Chaotic_code/decryptionprocess2.m

   1 function dimg =decryptionprocess(img,h,RK,Inv_SubBytes,Inv_Pbox,r)\r
   2 %%%%%%%%%%%%%% convert image to a vector seq\r
   3 %seq=double(reshape(img,1,[]));\r
   4 seq_bin=double(byte2bit(uint8(img))) ;\r
   5 decr_seq_binary=zeros(1,length(seq_bin));\r
   6 %%%%%%%%%%%%%%%%%%%% calculate the number of blocks%%%%%%%%%%%%%%%%%%%%%%%%\r
   7 nb= floor(length(seq_bin)/(8*h));\r
   8 RK_bin=double(reshape(byte2bit(RK),r,[]));\r
   9 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\r
  10 %%%%%%%%%%% Convert S-box to binary representation to avoid repeat the\r
  11 %%%%%%%%%%% byte2bit conversion\r
  12 Bin_Sbox  =double(Convert_Sbox_Bin(Inv_SubBytes));\r
  13 %%%%%%%%%%%%%%%%%%%% Applied the confusion process (r rounds)\r
  14 for it=1:nb\r
  15      temp=seq_bin((it-1)*8*h+1:it*h*8);\r
  16     for itr=r:-1:1       \r
  17         temp= temp(Inv_Pbox);\r
  18         temp=reshape(Bin_Sbox (double(bit2byte(temp))+1,:)',1,[]);\r
  19        % double(byte2bit(Inv_SubBytes(double(bit2byte(temp))+1)));\r
  20         %\r
  21 %         size(temp)\r
  22         %byte2bit(Inv_SubBytes(double(bit2byte(temp))+1));\r
  23         %temp= Inv_SubBytes(temp+1);\r
  24         temp=bitxor(temp,RK_bin(itr,1:h*8));   \r
  25     end\r
  26     decr_seq_binary((it-1)*8*h+1:it*h*8)=temp;\r
  27 end\r
  28 \r
  29 % Convert to Byte representation\r
  30 \r
  31 %valbin=reshape(valbin,Tb/8,8);\r
  32 dimg=uint8(bit2byte(decr_seq_binary));