A security device providing a security function for an image, a camera device including the same, and a system on chip (SOC) for controlling the camera device are provided. An image transmitting device may include an image processor configured to process an image to be transmitted to an external device, and a security circuit including a key shared with the external device. The security circuit may be configured to generate a tag used for image authentication by using data of a partial region of the image and the key based on region information for selecting the partial region of the image. The image transmitting device may be configured to transmit the tag, generated to correspond to the image, to the external device with data of the image.