1、PKI中撤销证书是通过维护一个证书撤销列表CRL来实现的。以下不会导致证书被撤销的是（  ）。
A.密钥泄漏
B.系统升级
C.证书到期
D.从属变更

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2、 杂凑函数SHAI的输入分组长度为（）比特
A、128
B、258
C、512
D、1024

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3、 特洛伊木马攻击的威胁类型属于（）
A、授权侵犯威胁
B、渗入威胁
C、植入威胁
D、旁路控制威胁

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4、 以下关于加密技术的叙述中，错误的是（）
A、对称密码体制的加密密钥和解密密钥是相同的
B、密码分析的目的就是千方百计地寻找密钥或明文
C、对称密码体制中加密算法和解密算法是保密的
D、所有的密钥都有生存周期

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5、下列关于公钥体制中说法不正确的是（）
A.在一个公钥体制中，一般存在公钥和私钥两种密钥
B.公钥体制中仅根据加密密钥来去确定解密密钥在计算上是可行的
C.公钥体制中的关于可以以明文方式发送
D.公钥密码中的私钥可以用来进行数字签名

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6、确保信息仅被合法实体访问，而不被泄露给非授权的实体或供其利用的特性是指信息的（  ）。
A.完整性
B.可用性
C.保密性
D.不可抵赖性

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7、 以下关于VPN的叙述中，正确的是（）
A、VPN指的是用户通过公用网络建立的临时的、安全的连接
B、VPN指的是用户自己租用线路，和公共网络物理上完全隔离的、安全的线路
C、VPN不能做到信息认证和身份认证
D、VPN只能提供身份认证，不能提供数据加密的功能

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8、IPSec协议可以为数据传输提供数据源验证、无连接数据完整性、数据机密性、抗重播等安全服务。其实现用户认证采用的协议是（  ）。
A. IKE协议
B. ESP协议
C. AH协议
D. SKIP协议

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9、下面对国家秘密定级和范围的描述中，不符合《中华人民共和国保守国家秘密法》要求的是（  ）。
A、对是否属于国家和属于何种密级不明确的事项,可由各单位自行参考国家要求确定和定级,然后报国家保密工作部门备案
B、各级国家机关、单位对所产生的秘密事项,应当按照国家秘密及其密级的具体范围的规定确定密级,同时确定保密期限和知悉范围
C、国家秘密及其密级的具体范围,由国家行政管理部门]分别会同外交、公安、国家安全和其他中央有关机关规定
D、对是否属于国家和属于何种密级不明确的事项,由国家保密行政管理部门,或省、自治区、直辖市的保密行政管理部门确定

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10、The modern study of symmetric-key ciphers relates mainly to the study of block ciphers and stream ciphers and to their applications. A block cipher is, in a sense, a modern embodiment of Alberti's polyalphabetic cipher: block ciphers take as input a block of （71 ）and a key, and output a block of ciphertext of the same size. Since messages are almost always longer than a single block, some method of knitting together successive blocks is required. Several have been developed, some with better security in one aspect or another than others. They are the mode of operations and must be carefully considered when using a block cipher in a cryptosystem.
The Data Encryption Standard (DES) and the Advanced Encryption Standard (AES) are( 72 )designs which have been designated cryptography standards by the US government (though DES's designation was finally withdrawn after the AES was adopted). Despite its deprecation as an official standard, DES (especially its still-approved and much more secure triple-DES variant) remains quite popular; it is used across a wide range of applications, from ATM encryption to e-mail privacy and secure remote access. Many other block ciphers have been designed and released, with considerable variation in quality. Many have been thoroughly broken. See Category: Block ciphers.
Stream ciphers, in contrast to the ‘block’type, create an arbitrarily long stream of key material, which is combined ( 73 )the plaintext bit-by-bit or character-by-character, somewhat like the one-time pad. In a stream cipher, the output( 74 )is created based on an internal state which changes as the cipher operates. That state change is controlled by the key, and, in some stream ciphers, by the plaintext stream as well. RC4 is an example of a well-known, and widely used, stream cipher; see Category: Stream ciphers.
Cryptographic hash functions (often called message digest functions) do not necessarily use keys, but are a related and important class of cryptographic algorithms. They take input data (often an entire message), and output a short fixed length hash, and do so as a one-way function. For good ones, ( 75 ) (two plaintexts which produce the same hash) are extremely difficult to find.
Message authentication codes (MACs) are much like cryptographic hash functions, except that a secret key is used to authenticate the hash value on receipt. These block an attack against plain hash functions.
（71）
A.plaintext
B.ciphertext
C.data
D.hash
（72）
A.stream cipher
B.hash function
C.Message authentication code
D.Block cipher
（73）
A.of
B.for
C.with
D.in
（74）
A.hash
B.stream
C.ciphertext
D.plaintext
（75）
A.collisions
B.image
C.preimage
D.solution

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