Cryptanalysis and design of symmetric primitives

This thesis focuses on the cryptanalysis and the design of block ciphers and hash functions. The thesis starts with an overview of methods for cryptanalysis of block ciphers which are based on differential cryptanalysis. We explain these concepts and also several combinations of these attacks. We propose new attacks on reduced versions of ARIA and AES. Furthermore, we analyze the strength of the internal block ciphers of hash functions. We propose the first attacks that break the internal block ciphers of Tiger, HAS-160, and a reduced round version of SHACAL-2. The last part of the thesis is concerned with the analysis and the design of cryptographic hash functions. We adopt a block cipher attack called slide attack into the scenario of hash function cryptanalysis. We then use this new method to attack different variants of GRINDAHL and RADIOGATÚN. Finally, we propose a new hash function called TWISTER which was designed and proposed for the SHA-3 competition. TWISTER was accepted for round one of this competition. Our approach follows a new strategy to design a cryptographic hash function. We also describe several attacks on TWISTER and discuss the security issues concerning these attack on TWISTER.