Cutting-Edge Cryptography Through the Lens of Secret Sharing

Secret sharing is a mechanism by which a trusted dealer holding a secret splits the secret into many shares and distributes the shares to a collection of parties. Associated with the sharing is a monotone access structure, that specifies which parties are qualified and which are not: any qualified subset of parties can (efficiently) reconstruct the secret, but no unqualified subset can learn anything about the secret. In the most general form of secret sharing, the access structure can be any monotone NP language. In this work, we consider two very natural extensions of secret sharing. In the first, which we call distributed} secret sharing, there is no trusted dealer at all, and instead the role of the dealer is distributed amongst the parties themselves. Distributed secret sharing can be thought of as combining the features of multiparty non-interactive key exchange and standard secret sharing, and may be useful in settings where the secret is so sensitive that no one individual dealer can be trusted with the secret. Our second notion is called functional secret sharing, which incorporates some of the features of functional encryption into secret sharing by providing more fine-grained access to the secret. Qualified subsets of parties do not learn the secret, but instead learn some function applied to the secret, with each set of parties potentially learning a different function. Our main result is that both of the extensions above are equivalent to several recent cutting-edge primitives. In particular, general-purpose distributed secret sharing is equivalent to witness PRFs, and general-purpose functional secret sharing is equivalent to indistinguishability obfuscation. Thus, our work shows that it is possible to view some of the recent developments in cryptography through a secret sharing lens, yielding new insights about both these cutting-edge primitives and secret sharing

High dimensional autocompensating quantum cryptography in optical fibers implemented with discrete and integrated photonic devices

O obxectivo global desta tese é contribuir ao deseño de novos sistemas de criptografía cuántica e ao desenvolvemento de dispositivos fotónicos discretos e integrados que implementen operacións específicas para implementalos usando multiplexación espacial. Deste xeito, na tese propoñense novos metodos de encriptación cuántica autocompensada, que fan uso dos modos espaciais propagados por diversas fibras ópticas (fibras de poucos modos e multinúcleo) para conseguir transmitir información en alta dimensión, correxindo tódalas fluctuacións que estes sofren ao longo da transmisión pola fibra. Ao mesmo tempo, deseñanse os distintos dispositivos fotónicos necesarios para implementar ditos métodos, baseados tanto en elementos ópticos discretos como en dispositivos integrados. En particular, na tese presentanse novos dispositivos para xerar estados cuánticos útiles en criptografía (baseados en estados vórtice), así como proxectores cuánticos capaces de medir ditos estados. Ademáis, na tese demóstrase a viabilidade de fabricar ditos dispositivos de xeito integrado por medio de intercambio iónico en vidrio

Moving Forward with Digital Disruption: What Big Data, IoT, Synthetic Biology, AI, Blockchain, and Platform Businesses Mean to Libraries

Digital disruption, also known as “the fourth industrial revolution,” is blurring the lines between the physical, digital, and biological spheres. This issue of Library Technology Reports (vol. 56, no. 2) examines today’s leading-edge technologies and their disruptive impacts on our society through examples such as extended reality, Big Data, the Internet of Things (IoT), synthetic biology, 3-D bio-printing, artificial intelligence (AI), blockchain, and platform businesses in the sharing economy. This report explains how new digital technologies are merging the physical and the biological with the digital; what kind of transformations are taking place as a result in production, management, and governance; and how libraries can continue to innovate with new technologies while keeping a critical distance from the rising ideology of techno-utopianism and at the same time contributing to social good

Big Data Security (Volume 3)

After a short description of the key concepts of big data the book explores on the secrecy and security threats posed especially by cloud based data storage. It delivers conceptual frameworks and models along with case studies of recent technology

Strategic Audit of Facebook Through the Lens of International Reputation

This report investigates the history and current situation of Facebook, an international social media firm based in Menlo Park, CA. Facebook faces a number of international controversies and growing resentment from its userbase. In an industry where people are synonymous with capital, a strategic recommendation will be made to help Facebook regain some of its users’ lost faith and hopefully recapture old markets. This report will analyze Facebook’s internal situation using the framework of SWOT analysis, and the external environment Facebook exists in through PEST analysis. These tools will provide a helpful foundation to understand Facebook’s competitive advantages, and render an educated recommendation

An improved image steganography scheme based on distinction grade value and secret message encryption

Steganography is an emerging and greatly demanding technique for secure information communication over the internet using a secret cover object. It can be used for a wide range of applications such as safe circulation of secret data in intelligence, industry, health care, habitat, online voting, mobile banking and military. Commonly, digital images are used as covers for the steganography owing to their redundancy in the representation, making them hidden to the intruders, hackers, adversaries, unauthorized users. Still, any steganography system launched over the Internet can be cracked upon recognizing the stego cover. Thus, the undetectability that involves data imperceptibility or concealment and security is the significant trait of any steganography system. Presently, the design and development of an effective image steganography system are facing several challenges including low capacity, poor robustness and imperceptibility. To surmount such limitations, it is important to improve the capacity and security of the steganography system while maintaining a high signal-to-noise ratio (PSNR). Based on these factors, this study is aimed to design and develop a distinction grade value (DGV) method to effectively embed the secret data into a cover image for achieving a robust steganography scheme. The design and implementation of the proposed scheme involved three phases. First, a new encryption method called the shuffle the segments of secret message (SSSM) was incorporated with an enhanced Huffman compression algorithm to improve the text security and payload capacity of the scheme. Second, the Fibonacci-based image transformation decomposition method was used to extend the pixel's bit from 8 to 12 for improving the robustness of the scheme. Third, an improved embedding method was utilized by integrating a random block/pixel selection with the DGV and implicit secret key generation for enhancing the imperceptibility of the scheme. The performance of the proposed scheme was assessed experimentally to determine the imperceptibility, security, robustness and capacity. The standard USC-SIPI images dataset were used as the benchmarking for the performance evaluation and comparison of the proposed scheme with the previous works. The resistance of the proposed scheme was tested against the statistical, X2 , Histogram and non-structural steganalysis detection attacks. The obtained PSNR values revealed the accomplishment of higher imperceptibility and security by the proposed DGV scheme while a higher capacity compared to previous works. In short, the proposed steganography scheme outperformed the commercially available data hiding schemes, thereby resolved the existing issues