kimlik no nuzu hangi algoritmayla ezberliyosunuz

public static bool TcDogrulaV2(string tcKimlikNo)
{
bool returnvalue = false;
if (tcKimlikNo. Length == 11)
{
Int64 ATCNO, BTCNO, TcNo;
long C1,C2,C3, C4, C5,C6,C7,C8, C9,Q1,Q2;

TcNo = Int64.Parse(tcKimlikNo);

ATCNO = TcNo / 100;
BTCNO = TcNo / 100;

C1 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C2 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C3 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C4 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C5 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C6 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C7 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C8 = ATCNO % 10; ATCNO = ATCNO / 10 ;
C9 = ATCNO % 10; ATCNO = ATCNO / 10 ;
Q1 = ((10-((((C1+C3+C5+C7+C9)*3)+(C2+C4+C6+C8))%10))%10);
Q2 = ((10-(((((C2+C4+C6+C8)+Q1)*3)+(C1+C3+C5+C7+C9))%10))%10);

returnvalue = ((BTCNO * 100)+(Q1 * 10)+Q2 == TcNo);
}
return returnvalue;
}