Current Issue : April - June Volume : 2016 Issue Number : 2 Articles : 5 Articles
We study the large-coalition asymptotics of fingerprinting and group testing and derive explicit decoders that\nprovably achieve capacity for many of the considered models. We do this both for simple decoders (which are fast but\ncommonly require larger code lengths) and for joint decoders (which may be slower but achieve the best code\nlengths). We further make the distinction between informed decoding, where the pirate strategy is exactly known,\nand uninformed decoding, and we design decoding schemes for both settings.\nFor fingerprinting, we show that if the pirate strategy is known, the Neyman-Pearson-based log-likelihood decoders\nprovably achieve capacity, regardless of the strategy. The decoder built against the interleaving attack is further\nshown to be a universal decoder, able to deal with arbitrary attacks and achieving the uninformed capacity. This\nuniversal decoder is shown to be closely related to the Lagrange-optimized decoder of Oosterwijk et al. and the\nempirical mutual information decoder of Moulin. Joint decoders are also proposed, and we conjecture that these also\nachieve the corresponding joint capacities.\nFor group testing, the simple decoder for the classical model is shown to be more efficient than the one of Chan et al.\nand it provably achieves the simple group testing capacity. For generalizations of this model such as noisy group\ntesting, the resulting simple decoders also achieve the corresponding simple capacities....
Recently, several digital watermarking techniques have been proposed for hiding data in the frequency\ndomain of moving image files to protect their copyrights. However, in order to detect the\nwater marking sufficiently after heavy compression, it is necessary to insert the watermarking\nwith strong intensity into a moving image, and this results in visible deterioration of the moving\nimage. We previously proposed an authentication method using a discrete wavelet transform for a\ndigital static image file. In contrast to digital watermarking, no additional information is inserted\ninto the original static image in the previously proposed method, and the image is authenticated\nby features extracted by the wavelet transform and characteristic coding. In the present study, we\ndeveloped an authentication method for a moving image by using the previously proposed method\nfor astatic image and a newly proposed method for selecting several frames in the moving image.\nNo additional information is inserted into the original moving image by the newly proposed method\nor into the original static image by the previously proposed method. The experimental results\nshow that the proposed method has a high tolerance of authentication to both compressions\nand vicious attacks....
Smartphone advertisement is increasingly used among many applications and allows developers to obtain revenue\nthrough in-app advertising. Our study aims at identifying potential security risks of mobile-based advertising services\nwhere advertisers are charged for their advertisements on mobile applications. In the Android platform, we\nparticularly implement bot programs that can massively generate click events on advertisements on mobile\napplications and test their feasibility with eight popular advertising networks. Our experimental results show that six\nadvertising networks (75 %) out of eight are vulnerable to our attacks. To mitigate click fraud attacks, we suggest three\npossible defense mechanisms: (1) filtering out program-generated touch events; (2) identifying click fraud attacks with\nfaked advertisement banners; and (3) detecting anomalous behaviors generated by click fraud attacks. We also discuss\nwhy few companies were only willing to deploy such defense mechanisms by examining economic misincentives on\nthe mobile advertising industry....
Information processing services are becoming increasingly pervasive, such as is demonstrated by the Internet of\nThings or smart grids. Given the importance that these services have reached in our daily life, the demand for security\nand privacy in the data processing appears equally large. Preserving the privacy of data during its processing is a\nchallenging issue that has led to ingenious new cryptographic solutions, such as fully homomorphic encryption (to\nname only one). An optimal cryptographic support for private data processing must in any case be scalable and\nlightweight. To this end, we discuss the application of standard (off-the-shelf) cryptography to enable the computation\nof any function under permanent disguise (encryption). Using a local form of multiparty computation (essentially in a\nnon-distributed fashion), we show how to execute any data processing algorithm in complete privacy. Our solution\ncan, for example, be used with smart grid equipment, when small hardware security modules are locally available\n(such as in smart meters)....
Information security is key important when we are trying to interconnect the wireless body sensor network with\nthe healthcare social network via mobile facilities. In this paper, we specially work on a secured electrocardiogram\n(ECG) signal transmission scheme to prevent further injuries for patients with heart diseases from human emotional\nstress. We proposed a dynamic encryption method via biometric information among frequency spectrums of ECG\nsignals, which can guarantee both high classification rate (>90 %) and system energy efficiency. At the same time,\ncooperative relays are applied for an additional spatial diversity gains. Simulation results show that the improved\ntransmission rate and signal power capacity can lower the probability of data intercept (LPI) and detection (LPD) by\ntaking the advantages of both temporal and spatial diversities. The network security thereby can be further\nimproved....
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