Abstract: An access control system, and a method of controlling an access to a controlled area, comprising an integrated-circuit card key having contact pads and a sufficient memory capacity to store key access information and transaction information, information in the integrated circuit integral therein at respective addresses, and an acceptor which includes a memory to store lock access information, and circuity for reading the key and lock access information, whenever the contact pads of the key is electrically engaged with the acceptor, comparing the key and lock access information, providing a control signal to the opening mechanism of an access controlled area based on a comparison, result and recording transactional information from the lock into the integrated circuit of the key at respective addresses.