reordtext.m

steganography tools to hide a text file in an image in true colour.

function reordtext(x)
%------------------------------------------------------------------------------------------
%  REORDTEXT
%  
%  The program reorders a file of text encrypt with desordtext.
%
%  Author: Francisco Echegorri  
%  E-mail: [e-mail]  
%  Created in September of 2002. 
%
%------------------------------------------------------------------------------------------
%
%  El programa reordena un archivo de texto encriptado con desordtext.
%
%------------------------------------------------------------------------------------------
if nargin<1
   x=input('enter a password (of up to 24 letters)\n','s');
end
load htext,F=char(F);b=find(F==255);n=length(F)-length(b);delete htext.mat
x=dalfa(x);x=keyexpansion(x);m=fix(sqrt(n));
for i=1:m
   X(i,1:m)=F(1:m);lon=length(F);F=F(m+1:lon);
end
p=m+1;long=length(F);
while long>=m
   X(p,1:m)=F(1:m);lon=length(F);F=F(m+1:lon);p=p+1;long=length(F);
end
Z=X;;MC=size(Z(1,:));MF=size(Z(:,1));NC=MC(1,2);NF=MF(1,1);w=x.*997;x=w-fix(w);
   y=randpermut(x,NF);z=randpermut(x,NC);
   for j=1:NC
      Y(:,z(j))=Z(:,j);
   end
   for i=1:NF
      X(y(i),:)=Y(i,:);
   end
   F=[];
   for i=1:NF
      a=X(i,1:NC);F=[F,a];
   end
c=find(F==255);F(c)=[];
save dtext F ,load dtext,u=char(F);dtext=F;
disp('                                                ')
save dctext.m,delete dctext.m
if char(dtext(1,1:8))=='function'
   diary('dctext.m'),disp(u),diary off,clc
   cd(pwd),dctext,cd(pwd)
else
   diary('dctext'),disp(u),diary off,clc
   disp('The decoded file this kept in dctext')
   open dctext
end
delete dtext.mat