A Pairing-Free Signature Scheme from Correlation Intractable Hash Function and Strong Diffie-Hellman Assumption

Goh and Jarecki (Eurocrypt 2003) showed how to get a signature scheme from the computational Diffie-Hellman assumption, and they introduced the name EDL for signatures of this type. The corresponding EDL family of signature schemes is remarkable for several reasons: elegance, simplicity and tight security. However, EDL security proofs stand in the random oracle model, and, to the best of our knowledge, extending this family without using an idealization of hash functions has never been successful. In this paper, we propose a new signature scheme belonging to the EDL family, which is simple, natural and efficient, without using the random oracle model. Our scheme is based on the very same assumption than the Boneh-Boyen scheme, namely the strong Diffie-Hellman assumption, with the precision that our groups are not bound to being bilinear. We also make use of a correlation-intractable hash function, for a particular relation related to discrete-logarithm. In addition to the theoretical interest of extending the EDL family with- out the random oracle model, our scheme is also one of the very few schemes which achieve discrete-log security properties without relying on pairings

Spartan Daily, September 25, 1995

Volume 105, Issue 17https://scholarworks.sjsu.edu/spartandaily/8732/thumbnail.jp

Healthy Start Vouchers Study:The Views and Experiences of Parents, Professionals and Small Retailers in England

This is the full final report of a qualitative study of views of the UK government's Healthy Start Scheme, which provides vouchers for fruit, vegetables, milk and vitamins for low income families with young children. This study explored the views of the health and social care professionals who are advocates for the scheme, the parents who are recipients and the retailers who accept the vouchers in their shops. This study provides key lessons for policy makers and practitioners to improve the accessibility and reach of the scheme

Effect of pre-exposure of sulfur and iron sulfide on H2S corrosion at different temperatures

The study has been carried out to investigate the effect of elemental sulfur and iron sulfide on corrosion behavior of carbon steel in sour environment. It was found that both compounds could form a protective layer of corrosion products even at low pH and high temperature levels. In general, bare steel electrode behaved as sacrificial anode in two metal galvanic coupling with sulfur or iron sulfide covered steel electrode. However, some examples of opposite behavior were observed in the tests with iron sulfide. The surface of bare steel electrode was coated with a thin black layer and had no evidence of changes due to corrosion. In other hand, surface of sulfur-covered electrode had well adherent thick dark film with traces of pitting. In the case with iron sulfide-covered electrode, the metal surface remained bright with crevice corrosion region

Long-span cold-formed steel single C-section portal frames

This thesis presents a comprehensive study of long-span cold-formed steel single C-section portal frames. The study includes the formulation of a nonlinear beam finite element for thin-walled sections, a series of full-scale frame tests and component tests, finite element modelling and advanced analysis followed by the formulation of design guidelines. The study was aimed at exploring the structural behaviour through experiment and numerical analysis towards developing provisions for the design of cold-formed steel portal frames using Advanced Analysis. A nonlinear thin-walled beam element for general open cross-sections was formulated, incorporating warping effect and non-coincident location of the shear centre and the centroid. It was successfully implemented in the geometric nonlinear analysis framework of the OpenSees finite element software. Towards investigating the behaviour and determining the ultimate strength, six full-scale tests on cold-formed steel single C-section portal frames were conducted. Separate tests were performed on frame connections, point-fastener connections and coupons to obtain the material parameters required for numerical modelling. Advanced shell finite element models of the full-scale frames and frame connections were created and validated against experimental results. The bolts and screws used for the connections between components were represented by point-based deformable fasteners. The force-deformation characteristics of the deformable fasteners were incorporated and successfully implemented in the Advanced Analysis. The strength of cold-formed steel single C-section portal frames determined by the Direct Strength Method and the Direct Design Method were compared. To account for inherent uncertainties in the strength of CFS portal frames, system resistance factors were derived. It was concluded that the Direct Design Method using Advanced Analysis is the likely future method for the design of cold-formed steel portal frames

Bench-scale assessment of membrane pre-treatment and seasonal fouling variations

Fouling -- Fouling indexes -- Membrane feed pretreatment -- Objectives and hypotheses -- Membrane clean water permeability -- Pre-filtration with laboratory filters : a cautionary tale -- MFI-UF calculation method -- Bench-scale assessment of membrane pre-treatment and seasonal fouling potential variations

Käyttäjien jäljittäminen ja kannusteiden hallinta älykkäissä liikennejärjestelmissä

A system for offering incentives for ecological modes of transport is presented. The main focus is on the verification of claims of having taken a trip on such a mode of transport. Three components are presented for the task of travel mode identification: A system to select features, a means to measure a GPS (Global Positioning System) trace's similarity to a bus route, and finally a machine-learning approach to the actual identification. Feature selection is carried out by sorting the features according to statistical significance, and eliminating correlating features. The novel features considered are skewnesses, kurtoses, auto- and cross correlations, and spectral components of speed and acceleration. Of these, only spectral components are found to be particularly useful in classification. Bus route similarity is measured by using a novel indexing structure called MBR-tree, short for "Multiple Bounding Rectangle", to find the most similar bus traces. The MBR-tree is an expansion of the R-tree for sequences of bounding rectangles, based on an estimation method for longest common subsequence that uses such sequences. A second option of decomposing traces to sequences of direction-distance-duration-triples and indexing them in an M-tree using edit distance with real penalty is considered but shown to perform poorly. For machine learning, the methods considered are Bayes classification, random forest, and feedforward neural networks with and without autoencoders. Autoencoder neural networks are shown to perform perplexingly poorly, but the other methods perform close to the state-of-the-art. Methods for obfuscating the user's location, and constructing secure electronic coupons, are also discussed