پديد آورنده :
ميرزايي، آرش
عنوان :
حمله متمايزكننده روي سيستم هاي رمز دنباله اي
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان ، دانشكده برق و كامپيوتر
صفحه شمار :
ده، 110ص: مصور، جدول، نمودار
يادداشت :
ص.ع. به: فارسي و انگليسي
استاد راهنما :
محمد دخبل عليان
استاد مشاور :
محمود مدرس هاشمي
توصيفگر ها :
بازيابي كليد , WG , MAG
تاريخ نمايه سازي :
21/11/88
دانشكده :
مهندسي برق و كامپيوتر
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتال
چكيده انگليسي :
Distinguishing Attack on Stream Ciphers Arash Mirzaei Arash mirzaei@ec iut ac ir 26 10 2009 Department of Electrical and Computer Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Persian Dr Mohammad Dakhil Alian mdalian@cc iut ac irAbstractRecently the information technology and its various branches including information security have been underfocus Thus the need for having efficient cryptographic algorithms that can simultaneously satisfy differentgoals such as the simple implementation high speed and high security is felt much more than the past Becauseof having different mentioned aspects stream ciphers have many applications in cryptosystems Securityanalysis of the stream ciphers is also one of the subjects that are getting a lot of attention There are two generaltypes of attacks on stream ciphers including key recovery and distinguishing attacks In a key recovery attack the goal of the attack is to extract some information about the key but in a distinguishing one the attacker tries todistinguish between the output of the stream cipher and a real random sequence In this thesis a brief introduction of the stream cipher and some important attacks on them are described andthen distinguishing attack and hypothesis testing as an important tool for applying this attack are explained indetail After that we look at a practical situation in which a distinguisher is used to derive information about theplaintext Applying the distinguishing attack on different structures of stream ciphers such as combining andfilter generators and clock controlled generators are described and a new attack on systems with linear stateupdating is presented Finally attacks on basic algorithms including ASG and summation generator as well asthe new ciphers MAG and WG are presented Also the complexities of the proposed attacks are compared withthe previous attacks on these ciphers KeywordsStream Ciphers Distinguishing Attacks Key Recovery WG MAG
استاد راهنما :
محمد دخبل عليان
استاد مشاور :
محمود مدرس هاشمي
