試題1

There are different ways to perform IP based DoS Attacks. The most common IP based DoS attack is that an attacker sends an extensive amount of connection establishment （1）(e.g. TCP SYN requests) to establish hanging connections with the controller or a DPS. Such a way, the attacker can consume the network resources which should be available for legitimate users. In other （2）, the attacker inserts a large amount of （3）packets to the data plane by spoofing all or part of the header fields with random values. These incoming packets will trigger table-misses and send lots of packet-in flow request messages to the network controller to saturate the controller resources. In some cases, an （4）who gains access to DPS can artificially generate lots of random packet-in flow request messages to saturate the control channel and the controller resources. Moreover, the lack of diversity among DPSs fuels fuels the fast propagation of such attacks.
Legacy mobile backhaul devices are inherently protected against the propagation of attacks due to complex and vendor specific equipment. Moreover, legacy backhaul devices do not require frequent communication with core control devices in a manner similar to DPSs communicating with the centralized controller. These features minimize both the impact and propagation of DoS attacks. Moreover, the legacy backhaul devices are controlled as a joint effort of multiple network element. For instance, a single Long Term Evilution（LTE）eNodeB  is connected up to 32 MMEs. Therefore, DoS/DDoS attack on a single core element will not terminate the entire operation of a backhaul device（5）the net work.

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試題2

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試題3

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試題4

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試題5

智能卡是指粘貼或嵌有集成電路芯片的一種便攜式卡片塑膠，智能卡的片內(nèi)操作系統(tǒng)（COS）是智能卡芯片內(nèi)的一個(gè)監(jiān)控軟件，以下不屬于COS組成部分的是（）
A、通訊管理模塊
B、數(shù)據(jù)管理模塊
C、安全管理模塊
D、文件管理模塊

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試題6

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試題7

數(shù)字簽名最常見的實(shí)現(xiàn)方法是建立在（）的組合基礎(chǔ)之上
A、公鑰密碼體制和對(duì)稱密碼體制
B、對(duì)稱密碼體制和MD5摘要算法
C、公鑰密碼體制和單向安全散列函數(shù)算法
D、公證系統(tǒng)和MD4摘要算法

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試題8

以下關(guān)于數(shù)字證書的敘述中，錯(cuò)誤的是（）
A、證書通常由CA安全認(rèn)證中心發(fā)放
B、證書攜帶持有者的公開密鑰
C、證書的有效性可以通過驗(yàn)證持有者的簽名
D、證書通常攜帶CA的公開密鑰

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試題9

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試題10

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