Elevator system and method of authenticating computing device to security controller of elevator system

An elevator system comprises a gateway device and a safety controller arranged to monitor at least one safety condition of the elevator system. The gateway device is configured to enable a computing device to establish a connection with the gateway device. The security controller is configured to: receive first authentication information from a gateway device, wherein the first authentication information is gateway authentication information; checking whether the gateway authentication information meets a first authentication condition or not; receiving, via the gateway device, second authentication information from the computing device if the gateway authentication information satisfies the first authentication condition; checking whether the second authentication information meets a second authentication condition or not; and authenticating the computing device if the second authentication information satisfies the second authentication condition, where the authenticated computing device is permitted for ma