A processing device is provided. A first storage unit stores a correspondence table which is indicative of a correspondence relationship between attributes of data and encryption levels for encrypting data. An obtaining unit obtains data. A first determination unit determines an encryption level according to an attribute of the data obtained by the obtaining unit, using the correspondence table stored in the first storage unit. An encryption unit encrypts the data obtained by the obtaining unit in the encryption level determined by the first determination unit. A second storage unit stores the data encrypted by the encryption unit.