问题 单项选择题

以下哪项功能电子签名(electronic signature)不能提供:()。

A.电子文件的保密性

B.电子文件的完整性

C.能鉴别文件签署者的身份

D.文件签署者同意电子文件的内容

答案

参考答案:A

解析:

本题考查电子签名技术的基础知识。

电子签名具有法律效用。从技术的角度,电子签名以电子形式存在,依附于电子文件并与其逻辑关联,可用以识别电子文件签署者身份,保证文件在传输过程中没有受到破坏(即保证电子文件的完整性),并表示签署者同意电子文件的内容。

保密性和完整性不是同一个概念,保密性要求信息不被泄露给未授权的人,完整性要求信息会受到各种原因的破坏。电子文件的保密性通常需要由加密技术来提供。电子签名技术和加密技术是相互独立的,虽然两者经常结合起来使用。

阅读理解

Jaguar(美洲虎) was very rare. It was said that there less than 20 jaguars in the world, one of which was living in the national zoo of Peru. In order to help this jaguar, Peruvians set up a zoo for it, where there were sheep and deer for the jaguar to eat. However, strange enough, no one had ever seen the jaguar hunt the deer and sheep. What they could see was its lying in its cave, sleeping and eating the meat provided by the zoo keepers.

At first, people thought that the jaguar felt too lonely, so they found a female tiger to accompany it. However, it did not make too much sense. The jaguar just sometimes went out of its cave with its “girlfriend” for a while before it came back to its house again' It is normal for the jaguar to be lazy here. Tiger is the king of forest but you simply put some small animals around him. That is why the jaguar shows no interest in going out' a visitor said. So people put five wolves into the jaguar's zoo. Since then, the jaguar did not go back to its cave any more . It either stands on top of the hill yelling or runs up and down the hill without sleeping all day long .

Actually, one creature without any rivals is a lifeless creature. If a man lives without rivals, he is likely to be satisfied with the present and will not fight for the better. He will hold back before all difficulties . Hard environment tends to make successful people . Therefore, we need some rivals to push us to go ahead in all difficulties and competitions in our lives. Due to our rivals, we can bring out our potential to the best. Due to our rivals, we will continuously improve our abilities when competing with them!

小题1:Why did Peruvians set up a zoo for the jaguar?

A.To protect this endangered animal.

B.To entertain people.

C.To satisfy people's curiosity.

D.To do some experiments.小题2:That the jaguar always lying in its cave leaves people an impression that __________.

A.it must be treated badly

B.it must be seriously sick

C.it must miss the forest

D.it needs to be accompanied小题3:What happened to the jaguar after it got five wolves around?

A.The jaguar remained the same.

B.The jaguar became very energetic.

C.The jaguar lost his girlfriend.

D.The jaguar got mad finally.小题4:What does the underlined word "rivals" in the last paragraph probably mean?

A.Colleagues.

B.Followers.

C.Competitors.

D.Relatives.小题5:What is the main idea of the passage?

A.How Jaguars can be protected.

B.Family plays an important part.

C.Enemies can inspire us to succeed.

D.jaguars like to stay with wolves.

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