A computing system has a computing device. The computing system has an input data path, which unidirectionally connects an interface device to the computing device, and an output data diode, which unidirectionally connects the computing device to the interface device. The input data path has a data lock which is connected to the interface device by a first terminal and to the computing device by a second terminal. The data lock has a storage unit for storing data and is configured such that the storage unit can be selectively connected solely to the first or second terminal but not to both terminals simultaneously. The computing device accepts data from the interface device solely if the data is transmitted to the computing device from the interface device via the input data path within a transmission session initiated by the computing device using the output data diode.