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
Product development has been a major activity in the food industry for over 40 years, but only gradually has it developed as a strategic business area and also as an advanced technology. For a long time it was essentially a craft, loosely related to the research and engineering areas in the company. The pressures for product development came very strongly from the needs of the growing supermarkets for a constantly changing, extensive mix of products and for continuous price promotions. So there was the drive for product difference
Product development management in the food system is complex, long term and capital intensive. It is total company management involving every function in the company- so it is managing either a microcosm of the company or an integration of the company functions. For a major innovation, the company may set up a new venture company or division; or a new group of people may form a new company. At this time when many new companies are being formed on the innovations of information technology and biotechnology, it is interesting to speculate on new venture companies in the food industry and the basis of their new innovations. But at the present time