Sharif Digital Repository

Block ciphers are the central tool in the design of security protocols. GOST is a block cipher that several attacks have been published on it during the past 20 years. One of them is the reflection attack that was first introduced in 2007. This attack utilizes similarities of some round functions of both encryption and decryption processes. In addition, there are approaches that combines techniques of the reflection attack and variants of the meet-in-the-middle attack. In this thesis, we study reflection-based attacks on GOST. We first describe the GOST block cipher and the reflection attack. Then, we review previous reflectionbased attacks such as reflection-meet-in-the-middle attack and... 

Researchers are continuously investigating the factors influencing the burden of disease. Studying these factors contributes to improving the health status of communities. Although previous studies have addressed the impact of digital technologies on health improvement, the effect of information and communication technology (ICT) usage on the disease burden in countries has not been empirically studied. Therefore, this study examines this impact and considers the level of development of countries as a moderating factor. Results from a panel data set of 1,079 observations across 83 countries over 13 years indicate that the use of information and communication technology reduces the disease... 

Regarding the range of power in small wind turbine ,the manufacturing cost is very important to produce it feasible . so cost factors should be considered in control strategy. small wind turbine operate at lower wind speed because they are located where the energy is needed rather than where the wind is high for example in residential or rural area in lower height. In these condition wind speed are changing more because of lower height .so the maximum power point tracking algorithm should have a fast dynamic. In order to have lower number of device there are no sensor for wind or generator’s speed .only the voltage and current of different part of the system is measured.
here the aim...