walsh investigation 中文意思是什麼

An investigation of the rijndael algorithm which is the advanced encryption standard of usa is taken in this thesis. we have focused on developing the cryptographic properties of the rijndael sbox from the viewpoint of boolean function, walsh spectrum and algebraic structures, on the attacks against the reduced variants of rijndael, and on the optimized implementations of rijndael. the key contributions follow below

本文對美國高級加密標準rijndael演算法進行了比較深入的研究，內容包括：從布爾函數、 walsh譜和代數結構的角度對其s盒密碼性質進行的研究，簡化演算法的攻擊方法以及演算法的優化實現問題，主要成果有： 1 、提出求解布爾函數表達式的兩種新方法，具有簡潔、易於編程實現、準確而快速的特點，應用於des演算法獲得與公開文獻相符的結果，應用於rijndael演算法首次求出其s盒布爾函數表達式。

Using the theories of probability, algebra and number theory comprehensively, we investigate a class of boolean functions with three - valued walsh spectrum in the first part of this dissertation : the properties of the extended semi - bent functions, which are constructed from any two bent functions, are studied, followed by the structure characteristics of the boolean functions satisfying propagation criterion with respect to all but two vectors ; the definition and cryptographic properties of k - order quasi - bent functions are proposed whose walsh spectrum takes on only three values. some sufficient and necessary conditions are offered to decide whether a boolean function is a k - order quasi - bent function ; a special method is presented to construct the k - order quasi - bent functions, whose cryptographic properties are explored by the matrix method, which is different from the method of walsh spectrum and that of autocorrelation of boolean functions ; the application of this kind of boolean functions in the fields of stream cipher, communications and block ciphers is discussed, which shows the great importance of the fc - order quasi - bent functions ; some methodology are proposed to construct the k - order quasi - bent functions, including the complete construction by using the characteristic matrices of boolean functions, and the recursive method by two known k - order quasi - bent functions we further extend our investigation to the ring zp, where p is a prime, and the similar results are presented as far as the p - valued quasi - generalized - bent functions are considered

本文首先綜合運用概率論、代數學、數論等基礎學科的理論知識，並以頻譜理論作為主要研究工具，對一類譜值分佈相對均勻的函數? ?廣半bent函數、 k階擬bent函數和p值k階擬廣義bent函數進行了系統、深入的研究，給出了廣半bent函數定義，並探討了廣半bent函數的密碼學性質；給出了k階擬bent函數和p值k階擬廣義bent函數的定義及等價判別條件；討論了k階擬bent函數和p值k階擬廣義bent函數與部分bent函數和p值廣義部分bent函數的關系，探討了它們的密碼學性質；給出了k階擬bent函數和p值k階擬廣義bent函數的典型構造方法，並將對k階擬bent函數的密碼性質的研究轉化到對一類特殊的矩陣的研究上；利用布爾函數的特徵矩陣原則上給出了k階擬bent函數的一種完全構造方法，還給出了從已有的p值k階擬廣義bent函數出發，遞歸構造變元個數更多的p值k階擬廣義bent函數的方法；初步探討了k階擬bent函數在序列密碼、分組密碼以及通信中的應用；給出了一類布爾函數walsh譜的分解式，並利用這類布爾函數的walsh譜分解式給出了一類近似穩定的布爾函數的構造，特殊情形下為k階擬bent函數；利用代數數論的知識考察了p值k階擬廣義bent函數的譜特徵，並給出了k階擬廣義bent函數與所有仿射函數的符合率特徵等等。