Search results for "Security"
showing 10 items of 1693 documents
Security of public key cryptosystems based on Chebyshev Polynomials
2004
Chebyshev polynomials have been recently proposed for designing public-key systems. Indeed, they enjoy some nice chaotic properties, which seem to be suitable for use in Cryptography. Moreover, they satisfy a semi-group property, which makes possible implementing a trapdoor mechanism. In this paper we study a public key cryptosystem based on such polynomials, which provides both encryption and digital signature. The cryptosystem works on real numbers and is quite efficient. Unfortunately, from our analysis it comes up that it is not secure. We describe an attack which permits to recover the corresponding plaintext from a given ciphertext. The same attack can be applied to produce forgeries …
Quantum Attacks on Classical Proof Systems - The Hardness of Quantum Rewinding
2014
Quantum zero-knowledge proofs and quantum proofs of knowledge are inherently difficult to analyze because their security analysis uses rewinding. Certain cases of quantum rewinding are handled by the results by Watrous (SIAM J Comput, 2009) and Unruh (Eurocrypt 2012), yet in general the problem remains elusive. We show that this is not only due to a lack of proof techniques: relative to an oracle, we show that classically secure proofs and proofs of knowledge are insecure in the quantum setting. More specifically, sigma-protocols, the Fiat-Shamir construction, and Fischlin's proof system are quantum insecure under assumptions that are sufficient for classical security. Additionally, we show…
Blockchain-Based Proof of Location
2016
Location-Based Services (LBSs) build upon geographic information to provide users with location-dependent functionalities. In such a context, it is particularly important that geographic locations claimed by users are trustworthy. Centralized verification approaches proposed in the last few years are not satisfactory, as they entail a high risk to the privacy of users. In this paper, we present and evaluate a novel decentralized, infrastructure-independent proof-of-location scheme based on blockchain technology. Our scheme guarantees both location trustworthiness and user privacy preservation.
Random Walk in a N-cube Without Hamiltonian Cycle to Chaotic Pseudorandom Number Generation: Theoretical and Practical Considerations
2017
Designing a pseudorandom number generator (PRNG) is a difficult and complex task. Many recent works have considered chaotic functions as the basis of built PRNGs: the quality of the output would indeed be an obvious consequence of some chaos properties. However, there is no direct reasoning that goes from chaotic functions to uniform distribution of the output. Moreover, embedding such kind of functions into a PRNG does not necessarily allow to get a chaotic output, which could be required for simulating some chaotic behaviors. In a previous work, some of the authors have proposed the idea of walking into a $\mathsf{N}$-cube where a balanced Hamiltonian cycle has been removed as the basis o…
Facebookin tietoturvasta
2015
Tämä työ sai alkunsa, kun kiinnostuin Internetin tietoturvasta Edward Snowdenin paljastusten myötä. Aluksi selvitän käsitteet sosiaalinen media ja tietoturva. Sitten yhdistän nämä käsitteet, tutkien sosiaalisen median tietoturvaa Facebookin tapauksessa. Esittelen tutkimuslähteiden valossa ilmenneitä keskeisempiä turvallisuusuhkia, jotka liittyvät Facebookiin ja vaikuttavat käyttäjien yksityisyyteen ja tietoturvaan. Tietoisuuden lisääminen mahdollisista uhista osoittautui parhaaksi keinoksi niiden torjunnassa. This work began when I became interested in Internet data security because of Edward Snowden revelations. First, I explain the concepts of social media and security. Then I combine the…
Success factors of Polish family businesses
2017
This article presents the results of a study carried out among family businesses operating in Poland. It is intended to supplement previously generated knowledge in the area of the operation of family businesses in the specific socio-economic and legal conditions in Poland. The objective was to collate the opinions of entrepreneurs regarding the need for visibility of the family and the family business status in business relations and the marketing activities of enterprises. The data were collected using in-depth interviews with the Polish family business owners. This paper outlines the conclusion of the study with respect to success factors such as: the trust among the family members, flex…
Glass Walls. Safe house e crisi dei mutui subprime: dal sogno americano all’incubo globale
2014
Assisted phytostabilization of soil from a former military area with mineral amendments.
2019
Abstract Due to the presence of toxic pollutants, soils in former military areas need remedial actions with environmentally friendly methods. Greenhouse experiments were conducted to investigate the aided phytostabilization of multi-heavy metals (HMs), i.e. Cd, Cr, Cu, Ni, Pb, Zn, in post-military soil by Festuca rubra and three mineral amendments (diatomite, dolomite and halloysite). The amendments were applied at 0 and 3.0% to each pot filled with 5 kg of polluted soil. After seven weeks of the phytostabilization, selected soil properties, biomass yield of F. rubra and immobilization of HMs by their accumulation in plant and redistribution among individual fractions in soil were determine…
Design of a virtual instrument for water quality monitoring across the Internet
2001
Abstract This article presents the design of a new distributed and multi-platform system for water quality monitoring, enhanced with powerful Internet capabilities. The measured variables are temperature, turbidity, pH, dissolved oxygen, and electrical conductivity. The signal-conditioning block has been simplified through the use of software routines for thermal compensation, hence, reducing the cost and dimensions. The system offers a wide variety of Internet capabilities, like e-mail alarm notifications, automatic storage of measured data in a remote machine via the FTP protocol, dynamic generation of HTML reports, real time graphs, and indicators visible from a remote web browser, etc. …
Kiberdraudu un drošības ietekme uz patērētāju uzvedību Fintech uzņēmumos
2021
Līdz ar daudzajiem tehnoloģiskajiem sasniegumiem, kas turpina attīstīties, un pasaule, kādu mēs pazītam, strauji mainās. FinTech pakalpojumi ir pārņēmuši ekonomiku kā daļa no šī modernā tehnoloģiju viļņa. FinTech firmas ir klātesošas gandrīz katrā ekonomikas daļā. Šī tehnoloģija tiek uzskatīta par transformējošu atklājumu, kas ir ietekmējis mūsu dzīvi un ekonomisko sistēmu; tā ir padarījusi sarežģītākus procesus pieejamākus visiem; tomēr FinTech ir radījis ievērojamas problēmas, piemēram, kiberuzbrukumus un pienācīgu noteikumu trūkumu. Klienti un valdības joprojām iepazīstas ar šiem jauninājumiem, jo šī konkrētā ekonomikas joma strauji attīstās. Patērētāji tiek ātri iesaistīti jaunos un lab…