CRYPTO

Unit 01 - Q073: In the DES algorithm the round key is __________ bit and the Round Input is ____________bits. A) 48, 32 B) 64, 32 C) 56, 24 D) 32, 32

ANSWER: A

Unit 01 - Q074: The number of unique substitution boxes in DES after the 48 bit XOR operation are A) 8 B) 4 C) 6 D) 12

ANSWER: A

Unit 01 - Q085: The 4 x 4 byte matrices in the AES algorithm are called A) States B) Words C) Transitions D) Permutations

ANSWER: A

Unit 01 - Q090: Which of the following modes does not implement chaining or dependency on previous stage computations? A) CTR, ECB B) CTR, CFB C) CFB, OFB D) ECB, OFB

ANSWER: A

Unit 01 - Q091: Which of the following modes of operation does not involve feedback? A) ECB B) CBC C) CTR D) OFB

ANSWER: A

Unit 01 - Q092: Which of the following is a natural candidates for stream ciphers? A) OFB B) CFB C) CBC D) ECB

ANSWER: A

Unit 01 - Q094: TRNG stands for A) True Random Number Generation B) Trust Random Number Generation C) Text Ring Number Generators D) None of the mentioned.

ANSWER: A

Unit 01 - Q098: Which among the following cannot be used in the case of stream ciphers? A) TRNG B) PRNGs C) PRFs D) None of the mentioned.

ANSWER: A

U011-Q001: What bit hash value does MD5 produce? { A)96 B)128 C)160 D)256

ANSWER: B

U05-Q001: What is the function of the S-Box in the AES algorithm? { A)Replaces data using a lookup table B)Shift the data C)Performs an exclusive-or operation using chained blocks D)Regenerate the key

ANSWER: B

U07-Q001: What is the term used for the secret key for symmetric encryption that is generated for use for a short period of time? { A)stream key B)session key C)sequence key D)master key

ANSWER: B

U09-Q001: Asymmetric key is also called { A)Secret key B)Public key C)Private key DNone of the mentioned

ANSWER: B

Unit 01 - Q002: The ________is the original message before transformation. A) ciphertext B) plaintext C) secret-text D) None of the mentioned.

ANSWER: B

Unit 01 - Q005: A(n) ______ algorithm transforms ciphertext to plaintext. A) encryption B) decryption C) Quadruple D) None of the mentioned.

ANSWER: B

Unit 01 - Q010: In a(n) ________ cipher, a pair of keys is used. A) symmetric-key B) asymmetric-key C) public-key D) None of the mentioned.

ANSWER: B

Unit 01 - Q011: In an asymmetric-key cipher, the sender uses the__________ key to encrypt plaintext A) private B) public C) All of the mentioned answers D) None of the mentioned.

ANSWER: B

Unit 01 - Q017: The ________ cipher reorders the plaintext characters to create a ciphertext. A) substitution B) transposition C) round D) None of the mentioned.

ANSWER: B

Unit 01 - Q019: A(n) _______is a keyless transposition cipher with N inputs and M outputs that uses a table to define the relationship between the input stream and the output stream. A) S-box B) P-box C) T-box D) None of the mentioned.

ANSWER: B

Unit 01 - Q024: DES uses a key generator to generate sixteen _______ round keys. A) 32-bit B) 48-bit C) 54-bit D) 42-bit

ANSWER: B

Unit 01 - Q025: DES was designed to increase the size of the DES key A) Double B) Triple C) Quadruple D) None of the mentioned.

ANSWER: B

Unit 01 - Q027: AES has _____ different configurations A) two B) three C) four D) five

ANSWER: B

Unit 01 - Q032: What risks arise when using the same key to encrypt both directions of a communication channel, that are not present if using different keys for the different directions? A) Message tampering by flipping bits in the ciphertext. B) Reflection attacks. C) Hash collisions. D) Eavesdropping attacks.

ANSWER: B

Unit 01 - Q033: In asymmetric key cryptography, the private key is kept by A) sender B) receiver C) sender and receiver D) all the connected devices to the network

ANSWER: B

Unit 01 - Q038: The Playfair Cipher uses a matrix of size A) 4 x 4 B) 5 x 5 C) 6 x 6 D) 7 x 7

ANSWER: B

Unit 01 - Q044: The Diffie-Hellman key exchange protocols needs ___ messages to finish key exchange. A) 1 B) 2 C) 3 D) 4

ANSWER: B

Unit 01 - Q070: Presenting an identifier to the security system is the __________ step. A) identification B) verification C) authentication D) clarification

ANSWER: A

Unit 01 - Q072: Which hash functions are used in S/MIME? A) MD5 and SHA-1 B) MD4 and MD5 C) MD5 and SHA-2 D) SHA-1 and SHA-2

ANSWER: A

Unit 01 - Q049: Today, many Internet businesses and users take advantage of cryptography based on this approach. A) public key infrastructure B) output feedback C) Encrypting File System D) single signon

ANSWER: A

U011-Q003: Which of the following is an update to Secure Hash Algorithm (SHA)? { A)SHA-1 B)SHA2 C)SHB D)SHAA

ANSWER: A

U012-Q001: Which of the following is derived from the message and a key and is used to verify the integrity of a message? { A)MAC B)BDC C)ERC D)CDC

ANSWER: A

U03-Q001: If both sender and receiver use the same key, the system is referred to as: { A)symmetric key encryption B)asymmetric key encryption C)public key encryption D)one key encryption

ANSWER: A

Unit 01 - Q0013: A ________ cilces one character with another character. A) substitution B) transposition C) round D) None of the mentioned.

ANSWER: A

Unit 01 - Q001: ________ is the science and art of transforming messages to make them secure and immune to attacks. A) Cryptography B) Cryptoanalysis C) Cryptography AND Cryptoanalysis D) None of the mentioned.

ANSWER: A

Unit 01 - Q003: The ________ is the message after transformation. A) ciphertext B) plaintext C) secret-text D) None of the mentioned.

ANSWER: A

Unit 01 - Q004: A(n) _______ algorithm transforms plaintext to ciphertext A) encryption B) decryption C) Quadruple D) None of the mentioned.

ANSWER: A

Unit 01 - Q006: A combination of an encryption algorithm and a decryption algorithm is called a ________. A) cipher B) secret C) key D) None of the mentioned.

ANSWER: A

Unit 01 - Q008: In a(n) ________ cipher, the same key is used by both the sender and receiver. A) symmetric-key B) asymmetric-key C) public-key D) None of the mentioned.

ANSWER: A

Unit 01 - Q009: In a(n) ________, the key is called the secret key. A) symmetric-key B) asymmetric-key C) public-key D) None of the mentioned.

ANSWER: A

Unit 01 - Q012: In an asymmetric-key cipher, the receiver uses the ______ key to decrypt ciphertext A) private B) public C) pre-shared key D) None of the mentioned.

ANSWER: A

Unit 01 - Q014: _________ ciphers can be categorized into two broad categories: monoalphabetic and polyalphabetic. A) Substitution B) Transposition C) round D) None of the mentioned.

ANSWER: A

Unit 01 - Q018: A(n) ______ is a keyless substitution cipher with N inputs and M outputs that uses a formula to define the relationship between the input stream and the output stream. A) S-box B) P-box C) T-box D) None of the mentioned.

ANSWER: A

Unit 01 - Q020: A modern cipher is usually a complex _____cipher made of a combination of different simple ciphers. A) round B) circle C) square D) None of the mentioned.

ANSWER: A

Unit 01 - Q021: DES is a(n) ________ method adopted by the U.S. government. A) symmetric-key B) asymmetric-key C) public-key D) None of the mentioned.

ANSWER: A

Unit 01 - Q028: ECB and CBC are ________ ciphers. A) block B) stream C) field D) None of the mentioned.

ANSWER: A

Unit 01 - Q030: The ________ method provides a one-time session key for two parties. A) Diffie-Hellman B) RSA C) DES D) AES

ANSWER: A

Unit 01 - Q031: The _________ attack can endanger the security of the Diffie-Hellman method if two parties are not authenticated to each other. A) man-in-the-middle B) ciphertext attack C) plaintext attack D) None of the mentioned.

ANSWER: A

Unit 01 - Q035: What is data encryption standard (DES)? A) block cipher B) stream cipher C) bit cipher D) None of the mentioned.

ANSWER: A

Unit 01 - Q036: Cryptanalysis is used A) to find some insecurity in a cryptographic scheme B) to increase the speed C) to encrypt the data D) None of the mentioned.

ANSWER: A

Unit 01 - Q041: The term keystream is usually connected with A) stream ciphers B) block ciphers C) public-key ciphers D) key-exchange protocols

ANSWER: A

Unit 01 - Q043: On which hard mathematical problem does RSA base its security? A) Factorization of big numbers B) Finding big prime numbers C) Multiplication of big prime numbers D) Exponentiation of big numbers

ANSWER: A

Unit 01 - Q045: Substitution ciphers. A) The order of plaintext letters is rearranged during encryption. B) Letters of the plaintext messages are replaced with other letters during the encryption. C) Exponentiation of big numbers D) None of the mentioned.

ANSWER: B

Unit 01 - Q047: In the symmetric key cryptography both sender and receiver posses ______ A) Different keys. B) Same key. C) Public key. D) None of the mentioned.

ANSWER: B

Unit 01 - Q050: This is the name for the issuer of a PKI certificate. A) man in the middle B) certificate authority C) Resource Access Control Facility D) script kiddy

ANSWER: B

Unit 01 - Q071: PGP provides authentication through the use of _________ . A) digital signatures B) asymmetric block encryption C) symmetric block encryption D) data compression

ANSWER: B

Unit 01 - Q075: Use Caesars Cipher to decipher the following: HQFUBSWHG WHAW A) ABANDONED LOCK B) ENCRYPTED TEXT C) ABANDONED TEXT D) ENCRYPTED LOCK

ANSWER: B

Unit 01 - Q076: Caesar Cipher is an example of A) Poly-alphabetic Cipher B) Mono-alphabetic Cipher C) Multi-alphabetic Cipher D) Bi-alphabetic Cipher

ANSWER: B

Unit 01 - Q078: On Encrypting thepepsiisintherefrigerator using Vignere Cipher System using the keyword HUMOR. we get cipher text A) abqdnwewuwjphfvrrtrfznsdokvl B) abqdvmwuwjphfvvyyrfznydokvl C) tbqyrvmwuwjphfvvyyrfznydokvl D) baiuvmwuwjphfoeiyrfznydokvl

ANSWER: B

Unit 01 - Q083: How many rounds does the AES-192 perform? A) 10 B) 12 C) 14 D) 16

ANSWER: B

Unit 01 - Q086: For the AES-128 algorithm there are __________ similar rounds and _________ round is different. A) 2 pair of 5 similar rounds ; every alternate B) 9 ; the last C) 8 ; the first and last D) 10 ; no

ANSWER: B

Unit 01 - Q087: Which of the 4 operations are false for each round in the AES algorithm: i) Substitute Bytes, ii) Shift Columns, iii) Mix Rows, iv) XOR Round Key. A) i) only B) ii) iii) and iv) C) ii) and iii) D) only iv)

ANSWER: B

Unit 01 - Q093: PRNG stands for A) Personal Random Number Generation B) Pseudo Random Number Generation C) Primitive Number Generators D) Private Number Generators

ANSWER: B

Unit 01 - Q096: PRNGs take in an input which is referred to as A) bit stream B) seed C) entropy source D) external variable

ANSWER: B

Unit 01 - Q097: The property that there should be equally likely number of 1s and 0s in a Pseudo Random Number sequence is A) Scalability B) Uniformity C) Stability D) Consistency

ANSWER: B

U01-Q001: Input message in Cryptography is called; { A)Plain text B)Cipher Text C)Plain and cipher D)None of the mentioned

ANSWER: C

U01-Q002: Which of the following involves looking at blocks of an encrypted message to determine whether any common patterns exist? { A)Quantum cryptography B)Algorithm errors C)Frequency analysis D)Brute-force attacks

ANSWER: C

U011-Q002: What bit hash value does Secure Hash Algorithm (SHA) produce? { A)96 B)128 C)160 D)256

ANSWER: C

U011-Q004: Hash algorithms are used to { A)Scramble data as part of the encryption process B)Create a digital signature that is unique to a given input file C)Create a delicious breakfast served with eggs over easy D)None of the mentioned

ANSWER: C

U02-Q002: The only cipher system said to be unbreakable by brute force is { A)AES B)DES C)One-time pad D)Triple DES

ANSWER: C

U04-Q001: What is the block cipher structure in DES? { A)SAC B)Shannon C)Feistel D)Rendell

ANSWER: C

U09-Q003: Which of the following is an asymmetric algorithm based on calculating logarithms? { A)ECC B)Diffie-Hellman C)El Gamal D)RSA

ANSWER: C

U09-Q004: The key exchange protocol is vulnerable to a __________ attack because it does not authenticate the participants. { A)chosen ciphertext B)man-in-the-middle C)replay D)differential cryptanalysis

ANSWER: C

Unit 01 - Q007: The _______ is a number or a set of numbers on which the cipher operates. A) cipher B) secret C) key D) None of the mentioned.

ANSWER: C

Unit 01 - Q015: The _______ cipher is the simplest monoalphabetic cipher. It uses modular arithmetic with a modulus of 26. A) transposition B) additive C) shift D) None of the mentioned.

ANSWER: C

Unit 01 - Q016: The Caesar cipher is a _______cipher that has a key of 3. A) transposition B) additive C) shift D) None of the mentioned.

ANSWER: C

Unit 01 - Q022: DES has an initial and final permutation block and _________ rounds. A) 14 B) 15 C) 16 D) None of the mentioned.

ANSWER: C

Unit 01 - Q023: The DES function has _______ components. A) 2 B) 3 C) 4 D) 5

ANSWER: C

Unit 01 - Q029: One commonly used public-key cryptography method is the ______ algorithm. A) DES B) RC4 C) RSA D) AES

ANSWER: C

Unit 01 - Q034: Which one of the following algorithm is not used in asymmetric-key cryptography? A) rsa algorithm B) diffie-hellman algorithm C) electronic code book algorithm D) None of the mentioned.

ANSWER: C

Unit 01 - Q039: S-boxes in DES map A) 2 to 4 bits B) 4 to 4 bits C) 6 to 4 bits D) 4 to 6 bits

ANSWER: C

Unit 01 - Q042: Which two important issues are addressed with public-key cryptography A) Production of big prime numbers and their multiplication B) Factorization of natural numbers and discrete logarithm problem C) Key distribution and Digital signatures D) Production of master and session keys

ANSWER: C

Unit 01 - Q046: When trying to crack a code using by trying all the possibilities, this method is known as ____________. A) Caesar cipher. B) Cyberspace C) Brute force attack D) Vegineer cipher

ANSWER: C

Unit 01 - Q048: This is an encryption/decryption key known only to the party or parties that exchange secret messages. A) e-signature B) digital certificate C) private key D) security token

ANSWER: C

Unit 01 - Q077: Which are the most frequently found letters in the English language ? A) e,a B) e,o C) e,t D) e,i

ANSWER: C

Unit 01 - Q079: DES follows A) Hash Algorithm B) Caesars Cipher C) Feistel Cipher Structure D) SP Networks

ANSWER: C

Unit 01 - Q081: The DES algorithm has a key length of A) 128 Bits B) 32 Bits C) 64 Bits D) 16 Bits

ANSWER: C

Unit 01 - Q084: How many rounds does the AES-256 perform? A) 10 B) 12 C) 14 D) 16

ANSWER: C

Unit 01 - Q088: Which of the following is false for ECB mode of operation? i) The Plain text is broken into blocks of size 128 bytes, ii) Blocks can be swapped, repeated, replaced without recipient noticing, iii) Good for short data ,iv) Encryption of each block is done separately using a randomly generated key for each block. A) i) only B) ii) and iii) C) i) and iv) D) i) ii) and iv)

ANSWER: C

Unit 01 - Q095: TRNGs take in an input which is referred to as A) random variable B) external variable C) entropy source D) bit stream

ANSWER: C

U013-Q001: When a user is computing the hash of a message and then encrypting the hash with his private key, he is producing: { A)hash code B)a timestamp C)a message digest D)a digital signature

ANSWER: D

U02-Q001: Which type of cipher is a simple coding system that changes one character or symbol into another? { A)Reverseography B)Steganography C)Transposition D)Substitution

ANSWER: D

U06-Q001: The main reason why Triple-DES was not kept as the only standard for block ciphers and have been replaced by AES is that { A)it has too short key B)it has too long key C)it is patented D)it is slow

ANSWER: D

U09-Q002: Which of the following is based on the idea of using large integer numbers for the basis of asymmetric encryption? { A)ECC B)Diffie-Hellman C)El Gamal D)RSA

ANSWER: D

Unit 01 - Q026: is a round cipher based on the Rijndael algorithm that uses a 128-bit block of data. A) DES B) 3DES C) RC4 D) AES

ANSWER: D

Unit 01 - Q037: In a known plaintext attack the attacker knows A) predetermined selected ciphertext B) one plaintext and one key C) one ciphertext and one key D) plaintext and ciphertext

ANSWER: D

Unit 01 - Q040: What is the biggest advantage of CBC mode of operation A) It can encrypt in parallel different parts of the messages B) It does not need Initialization Vector (IV) C) The Initialization Vector (IV) is secret � so the length of the secret key is doubled D) A ciphertext block depends on all blocks before it

ANSWER: D

Unit 01 - Q080: The DES Algorithm Cipher System consists of ____________rounds (iterations) each with a round key A) 12 B) 18 C) 9 D) 16

ANSWER: D

Unit 01 - Q082: AES uses a ____________ bit block size and a key size of __________ bits. A) 128; 128 or 256 B) 64; 128 or 192 C) 256; 128, 192, or 256 D) 128; 128, 192, or 256

ANSWER: D

Unit 01 - Q089: Which of the following statements are true? i) In the CBC mode, the plaintext block is XORed with previous ciphertext block before encryption; ii) The CTR mode does not require an Initialization Vector; iii) The last block in the CBC mode uses an Initialization Vector; iv) In CBC mode repetitions in plaintext do not show up in ciphertext. A) iii) B) ii) and iv) C) All the Statements are true D) i) ii) and iv)

ANSWER: D

Unit 01 - Q099: Frequency Test is A) a test to determine whether the number of runs of ones and zeros of various lengths is as expected B) a test to detect if a sequence can be significantly compressed without loss of information C) a test for the check of evenness in the 1s and 0s D) a test to determine whether the number of ones and zeros in a sequence is approx the same as in a truely random o/p

ANSWER: D