Question

Assuming a 32 bit block in DES consisting of 101010……., Perform the Expansion Permutation and find the bit no. 1, 16, 33, and 43.​

Answer 1

Answer:

Data encryption standard (DES) has been found vulnerable against very powerful attacks and therefore, the popularity of DES has been found slightly on decline.

DES is a block cipher, and encrypts data in blocks of size of 64 bit each, means 64 bits of plain text goes as the input to DES, which produces 64 bits of cipher text. The same algorithm and key are used for encryption and decryption, with minor differences. The key length is 56 bits. The basic idea is show in figure.