A device and a method for processing an image by a multimedia device that supports encryption and decryption are provided. The device includes a thumbnail image of an original image is obtained and the original image is encrypted using a first encryption scheme. An encrypted image frame is generated such that the encrypted image frame includes an identity field in which marker information is recorded between a first image field in which the obtained thumbnail image is recorded and a second image field in which the encrypted original image is recorded. The marker information indicates whether the encrypted image frame includes the second image field.