Security mobile storage apparatus and the control method

PURPOSE: A removable storage device and a controlling method for the device are provided to improve the performance of security by encrypting regular data and offering the decrypted data stored in a security area. CONSTITUTION: A general area(210) stores a removable storage device agent. The removable storage device agent controls a security removable storage device, encrypts a primary key using a password, and decodes the encrypted primary key described above. A security area(220) stores data encrypted with the primary key and allows access after verification is successful. A hidden area(230) stores a security policy and encrypted primary key. The hidden area stores a random number generation value and the number of occurrences to generate a sub key for the encryption and decryption of the primary key.