This chapter throws light on major multimedia data security techniques. It has become so essential in today's society which uses multimedia data in almost all walks of life. There are a lot of multimedia data transactions carried out every day. Thus, to ensure data security the techniques, steganography and watermarking are frequently used. In steganography and watermarking techniques, the data to be hidden is encrypted and fed into a transparent layer like documents, images, and it is decrypted at the receiving end by the recipient. Generally, steganographic communications are one-to-one while watermarking is one-to-many. Besides these techniques, certain other techniques are also used in the application for providing security to multimedia data. From this chapter, a detailed content about steganography and watermarking can be obtained.
TopThe recent growth in Multimedia communication has been enormous. Multimedia data comprises of various media types namely image, video, audio etc. These data have vast source of information of different file types or different file formats. Managing different types of multimedia data is called as MultiMedia Database Management System (MM-DBMS). Using this MM-DBMS, storing, delivering, modifying and many other operations can be performed. The contents of the MM-DBMS include media data, format of the data, keyword of the data, and also feature of the data. Media data is the main and actual data that represent an object. Various information about the format of the data like resolution, sampling rate, encoding scheme etc., can be obtained. This information is obtained after making certain process with the multimedia data. The phases on multimedia include acquisition, processing and encoding phase. Next to media data format, media keyword is the point to be considered. Keywords of media will give information about the created data. This information includes date, time, and also place of observation of the data. Last content of the MM-DBMS is the feature of the data. The feature content of the multimedia speaks about the colors in the media with their distribution, what kind of texture is used in it, and also the types of shapes present in the data.
Multimedia data is used in almost every walk of life like social networking, science, research etc. along with their contents. As the volume or size of the MM-DBMS is increasing rapidly, the developers still face many challenges to meet the requirements of the end users. Some of the major challenges to be focused by the developers are modelling, design, storage, performance, queries & retrieval, security, etc. Multimedia databases can be applied to wide range of areas. Some of them to be noted are Documents & record management, knowledge dissemination, education & training, real-time control & monitoring, and so on.
After having a short description about the multimedia, MM-DBMS, the concept can be forwarded towards multimedia communications. Communication is needed to transfer data or information from person to person. The data to be communicated can be of any file format like text, images, audio, and video. These file formats can be classified based on the media types. Four major classifications of media types are Audio, Video, Graphics, and Text. Audio media type is used for music, VoIP, and Podcasts and some of the file formats that are included in this type are MP3, Waveform Audio File Format (WAV), and Audio Interchange File Format (AIFF). Video is used for video streaming, also for films and video conferencing. MPEG, Audio Video Interleave (AVI), and MP4 are certain file formats supported in this type. All types of images, icon, infographics, charts and visual representations are grouped under Graphics. File formats supported under this classification are JPEG, PNG, TIFF, GIF and many more. Among the four major classifications of media types, only Text will be in human readable form like HyperText Markup Language (HTML), TeXT (TXT), Rich Text Format (RTF). Each and every file format of graphics has their own sub-classification.
Almost every stream of society has become a major user of multimedia communication. Today a lot of data transformations are carried out. Each and every person is posting images and text messages in social networking cites for example Facebook, Twitter and also sharing information through Whatsapp, Messenger etc., So it is necessary to ensure data security from the intruders. In that case, it is particularly important for the protection and enforcement of intellectual possessions. In these scenarios, the greatest challenge for the developers is to increase the security; also the application should be user friendly. If the application is more user friendly, there is a huge possibility of attacks. If the application has implementation of complex security, then the application lowers in friendliness to the users. The balancing of both the criteria is biggest research challenge. This chapter throws light on multimedia data security. Though there are lot many algorithms or techniques proposed in day to day technology, most of the multimedia data security concentrates on steganography and watermarking techniques. In existing technologies, much research is going to provide better security for any type of application domain. Researchers are striving hard to give solution to the challenges they face in data security, in specific multimedia security. As advancement towards security, the researchers are working on hybrid techniques, to check whether the combination provides improved security. The detailed description about different types of multimedia data security is presented in this chapter.