rsa_enc.asv

RSA encrption algorithms

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% This program applies (RSA)                                        %
% Developed by Hiba Al-younes                                       %
% 5th Year, Computer Engineering Department, University of Damascus %
% Information and Network Security Material                         %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
function RSA_ENC()
format long
%generate primary parameters (p & q)
maple('z1:=',randint(1,1,[12 20]));
p=maple('nextprime(z1)');
p=str2double(p);
maple('z2:=',randint(1,1,[22 30]));
q=maple('nextprime(z2)');
q=str2double(q);
%compute n=p*q.
n=p*q;
maple('n1:=',n);
% opening the file being ciphered
f=fopen('message.txt');
[msg,count]=fread(f);
fclose(f);
%compute olar function .
Qn=olar(n);
maple('Qn1:=',Qn);
%compute general key .
maple('z3:=',randint(1,1,30));
e=maple('nextprime(z3)');
e=str2double(e);
while(gcd(Qn,e)~=1)
    maple('z3:=',randint(1,1,30));
    e=maple('nextprime(z3)');
    e=str2double(e);
end
maple('e1:=',e);
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% Compute Cipher text %
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 Ciphertext=[]; 
 for i=1:1:count
    maple('msg1:=',msg(i));
    c=maple('(msg1) &^(e1) mod (n1)');
    c=str2double(c);
    Ciphertext = [Ciphertext c];
 end
 save('RSA','Ciphertext','n','e');
 f=fopen('cipher message.txt','w');
 cn=fwrite(f,Ciphertext);
 fclose(f);
 open 'cipher message.txt';