Padlock

A system comprising a padlock and a padlock manager;

• the padlock comprising a body, a shackle and a latch, the latch being operable to retain the shackle in a closed state with respect to the body, wherein the padlock comprises processing electronics capable of being in a dormant state or an active state, comprising:
• a motion detector for detecting motion of the padlock;
• a controller operable to place the processing electronics in the active state on detection of motion of the padlock;
• and
• a transmitter and receiver that are embodied by a wireless communications interface that comprises a cellular wireless communications interface;
• the transmitter being operable, in the active state, to use the cellular wireless communications interface to transmit a cellular wireless communication comprising an activation message on entry of the processing electronics into the active state;
• and
• the receiver being operable, in the active state, to use the cellular wireless communications interface to receive a cellular wireless communication comprising an authorisation message;
• wherein, in the dormant state, the transmitter and receiver are inoperable;
• and
• the padlock manager is operable to receive the activation message from the padlock and to issue the authorisation message to the padlock.