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%% Copyright: 2010 Integrated Sytems Laboratory, ETH Zurich
%%            http://www.iis.ee.ethz.ch/~sha3
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function s = GExp256(block)
%clear; clc;

g =[[1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 1, 3, 0, 0, 3, 3, 3, 3, 0, 0, 2, 0, 0, 3, 0, 2, 3, 2, 2, 1, 0, 2, 2, 3, 0, 3, 0, 0, 1, 0, 2, 1, 2, 3, 3, 3, 1, 2, 3, 3, 0, 1, 1, 1, 3, 1, 1, 1, 1, 0, 0, 3, 0, 0, 0, 3, 1, 3, 3, 2, 2, 2, 3, 0, 0, 2, 2, 3, 0, 1, 1, 2, 0, 1, 2, 1, 3, 0, 1, 2, 3, 1, 0, 1, 2, 1, 3, 3, 3, 3, 3, 2, 1, 1, 0, 2, 3, 2, 1, 0, 2, 3, 1, 1, 0, 2, 3, 3, 2, 0, 2, 0];
    [0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 3, 0, 2, 1, 1, 1, 3, 0, 1, 2, 0, 2, 3, 1, 0, 2, 3, 1, 1, 1, 3, 0, 3, 2, 3, 0, 3, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 3, 3, 2, 2, 3, 0, 2, 2, 2, 1, 0, 2, 3, 0, 0, 2, 0, 3, 1, 2, 3, 3, 0, 3, 0, 1, 3, 0, 3, 3, 2, 0, 2, 3, 0, 1, 3, 3, 3, 0, 0, 0, 1, 3, 0, 1, 3, 1, 1, 1, 1, 2, 1, 2, 1, 1, 0, 2, 1, 1, 1, 0, 0, 2, 1, 1, 0, 1, 1, 2, 1, 2];
    [0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 0, 3, 3, 2, 0, 3, 3, 1, 3, 1, 1, 2, 2, 2, 2, 3, 1, 3, 0, 1, 0, 0, 1, 0, 1, 2, 3, 3, 3, 0, 2, 0, 2, 2, 3, 2, 1, 2, 2, 1, 0, 0, 1, 0, 2, 3, 1, 1, 2, 1, 2, 2, 3, 0, 2, 1, 2, 1, 0, 3, 2, 1, 0, 3, 1, 0, 1, 0, 0, 0, 3, 0, 1, 2, 3, 3, 3, 0, 2, 2, 3, 0, 2, 2, 3, 3, 1, 3, 3, 3, 0, 1, 2, 2, 0, 3, 1, 1, 1, 0, 3, 3, 3, 2, 0, 3, 2, 0, 1, 2, 3];
    [0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 0, 3, 3, 2, 0, 3, 3, 1, 3, 1, 1, 2, 2, 2, 2, 3, 1, 3, 0, 1, 0, 0, 1, 0, 1, 2, 3, 3, 3, 0, 2, 0, 2, 2, 3, 2, 1, 2, 2, 1, 0, 0, 1, 2, 2, 3, 1, 1, 2, 1, 2, 2, 3, 0, 2, 1, 2, 1, 0, 3, 2, 1, 0, 3, 1, 0, 1, 0, 0, 0, 3, 0, 1, 2, 3, 3, 3, 0, 2, 2, 3, 0, 2, 2, 3, 3, 1, 3, 3, 3, 0, 1, 2, 2, 0, 3, 1, 1, 1, 0, 3, 3, 3, 2, 0, 3, 1, 0, 0, 1];
    [0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 1, 2, 0, 0, 0, 1, 3, 3, 3, 3, 3, 1, 2, 2, 0, 1, 0, 1, 0, 3, 2, 3, 3, 0, 2, 0, 1, 3, 3, 1, 2, 2, 1, 3, 1, 3, 1, 1, 2, 2, 3, 0, 1, 3, 2, 3, 3, 2, 1, 1, 1, 1, 2, 2, 0, 1, 1, 2, 0, 3, 2, 0, 2, 1, 2, 1, 2, 0, 0, 1, 2, 0, 2, 2, 0, 1, 3, 2, 1, 3, 3, 2, 2, 2, 3, 1, 0, 0, 2, 0, 1, 2, 1, 1, 0, 1, 2, 2, 1, 3, 2, 1, 2, 3, 1, 1, 3, 3, 1, 3, 1];
    [0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 1, 2, 2, 2, 2, 3, 3, 3, 2, 3, 3, 3, 2, 3, 2, 0, 1, 2, 0, 2, 3, 1, 3, 2, 2, 0, 2, 3, 2, 2, 3, 0, 3, 1, 2, 2, 3, 3, 2, 1, 0, 3, 3, 0, 1, 0, 0, 2, 1, 3, 1, 1, 2, 0, 3, 3, 3, 3, 1, 2, 0, 0, 2, 0, 3, 3, 2, 3, 3, 0, 2, 3, 3, 1, 2, 1, 0, 3, 3, 0, 3, 1, 3, 1, 1, 3, 2, 2, 0, 1, 2, 1, 1, 0, 2, 0, 1, 2, 0, 1, 1, 2, 2, 2, 3, 3, 2, 3, 3, 2];
    [0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 0, 2, 1, 0, 0, 0, 0, 3, 3, 2, 2, 3, 1, 3, 3, 1, 3, 1, 2, 2, 1, 3, 1, 1, 1, 2, 2, 3, 2, 2, 1, 3, 1, 2, 1, 2, 3, 0, 1, 3, 1, 2, 3, 1, 0, 3, 2, 3, 0, 2, 3, 3, 1, 1, 0, 3, 1, 1, 2, 2, 0, 0, 0, 0, 3, 1, 1, 3, 1, 0, 2, 0, 1, 2, 0, 3, 2, 2, 1, 1, 0, 0, 0, 0, 0, 3, 3, 1, 0, 0, 1, 2, 1, 1, 0, 2, 3, 3, 1, 3, 2, 2, 2, 2, 3, 0, 1, 2, 2, 1, 1];
    [0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 3, 1, 0, 2, 2, 3, 3, 3, 0, 3, 1, 2, 2, 0, 1, 1, 0, 3, 1, 0, 2, 0, 3, 0, 1, 2, 1, 2, 3, 3, 0, 3, 3, 0, 2, 1, 0, 0, 0, 3, 1, 2, 0, 3, 0, 0, 1, 2, 3, 3, 0, 1, 3, 3, 1, 2, 1, 0, 2, 3, 0, 0, 3, 0, 0, 2, 1, 2, 1, 2, 0, 2, 2, 1, 3, 3, 3, 3, 3, 0, 2, 0, 0, 1, 2, 1, 3, 0, 0, 2, 3, 2, 0, 3, 1, 3, 3, 0, 2, 3, 3, 0, 3, 3, 2, 0, 0, 3, 0, 2, 2, 0];
    [0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 3, 1, 0, 2, 2, 3, 3, 3, 0, 3, 1, 2, 2, 0, 1, 1, 0, 3, 1, 0, 2, 0, 3, 0, 1, 2, 1, 2, 3, 3, 0, 3, 3, 0, 2, 1, 0, 0, 0, 3, 1, 2, 0, 3, 3, 0, 1, 2, 3, 3, 0, 1, 3, 3, 1, 2, 1, 0, 2, 3, 0, 0, 3, 0, 0, 2, 1, 2, 1, 2, 0, 2, 2, 1, 3, 3, 3, 3, 3, 0, 2, 0, 0, 1, 2, 1, 3, 0, 0, 2, 3, 2, 0, 3, 1, 3, 3, 0, 2, 3, 3, 0, 3, 3, 2, 0, 0, 3, 0, 1, 2];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 3, 1, 2, 3, 1, 2, 0, 0, 1, 3, 3, 1, 3, 1, 0, 2, 1, 3, 0, 1, 0, 1, 1, 3, 2, 3, 2, 1, 2, 2, 2, 2, 0, 1, 1, 1, 2, 1, 0, 2, 2, 0, 0, 2, 1, 2, 3, 0, 3, 2, 2, 3, 1, 0, 1, 3, 1, 2, 0, 3, 1, 3, 2, 2, 0, 3, 1, 1, 0, 1, 1, 2, 3, 0, 1, 3, 2, 1, 3, 0, 2, 1, 3, 2, 3, 1, 2, 0, 3, 1, 2, 2, 3, 0, 1, 0, 2, 3, 2, 0, 0, 3, 1, 0, 3, 3, 2, 0, 2, 3, 3, 3, 3];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 3, 3, 1, 0, 2, 3, 0, 3, 1, 1, 1, 3, 0, 1, 3, 0, 0, 1, 0, 0, 3, 3, 0, 2, 2, 2, 2, 2, 2, 1, 0, 2, 1, 0, 3, 0, 0, 0, 0, 2, 1, 3, 2, 2, 2, 0, 0, 0, 1, 2, 1, 2, 2, 2, 1, 0, 1, 2, 3, 3, 1, 0, 2, 0, 3, 2, 0, 0, 2, 0, 0, 3, 3, 1, 3, 2, 2, 1, 3, 1, 1, 3, 3, 3, 3, 0, 0, 3, 3, 1, 2, 0, 3, 1, 1, 2, 1, 3, 3, 0, 0, 0, 3, 2, 3, 2, 3, 0, 3, 1, 1, 3, 2, 0];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 3, 3, 1, 0, 2, 3, 0, 3, 1, 1, 1, 3, 0, 1, 3, 0, 0, 1, 0, 0, 3, 3, 0, 2, 2, 2, 2, 2, 2, 1, 0, 2, 1, 0, 3, 0, 0, 0, 0, 2, 1, 3, 2, 2, 2, 0, 1, 0, 1, 2, 1, 2, 2, 2, 1, 0, 1, 2, 3, 3, 1, 0, 2, 0, 3, 2, 0, 0, 2, 0, 0, 3, 3, 1, 3, 2, 2, 1, 3, 1, 1, 3, 3, 3, 3, 0, 0, 3, 3, 1, 2, 0, 3, 1, 1, 2, 1, 3, 3, 0, 0, 0, 3, 2, 3, 2, 3, 0, 3, 1, 1, 2, 2];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 3, 3, 1, 0, 2, 3, 0, 3, 1, 1, 1, 3, 0, 1, 3, 0, 0, 1, 0, 0, 3, 3, 0, 2, 2, 2, 2, 2, 2, 1, 0, 2, 1, 0, 3, 0, 0, 0, 0, 2, 1, 3, 2, 2, 2, 3, 1, 0, 1, 2, 1, 2, 2, 2, 1, 0, 1, 2, 3, 3, 1, 0, 2, 0, 3, 2, 0, 0, 2, 0, 0, 3, 3, 1, 3, 2, 2, 1, 3, 1, 1, 3, 3, 3, 3, 0, 0, 3, 3, 1, 2, 0, 3, 1, 1, 2, 1, 3, 3, 0, 0, 0, 3, 2, 3, 2, 3, 0, 0, 1, 1, 0];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 3, 2, 2, 2, 3, 1, 1, 3, 2, 1, 3, 1, 2, 1, 3, 1, 1, 0, 1, 3, 2, 2, 0, 0, 0, 1, 2, 3, 2, 2, 0, 2, 2, 2, 1, 0, 1, 2, 2, 3, 1, 1, 2, 3, 1, 0, 3, 2, 1, 3, 2, 1, 2, 0, 2, 2, 2, 0, 2, 0, 3, 0, 0, 2, 1, 2, 0, 0, 1, 1, 0, 0, 2, 3, 3, 1, 2, 1, 3, 2, 3, 0, 0, 3, 3, 1, 0, 1, 1, 1, 2, 2, 0, 1, 2, 1, 1, 2, 3, 2, 1, 3, 3, 1, 2, 1, 2, 0, 3, 2, 1, 0, 0, 1];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 2, 3, 3, 3, 1, 0, 1, 3, 0, 2, 1, 1, 1, 0, 2, 0, 2, 1, 2, 1, 1, 2, 1, 0, 3, 2, 1, 0, 3, 1, 3, 3, 2, 3, 1, 3, 1, 3, 1, 1, 0, 2, 2, 1, 1, 2, 0, 2, 1, 0, 0, 2, 2, 0, 3, 0, 2, 2, 1, 1, 0, 1, 2, 1, 1, 3, 1, 3, 3, 3, 3, 0, 0, 1, 3, 3, 1, 2, 2, 3, 3, 0, 0, 3, 3, 3, 3, 0, 0, 1, 2, 1, 1, 0, 0, 2, 1, 1, 2, 1, 2, 1, 1, 3, 2, 1, 0, 1, 0, 1];
    [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 3, 3, 2, 0, 0, 2, 2, 2, 2, 0, 0, 1, 0, 0, 2, 0, 1, 2, 1, 1, 3, 0, 1, 1, 2, 0, 2, 0, 0, 3, 0, 1, 3, 1, 2, 2, 2, 3, 1, 2, 2, 0, 3, 3, 3, 2, 3, 3, 3, 3, 0, 0, 2, 0, 0, 0, 2, 3, 2, 2, 1, 1, 1, 2, 0, 0, 1, 1, 2, 0, 3, 3, 1, 0, 3, 1, 3, 2, 0, 3, 1, 2, 3, 0, 3, 1, 3, 2, 2, 2, 2, 2, 1, 3, 3, 0, 1, 2, 1, 3, 0, 1, 2, 3, 3, 0, 1, 2, 2, 3, 0, 0, 1, 1]];

msg=zeros(1,16);
temp=dec2bin(block,8);
for i=1:4
    for j=1:4
        msg((i-1)*4+j)=bin2dec(temp(i,2*j-1:2*j));
    end
end

e=zeros(1,128);
for k=1:128
    for i=1:16
        if g(i,k)==0
            s=0;
        elseif g(i,k)==1
            s=msg(i);
        elseif g(i,k)==2
            if msg(i)==0 || msg(i)==1
                s=bitshift(msg(i),1);
            elseif msg(i)==2
                s=3;
            else
                s=1;
                         
            end
            
        else
            if msg(i)==0 || msg(i)==1
                s=bitxor(bitshift(msg(i),1), msg(i));
            elseif msg(i)==2
                s=1;
            else
                s=2;
            end
        end
        
        e(k)=bitxor(e(k),s) ;
       
    end
end



%T0 = zeros(8,16);
T1 = zeros(8,16);
%M1 = zeros(8,32);
for i=1:8
    %T0(i,:) = d(16*(i-1)+1:(16*i));
    T1(i,:) = e(16*(i-1)+1:(16*i));
%     for j=1:16
%         %M0(i,2*j-1:2*j)=dec2bin(T0(i,j),2);
%         M1(i,2*j-1:2*j)=dec2bin(T1(i,j),2);
%     end

                
end
%M0=uint8(M0-48);
%M1=uint8(M1-48);
s=zeros(1,8,'uint32');
for i=1:8
    tmp=dec2bin(T1(i,:))';
    tmp=tmp(:)';
    s(i)=bin2dec(tmp);
end
    



% q=4;
% m0=zeros(8,32,'uint8');
% m1=zeros(8,32,'uint8');
% for i=1:q
%     for j=1:16
%         m0(i,j) = M0(i,2*j-1);
%         m0(i,16+j) = M0(q+i,2*j-1);
%         m0(q+i,j) = M0(i,2*j);
%         m0(q+i,16+j) = M0(q+i, 2*j);
%         m1(i,j) = M1(i,2*j-1);
%         m1(i,16+j) = M1(q+i,2*j-1);
%         m1(q+i,j) = M1(i,2*j);
%         m1(q+i,16+j) = M1(q+i, 2*j);
%         
%     end
% end
% isequal(m0, m1)
% 
% 
% m0=num2str(m0);
% 
% m1=num2str(m1);
%disp('Expansion Matrix :');
%disp(m0);

%expansion lut
% tmp=zeros(1,32);
% for i=1:16
%     tmp(1, 2*i-1:2*i) = dec2bin(msg(i),2);
% end
% tmp = uint8(tmp-48);
% 
% b=zeros(1,4);
% for i=1:4
%     b(i)=bin2dec(num2str(tmp(8*(i-1)+1:8*i)));
%     
% end
% 
% b=b+1;
% 
% s = zeros(8,1);
% for i=1:8
%     s(i) = Exp256(i, b);
% end
% s=dec2bin(s, 32);
% %disp('Expansion Matrix using LUT:');
% %disp(s '\n');
% 
% %compare results
% isequal(s,m1);
%  
% %reverse calc
% MRev = zeros(8,32);
% for i=1:q
%     for j=1:16
%         MRev(i,2*j-1) = s(i,j);
%         MRev(q+i,2*j-1) = s(i,16+j);
%         MRev(i,2*j) = s(q+i,j);
%         MRev(q+i, 2*j) = s(q+i,16+j);
%                 
%     end
% end
% MRev = MRev-48;
% sum(sum(MRev))
% sum(sum(M0))
% MRev=num2str(MRev)
% M0=num2str(M0)




% %m0=zeros(8,32);
% for i=1:q
%     for j=1:16
%         m0(i,j) = MRev(i,2*j-1);
%         m0(i,16+j) = MRev(q+i,2*j-1);
%         m0(q+i,j) = MRev(i,2*j);
%         m0(q+i,16+j) = MRev(q+i, 2*j);
%         
%     end
% end

end