Implementation and improvement of serpent encryption algorithm

مقدم أطروحة جامعية

al-Amiree, Janan Atiyyah Mahdi

الجامعة

الجامعة التكنولوجية

الكلية

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القسم الأكاديمي

قسم علوم الحاسوب

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2004

الملخص الإنجليزي

The current standards for shared -key encryption are : Two Fish, Serpent.

Mars, Rc6 and Randal as final list candidates.

Although Serpent has provided a secure encryption algorithm an improvement will be submitted and implemented for this Serpent algonthm which is well suited for the next generation. In this thesis a improved algorithm is designed to take advantage of the powerful algorithm, which is supported by Serpent algorithm with overcoming weakness, resulting in a much improved security / per formance trade off over existing chippers. As a result, this improved algorithm offers more secure than Serpent.

The block size can be increased to 256 bits instead of 128 bits by using round function in a Feistel construction, also the improved algorithm uses key dependent function before and after each round instead of initial and final permutation which uses fixed tables.

This give the algorithm, aprotection against differential and linear cryptanalysis. The results obtained illustrate that the improved algorithm uses the same algonthm criteria for encryption and decryption with some key schedules and adopts key -dependent permutation and substitution to provide protection against differential and linear cryptanalysis. The execution time of the circuit algonthm was 23.9 second for 100000 bytes, while after the improved was 20.77 second for 100000 bytes. Also the average of avalanche effect of the circuit algorithm is 61.1, while the average avalanche effect of the algorithm after improvement is 132.

6.

The large key and input block size of the improved algorithm cause exhaustive key search and the matching ciphertext attack are infeasible. The algorithm was implemented using a programming of visual C++to provide a good user interface.

التخصصات الرئيسية

تكنولوجيا المعلومات وعلم الحاسوب

الموضوعات

• التشفير
• شبكات الحاسوب
• الإجراءات الأمنية
• البيانات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-305531