Search for dissertations about: "cryptanalysis"

Showing result 1 - 5 of 9 swedish dissertations containing the word cryptanalysis.

  2. 1. Cryptanalysis of Selected Stream Ciphers

    Author : Paul Stankovski; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Stream cipher; cryptanalysis; FCSR; state recovery; linear relations; optimal sampling; distinguisher; HC; nonrandomness; greedy bit set algorithm.;

    Abstract : The aim of this dissertation is to show some cryptanalytical results on a selection of stream ciphers. We have grouped theory and results into three main parts. The first part focuses on the FCSR-based constructions X-FCSR and F-FCSR-H v3. For the X-FCSR family of stream ciphers we perform a severe state recovery attack. READ MORE

  4. 2. Some Notes on Post-Quantum Cryptanalysis

    Author : Erik Mårtensson; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cryptography; Post-quantum cryptography; LWE; BKW; Cryptanalysis; Lattice sieving; SVP; Lattice-based cryptography; Code-based cryptography;

    Abstract : Cryptography as it is used today relies on a foundational level on the assumptionthat either the Integer Factoring Problem (IFP) or the DiscreteLogarithm Problem (DLP) is computationally intractable. In the 1990s PeterShor developed a quantum algorithm that solves both problems in polynomialtime. READ MORE

  5. 3. Some Words on Cryptanalysis of Stream Ciphers

    Author : Alexander Maximov; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VMPC; Dragon; Grain; A5 1; SNOW 2.0; Scream; large distributions; correlation attacks; distinguishing attacks; algorithms; Cryptography; cryptanalysis; RC4; RC4A; Computer science; numerical analysis; systems; control; Datalogi; numerisk analys; system; kontroll;

    Abstract : In the world of cryptography, stream ciphers are known as primitives used to ensure privacy over a communication channel. One common way to build a stream cipher is to use a keystream generator to produce a pseudo-random sequence of symbols. READ MORE

  6. 4. On the Design and Analysis of Stream Ciphers

    Author : Martin Hell; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; weak feedback polynomials; bit-search generator; self-shrinking generator; Achterbahn; Pomaranch; Grain-128; Grain; stream ciphers; cryptography; cryptanalysis; Informatics; systems theory; Informatik; systemteori;

    Abstract : This thesis presents new cryptanalysis results for several different stream cipher constructions. In addition, it also presents two new stream ciphers, both based on the same design principle. The first attack is a general attack targeting a nonlinear combiner. READ MORE

  7. 5. Some results on fast correlation attacks

    Author : Fredrik Jönsson; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Technological sciences; stream ciphers; linear feedback shift registers; cryptology; correlation attacks; cryptanalysis; Teknik; Informatics; systems theory; Informatik; systemteori;

    Abstract : This thesis presents new results on fast correlation attacks on stream ciphers. In particular, fast correlation attacks on stream ciphers containing linear shift registers with an arbitrary number of taps, are considered. A general introduction to stream ciphers and correlation attacks is given. READ MORE