NETWORK SECURITY
CONFIDENTIALITY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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12
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18
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9
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16
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Detailed explanation-1: -Explanation: The DES Algorithm Cipher System consists of 16 rounds (iterations) each with a round key. Explanation: DES encrypts blocks of 64 bits using a 64 bit key. 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.
Detailed explanation-2: -From Schneier’s description of DES in Chapter 12 of Applied Cryptography (12.3): DES with any number of rounds fewer than 16 could be broken with a known-plaintext attack more efficiently than by a brute-force attack. This explains the “Why not less than 16".
Detailed explanation-3: -The Data Encryption Standard is a symmetric-key block Cipher based on Feistel structure. It uses 16 rounds of Feistel Structure. It was developed in the early 1970s and was approved as a federal standard in November 1976. It was reaffirmed as a standard in 1983, 1988 and again in 1999.