20.500.12556/DKUM-74237 Steganografski algoritem za skrivanje informacij v frekvenčnem prostoru zvočnih posnetkov diplomsko delo Steganographic algorithm for hiding information within the frequency domain of audio signals V diplomskem delu predstavimo potek procesa izgubnega stiskanja digitalnega zvočnega posnetka ter steganografski postopek skrivanja informacij v frekvenčni domeni posnetka. Predstavimo kako s pomočjo spremenjene diskretne kosinusne transformacije in okenske funkcije pridobimo frekvenčni prostor. Skrivno sporočilo najprej zašifriramo s šifrirnim standardom AES in ga nato skrijemo v koeficiente spremenjene diskretne kosinusne transformacije s steganografskim algoritmom F5 ali LSB. Koeficiente na koncu stisnemo z algoritmom DEFLATE. V rezultatih preizkusimo oba steganografska algoritma pod različnimi pogoji. S kvantitativnimi kriteriji nato preverimo uspešnost algoritmov in ugotovimo kateri je boljši v določeni situaciji. In thesis we present a lossy compression of a digital sound recording and steganographic process of hidding information in the frequency domain of the recording. We present how we obtain frequency space by using discrete cosine transform and window function. At first we encrypt the secret message with the AES encryption standard and then hide it in the coefficients of the modified discrete cosine transformation with the steganographic algorithm F5 or LSB. The coefficients are then compressed using the DEFLATE algorithm. We test both steganographic algorithms under different conditions. With quantitative criteria we check the performance of the algorithms and find out which is better in a given situation. steganografija LSB F5 MDCT zvočni posnetek steganography LSB F5 MDCT audio recording true true false [T. Toplak] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2019-08-20 09:55:37 2019-11-12 07:43:49 2022-08-09 08:29:22 2019-12-15 03:10:34 2019 0 Maribor 0 Maribor VIII, 27 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 004.627.021(043.2) 22860566 URN:SI:UM:DK:FNIEUPH3 UN_Toplak_Tim_2019.pdf UN_Toplak_Tim_2019.pdf 1 38A13C6504C6E830AEEE1B92066E4104 ab1ecc75900db0605f495a9a0899a86626dd836b00c14868c3848c873f2d09dd d42cf3a7-7c10-11eb-bb7a-00155d0001ca 20.500.12556/dkum/07901fda-36da-4359-8ff9-2b08aca77d8a https://dk.um.si/Dokument.php?lang=slv&id=136018 Fakulteta za elektrotehniko, računalništvo in informatiko 0 0 0