Question

DES has an initial and final permutation block and _ rounds

(A) 14

(B) 15

(C) 16

(D) none of the above​

Answer 1

Explanation:

Ur correct answer is option c)

16 rounds

Answer 2

Answer:

(C) 16

Explanation:

DES i.e. Data Encryption Standard is a symmetric-key block cipher that encrypts data in blocks of size of 64 bits each. It means 64 bits of plain text go as the input to DES and produces 64 bits of ciphertext. The same key is used for encryption and decryption with minor differences.

For Example - If in the Initial permutation, 58th bit is the input then it becomes the 1st bit in the output. Then in the final permutation, the first bit in the input becomes the 58th bit in the output. We can also say that if the rounds between the Initial and Final permutations do not exist then the 58th bit entering the initial permutation is the same as the 58th bit leaving the final permutation.

DES uses 16 rounds and each round is a Feistel cipher.

Therefore, DES has an initial and final permutation block and 16 rounds.

Hence, option (C) 16 is the correct answer.

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To learn more about DES, visit:

https://brainly.in/question/27204324?msp_srt_exp=4

https://brainly.in/question/7698160?msp_srt_exp=4