Modular arithmetic – Used to define a finite field – a = b mod n means that if a and b are divided by n they produce the same remainder – a*b mod n can result in 0 even if a and b are not 0
Iterating Block ciphers Definition A product cipher combines two or more transformations in a manner intending that the resulting cipher is more secure than the individual components. Definition An iterated block cipher is a block cipher involving the sequential repetition of an internal function called a round function. Parameters include the number of rounds Nr, the block bitsize n, and the bitsize k of the input key K from which Nr subkeys Ki (round keys) are derived. For invertibility (allowing unique decryption), for each value Ki the round function is a bijection on the round input
一、词汇和语法(本大题共 20 小题,每小题 1 分,共 20 分) 根据句子的意思选择一个正确的答案,错选、多选或未选均无分。 1. It‘s______ by coach from Melbourne to Sydney. A. a nine hour‘s journey B. a nine hour journey C. a nine hours‘ journey D. a nine-hours journey
a. c .balance indicator,交流平衡指示器 a. c. bridge,交流电桥 a. c. current calibrator,交流电流校准器 a. c. current distortion,交流电流失真 a. c. induced polarization instrument,交流激电仪
Unit 7 The Fundamentals of computer Software Text 1 Data Structure A data structure is a data type. Its values are composed of component elements that are related by some structure Since a data structure is a data type, it has a set of operations on its values. In addition, there
The length of a sound is the length of time during which it is held on continuously in a given word or phrase. The principal facts concerning length in English are given in the following rules: 203. Length of vowels 1. English vowels /i:/, /a: / /:/, /u:/, /a: /are longer than the other English vowels in similar context, i.e., when surrounded by the same sounds, and pronounced with the same degree of stress. Thus