3.18 and 3.20

for the program in matlab or python

solve 3.18 and then program it in python or matlab

om uwmguurus ruer o pened DES, described in Appendix G. 3.16 Refer to Figure G.2, which depicts key generation for S-DES. a. How important is the initial P10 permutation function? Low important are the two LS-1 shift functions? 3.17 The equations for the variables q and for S-DES are defined in the section on S-DES analysis. Provide the equations for sand. 3.18 Using S-DES, decrypt the string (10100010) using the key (0111111101) by hand. Show intermediate results after each function (IP, Fx, SW, FK,IP-). Then decode the first 4 bits of the plaintext string to a letter and the second 4 bits to another letter where we encode A through P in base 2 (i.e. A = 0000, B = 0001, ..., P=1111). Hint. As a midway check, after the application of SW. the string should be (00010011). Programming Problems 3.19 Create software that can encrypt and decrypt using a general substitution block cipher. 3.20 Create software that can encrypt and decrypt using S-DES. Test data: use plaintext, ciphertext, and key of Problem 3.18. om uwmguurus ruer o pened DES, described in Appendix G. 3.16 Refer to Figure G.2, which depicts key generation for S-DES. a. How important is the initial P10 permutation function? Low important are the two LS-1 shift functions? 3.17 The equations for the variables q and for S-DES are defined in the section on S-DES analysis. Provide the equations for sand. 3.18 Using S-DES, decrypt the string (10100010) using the key (0111111101) by hand. Show intermediate results after each function (IP, Fx, SW, FK,IP-). Then decode the first 4 bits of the plaintext string to a letter and the second 4 bits to another letter where we encode A through P in base 2 (i.e. A = 0000, B = 0001, ..., P=1111). Hint. As a midway check, after the application of SW. the string should be (00010011). Programming Problems 3.19 Create software that can encrypt and decrypt using a general substitution block cipher. 3.20 Create software that can encrypt and decrypt using S-DES. Test data: use plaintext, ciphertext, and key of Problem 3.18