public string Encode(PublicKey key, string message)
{
string cipherText;
int mLen = message.Length;
if (mLen > key.getK() + 11)
{
throw new MessageTooLongException();
}
BigInteger psLen = key.getK() - mLen - 3;
string ps = "";
char randomByte;
Random random = new Random(1);
for (int i = 0; i < psLen; i++)
{
while ((randomByte = Convert.ToChar(random.Next() % 256)) == '0')
{
;
}
ps += randomByte;
}
string em = "02" + ps + "0" + message;
BigInteger m = OS2IP(em);
m = PowModul(m, key.getE(), key.GetN());
cipherText = I2OSP(m, key.getK());
return(cipherText);
}
public void Start(string cipherText)
{
BigInteger r;
BigInteger previousS;
bool finded;
int i = 0;
while (true)
{
switch (i)
{
case 0:
CheckItems(cipherText);
Intervals.Add(new Interval()
{
Left = 2 * B,
Right = 3 * B - 1
}
);
S0 = S;
break;
case 1:
S = PublicKey.GetN() / (2 * B);
CheckItems(cipherText);
NarrowInterval();
if (CheckIntervals())
{
return;
}
break;
default:
if (Intervals.Count == 1)
{
finded = false;
previousS = S;
r = 2 * (Intervals[0].Right * previousS - 2 * B) / PublicKey.GetN();
while (!finded)
{
S = (2 * B + r * PublicKey.GetN()) / Intervals[0].Right;
rightS = (3 * B + r * PublicKey.GetN()) / Intervals[0].Left;
for (; S < rightS; S++)
{
try
{
CheckItem(cipherText);
}
catch (DecryptionErrorExecption)
{
continue;
}
finded = true;
break;
}
r++;
}
}
else
{
S++;
CheckItems(cipherText);
}
NarrowInterval();
if (CheckIntervals())
{
return;
}
break;
}
i++;
}
}
