问题 单项选择题

将获得的信息再次发送,以在非授权情况下进行传输,这种攻击属于( )。

A.消息篡改

B.拒绝服务

C.重放

D.伪装

答案

参考答案:C

解析: 选项A)。消息篡改是指修改合法消息的一部分或延迟消息的传输以获得非授权作用;选项B),拒绝服务是指阻止或禁止常地使用或管理通信设施,拒绝服务的另种形式是破坏某实体网络,或者使网络失效,或者使其过载以降低性能;选项C),重放攻击指将获得的信息再次发送,以在非授权的情况下进行传输;选项D),伪装是指实体假装别的实体,伪装的例子有:捕获认征信息,并在其后利用认证信息进行重放,以获得比其他实体更多的权限。

填空题
单项选择题

Brian arrived at San Francisco airport two hours before the flight to Paris. He was wearing three shirts, a jacket, two pairs of socks, a pair of shorts, and two pairs of jeans. He was carrying one small backpack, which was very full, but he didn’t have any other luggage. Brian needed to meet a man named Tony before he checked in for his flight. He found Tony near the Air France counter. Tony gave him a round trip ticket and a small package.

"Give this package to Jean Paul at the airport in Paris. He will have a sign with your name on it. I think you can find him easily," Tony said," You don’t have any luggage, right"

"Only this backpack," Brian answered. "You said I could bring one carry on bag. "

"That’s right. One carry on bag is fine. Have a good trip. "

"Thanks. "

is Brian a criminal Not at all. He is an air courier. And he paid only $ 110 for the round trip ticket to Paris. Air couriers get cheap airline tickets because they take important packages and papers to foreign countries. Businesses sometimes need to get packages and papers to people in foreign countries by the next day. Often, the only way they can do this is to use an air courier company. It is not cheap for a business to send a package with an air courier, but it is quick.

Every year about 80,000 people worldwide travel as air couriers. The number of tickets for courier travel is growing by about 10 percent a year. However, air courier travel isn’t for everyone. But if you have very little money, can be flexible about your travel plans, and don’t mind wearing the same clothes for a week, it can be a great way to take a vacation!

Why was Brian wearing so many clothes for his travel()

A.Because they were the uniforms for air couriers.

B.Because that made him easier to be recognized.

C.Because his backpack had no room for his clothes.

D.Because he did not have any luggage with him.