src/ScharedSecret.java

   1 import java.sql.Time;
   2 import java.util.Random;
   3
   4 public class ScharedSecret {
   5         static Random rand=new Random();
   6
   7         public static int r10(){
   8                 return rand.nextInt(10);
   9         }
  10
  11         public static int[] encodeBit(boolean bit){
  12                 int threshold=22;
  13                 int dist=3;
  14
  15                 int low = threshold-dist;
  16                 int high = threshold+dist;
  17
  18                 int d1,d2,d3,d4,d5;
  19                 //System.out.println("\nbit: "+(bit?1:0));
  20                         if (bit){
  21                                 //System.out.println("bounds: ["+threshold+"..."+high+"]");
  22                                 d1=r10();
  23                                 while(d1+18<threshold) d1=r10();
  24                                 //System.out.println("d1 = "+d1);
  25
  26                                 d2=r10();
  27                                 while (d1+d2+9<threshold||d1+d2>high) d2=r10();
  28                                 //System.out.println("d2 = "+d2);
  29
  30                                 d3=r10();
  31                                 while (d1+d2+d3<threshold||d1+d2+d3>high)d3=r10();
  32                                 //System.out.println("d3 = "+d3);
  33
  34                                 d4=r10();
  35                                 while (d1+d2+d3+d4 > high) d4=r10();
  36                                 //System.out.println("d4 = "+d4);
  37
  38                                 d5=r10();
  39                                 while (d1+d2+d3+d4+d5 > high) d5=r10();
  40                                 //System.out.println("d5 = "+d5);
  41
  42
  43                         } else {
  44                                 //System.out.println("bounds: ["+low+"..."+threshold+"]");
  45                                 d1=r10();
  46                                 while(d1+18<low) d1=r10();
  47                                 //System.out.println("d1 = "+d1);
  48
  49                                 d2=r10();
  50                                 while (d1+d2+9<low) d2=r10();
  51                                 //System.out.println("d2 = "+d2);
  52
  53                                 d3=r10();
  54                                 while (d1+d2+d3>threshold||d1+d2+d3<low)d3=r10();
  55                                 //System.out.println("d3 = "+d3);
  56
  57                                 d4=r10();
  58                                 while (d1+d2+d3+d4>threshold||d1+d2+d3+d4<low) d4=r10();
  59                                 //System.out.println("d4 = "+d4);
  60
  61                                 d5=r10();
  62                                 while (d1+d2+d3+d4+d5 > threshold||d1+d2+d3+d4+d5<low) d5=r10();
  63                                 //System.out.println("d5 = "+d5);
  64                         }
  65
  66                         //System.out.println(""+d1+d2+d3+d4+d5+" ("+(d1+d2+d3+d4+d5)+")");
  67                 int[] result = {d1,d2,d3,d4,d5};
  68                 return result;
  69         }
  70
  71         public static String[] encodeChar(char c){
  72                 String binary = Integer.toBinaryString(c & 0xFF);
  73
  74                 while (binary.length()<8) binary='0'+binary;
  75                 System.out.print(binary+" ");
  76                 String code1="";
  77                 String code2="";
  78                 String code3="";
  79                 String code4="";
  80                 String code5="";
  81                 for (int i=0; i<8;i++){
  82                         int[] digits = encodeBit(binary.charAt(i)=='1');
  83                         int index = rand.nextInt(4);
  84                         code1+=digits[index];
  85                         if (index!=4)digits[index]=digits[4]; // move last digit to position of used digit
  86
  87                         index = rand.nextInt(3);
  88                         code2+=digits[index];
  89                         if (index!=3)digits[index]=digits[3]; // move last digit to position of used digit
  90
  91                         index = rand.nextInt(2);
  92                         code3+=digits[index];
  93                         if (index!=2)digits[index]=digits[2]; // move last digit to position of used digit
  94
  95                         index = rand.nextInt(1);
  96                         code4+=digits[index];
  97                         code5+=digits[1-index];
  98                 }
  99                 String[] result = {code1,code2,code3,code4,code5};
 100                 return result;
 101         }
 102
 103         public static void main(String[] args) {
 104                 String secret="gnome-keyring";
 105                 String code1="";
 106                 String code2="";
 107                 String code3="";
 108                 String code4="";
 109                 String code5="";
 110                 System.out.print("  Binary: ");
 111                 for (int i=0; i<secret.length();i++){
 112                         String[] codes = encodeChar(secret.charAt(i));
 113                         code1+=codes[0]+" ";
 114                         code2+=codes[1]+" ";
 115                         code3+=codes[2]+" ";
 116                         code4+=codes[3]+" ";
 117                         code5+=codes[4]+" ";
 118                 }
 119                 System.out.println();
 120                 System.out.println("\nSecret 1: "+code1);
 121                 System.out.println("\nSecret 2: "+code2);
 122                 System.out.println("\nSecret 3: "+code3);
 123                 System.out.println("\nSecret 4: "+code4);
 124                 System.out.println("\nSecret 5: "+code5);
 125                 System.out.print("\nChecksum: ");
 126                 for (int i=0; i<code1.length(); i++){
 127
 128                         if (i%9==8) {
 129                                 System.out.print(" ");
 130                         } else {
 131                                 System.out.print((code1.charAt(i)+code2.charAt(i)+code3.charAt(i)+code4.charAt(i)+code5.charAt(i))>(240+22)?1:0);
 132                         }
 133                 }
 134         }
 135 }