A nonvolatile memory system is disclosed. The nonvolatile memory system includes a host device and a storage device connected to the host device through a physical cable including a power line and a data line. The storage device includes: a nonvolatile memory; a link controller configured to temporarily deactivate the data line while supplying power from the host device through the power line; and a memory controller including a user verification circuit configured to authenticate a user of the storage device and change a state of the memory controller according to a verification result, a relink trigger circuit configured to control the link controller based on the state change of the memory controller, and a data processing circuit configured to encrypt and decrypt data.