Caesarts Cipher encryption algorithm assistance
2 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Caesar's cypher is the simplest encryption algorithm. It adds a fixed value to the ASCII (unicode) value of each character of a text. In other words, it shifts the characters. Decrypting a text is simply shifting it back by the same amount, that is, it substract the same value from the characters. Write a function called caesar that accepts two arguments: the first is the character vector to be encrypted, while the second is the shift amount. The function returns the output argument coded, the encrypted text. The function needs to work with all the visible ASCII characters from space to ~. The ASCII codes of these are 32 through 126. If the shifted code goes outside of this range, it should wrap around. For example, if we shift ~ by 1, the result should be space. If we shift space by -1, the result should be ~.
Here are a few things you may want to try with MATLAB before starting on this assignment:
double(' ')
ans =
32
double('~')
ans =
126
char([65 66 67])
ans =
'ABC'
' ' : '~'
ans =
' !"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~'
And here are a few example runs:
caesar('ABCD',1)
ans =
'BCDE'
caesar('xyz ~',1)
ans =
'yz{! '
caesar('xyz ~',-1)
ans =
'wxy~}'
Code to Call your Function:
coded = caesar('ABCD', 3)
decoded = caesar(coded, -3)
wrap = caesar('1234', 96)
back = caesar(wrap, -96)
Hi there, I am having trouble with the caesars cypher question for week 8 homework assignments and I was wondering if I could get some help with the code that I have so far. Here is what I have, any help would be appreciated.
function coded = caesar(v,n)
v = char(32:126)
secret = v + 2
mod(v,126)
coded = char(mod(v,126))
end
ps. I feel embarrased posting this I am trying to figure it out but it is very difficult for me.
20 commentaires
evan muas
le 29 Déc 2019
A link to my answer on stackexchange
https://stackoverflow.com/a/59522032/10810614
Réponses (4)
Akhil Thomas
le 16 Mai 2020
function
y = caesar2(ch, key)
v = ' ' : '~';
[~, loc] = ismember(ch, v);
v2 = circshift(v, -key);
y = v2(loc);
end
0 commentaires
Akhil Thomas
le 16 Mai 2020
function txt = caesar(txt,key)
txt = double(txt) + key;
first = double(' ');
last = double('~');
% use mod to shift the characters - notice the + 1
% this is a common error and results in shifts
% being off by 1
txt = char(mod(txt - first,last - first + 1) + first);
end
0 commentaires
Shaun Olisagu
le 27 Juil 2020
function coded = caesar(text, amount)
new_text = double(text)
text_shift = new_text + amount
coded = char(mod(text_shift,(32:126,32)))
end
Pls help. I've been on this for quite a long time now
0 commentaires
Yifan He
le 28 Juil 2022
Modifié(e) : Walter Roberson
le 28 Juil 2022
function coded = caesar(v,s)
x = double(v);
y = x + s;
if y >= 32
n = fix((y-32)/95);
else
n = fix((y-126)/95);
end
z = y - 95*n;
coded = char(z);
2 commentaires
Yifan He
le 28 Juil 2022
It still make sense. This problem is a step function in mathematics, actually. z=f(y)=y-95n (32+95n ≤ y ≤ 126+95n,n∈Z)
Voir également
Catégories
En savoir plus sur Encryption / Cryptography dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!