Search for dissertations about: "cipher"

Showing result 1 - 5 of 12 swedish dissertations containing the word cipher.

  2. 1. On LFSR based Stream Ciphers - analysis and design

    Author : Patrik Ekdahl; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; self-shrinking generator; shrinking generator; E0; A5; sober; stream cipher; LFSR; snow; Informatics; systems theory; Informatik; systemteori;

    Abstract : Stream ciphers are cryptographic primitives used to ensure privacy in digital communication. In this thesis we focus on stream ciphers built using Linear Feedback Shift Registers (LFSRs). Several different stream ciphers are analysed and new attacks are presented. In addition, two new stream ciphers are presented, both based on the same design. READ MORE

  4. 2. 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

  5. 3. 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

  6. 4. 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

  7. 5. On Some Symmetric Lightweight Cryptographic Designs

    Author : Martin Ågren; Institutionen för elektro- och informationsteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Lightweight cryptography; integrity; authentication; symmetric cryptography; stream ciphers; block ciphers; Grain-128a; BEAN; KTANTAN; textsc{PRINTcipher}; FCSR combiner; related-key attack; linear cryptanalysis; linear correlations; invariant subspace attack.;

    Abstract : This dissertation presents cryptanalysis of several symmetric lightweight primitives, both stream ciphers and block ciphers. Further, some aspects of authentication in combination with a keystream generator is investigated, and a new member of the Grain family of stream ciphers, Grain-128a, with built-in support for authentication is presented. READ MORE