M Tech Dissertations

Permanent URI for this collectionhttp://ir.daiict.ac.in/handle/123456789/3

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    Contributions to parasitic computing
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2005) Jain, Rajul; Mathuria, Anish M.
    Internet is a huge connection of networks. To ensure reliable communication on the Internet a layered architecture is used, with various protocols functional at each layer. The way these protocols are used on the Internet, it is possible to exploit them to do computations covertly. This kind of computing is known as Parasitic Computing. Parasitic computing is a kind of covert exploitation in which the parasite hides the computation in standard communication protocol and sends it to target(s), who unwillingly produce the output of the hidden computation as part of the communication session. We show that Internet checksum based parasitic computing can be used to solve three well-known problems, Discrete Fourier Transform, Matrix multiplication and Pattern matching. We describe how CRC checksum can be used to do primality testing using parasitic computing. A more efficient implementation of Internet checksum based parasitic computing is proposed and simulated. A comparison based on false negatives with the existing implementation is given. Results show that the proposed scheme performs better in terms of the selected parameter of false negatives. However, there is additional communication overhead associated with it. Parasitic computing can be applied in the field of security protocols. A novel sorting algorithm, Ker-sort is devised by exploiting ticket lifetimes in Kerberos and tested on Kerberos version 5.0. Run time analysis of the algorithm is given, and a comparison with existing distributed sorting algorithms is also presented. Brute-force cryptanalysis involves doing an exhaustive search in the key space. Using parasitic computing the parasite can offload the encryption or decryption operations involved in doing exhaustive search to the target(s). A theoretical cryptanalysis of SKIP and IP authentication header protocols using distributed exhaustive search is proposed.
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    ItemOpen Access
    Hybrid approach to digital image watermarking using singular value decomposition and spread spectrum
    (Dhirubhai Ambani Institute of Information and Communication Technology, 2005) Bhandari, Kunal; Jadhav, Ashish
    We have seen an explosive growth in digitization of multimedia (image, audio and video) content and data exchange in the Internet. Consequently, digital data owners are able to massively transfer multimedia documents across the Internet. This leads to wide interest in security and copyright protection of multimedia documents. Watermarking technology has evolved during the last few years to ensure the authenticity of multimedia content. We compare the widely used spread spectrum technique with the newly evolved technique based on Singular Value Decomposition (SVD) for watermarking digital images. The techniques are tested for a variety of attacks and the simulation results show that the watermarks generated by both the techniques have complimentary robustness properties. We propose a new hybrid technique for watermarking digital images, combining both paradigms, which is capable of surviving an extremely wide range of attacks. Our technique first embeds a watermark in an image using spread spectrum concepts and then to increase the robustness, another SVD based watermark is added such that they do not interfere with each other. Our technique is robust against a wide range of distortions like filtering, noise adding, lossy compression, print & rescan and non-linear deformations of the signal such as, histogram manipulation, dithering and gamma correction. The watermark added by our technique is perceptually invisible. The effectiveness of this technique is demonstrated against a variety of standard image processing attacks.