IDEA區塊演算法的延伸與實作

Abstract

在1990年由X. Lai與J. Massey兩位博士所提出的IDEA是比DES更安全的區塊加密法。它利用混合不同的代數群之間的運算來提昇密碼系統的安全性。在本論文中，我們首先簡介IDEA的架構與key scheduling，接下來將IDEA密碼系統的行為數學化，並比較C與JAVA的Performance。接下來，我們擴增子區塊加密從16位元到32位元，故我們必須從新定義基本的function，將乘法同模擴充到32位元並做適當的修改，延伸的IDEA系統將可提高加密的安全性與彈性。

IDEA is invented by Dr. X. Lai and Dr. J. Massey In 1990, which is a more secure block cipher than DES. IDEA use the mixing operations form different algebraic group to improve its security. In this paper, we first introduce the architecture of IDEA and key scheduling, and use mathematical model to describe it. Then we extend the inner sub-blocks from 16 bits to 32bits. So we must redefine and check the basic functions, extend the multiplication of integers to 32bits and do some proper modification. The extended IDEA can enhance the security and flexibility of the cryptography system.