Question

[MATLAB] Write a function called hw4_problem3 that implements the Vigenere cipher. The Vigenere cipher is an enhanced version of the Caesar’s cipher: instead of a single shift value, it uses a vector of shifts: the first character of the text is shifted by the first shift value, the second by the second and so on. When we run out of shift values, we go back to the first and start over. The function takes two inputs: txt, a character array containing the text we need to encrypt and key, a vector of integer scalars specifying the shift values. You do NOT need to check the assumptions on the inputs. The function returns the encrypted text as a character vector. We shift all visible characters from space to ~ and wrap around after ~. So ~ shifted by one is space and space shifted by minus one is ~.

Answer 1

`Hey,

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clc%clears screen
clear all%clears history
close all%closes all files
format long
hw4_problem3(' ',-[1])

function s=hw4_problem3(txt,v)
s=txt;
for i=1:length(s)
if(s(i)>=32&s(i)<=126)
if(s(i)+v(i)>=32&s(i)+v(i)<=126)
s(i)=char(mod(s(i)+v(i)-32,94)+32);
else
s(i)=char(mod(s(i)+v(i)-32,95)+32);
end
end
end
end

Kindly revert for any queries

Thanks.