CEH CH 10: Cryptographic Attacks and Defenses
George has been sniffing the encrypted traffic between Bill and Al. He has noticed an increase in traffic and believes the two are planning a new venture. What is the name of this form of attack? a. Inference attack b. Cipher-text attack c. Chosen cipher-text attack d. Replay attack
a
Which of the following certification trust models can be described as allowing participants to trust other participants' PKI? a. Cross-certification b. Web of trust c. Hierarchy of trust d. Shared trust
a
Which of the following does a digital signature not provide? a. Privacy b. Integrity c. Authentication d. Nonrepudiation
a
Which of the following does symmetric encryption provide? a. Privacy b. Integrity c. Authentication d. Nonrepudiation
a
Why are hashing algorithms like bcrypt used now instead of MD5 ? a. It is harder to find collisions. b. The algorithm is secret. c. It uses 3 levels of symmetric encryption. d. The MD5 hash algorithm was exposed and made public.
a
Encryption routines can use a variety of cryptographic functions and logical operations. One such technique is the XOR. Using the XOR function, which of the following is correct? 10101100 00110101 a. 01100110 b. 10011001 c. 10101100 d. 10010011
b
Ginny has a co-worker's WinZip file with several locked documents that are encrypted, and she would like to hack it. Ginny also has one of the locked files in its unencrypted state. What's the best method to proceed? a. Cipher-text only attack b. Known plain-text attack c. Chosen cipher-text attack d. Replay attack
b
How long is the DES encryption key? a. 32 bits b. 56 bits c. 64 bits d. 128 bits
b
One of the reasons 3DES was adopted is because it is stronger than DES. What is the key length of 3DES? a. 192 bits b. 168 bits c. 64 bits d. 56 bits
b
RSA is an example of which of the following? a. Digital signature b. Asymmetric algorithm c. Symmetric algorithm d. Hashing algorithm
b
When discussing hashing algorithms, how would you best describe collisions? a. When two clear-text inputs are fed into an asymmetric algorithm and produce the same encrypted output b. When two messages produce the same digest or hash value c. When two clear-text inputs are fed into a symmetric algorithm and produce the same encrypted output d. When a steganographic program produces two images that look the same, except that one has text hidden in it
b
When would a hashing algorithm be used in conjunction with a sender's private key? a. Hashing b. Digital signatures c. Symmetric encryption d. PKI
b
Which of the following can be used to provide confidentiality and integrity? a. Steganography b. Asymmetric encryption c. A hash d. Symmetric encryption
b
Which of the following is an example of a hashing algorithm? a. Blowfish b. MD5 c. RC4 d. RSA
b
Which of the following would be best suited to streaming voice communication? a. DES b. RC4 c. MD5 d. Tiger
b
Caesar's cipher is also known as what? a. ROT13 b. ATBASH c. ROT3 d. A hashing algorithm
c
How many bits of plain text can DES process at a time? a. 192 bits b. 168 bits c. 64 bits d. 56 bits
c
When using digital signatures, which of the following does the recipient utilize when verifying the validity of the message? a. Secret key b. Session key c. Public key d. Private key
c
Which of the following is an example of a symmetric encryption algorithm? a. Diffie-Hellman b. MD5 c. RC4 d. RSA
c
Which of the following is not correct about the registration authority? a. The RA can accept requests. b. The RA can take some of the load off the CA. c. The RA can issue certificates. d. The RA can verify identities.
c
While shoulder surfing some co-workers, you notice one executing the following command: ./john /etc/shadow. What is the co-worker attempting to do? a. Crack the user's PGP public key b. Crack the user's PGP secret key c. Crack the password file d. Crack an EFS file
c
You have become worried that one of your co-workers accessed your computer and copied the secring.skr file while you were on break. What would that mean? a. Your Windows logon passwords have been stolen. b. Your Linux password has been stolen. c. Your PGP secret key has been stolen. d. Nothing. That is a bogus file.
c
A small company that you consult for has asked your advice on how to set up an encrypted email service. The company does not want to pay a license fee or manage a server for these services. What should you recommend? a. MIME b. SSL c. HTTPS d. PGP
d
During the exam, if you were asked to make two lists of symmetric and asymmetric algorithms, which of the following would you place in the symmetric algorithm category? a. ElGamal b. Diffie-Hillman c. ECC d. Rijndael
d
Jake has just been given a new hacking tool by an old acquaintance. Before he installs it, he would like to make sure that it is legitimate. Which of the following is the best approach? a. Ask his friend to provide him with the digital certificate of the tool's creator. b. Ask his friend to provide him with a digital certificate. c. Load the tool and watch it closely to see if it behaves normally. d. Compare the tool's hash value to the one found on the vendor's website.
d
Tiger is an example of what? a. Digital signature b. Asymmetric algorithm c. Symmetric algorithm d. Hashing algorithm
d
Which of the following binds a user's identity to a public key? a. Digital signature b. Hash value c. Private key d. Digital certificate
d
Which of the following is a serious vulnerability in the popular OpenSSL cryptographic software library? a. FREAK b. POODLE c. Shellshock d. Heartbleed
d
Which of the following is usually discussed in addition to the concepts of AIC when dealing with cryptographic systems? a. Privacy b. Speed c. Hacking d. Nonrepudiation
d
Which of the following properly describes the steps to create an encrypted message that contains a digital signature using PKI? Place the steps in the correct order. 1. Encrypt the message with the recipient's public key. 2. Create a hash of the message. 3. Create the message to be sent. 4. Encrypt the hash with your private key. a. 1, 2, 3, 4 b. 3, 2, 1, 4 c. 1, 3, 2, 4 d. 3, 2, 4, 1
d
