问题 单项选择题

信息认证的内容包括信息的来源,信息的完整性,信息的序号和时间。信息序号和时间的认证主要是为了 (43)

答案

参考答案:B

解析:
本题考查的是信息认证的内容。信息的完整性要靠信息认证来实现,信息认证是信息的合法接收者对消息的真伪进行判定的技术。信息认证的内容包括:信息的来源、信息的完整性、信息的序号和时间的认证。信息的来源的认证是使用数字签名技术和身份识别技术鉴别信息发送者的身份,明确信息的来源。信息内容的认证即是对完整性的检验。信息序号和时间的认证主要是为了阻止信息的重放攻击。常用的方法有:消息的流水作业号、链接认证符、随机数认证法和时间戳等。

阅读理解

Father Maurice Chase used a special way to celebrate his 90th birthday. The Catholic priest(神父) took $ 15,000 in cash to Los Angeles’ Skid Row (贫民区) and gave it away. Twenty wheelchair – bound people received $100 bills, while the rest received $1to $ 3 each.

“I come out here to tell them that God loves them and I love them and that some one is concerned about them,” Chase said.

Chase has given away cash and blessings every Sunday at the same corner for 24 years.Several hundred people wait for him every week.

He makes a point of coming on Thanksgiving and Christmas, too, but this is the first year he spent his birthday in the downtown neighborhood where people live mainly in shelters and on dirty sidewalks.

“ It’s the place that makes me the happiest.I just love it,” said Chase. “I look forward to coming here.”

The money comes from donations he receives from rich and famous people he met during his work as assistant to the president of Loyola Marymount University.

The crowd broke into choruses of “Happy Birthday” several times. Some people presented him birthday cards, to his delight.

Travis Kemp, a 51 – year – old disabled man with long black hair, was one of the lucky 20 to receive $ 100. He said he had no special plans for spending the money. “He has a lot of respect from me,” Kemp said. “I know I couldn’t do it.”

小题1:On his 90 th birthday, Chase      

A.handed out cash to the needy

B.collected money for poor people

C.visited poor people’s homes with gifts

D.held a party at Los Angeles’ Skid Row小题2:Which of the following makes Chase feel the happiest?

A.Celebrating his birthday with his neighbours.

B.Working in Loyola Marymount University.

C.Celebrating Christmas with the people he has helped.

D.Going to Los Angeles’ Skid Row to help people there.小题3:What’s the source of the money Chase used to help people?

A.All his savings.

B.His earnings as a Catholic priest.

C.Donations from the wealthy and celebrities(名人).

D.Donations from Loyola Marymount University.小题4:Travis Kemp is mentioned in the text to show .

A.he was the luckiest person on that day

B.the disabled need to be taken care of

C.Chase is greatly appreciated by the needy

D.even old people came to celebrate Chase’s birthday小题5:Which statement is CORRECT according to the passage?

A.Every recipient could get $100 in cash from Father Maurice Chase.

B.Father Maurice Chase gave the cash away not only on his birthday but also on other occasions.

C.Although Father Maurice Chase gave the cash away on his birthday, he didn’t receive anything in return.

D.Father Maurice Chase earned a lot of money as assistant to the president of Loyola Marymount University.

单项选择题