推 m80126colin : 05/29 09:36
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課程名稱︰密碼學
課程性質︰選修
課程教師︰陳君明
開課學院：理學院
開課系所︰數學系
考試日期（年月日）︰2012/5/22
考試時限（分鐘）：40 min
是否需發放獎勵金：是
（如未明確表示，則不予發放）
試題 :
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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