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Mobile users are often faced with a trade-off between security and convenience. Either users do not use any security lock and risk compromising their data, or they use security locks but then have to inconveniently authenticate every time they use the device. Rather than exploring a new authentication scheme, we address the problem of deciding when to(More)
In this paper, we propose a novel data hiding scheme with reversibility based on exploiting modification direction (EMD). One cover image is first chosen and prepared to generate two visually similar steganographic images. During the secret embedding, the pixels in the first steganographic image are modified by no more than one gray level to embed secret(More)
Wireless network coding has been shown to reduce the number of transmissions by exploiting the broadcast nature of the wireless medium. Multiple packets may be encoded into a single packet when their respective next hops have enough information to decode them. Previous research has shown that packets belonging to different flows may be encoded (interflow(More)
This paper demonstrates a rapid and full hitless defragmentation method in elastic optical networks exploiting a new technique for fast wavelength tracking in coherent receivers. This technique can be applied to a single-carrier connection or each of the subcarriers forming a super-channel. A proof-of-concept demonstration shows hitless defragmentation of a(More)
Mobile phones are becoming the convergent platform for personal sensing, computing, and communication. This paper attempts to exploit this convergence towards the problem of automatic image tagging. We envision <i>TagSense</i>, a mobile phone based collaborative system that senses the people, activity, and context in a picture, and merges them carefully to(More)
In this paper, we propose a novel joint data-hiding and compression scheme for digital images using side match vector quantization (SMVQ) and image inpainting. The two functions of data hiding and image compression can be integrated into one single module seamlessly. On the sender side, except for the blocks in the leftmost and topmost of the image, each of(More)
In this paper, we propose a novel fragile watermarking scheme with content restoration capability. Authentication-bits are produced using the image hashing method with a folding operation. The low-frequency component of the nonsubsampled contourlet transform (NSCT) coefficients is used to encode the restoration-bits for each block by the adaptive bit(More)
Cloud-of-clouds storage exploits diversity of cloud storage vendors to provide fault tolerance and avoid vendor lock-ins. Its inherent diversity property also enables us to offer keyless data security via dispersal algorithms. However, the keyless security of existing dispersal algorithms relies on the embedded random information, which breaks data(More)
In this paper, we propose an adaptive reversible steganographic scheme based on the just noticeable distortion (JND). First, the JND value of each cover pixel is calculated using the frequency model of the human visual system (HVS). Then, the prediction value of the cover pixel is acquired by anisotropic interpolation, and also the pixel distribution(More)