212-81 by EC-COUNCIL Valid Free Exam Practice Test

Question 1

In steganography, ________ is the data to be covertly communicated (in other words, it is the message you wish to hide).

A. Carrier B. Signal C. Channel D. Payload

Correct Answer: D

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Question 2

A symmetric block cipher designed in 1993 by Bruce Schneier. Was intended as a replacement for DES. Like DES it is a 16 round Feistel working on 64bit blocks. Can have bit sizes 32bits to 448bits.

A. Serpent B. Skipjack C. Blowfish D. MD5

Correct Answer: C

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Question 3

Frank is trying to break into an encrypted file... He is attempting all the possible keys that could be used for this algorithm. Attempting to crack encryption by simply trying as many randomly generated keys as possible is referred to as what?

A. Rainbow table B. Kasiski C. Frequency analysis D. Brute force

Correct Answer: D

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Question 4

If you wished to see a list of revoked certificates from a CA, where would you look?

A. CRL B. RA C. RFC D. CA

Correct Answer: A

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Question 5

The reverse process from encoding - converting the encoded message back into its plaintext format.

A. Whitening B. Decoding C. Substitution D. Encoding

Correct Answer: B

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Question 6

With Electronic codebook (ECB) what happens:

A. The message is divided into blocks and each block is encrypted separately. This is the most basic mode for symmetric encryption B. The cipher text from the current round is XORed with the plaintext from the previous round C. The cipher text from the current round is XORed with the plaintext for the next round D. The block cipher is turned into a stream cipher

Correct Answer: A

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Question 7

Modern symmetric ciphers all make use of one or more s-boxes. Both Feistel and non-Feistel ciphers use these s-boxes. What is an s-box?

A. A shifting box where input bits are shifted B. Another name for the round function C. A black box for the algorithm implementation D. A substitution box where input bits are replaced

Correct Answer: D

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Question 8

Which of the following is a type of encryption that has two different keys. One key can encrypt the message and the other key can only decrypt it?

A. Symmetric B. Stream cipher C. Asymmetric D. Block cipher

Correct Answer: C

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Question 9

Which method of password cracking takes the most time and effort?

A. Dictionary attack B. Shoulder surfing C. Brute force D. Rainbow tables

Correct Answer: C

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Question 10

Fred is using an operating system that stores all passwords as an MD5 hash. What size is an MD5 message digest (hash)?

A. 160 B. 256 C. 128 D. 512

Correct Answer: C

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Question 11

The greatest weakness with symmetric algorithms is _____.

A. They are slower than asymmetric B. The problem of generating keys C. They are less secure than asymmetric D. The problem of key exchange

Correct Answer: D

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Question 12

Which of the following is not a key size used by AES?

A. 256 bits B. 128 bits C. 512 b D. 192 bits

Correct Answer: C

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Question 13

Ciphers that write message letters out diagonally over a number of rows then read off cipher row by row. Also called zig-zag cipher.

A. ROT-13 B. Vigenere Cipher C. Null Cipher D. Rail Fence Cipher

Correct Answer: D

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Question 14

Which of the following is a key exchange protocol?

A. MQV B. AES C. DES D. RSA

Correct Answer: A

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Question 15

Which of the following algorithms uses three different keys to encrypt the plain text?

A. Skipjack B. 3DES C. AES D. Blowfish

Correct Answer: B

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EC-COUNCIL Certified Encryption Specialist - 212-81 Exam Practice Test