351 research outputs found
Not Just Regular Decoding: Asymptotics and Improvements of Regular Syndrome Decoding Attacks
No full textCryptographic constructions often base security on structured problem variants to enhance efficiency or to enable advanced functionalities. This led to the introduction of the Regular Syndrome Decoding (RSD) problem, which guarantees that a solution to the Syndrome Decoding (SD) problem follows a particular block-wise structure. Despite recent attacks exploiting that structure by Briaud and Øygarden (Eurocrypt ’23) and Carozza, Couteau and Joux (CCJ, Eurocrypt ’23), many questions about the impact of the regular structure on the problem hardness remain open. In this work we initiate a systematic study of the hardness of the RSD problem starting from its asymptotics. We classify different parameter regimes revealing large regimes for which RSD instances are solvable in polynomial time and on the other hand regimes that lead to particularly hard instances. Against previous perceptions, we show that a classification solely based on the uniqueness of the solution is not sufficient for isolating the worst case parameters. Further, we provide an in-depth comparison between SD and RSD in terms of reducibility and computational complexity, identifying regimes in which RSD instances are actually harder to solve. We provide the first asymptotic analyses of the algorithms presented by CCJ, establishing their worst case decoding complexities as and , respectively. We then introduce regular-ISD algorithms by showing how to tailor the whole machinery of advanced Information Set Decoding (ISD) techniques from attacking SD to the RSD setting. The fastest regular-ISD algorithm improves the worst case decoding complexity significantly to . Eventually, we show that also with respect to suggested parameters regular-ISD outperforms previous approaches in most cases, reducing security levels by up to 30 bits
MR-DSS – Smaller MinRank-Based (Ring-)Signatures
No full textIn the light of NIST’s announced reopening of the call for digital signature proposals in 2023 due to lacking diversity, there is a strong need for constructions based on other established hardness assumptions. In this work we construct a new post-quantum secure digital signature scheme based on the problem, a problem with a long history of applications in cryptanalysis that led to a strong belief in its hardness. Initially following a design by Courtois (Asiacrypt \u2701) based on the Fiat--Shamir transform, we make use of several recent developments in the design of sigma protocols to reduce signature size and improve efficiency. This includes the recently introduced paradigm (Eurocrypt \u2719) and combinations with -- techniques (CCS \u2718). Moreover, we introduce several improvements to the core of the scheme to further reduce its signature size
A Faster Algorithm for Finding Closest Pairs in Hamming Metric
No full textWe study the Closest Pair Problem in Hamming metric, which asks to find the pair with the smallest Hamming distance in a collection of binary vectors. We give a new randomized algorithm for the problem on uniformly random input outperforming previous approaches whenever the dimension of input points is small compared to the dataset size. For moderate to large dimensions, our algorithm matches the time complexity of the previously best-known locality sensitive hashing based algorithms. Technically our algorithm follows similar design principles as Dubiner (IEEE Trans. Inf. Theory 2010) and May-Ozerov (Eurocrypt 2015). Besides improving the time complexity in the aforementioned areas, we significantly simplify the analysis of these previous works. We give a modular analysis, which allows us to investigate the performance of the algorithm also on non-uniform input distributions. Furthermore, we give a proof of concept implementation of our algorithm which performs well in comparison to a quadratic search baseline. This is the first step towards answering an open question raised by May and Ozerov regarding the practicability of algorithms following these design principles
Countering the Risks of Vocationalisation in Master’s Programmes in International Development (article pre-print)
No full textPre-print of article:
Denskus, T., & Esser, D. E. (2015). Countering the risks of vocationalisation in master's programmes in international development. Learning and Teaching, 8(2), 72-85. doi:http://dx.doi.org/10.3167/latiss.2015.08020
From Stakeholder Management to Stakeholder Accountability
No full textConfronted with mounting pressure to ensure accountability vis-Ã -vis customers, citizens and beneficiaries, organizational leaders need to decide how to choose and implement so-called accountability standards. Yet while looking for an appropriate standard, they often base their decisions on cost-benefit calculations, thus neglecting other important spheres of influence pertaining to more broadly defined stakeholder interests. We argue in this paper that, as a part of the strategic decision for a certain standard, management needs to identify and act according to the needs of all stakeholders. We contend that the creation of a dialogical understanding among affected stakeholders cannot be a mere outcome of applying certain accountability standards, but rather must be a necessary precondition for their use. This requires a stakeholder dialogue prior to making a choice. We outline such a discursive decision framework for accountability standards based on the Habermasian concept of communicative action and, in the final section, apply our conceptual framework to one of the most prominent accountability tools (AA 1000). Copyright Springer 2006accountability standards, discourse ethics, Habermas, organizational accountability, stakeholder management, stakeholder dialogue,
A problemática da interpretação no pensamento de Josef Esser
No full textTHE AIM OF THIS PAPER IS TO INVESTIGATE THE IMPORTANCE OF THE INTERPRETATION IN THE JOSEF ESSER'S CONCEPTION AND THE INFLUENCE OF HIS THOUGHT IN THE CONTEMPORARY LEGAL CULTURE. FOLLOWING THE AUTHOR'S THOUGHT, THE SUBJECT'S APPROACH IS FOCUSED ON THE PROBLEM OF LAW'S INTERPRETATION/APPLICATION, THAT LEADS, EQUALLY, TO A REEVALUATION OF THE METHODOLOGICAL QUESTION. THEREFORE, THE STUDY GOES TO THE ANALYSIS OF SOME CONCEPTS USED BY ESSER, AS WELL AS TO THE METHODOLOGY DEVELOPED BY THE AUTHOR, INSTRUMENTS THROUGH WHICH IT DISCLOSES THE INTERPRETATIVE PROCESS HE CONSIDERED. THE IMPORTANCE OF THIS APPROACH REFLECTED ON THE EXAMINATION OF THE JURISDICTIONAL ACTIVITY THAT GAINS RELIEF AT THE MOMENT THAT IT IS SEEN AS A CREATIVE PERFORMANCE, FOCUSED ON THE SOLUTION OF THE CONCRETE CASE, THAT IS, PARALLELY, SUBMITTED TO THE CONTROLS THAT ARE GUIDED FOR ATTAINMENT OF A FAIR DECISION. O OBJETIVO DESTE TRABALHO É INVESTIGAR A IMPORTÂNCIA DA INTERPRETAÇÃO NA CONCEPÇÃO DE JOSEF ESSER E A INFLUÊNCIA DESTE PENSAMENTO NA CULTURA JURÍDICA CONTEMPORÂNEA. SEGUINDO O PENSAMENTO DO AUTOR, A ABORDAGEM DO TEMA É FOCADA NO PROBLEMA DA INTERPRETAÇÃO/APLICAÇÃO DO DIREITO, O QUE CONDUZ, IGUALMENTE, A UMA REAVALIAÇÃO DA QUESTÃO METODOLÓGICA. O ESTUDO DIRIGE-SE, PORTANTO, À ANÁLISE DE ALGUNS CONCEITOS UTILIZADOS POR ESSER, ASSIM COMO À METODOLOGIA DESENVOLVIDA PELO AUTOR, INSTRUMENTOS POR MEIO DOS QUAIS SE DESCORTINA O PROCESSO INTERPRETATIVO POR ELE PROPOSTO. A IMPORTÂNCIA DESSA ABORDAGEM REFLETE-SE NO EXAME DA ATIVIDADE JURISDICIONAL QUE GANHA RELEVO A PARTIR DO MOMENTO EM QUE É VISTA COMO UMA ATUAÇÃO CRIATIVA, VOLTADA PARA A SOLUÇÃO DO CASO CONCRETO, ESTANDO, PARALELAMENTE, SUBMETIDA A CONTROLES QUE SÃO ORIENTADOS PARA OBTENÇÃO DE UMA JUSTA DECISÃO.
«Esser a se stessi la so libertà»
No full textThe paper provides a brief new reading of Giacomo Noventa’s poetry, which tries to systematize a poetic thought such unorthodox, by using in particular the prose reflections of the author on his poems
MiRitH: Efficient Post-Quantum Signatures from MinRank in the Head
No full textSince 2016’s NIST call for standardization of post-quantum cryptographic primitives, developing efficient post-quantum secure digital signature schemes has become a highly active area of research. The difficulty in constructing such schemes is evidenced by NIST reopening the call in 2022 for digital signature schemes, because of missing diversity in existing proposals. In this work, we introduce the new postquantum digital signature scheme MiRitH. As direct successor of a scheme recently developed by Adj, Rivera-Zamarripa and Verbel (Africacrypt ’23), it is based on the hardness of the MinRank problem and follows the MPC-in-the-Head paradigm. We revisit the initial proposal, incorporate design-level improvements and provide more efficient parameter sets. We also provide the missing justification for the quantum security of all parameter sets following NIST metrics. In this context we design a novel Grover-amplified quantum search algorithm for solving the MinRank problem that outperforms a naive quantum brute-force search for the solution.
MiRitH obtains signatures of size 5.7 kB for NIST category I security and therefore competes for the smallest signatures among any post-quantum signature following the MPCitH paradigm.
At the same time MiRitH offers competitive signing and verification timings compared to the state of the art. To substantiate those claims we provide extensive implementations. This includes a reference implementation as well as optimized constant-time implementations for Intel processors (AVX2), and for the ARM (NEON) architecture. The speedup of our optimized AVX2 implementation relies mostly on a redesign of the finite field arithmetic, improving over existing implementations as well as an improved memory management
Elevers erfaringer og erfaringskvaliteter med idrett og andre bevegelsesaktiviteter, og dets påvirkning på kroppsøvingsfaget - En blandet metode studie
No full textFormål: Oppgaven skal undersøke erfaringer og erfaringskvaliteter 10. trinns elever har til idrett og andre bevegelsesaktiviteter, og hvordan dette påvirker erfaringen til kroppsøvingsfaget. Kunnskapen som resulterer av prosjektet vårt, skal på lang sikt bidra til å kunne tilrettelegge for at alle elever kan oppleve mestring og inkludering i kroppsøving.
Teori: Teorien baserer seg på Klafkis kritisk-konstruktive dannelsesteori og didaktikk.
Metode: Det er benyttet blandede metoder med tverrsnittdesign for å besvare problemstillingen. Utvalget for kvantitativ metode var 119 10. trinns elever ved to ungdomsskoler i Viken, og for kvalitativ metode var det totalt 3 10. trinns elever. Datamaterialet er samlet inn gjennom spørreskjema og intervju. Studien er validitet- og reliabilitetstestet.
Resultater: De overordnede funnene i studien antyder at de organiserte og uorganiserte elevene driver med aktivitet fordi de selv ønsker det. De fleste elevene liker faget i positiv grad, spesielt guttene og de organiserte. Innholdet i kroppsøvingsfaget domineres av ballspill og til dels grunntrening, og moderne aktiviteter for liten plass. Det er guttene og de organiserte elevene som har mest positive og minst negative erfaringer med innholdet. Resultatet angående dannelsesdimensjonene viser at elevene erfarer dimensjonene i noe ulike grad. De erfarer lite av medbestemmelse, større grad av solidaritet og nøytralt av selvbestemmelse. Når det kommer til læring i kroppsøving kommer det frem at elevene lærer i noe positiv grad både solidaritet, og helse og velvære. Når det kommer til hvilke aktiviteter elevene lærer dominerer ulike idretter, mens dans, lek og friluftsliv erfarer de å lære i mindre grad
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