A technique for improving data security is provided. To be specific, in a memory system including an information processing apparatus and a semiconductor memory device, the semiconductor memory device has an interface section that transmits, to the information processing apparatus, data read out from a memory core according to a plurality of communication protocols having different signal transmission/reception methods. Based on a switch command inputted from the information processing apparatus, a communication protocol selection section inputs, to the interface section, a selection signal for selecting a particular communication protocol from the plurality of communication protocols.