public long Decrypt(Tuple tuple, Key.PrivateKey key)
{
var a = tuple.a;
var b = tuple.b;
var p = key.P;
var x = key.X;
// q = (a^x)^-1
var q = modular_pow(a, p - 1 - x, p);
var m = (b * q) % p;
return m;
}
public void Encrypt(string fileName, Key.PublicKey key)
{
tuples.Clear();
FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
// Block Message Length based on value of P in key
int blockLength = getBitLength(key.P);
int n_blockLength = blockLength;
// byte to read from file
int n_byte = 8;
int byte_read = fs.ReadByte();
// Message that want to be encrypt
long message = 0;
// Process Message
while (byte_read >= 0)
{
int temp_bit = -1;
while (byte_read >= 0 && message < key.P && n_blockLength > 0)
{
if (n_byte == 0)
{
// Read next byte of file
byte_read = fs.ReadByte();
n_byte = 8;
if (byte_read < 0) break;
}
int bit = (byte_read >> (n_byte - 1)) % 2 == 0 ? 0 : 1;
message = (message << 1 )+ bit;
n_byte--;
n_blockLength--;
}
// if Message more than block or P
if (message >= key.P || n_blockLength < 0)
{
temp_bit = (byte_read >> (n_byte - 1)) % 2 == 0 ? 0 : 1;
message = message >> 1;
}
long k = key.P-2; // Must be random
long a = modular_pow(key.G, k, key.P);
long b = modular_pow(message, key.Y, k, key.P);
Tuple t = new Tuple();
t.a = a;
t.b = b;
tuples.Add(t);
message = 0;
n_blockLength = blockLength;
// if only the temp_bit have any value
if (temp_bit >= 0)
{
message = message << 1 + temp_bit;
n_blockLength--;
}
}
fs.Close();
}
public void Encrypt(string fileName, Key.PublicKey key)
{
tuples.Clear();
FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
// Block Message Length based on value of P in key
int blockLength = getByteLength(key.P);
int n_blockLength = blockLength;
System.Diagnostics.Debug.WriteLine(blockLength);
// byte to read from file
int byte_read = 0;
// Message that want to be encrypt
long message = 0;
// Process Message
while (byte_read >= 0)
{
int temp_byte = -1;
while (byte_read >= 0 && message < key.P && n_blockLength > 0)
{
byte_read = fs.ReadByte();
if (byte_read < 0) break;
message = 256 * message + byte_read;
n_blockLength--;
System.Diagnostics.Debug.WriteLine((char)byte_read);
}
// if Message more than block or P
if (message >= key.P )
{
temp_byte = byte_read;
message = message/256;
}
long k = 1520; // Must be random
long a = modular_pow(key.G, k, key.P);
long b = modular_pow(message, key.Y, k, key.P);
Tuple t = new Tuple();
t.a = a;
t.b = b;
tuples.Add(t);
System.Diagnostics.Debug.WriteLine("process :" + (char)message + "," + message);
//Console.WriteLine(message);
message = 0;
n_blockLength = blockLength;
// if only the temp_bit have any value
if (temp_byte >= 0)
{
message = message*256 + temp_byte;
n_blockLength--;
}
}
System.Diagnostics.Debug.WriteLine("Count Encrypt : " + tuples.Count());
fs.Close();
}
public List<Tuple> ReadTuplesFromFile(string fileName, Key.PrivateKey key)
{
var tuples = new List<Tuple>();
// Read text - init
BinaryReader br = new BinaryReader(File.OpenRead(fileName));
// Get block length
int blockLength = getByteLength(key.P);
int pos = 0;
char currentChar;
string hexString;
while (pos < br.BaseStream.Length)
{
br.ReadChar(); // (
++pos;
currentChar = br.ReadChar();
++pos;
hexString = "";
while (currentChar != ',')
{
hexString += currentChar;
currentChar = br.ReadChar();
++pos;
}
long a = long.Parse(hexString, System.Globalization.NumberStyles.HexNumber);
currentChar = br.ReadChar();
++pos;
hexString = "";
while (currentChar != ')')
{
hexString += currentChar;
currentChar = br.ReadChar();
++pos;
}
long b = long.Parse(hexString, System.Globalization.NumberStyles.HexNumber);
Tuple t = new Tuple();
t.a = a;
t.b = b;
tuples.Add(t);
}
return tuples;
}
