1. 每时每刻 可信安全 1The DES algorithm is an example of what type of cryptography? A Secret Key B Two-key C Asymmetric Key D Public Key A

2. 每时每刻 可信安全 2 Which type of attack is based on the probability of two different messages using the same hash function producing a common message digest? A Differential cryptanalysis B Differential linear cryptanalysis C Birthday attack D Statistical attack C

3. 每时每刻 可信安全 3 Which of the following is not a weakness of symmetric cryptography? A Limited security B Key distribution C Speed D Scalability C

4. 每时每刻 可信安全 4 Which of the following services is not provided by the digital signature standard (DSS)? A Encryption B Integrity C Digital signature D Authentication A

5. 每时每刻 可信安全 5 In a hierarchical PKI the highest CA is regularly called Root CA, it is also referred to by which one of the following term? A Subordinate CA B Top CA C Big CA D Master CA B

6. 每时每刻 可信安全 6 Which of the following statements pertaining to Secure Sockets Layer (SSL) is false? A The SSL protocol was developed by Netscape to secure Internet client-server transactions. B The SSL protocol's primary use is to authenticate the client to the server using public key cryptography and digital certificates. C Web pages using the SSL protocol start with HTTPS. D SSL can be used with applications such as Telnet, FTP and email protocols. B

7. 每时每刻 可信安全 7 Public Key Infrastructure (PKI) is the use of asymmetric key encryption between parties in which the originator encrypts information using the intended recipient's "public" key. The recipients use their own "private" key to decrypt the information. The "Infrastructure" of this methodology assumes that: A The sender and recipient have reached a mutual agreement on the encryption key exchange that they will use. B The channels through which the information flows are secure. C The recipient's identity can be positively assured to the sender. D The sender of the message is the only other person with access to the recipient's private key. C

8. 每时每刻 可信安全 8 What attribute is included in a X.509-certificate? A Distinguished name of the subject B Telephone number of the department C secret key of the issuing CA D the key pair of the certificate holder A

9. 每时每刻 可信安全 9 Which of the following is more suitable for a hardware implementation? A Stream ciphers B Block ciphers C Cipher block chaining D Electronic code book A

10. 每时每刻 可信安全 10 What algorithm has been selected as the AES algorithm, replacing the DES algorithm? A RC6 B Twofish C Rijndael D Blowfish C

11. 每时每刻 可信安全 11 In what type of attack does an attacker try, from several encrypted messages, to figure out the key used in the encryption process? A Known-plaintext attack B Ciphertext-only attack C Chosen-Ciphertext attack D Known-Ciphertext attack B

12. 每时每刻 可信安全 Which of the following can be best defined as computing techniques for inseparably embedding unobtrusive marks or labels as bits in digital data and for detecting or extracting the marks later? A Steganography B Digital watermarking C Digital enveloping D Digital signature B

13. 每时每刻 可信安全 13 Which of the following encryption methods is unbreakable? A Symmetric ciphers B DES codebooks C One-time pads D Elliptic-curve cryptography C

14. 每时每刻 可信安全 14 What is called a mathematical encryption operations that can not be reversed? A One-way hash B DES C Transposition D Substitution A

15. 每时每刻 可信安全 15 Which of the following protects Kerberos against replay attacks? A Tokens B Passwords C Cryptography D Time stamps D

16. 每时每刻 可信安全 16 What kind of Encryption technoloy VeriSIGN's SSL utilize? A Secret key B Hybrid: Symmetric and asymmetric cryptography C Public Key D Asymmetric key B

17. 每时每刻 可信安全 17 Which of the following statements is true about data encryption as a method of protecting data? A It verifies the accuracy of the data. B It is usually easily administered. C It requires careful key management. D It makes few demands on system resources. C

18. 每时每刻 可信安全 18 What is used to bind a document to its creation at a particular time? A Network Time Protocol (NTP) B Digital Signature C Digital Timestamp D Certification Authority (CA) C

19. 每时每刻 可信安全 19 The Secure Hash Algorithm (SHA-1) creates: A a fixed length message digest from a fixed length input message B a variable length message digest from a variable length input message C a fixed length message digest from a variable length input message D a variable length message digest from a fixed length input message C

20. 每时每刻 可信安全 20 Which of the following is true about Kerberos? A It utilizes public key cryptography. B It encrypts data after a ticket is granted, but passwords are exchanged in plain text. C It depends upon symmetric ciphers. D It is a second party authentication system. C

21. 每时每刻 可信安全 21 What is the key size of the International Data Encryption Algorithm (IDEA)? A 64 bits B 128 bits C 160 bits D 192 bits B

22. 每时每刻 可信安全 22 What is the effective key size of DES? A 56 bits B 64 bits C 128 bits D 1024 bits A

23. 每时每刻 可信安全 23 Which of the following threats is not addressed by digital signature and token technologies? A spoofing B replay attacks C password compromise D denial-of-service D

24. 每时每刻 可信安全 24 What enables users to validate each other's certificate when they are certified under different certification hierarchies? A Cross-certification B Multiple certificates C Redundant certification authorities D Root certification authorities A

25. 每时每刻 可信安全 25 The RSA Algorithm uses which mathematical concept as the basis of its encryption? A Geometry B Irrational numbers C PI (3.14159...) D Large prime numbers D