A decryption method for use in displaying data includes the steps of executing a display instruction of an object inclusive of a plurality of data, displaying an unencrypted data, but not an encrypted data, of the data on a display unit according to the display instruction, detecting a trigger signal during the state of displaying the unencrypted data but not displaying the encrypted data, entering a password-receiving state in response to the trigger signal and detecting a password signal during the password-receiving state, determining whether the password signal matches a default password, and displaying the unencrypted data and the encrypted data on the display unit when the password signal matches the default password. Therefore, with the decryption method, no person other than the object owner is aware of the encrypted data.