A Chaos Robustness Criterion for 2D Piecewise Smooth Map with Applications in Pseudorandom Number Generator and Image Encryption with Avalanche Effect

Algorithm 1

N=20000;

K=randi([⁢0 254],1,255);

S=[0:255-1];j=0;

for i=1:255

   j=mod(j+S(i)+K(i),255);

      Sk=S(j+1);

       S(j+1)=S(i);

         S(i)=Sk;

end

    C=zeros(1,N); j=0;i=0; k=1;

for l=1:N/8

     i=mod(i+1,255);

      j=mod(j+S(i+1),255);

       Sk=S(j+1);

        S(j+1)=S(i+1);

         S(i+1)=Sk;

  C(l)=S(mod(S(j+1)+S(i+1),255)+1);

end

  C=(dec2bin(C))’;

  C=C(:);

   C=bin2dec(C);