A simple method for detecting the possible changes of hidden information of watermarked image in an MMS message
After expanding the use of computer and its affect on different aspect of life, the copyright issue has gained many attractions. For this purpose watermarking methods are proposed. In these methods a code is embedded into digital material that can be used to approve ownership, it can be visible or invisible to the user. On the other hand with the rapid growth of mobile phones, mobile telecommunication companies starting to add additional features to their mobile phones such as MMS (Multimedia Messaging Service) in order to attract more customers. MMS is a technology that allows mobile phones sending messages that includes multimedia objects esp. images. For copyright protection of images which are sent through MMS, ones can use watermarking methods. But there is possibility of damaging or changing the hidden information while MMS is transferred. In this paper a new method is proposed for detecting the cause of destroying or changing hidden data in an MMS message. For this purpose, in addition to the image, the copyright notes are also hidden in an audio file and sent along with the image. So while extracting the hidden information from MMS message, if copyright notes which are extracted from both image and audio file are different, it can be concluded that the hidden data are damaged or changed.