Smart key for vehicle and system

A smart key configured to control a plurality of vehicles comprising a first vehicle and a second vehicle, the smart key comprising:

• a first communication unit configured to exchange information with the plurality of vehicles;
• an information acquisition device configured to acquire user information associated with a user of the smart key;
• at least one processor;
• and
• at least one computer memory coupled to the at least one processor and having stored thereon instructions which, when executed by the at least one processor, causes the at least one processor to perform operations comprising:
• based on the user information, selecting, as a vehicle to enter, at least one vehicle among the plurality of vehicles based on the user information and based on information associated with the plurality of vehicles;
• exchanging, through the first communication unit, a signal with the selected at least one vehicle, and
• simultaneously transmitting, through the first communication unit, a first signal configured to control the first vehicle and a second signal configured to control the second vehicle.