افزايش بازدهي جاسازي پنهان نگاري در رسانه هاي صوتي

چكيده انگليسي :

Increasing the embedding performance in audio steganography Hassan Shafiee Alavijeh h shafieealavijeh@ec iut ac ir Date of Submission 2013 01 24 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor s Name Dr Masood Omoomi omoomi@cc iut ac irAdvisor s Name Dr M Khosravifard khosravi@cc iut ac ir Abstract Cryptography has been used as a tool for safekeeping of secret information and forprotecting valuable information from unpermitted access Besides hiding the information it is alsoimportant in some occasions to hide any relationship between the two parties incorporating in asecure communication The science of hiding a message in a cover media such as audio video andimage is generally known as steganography Steganography along with cryptography can providea high level of security for information exchange Steganalysis methods have been developed tocounteract the steganography methods These methods try to find the existence of hiddeninformation in cover media The development of steganography in digital media was started from 1994 when a paper waspublished on hiding information in least significant bits of cover media After 9 11 terrorist attackand the possibility of using steganography by the terrorist groups steganography and steganalysiswas regarded with more attention and the first methods of steganalysis were developed Newmethods for steganography and steganalysis are being developed rapidly and grow up in acounteracting environment Different methods of steganography in digital media can be categorizedin different ways One of the categorizations is based on the cover media type The cover objectcan be one of the different types of digital media such as video audio or image One of the mostimportant factors in steganography is the embedding efficiency of the steganography plan which isdefined as ratio of the embedded bits in the cover object to sample changes in the media Differentmethods have already been proposed for increasing embedding efficiency However increasingembedding efficiency in audio steganography is still a challenging problem In this thesis after reviewing of different methods of audio steganography a newsteganography method with high embedding efficiency is proposed The proposed methodincreases the audio quality of the generated signal and embedding efficiency by exploiting humanauditory system and decreasing the distortions caused by embedding process The efficiency of theproposed method is measured by implementation of the method and is compared with theefficiency of existing methods The quality of the obtained signal is also tested using the audioquality measurement model and the superiority of the proposed method over other method isverified Keywords Steganography Steganalysis Embedding efficiency Auditory system

شفيعي علويجه، حسن

افزايش بازدهي جاسازي پنهان نگاري در رسانه هاي صوتي

پنهان شكني , سيستم شنوايي