作者fei6409 (fei6409)
看板NTU-Exam
标题[试题] 100下 陈君明 密码学 第二次小考
时间Sun May 27 02:41:38 2012
课程名称︰密码学
课程性质︰选修
课程教师︰陈君明
开课学院:理学院
开课系所︰数学系
考试日期(年月日)︰2012/5/22
考试时限(分钟):40 min
是否需发放奖励金:是
(如未明确表示,则不予发放)
试题 :
1) Output size of SHA-1 ____bits
Output size of SHA-2 ____, 256, ____, or 512 bits
2) A cryptographic hash function h should satisfy:
(a) One -way Property: Given y, hard to find x such that ________
(b) Weak collision resitant: Given x, hard to find x' (≠ x) with ________
(c) Strong collision resistant: Hard to find any __________
3) Assume no February 29 birthday:
(a) What is the probability that two peole have the same birthday?
(b) What is the probability that any two people have the same birthday? In
particular, what is the probability for n = 23?
4) The sequence generated by an LFSR of linear complexity 4: 1, 0, 1, 0, 1, 1,
0, 0, 1, 0:
(a) The corresponding connection polynomial is ________
(b) The period of the sequence is ________
(c) The next four bits (11th ~ 14th) are ________
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