Storage device, storage device system and information terminal

A storage device system, comprising:

• a storage device including a nonvolatile memory and a first controller controlling the nonvolatile memory;
• and
• an external host provided outside the storage device, the external host including a second controller controlling an interface with the storage device;
• wherein the second controller detects a logical address of an old data area for a deleted or overwritten file, and writes invalid data to the logical address of the old data area for the deleted or overwritten file.

A storage device system, comprising:

• a storage device including a nonvolatile memory and a first controller controlling the nonvolatile memory;
• and
• an external host provided outside the storage device, the external host including a second controller controlling an interface with the storage device;
• wherein the second controller detects a logical address of an old data area for a deleted or overwritten file, and outputs predetermined invalid data upon receiving, from the external host, a read command to read data from the logical address of the old data area for the deleted or overwritten file.