Blar i NTNU Open på forfatter "Gjøsteen, Kristian"

Viser treff 41-60 av 96

    • Improving on the Number Field Sieve 

      Ørke, Per Kristian (Master thesis, 2015)
      We look at efficient methods for computing logarithms in finite fields of any type. To achieve this, we first develop methods for factoring integers and computing discrete logarithms in fields of prime order using algebraic ...

    • Improving the Norwegian Internet Voting Protocol 

      Øberg, Marianne Wiik (Master thesis, 2011)
      We have in this thesis looked at possible improvements with respect to security for the Norwegian Internet voting protocol. We have made a new protocol with independent secret keys, where all the encryptions of the votes ...

    • Index Calculus Attacks on Hyperelliptic Curves 

      Rasmussen, Lars Lone (Master thesis, 2009)
      Hyperelliptic curves could be considered against elliptic curves for cryptography by virtue of using smaller fields and therefore being faster, but they have several weaknesses. Index calculus attacks are effective against ...

    • Instantiating the GPV-framework 

      Garli, Emil Haagensen (Bachelor thesis, 2022)
      De fleste kryptosystemer som brukes i dag baserer sikkerheten sin på ett av tre matematisk vanskelige problemer: faktorisering av store heltall, diskré logarithmer eller elliptisk kurve diskré logaritmer. Disse problemer ...

    • Isogeny Based Cryptography 

      Strand, Trym (Master thesis, 2019)
      Vi undersøker hvor brukbart tre forskjellige kryposystem er in en post-kvantum verden. Rostovtsev-Stolbunov offentlig nøkkel protokollen, som bruker isogenyer mellom elliptiske kurver, viser seg å være usikre mot ...

    • Key Exchange in Special Circumstances 

      Fondevik, Elsie Mestl (Doctoral theses at NTNU;2024:246, Doctoral thesis, 2024)

    • Lattice-Based Proof of Shuffle and Applications to Electronic Voting 

      Aranha, Diego F.; Baum, Carsten; Gjøsteen, Kristian; Silde, Tjerand; Tunge, Thor (Peer reviewed; Journal article, 2021)
      A verifiable shuffle of known values is a method for proving that a collection of commitments opens to a given collection of known messages, without revealing a correspondence between commitments and messages. We propose ...

    • Lattice-Based Zero Knowledge 

      Hegge, Einar Bogsnes (Master thesis, 2020)
      Vi presenterer 3 protokoller som benytter seg av lattice-basert zero-knowledge. Disse protokollene baserer sin sikkerhet på at det er vanskelig å løse det tilnærmede korteste vektor problemet, og kort heltallsløsning ...

    • Lattice-Based Zero-Knowledge Proofs From Commitments 

      Stjernberg, Tiril (Master thesis, 2023)
      Hovedformålet med denne oppgaven er å studere den nyeste lattice baserte zero-knowledge protokollen som ble introdusert av Lyubashevsky, Nguyen og Plançon. Vi starter med å introdusere de kryptografiske definisjonene og ...

    • Machine checked proofs for MLWE based encryption using EasyCrypt 

      Goldhahn, Oskar (Master thesis, 2023)
      Med den truende faren til kvantedatamaskiner trenger vi offentlig nøkkel-kryptografi som ikke avhenger av diskret logaritme-problemet og andre problemer som kan løses effektivt på kvantedatamaskiner. En fremgangsmåte er å ...

    • Machine-Checked Proofs of Privacy Against Malicious Boards for Selene & Co 

      Drăgan, Constantin Cătălin; Dupressoir, François; Estaji, Ehsan; Gjøsteen, Kristian; Haines, Thomas; Ryan, Peter Y. A.; Rønne, Peter B.; Solberg, Morten Rotvold (Chapter, 2022)
      Privacy is a notoriously difficult property to achieve in complicated systems and especially in electronic voting schemes. Moreover, electronic voting schemes is a class of systems that require very high assurance. The ...

    • Malicious cryptography 

      Galteland, Herman (Doctoral theses at NTNU;2020:116, Doctoral thesis, 2020)

    • Malware, Encryption, and Rerandomization - Everything is Under Attack 

      Galteland, Herman; Gjøsteen, Kristian (Journal article; Peer reviewed, 2017)
      A malware author constructing malware wishes to infect a specific location in the network. The author will then infect n initial nodes with n different variations of his malicious code. The malware continues to infect ...

    • Masteroppgave i kryptografi 

      Sigfusdottir, Gudrun (Master thesis, 2015)
      In this paper we look at the use of bootstrapping and squashing in order to make an encryption scheme fully homomorphic. The focus will be on what this is and how it can be used. The main focus will be on how this is applied ...

    • Mixnets and Verifiable Shuffling 

      Damsgård, Åshild Bryn (Master thesis, 2018)
      In this thesis we consider different mix network protocols. First, we discuss a protocol called cMix. We describe the concept of verifiable shuffling, that enable mixnodes to prove that they operate correctly according to ...

    • Modelling Oblivious Transfer in EasyCrypt 

      Furuberg, Mikkel Langtangen (Master thesis, 2018)
      We describe how to construct an oblivious transfer protocol which security is based on subset membership problems and smooth projective hash functions. A specific protocol based on the two-message oblivious transfer protocols ...

    • Multivariate Public Key Cryptography 

      Skanthamany, Anojan (Bachelor thesis, 2022)
      I denne oppgaven, så er målet å introdusere leseren til noen multivariate offentlig kryptografiske systemer. Vi vil gå gennom tre slike systemer. Disse systemene er Matsumoto Imai, Oil and Vinegar, og Rainbow. Vi vil gå ...

    • Multivariate Quadratic Cryptosystems 

      Milne, Simon Alexander (Master thesis, 2019)
      Vi beskriver egenskapene til multivariate ligningssystemer, og både egenskapene til Grøbnerbaser, og hvordan man beregner dem. Videre beskriver vi to multivariate kvadratiske kryptosystemer, kryptosystemet Matsumoto-Imai ...

    • Number Field Sieve 

      Spaans, Ruben Grønning (Master thesis, 2013)
      The Number Field Sieve (NFS) is the fastest known general method for factoring integers having more than 120 digits. In this thesis we will will study the algebraic number theory that lies behind the algorithm, describe ...

    • Offline Assisted Group Key Exchange 

      Boyd, Colin Alexander; Davies, Gareth Thomas; Gjøsteen, Kristian; Jiang, Yao (Journal article; Peer reviewed, 2018)
      We design a group key exchange protocol with forward secrecy where most of the participants remain offline until they wish to compute the key. This is well suited to a cloud storage environment where users are often offline, ...