Fulltext

Apply Block Ciphers Using Tiny Encryption Algorithm (TEA)

تطبيق خوارزمية التجفير المتناظرة المفتاح (تيَ)

Hana Rashied Ismaeel هناء رشيد اسماعيل

Baghdad Science Journal مجلة بغداد للعلوم
ISSN: 20788665 24117986 Year: 2010 Volume: 7 Issue: 2 Pages: 1061-1069
Publisher: Baghdad University جامعة بغداد

Abstract

Ciphers can be either symmetric-key or public-key. Symmetric-key ciphers are the most famous and important elements in many cryptographic systems. Individually, they provide confidentiality and privacy. The Aim of this paper is to Apply symmetric block ciphers algorithm which is called Tiny Encryption algorithm (TEA). There are many types of block cipher use different techniques and functions using basic arithmetic operations such as XOR, addition, subtraction, multiplication, bitwise shift, and division. TEA cipher uses XOR, addition and bitwise shift. The paper presents how a block cipher could be constructed in general, it includes an observation of the history, inventors, and algorithms of the TEA block ciphers. It also discuss the manner did the programming took in terms of modularity, simplicity, resource reservation, in the previous algorithm the user cannot enter the plain text as a characters, it must enter the ASCII cod of the characters we write a lot e of functions to solve this problem also we enable the user to save his message in text file to make him use it to receive a message from email ,Also the time of encryption and decryption are calculated to measure the performance of the algorithm., The implementation of TEA is made using C/C++ Borland compiler version( 4.5).

ان طرق التجفير (Ciphers) تكون على نوعين اما متناظرة المفتاح (symmetric-key) او عامة المفتاح(public-key).وتعتبر الطريقة المتناظرة المفتاح هي الطريقة الاكثر اهمية وشيوعا في عدد كبير من انظمة التجفير ( (cryptographic .ان الهدف من هذا البحث هو تنفيذ الخوارزميةالمتناظرة المفتاح والتي تدعى Tiny Encryption Algorithm(TEA)هذه الطريقة في التجقير تستخدم العمليات الرياضية مثل (addition ,bitwise shift and XOR).تم اضافة دوال الى الخوارزمية. بحيث تمكن المستفيد من ادخال النص و المفتاح بشكل حروف لانه بالخوارزمية الاصلية يتم ادخال النص بال( ( hexa-decimalكما سمح للمستخدم باستخدام الملفا ت لخزن النص المراد تجفيره استخدمت لغتي (C and C+ +version 4.5) لتنفيذ البرامج وتم حساب الوقت المستخدم للتجفير لقياس كفاءة الاداء.

Keywords

TEA --- Symmetric-key --- Encryption --- Decryption --- Cryptography --- Feistel Ciphers --- plaintext --- cipher text --- block ciphers