates that the water content is decreased to below a predetermined level, the first message is read out from the memory and outputted through the speaker to urge a user to supply water. The residual steam of the heat engine is used to heat a distillation device in which a first partial flow of the saline water is distilled. The ventilation system is further characterised in that it comprises catalysing means for catalysing hydration of carbon dioxide contained in at least a portion of the stale air into a solution of carbonate ions and hydrogen ions, and thereby removing carbon dioxide from said portion of the stale air and obtaining clean air. An object’s identity can be verified by requesting the smart chip to perform a data transformation using its identity private key, and performing the complement using the public key.