擴展式IDEA

Abstract

我們針對X.Lai and J.Massey在90年歐密提出的PES/IPES(IDEA)[1][2]加以重新定義各項基本運算，並一一加以證明其代數原理，完成基本擴展運算與完整擴展運算，並整理提出三項子金鑰產製流程，分別就歷年來之各種針對IDEA的密碼攻擊方法加以分析，並綜整各種塊狀密碼之基本運作模式及探討快速運算之解決方案，得到我們的Extended IDEA不僅擴展了處理區塊之長度，更擴展了安全度，配合適當的子金鑰產製流程，將可抵擋目前世上之各種攻擊方法。

We redefine some of the basic operations of PES/IPES(IDEA)[1][2], which was proposed by X. Lai and J. Massey in EUROCRYPT 90, and we analyze the algebraic principles of those operations individually. Therefore, we complete two solutions, basic solution and advanced solution, to an extended IDEA. We use three kinds of key scheduling in this scheme. In the same time, we analyze the possible attack that focus on IDEA. Describing the operation modes of cryptographic systems as well as on implementation aspects to speed up the operation is also discussed. Our solutions not only expand the block size, but also make the extended IDEA more secure. It can withstand all kind of attacks efficiently with our key scheduling.