A security system for remotely locking and unlocking closure members of a motor vehicle 10 is disclosed in which a hand gesture recognition device is associated with a keyless entry system having a security device 23 and a portable unit 19. The hand gesture recognition device includes at least one sensitised area 25 for detecting a hand gesture, an input/output device positioned in the passenger compartment for selecting or creating at least one pattern gesture which can be recognised by the sensitised area 25 and a gesture recognition module for transmitting an authorized code signal to the security device 23 upon recognition of the selected or created gesture over the sensitized area. Such a gesture pattern can easily be modified from the I/O device by the user and ensure an improved security to a conventional keyless entry system.