Abstract: According to one embodiment, a memory system includes a nonvolatile memory and a controller. The controller enables a first access authority to a first storage area which is at least a partial storage area of the nonvolatile memory and sets a first time limit at which the first access authority becomes disabled. The first access authority is assigned to first user identification information. The controller disables the first access authority in a case where current time exceeds the first time limit.

Abstract: A communication system includes a host, and a memory system including a non-volatile memory and a controller configured to execute operations including writing of data to the non-volatile memory based on a request from the host. Information is transmitted by one of the host or the memory system after a predetermined period has elapsed while power is supplied from the host to the non-volatile memory. The information includes a number for identifying either the host or the memory system that transmitted the information and diagnostic information used for determining if there is a risk of loss of data stored in the non-volatile memory.

Abstract: A communication system includes a host, and a memory system including a non-volatile memory and a controller configured to execute operations including writing of data to the non-volatile memory based on a request from the host. Information is transmitted by one of the host or the memory system after a predetermined period has elapsed while power is supplied from the host to the non-volatile memory. The information includes a number for identifying either the host or the memory system that transmitted the information and diagnostic information used for determining if there is a risk of loss of data stored in the non-volatile memory.