587 research outputs found
Aplikace samoopravných kódů v steganografii
Modern steganography is a relatively new discipline with many applications in information security. Contrary to the cryptography which is trying to make a message unreadable to third party using cryptographic algorithms, the aim of steganography is to hide a communication between parties. Applications of error-correcting codes and covering functions markedly increases abilities and security of steganographic algorithms. This thesis is attended to steganography using error-correcting codes which has the best results nowadays regarding embedding efficiency. New constructions will help us to work with non-linear codes and providing new steganographic algorithms. We will see that these algorithms have a better ability to hide communication, resp. a message in a digital medium. Further improvements can be made using applications of general q-ary codes. Many new questions are coming out with that which need to be answered. Several comparisons are showing that the area of steganography is in a beginning and we will be participants of such a progress as cryptography experienced in the last two decades.Department of AlgebraKatedra algebryFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult
Improving success probability and embedding efficiency in code based steganography
For stegoschemes arising from error correcting codes, embedding depends on a
decoding map for the corresponding code. As decoding maps are usually not
complete, embedding can fail. We propose a method to ensure or increase the
probability of embedding success for these stegoschemes. This method is based
on puncturing codes. We show how the use of punctured codes may also increase
the embedding efficiency of the obtained stegoschemes
Product Perfect Codes and Steganography
A new coding technique to be used in steganography is evaluated. The performance
of this new technique is computed and comparisons with the well-known theoretical
upper bound, Hamming upper bound and basic LSB are established
Wet paper codes and the dual distance in steganography
In 1998 Crandall introduced a method based on coding theory to secretly embed
a message in a digital support such as an image. Later Fridrich et al. improved
this method to minimize the distortion introduced by the embedding; a process
called wet paper. However, as previously emphasized in the literature, this
method can fail during the embedding step. Here we find sufficient and
necessary conditions to guarantee a successful embedding by studying the dual
distance of a linear code. Since these results are essentially of combinatorial
nature, they can be generalized to systematic codes, a large family containing
all linear codes. We also compute the exact number of solutions and point out
the relationship between wet paper codes and orthogonal arrays
Efficient And Robust Video Steganography Algorithms For Secure Data Communication
Nowadays, the science of information hiding has gained tremendous significance due to advances in information and communication technology. The performance of any steganography method relies on the imperceptibility, embedding capacity, and robustness against attacks. This research provides solutions for the existing video steganography problems by proposing new and effective methods for digital video steganography. The key objectives of our paper are as follows: 1) a highly secure video steganography algorithm based on error correcting codes (ECC); 2) an increased payload video steganography algorithm in the discrete wavelet domain based on ECC; 3) a novel video steganography algorithm based on Kanade-Lucas-Tomasi (KLT) tracking and ECC; 4) a robust video steganography algorithm in the wavelet domain based on KLT tracking and ECC; and 5) a video steganography algorithm based on multiple object tracking and ECC. The experimental results from our research demonstrate that our proposed algorithms achieve higher embedding capacity as well as better imperceptibility of stego videos. Furthermore, the preprocessing stages increase the security and robustness of the proposed algorithms against attacks when compared to state-of-the-art steganographic methods
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