private void button3_Click(object sender, EventArgs e)
{
Stopwatch d1 = new Stopwatch();
LFSR obj1 = new LFSR();
obj1.TapPosIndx = (int)nudMaskSize.Value;
if (textBox1.Text.Length > 10)
{
MessageBox.Show("please enter an initial seed less than 10 characters");
}
else
{
string seed = ImageOperations.AlphanumericSeed(textBox1.Text);
obj1.Seed = Convert.ToInt64(seed, 2); //5adet el string as bits where 2 means binary
int SeedLength = (textBox1.Text.Length * 6);
d1.Start();
ImageMatrix = ImageOperations.Encryption(ImageMatrix, ref obj1.Seed, obj1.TapPosIndx, SeedLength);
d1.Stop();
ImageOperations.DisplayImage(ImageMatrix, pictureBox2);
MessageBox.Show("RunTime = " + Convert.ToString(d1.Elapsed.TotalMinutes));
}
}
public static String FindValues(int pos, String Data)
{
//String BinaryData = Convert.ToString(System.Convert.ToInt32(valueByte), 2);
LFSR a = new LFSR(Data, pos);
for (int i = 1; i < Data.Length; ++i)
{
a.Shift();
}
String temp = Convert.ToInt32(a.Registry, 2).ToString();
return(temp);
}
public static byte GeneratingBits(ref long seed, int tap, int SeedLength)
{
LFSR Register = new LFSR();
Register.Seed = seed; //Initial value of the LFSR entered by user
for (int i = 0; i < 8; i++)
{
Register.One = Register.One << SeedLength; //Shiftting the One Variable until it reaches the end of the Initial Seed
Register.LeftMostBit = (Register.One & Register.Seed); //ANDing the One with the leftMostBit of the initial seed to know the value of it.
Register.LeftMostBit = Register.LeftMostBit >> SeedLength; //Getting the LeftMostBit's vale
Register.One = 1; //Re-Initializing the One Variable.
Register.One = Register.One << tap; //Shiftting the One Variable until it reaches to the tap Position
Register.TapPosValue = (Register.One & Register.Seed); //ANDing the One with the Tap Position's Value to know it.
Register.TapPosValue = Register.TapPosValue >> tap; //Getting the Tap Position 's Value.
Register.One = 1; //Re-Initializing the One Variable.
Register.XORedValue = (Register.LeftMostBit ^ Register.TapPosValue); //XORing the LeftMostBit with the TapPosition's Value to get
//the new bit.
Register.Key[i] = Register.XORedValue; //Starting to fill the 8-bit Key
Register.Seed = Register.Seed << 1; //Shift the seed one step to the left
Register.Seed = (Register.Seed | Register.XORedValue); //Setting the new Register Seed.
Register.One = 1; //Re-Initializing the One Variable for the next Loop.
seed = Register.Seed;
}
// Converting the Key Array into 1 BYTE to XOR it with the pixel component.
int index = 8 - Register.Key.Length;
byte res = 0;
foreach (int i in Register.Key)
{
if (i == 1)
{
res |= (byte)(1 << (7 - index));
}
index++;
}
return(res);
}
private void button1_Click(object sender, EventArgs e)
{
Stopwatch d1 = new Stopwatch();
LFSR obj1 = new LFSR();
obj1.TapPosIndx = (int)nudMaskSize.Value;
obj1.Seed = Convert.ToInt64(textBox1.Text, 2); //5adet el string as bits where 2 means binary
int SeedLength = textBox1.Text.Length - 1;
d1.Start();
ImageMatrix = ImageOperations.Encryption(ImageMatrix, ref obj1.Seed, obj1.TapPosIndx, SeedLength);
d1.Stop();
ImageOperations.DisplayImage(ImageMatrix, pictureBox2);
MessageBox.Show("RunTime = " + Convert.ToString(d1.Elapsed.TotalMinutes));
} //Encryption & decryption
//This function Encrypt or Decrypt the image
//O(N^2)
public bool EncDec(string seed, int tap)
{
LFSR lf = new LFSR(seed, tap);
int R, G, B, oldBlue, oldGreen, oldRed;
unsafe
{
// locking the bits in order to start making operations on them
BitmapData bitmapData = img.LockBits(new Rectangle(0, 0, img.Width, img.Height), ImageLockMode.ReadWrite, img.PixelFormat);
int bytesPerPixel = System.Drawing.Bitmap.GetPixelFormatSize(img.PixelFormat) / 8;
int heightInPixels = bitmapData.Height;
int widthInBytes = bitmapData.Width * bytesPerPixel;
byte * ptrFirstPixel = (byte *)bitmapData.Scan0;
for (int y = 0; y < heightInPixels; y++)
{
byte *currentLine = ptrFirstPixel + (y * bitmapData.Stride); // A pointer that points on each line
for (int x = 0; x < widthInBytes; x = x + bytesPerPixel)
{
//Generate 8bits for each color
R = (int)lf.Kstep(8);
G = (int)lf.Kstep(8);
B = (int)lf.Kstep(8);
oldBlue = currentLine[x];
oldGreen = currentLine[x + 1];
oldRed = currentLine[x + 2];
// Generate and set the new pixel value
currentLine[x] = (byte)(oldBlue ^ B);
currentLine[x + 1] = (byte)(oldGreen ^ G);
currentLine[x + 2] = (byte)(oldRed ^ R);
}
}
//Unlocking the bits
img.UnlockBits(bitmapData);
}
return(true);
}
public static RGBPixel[,] Encryption(RGBPixel[,] ImageMatrix, ref long seed, int tap, int SeedLength)
{
int width = GetWidth(ImageMatrix);
int height = GetHeight(ImageMatrix);
byte Key = 0;
RGBPixel[,] EncreptedImage = new RGBPixel[height, width];
for (int i = 0; i < height; i++)
{
for (int j = 0; j < width; j++)
{
Key = LFSR.GeneratingBits(ref seed, tap, SeedLength);
EncreptedImage[i, j].red = (byte)(ImageMatrix[i, j].red ^ Key);
Key = LFSR.GeneratingBits(ref seed, tap, SeedLength);
EncreptedImage[i, j].green = (byte)(ImageMatrix[i, j].green ^ Key);
Key = LFSR.GeneratingBits(ref seed, tap, SeedLength);
EncreptedImage[i, j].blue = (byte)(ImageMatrix[i, j].blue ^ Key);
}
}
return(EncreptedImage);
}
