Blar i NTNU Open på forfatter "Gjøsteen, Kristian"

Viser treff 81-97 av 97

    • Security notions for cloud storage and deduplication 

      Boyd, Colin Alexander; Davies, Gareth Thomas; Gjøsteen, Kristian; Raddum, Håvard; Toorani, Mohsen (Journal article; Peer reviewed, 2018)
      Cloud storage is in widespread use by individuals and enterprises but introduces a wide array of attack vectors. A basic step for users is to encrypt their data, yet it is not obvious what security properties are required ...

    • Security of Signatures in The Quantum Random Oracle Model 

      Henriksen, Aurora Lucie (Master thesis, 2023)
      Målet med denne oppgaven er å studere beviselig sikkerhet i \emph{post-kvante kryptografi} (PQC) og andvende dette mot CRYSTALs gitter baserte signatur Dilithium. Først definerer vi den nødvendige teorien for å forstå ...

    • Side channels in deduplication: trade-offs between leakage and efficiency 

      Armknecht, Frederik; Boyd, Colin Alexander; Davies, Gareth Thomas; Gjøsteen, Kristian; Toorani, Mohsen (Chapter, 2017)
      Deduplication removes redundant copies of files or data blocks stored on the cloud. Clientside deduplication, where the client only uploads the file upon the request of the server, provides major storage and bandwidth ...

    • Special number field sieve 

      Bøhler, Per Reidar (Master thesis, 2008)
      Integer factorization is a problem not yet solved for arbitrary integers. Huge integers are therefore widely used for encrypting, e.g. in the RSA encryption scheme. The special number field sieve holds the current factorization ...

    • A study on tighter and more efficient isogeny-based cryptographic protocols 

      Veroni, Mattia (Doctoral theses at NTNU;2023:100, Doctoral thesis, 2023)
      This PhD thesis addresses the following research questions: • RQ 1: Can we prove tight reductions on isogeny-based schemes? • RQ 2: How sound are the assumptions underlying some computational problems in isogeny-based ...

    • Subgroup membership problems and public key cryptosystems 

      Gjøsteen, Kristian (Doktoravhandlinger ved NTNU, 1503-8181; 2004:69, Doctoral thesis, 2004)
      Public key encryption was first proposed by Diffie and Hellman [16], and widely popularised with the RSA cryptosystem [37]. Over the years, the security goals of public key encryption have been studied [17, 22], as have ...

    • Success-rate Estimation for Side Channel Analysis 

      Jordal, Sigurd (Master thesis, 2021)
      Denne masteroppgaven utforsker teori og teknikker innenfor side-kanals-angrep og side-kanals-analyse. Først definerer vi den matematiske modellen for lekkasje, og hva angrep-scenarioet er i side-kanals-angrep i form av ...

    • The Handling of Noise and Security of Two Fully Homomorphic Encryption Schemes 

      Hovd, Martha Norberg (Master thesis, 2017)
      Noise is introduced as a means to ensure security of encryption schemes in general, and fully homomorphic encryption schemes in particular. Strategies to control the growth of this and thereby guarantee correct decryption ...

    • The MPC-in-the-head paradigm and its applications 

      Lajord, Ola (Master thesis, 2023)
      Hovedformålet med denne oppgaven er å studere MPC-i-hodet-teknikken og anvendelser av denne. Vi starter med å introdusere nødvendig bakgrunnsteori for forpliktelsesprotokoller, kunnskapsløse bevis og sikker flerpartiberegning ...

    • The Number Field Sieve 

      Trondsen, Elin Margrete (Master thesis, 2012)
      We present two algorithms for splitting a general composite number, the quadratic sieve algorithm (QS) and the general number field sieve algorithm (NFS). The former is the method of choice for integers between 50 and 110 ...

    • The Number Field Sieve for Discrete Logarithms 

      Haarberg, Henrik Røst (Master thesis, 2016)
      We present two general number field sieve algorithms solving the discrete logarithm problem in finite fields. The first algorithm presented deals with discrete logarithms in prime fields, while the second considers prime ...

    • The Smart-Vercauteren Fully Homomorphic Encryption Scheme 

      Klungre, Vidar (Master thesis, 2012)
      We give a review of the Smart-Vercauteren fully homomorphic encryp-tion scheme presented in 2010. The scheme follows Craig Gentry sblueprint of first defining a somewhat homomorphic encryption scheme,and prove that it is ...

    • Tight Security for Authenticated Key Exchange Protocols and Signature Schemes 

      Ringerud, Magnus (Doctoral theses at NTNU;2023:244, Doctoral thesis, 2023)

    • Verifiable Decryption in the Head 

      Gjøsteen, Kristian; Haines, Thomas Edmund; Müller, Johannes; Rønne, Peter B.; Silde, Tjerand (Peer reviewed; Journal article, 2022)
      In this work we present a new approach to verifiable decryption which converts a 2-party passively secure distributed decryption protocol into a 1-party proof of correct decryption. This leads to an efficient and simple ...

    • Verifiable Shuffled Decryption 

      Strand, Martin (Master thesis, 2013)
      We describe the Verifiable Shuffled Decryption problem, and present five solutions based on adapting several existing verifiable shuffles. All but one may have potential for implementation, the choice of which would depend ...

    • WalnutDSA: Another attempt at braid group cryptography 

      Ringerud, Magnus (Master thesis, 2019)
      Hovedformålet med denne oppgaven er å studere det digitale signatursystemet WalnutDSA, som ble foreslått til det amerikanske National Institute of Standards and Technology (NIST) sin ``Post-Quantum Cryptography Standardization'' ...

    • Zero-Knowledge Protocols for proof of Correct Shuffle using Lattices 

      Edstrøm, Ole Martin (Master thesis, 2022)
      Hovedformålet med denne oppgaven er å studere protokoller for kunskapsløse bevis av korrekt ommstokning ved bruk av gitter. For å forstå utregningene gjort i protkollene og hvorfor protokollene er sikre, har vi dedikert ...