Info

This question is closed. Reopen it to edit or answer.

How to decrypt the cipher-text generated by RC4 stream cipher?

1 view (last 30 days)
Abdul Gaffar
Abdul Gaffar on 7 Apr 2020
Closed: Walter Roberson on 7 Apr 2020
I am encrypting 'text' message using keystream generated by RC4 stream cipher. But while decrypting the ciphertext generated by RC4 cipher, I am not getting the exact plain-text. I have attached my code.
%% \***---*** Text Encryption & Decryption using 'RC4' stream cipher ***---***/ %%
plain_text = 'MatLab R2020a';
P = double(plain_text);
S = [123, 34, 255, 76, 89, 155, 53, 0, 3, 82, 19, 45, 76]; % Keystream generated by RC4
E = bitxor(S, P); % Encryption
cipher_text = char(E); % O/p in text form
disp(cipher_text);
%% ************* For Decryption; You need keystream S and cipher_text ***********
d_cipher_text = '6C 8ùR1b!-'; % cipher_text copied from 'Workspace'
dP = double(d_cipher_text);
dE = bitxor(S, dP); % Decryption
dec_text = char(dE); % O/p in text form
disp(dec_text);
%% Conclusion: plain_text and dec_text are not same!!

Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!