Blind multi-signature scheme based on factoring and discrete logarithm problem

One of the important objectives of information security systems is providing authentication of the electronic documents and messages. In that, blind signature schemes are an important solution to protect the privacy of users in security electronic transactions by highlighting the anonymity of participating parties. Many studies have focused on blind signature schemes, however, most of the studied schemes are based on single computationally difficult problem. Also digital signature schemes from two difficult problems were proposed but the fact is that only finding solution to single hard problem then these digital signature schemes are breakable. In this paper, we propose a new signature schemes base on the combination of the RSA and Schnorr signature schemes which are based on two hard problems: IFP and DLP. Then expanding to propose a single blind signature scheme, a blind multi-signature scheme, which are based on new baseline schemes

Community-Based Measures to Against the COVID-19: An Experience From Vietnam With Consecutive 3 Months of no New Infection in the Community During the First Wave of Pandemic

Vietnam has faced a high risk of transmission of COVID-19 during the pandemic. Despite the specific challenges that come with a low-resource country, the Vietnamese government has provided a sustainable response, demonstrating both great capacity and rapid decision-making to manage the entirety of the COVID-19 outbreak with lessons learned from the SARS and H1N1 epidemics in 2003 and 2009, respectively. A rapid response, specific epidemiological F0–F5 tracing system, and public education are some of the key measures that have helped Vietnam to control the outbreak. As of July 15, 2020, Vietnam has reported 373 accumulated confirmed cases and no deaths within the last 90 consecutive days of no new infections in the community. Vietnam can now consider declaring an end to the COVID-19 crisis on their part

Technological CAD/CAM chain for automated polishing of geometrically complex workpieces

Despite recent advances in automation technology, geometrically complex workpieces are still often finished manually. An example for this is the post-processing of dental prostheses, which display exceptionally high surface requirements. Aiming for an improved quality assurance, this article presents a methodology for an adaptive tool path planning for polishing of geometrically complex workpieces. For this purpose, the initial roughness of the workpiece is determined using a machine-integrated measuring system. Next, suitable process parameters are selected based on machine knowledge and the adapted NC code of the polishing process is generated and simulated. The results of the simulation and the actual polishing process are compared afterwards and transformed into process knowledge. Thus, the adaption of the process parameters and the quality of the simulation are continuously improved. The article highlights the implementation of the methodology with special emphasis on the selection of the process parameters

La fonction de partition de Minc et une conjecture de Segal pour certains spectres de Thom

On construit dans cet article une résolution injective minimale dans la catégorie \U des modules instables sur l'algèbre de Steenrod modulo $2$, de la cohomologie de certains spectres obtenus à partir de l'espace de Thom du fibré, associé à la représentation régulière réduite du groupe abélien élémentaire $(\Z/2)^n$, au dessus de l'espace $B(\Z/2)^n$. Les termes de la résolution sont des produits tensoriels de modules de Brown-Gitler $J(k)$ et de modules de Steinberg $L_n$ introduits par S. Mitchell et S. Priddy. Ces modules sont injectifs d'après J. Lannes et S. Zarati, de plus ils sont indécomposables. L'existence de cette résolution avait été conjecturée par Jean Lannes et le deuxième auteur. La principale indication soutenant cette conjecture était un résultat combinatoire de G. Andrews : la somme alternée des séries de Poincaré des modules considérées est nulle