Symmetric Ciphers Questions and Answers – The Data Encryption Standard (DES) and It’s Strength – I

This set of Cryptography Multiple Choice Questions & Answers (MCQs) focuses on “The Data Encryption Standard (DES) and It’s Strength”.

1. DES follows
a) Hash Algorithm
b) Caesars Cipher
c) Feistel Cipher Structure
d) SP Networks
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2. The DES Algorithm Cipher System consists of ____________rounds (iterations) each with a round key
a) 12
b) 18
c) 9
d) 16
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3. The DES algorithm has a key length of
a) 128 Bits
b) 32 Bits
c) 64 Bits
d) 16 Bits
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4. In the DES algorithm, although the key size is 64 bits only 48bits are used for the encryption procedure, the rest are parity bits.
a) True
b) False
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5. 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
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6. In the DES algorithm the Round Input is 32 bits, which is expanded to 48 bits via ____________
a) Scaling of the existing bits
b) Duplication of the existing bits
c) Addition of zeros
d) Addition of ones
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7. The Initial Permutation table/matrix is of size
a) 16×8
b) 12×8
c) 8×8
d) 4×8
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8. The number of unique substitution boxes in DES after the 48 bit XOR operation are
a) 8
b) 4
c) 6
d) 12
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9. In the DES algorithm the 64 bit key input is shortened to 56 bits by ignoring every 4th bit.
a) True
b) False
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Sanfoundry Global Education & Learning Series – Cryptography and Network Security.

To practice all areas of Cryptography and Network Security, here is complete set of 1000+ Multiple Choice Questions and Answers.