Example #1
0
        internal bool FindTwoFactorsWithFermat( Integer Product, Integer P, Integer Q, ulong MinimumX )
        {
            ECTime StartTime = new ECTime();
            StartTime.SetToNow();

            Integer TestSqrt = new Integer();
            Integer TestSquared = new Integer();
            Integer SqrRoot = new Integer();

            TestSquared.Copy( Product );
            IntMath.Multiply( TestSquared, Product );
            IntMath.SquareRoot( TestSquared, SqrRoot );
            TestSqrt.Copy( SqrRoot );
            IntMath.DoSquare( TestSqrt );
            // IntMath.Multiply( TestSqrt, SqrRoot );
            if( !TestSqrt.IsEqual( TestSquared ))
              throw( new Exception( "The square test was bad." ));

            // Some primes:
            // 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97,
            // 101, 103, 107

            P.SetToZero();
            Q.SetToZero();
            Integer TestX = new Integer();
            SetupQuadResArray( Product );

            ulong BaseTo37 = QuadResBigBase * 29UL * 31UL * 37UL;
            // ulong BaseTo31 = QuadResBigBase * 29UL * 31UL;
            ulong ProdModTo37 = IntMath.GetMod64( Product, BaseTo37 );
            // ulong ProdModTo31 = IntMath.GetMod64( Product, BaseTo31 );
            for( ulong BaseCount = 0; BaseCount < (29 * 31 * 37); BaseCount++ )
              {
              if( (BaseCount & 0xF) == 0 )
            Worker.ReportProgress( 0, "Find with Fermat BaseCount: " + BaseCount.ToString() );

              if( Worker.CancellationPending )
            return false;

              ulong Base = (BaseCount + 1) * QuadResBigBase; // BaseCount times 223,092,870.
              if( Base < MinimumX )
            continue;

              Base = BaseCount * QuadResBigBase; // BaseCount times 223,092,870.
              for( uint Count = 0; Count < QuadResArrayLast; Count++ )
            {
            // The maximum CountPart can be is just under half the size of
            // the Product. (Like if Y - X was equal to 1, and Y + X was
            // equal to the Product.)  If it got anywhere near that big it
            // would be inefficient to try and find it this way.
            ulong CountPart = Base + QuadResArray[Count];
            ulong Test = ProdModTo37 + (CountPart * CountPart);
            // ulong Test = ProdModTo31 + (CountPart * CountPart);
            Test = Test % BaseTo37;
            // Test = Test % BaseTo31;
            if( !IntegerMath.IsQuadResidue29( Test ))
              continue;

            if( !IntegerMath.IsQuadResidue31( Test ))
              continue;

            if( !IntegerMath.IsQuadResidue37( Test ))
              continue;

            ulong TestBytes = (CountPart & 0xFFFFF);
            TestBytes *= (CountPart & 0xFFFFF);
            ulong ProdBytes = Product.GetD( 1 );
            ProdBytes <<= 8;
            ProdBytes |= Product.GetD( 0 );

            uint FirstBytes = (uint)(TestBytes + ProdBytes);
            if( !IntegerMath.FirstBytesAreQuadRes( FirstBytes ))
              {
              // Worker.ReportProgress( 0, "First bytes aren't quad res." );
              continue;
              }

            TestX.SetFromULong( CountPart );
            IntMath.MultiplyULong( TestX, CountPart );
            TestX.Add( Product );

            // uint Mod37 = (uint)IntMath.GetMod32( TestX, 37 );
            // if( !IntegerMath.IsQuadResidue37( Mod37 ))
              // continue;

            // Do more of these tests with 41, 43, 47...
            // if( !IntegerMath.IsQuadResidue41( Mod37 ))
              // continue;

            // Avoid doing this square root at all costs.
            if( IntMath.SquareRoot( TestX, SqrRoot ))
              {
              Worker.ReportProgress( 0, " " );
              if( (CountPart & 1) == 0 )
            Worker.ReportProgress( 0, "CountPart was even." );
              else
            Worker.ReportProgress( 0, "CountPart was odd." );

              // Found an exact square root.
              // P + (CountPart * CountPart) = Y*Y
              // P = (Y + CountPart)Y - CountPart)

              P.Copy( SqrRoot );
              Integer ForSub = new Integer();
              ForSub.SetFromULong( CountPart );
              IntMath.Subtract( P, ForSub );

              // Make Q the bigger one and put them in order.
              Q.Copy( SqrRoot );
              Q.AddULong( CountPart );

              if( P.IsOne() || Q.IsOne())
            {
            // This happens when testing with small primes.
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, "Went all the way to 1 in FindTwoFactorsWithFermat()." );
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, " " );
            P.SetToZero(); // It has no factors.
            Q.SetToZero();
            return true; // Tested everything, so it's a prime.
            }

              Worker.ReportProgress( 0, "Found P: " + IntMath.ToString10( P ) );
              Worker.ReportProgress( 0, "Found Q: " + IntMath.ToString10( Q ) );
              Worker.ReportProgress( 0, "Seconds: " + StartTime.GetSecondsToNow().ToString( "N1" ));
              Worker.ReportProgress( 0, " " );
              throw( new Exception( "Testing this." ));
              // return true; // With P and Q.
              }
            // else
              // Worker.ReportProgress( 0, "It was not an exact square root." );

            }
              }

            // P and Q would still be zero if it never found them.
            return false;
        }
Example #2
0
        internal void MakeRSAKeys()
        {
            int ShowBits = (PrimeIndex + 1) * 32;
            // int TestLoops = 0;

            Worker.ReportProgress( 0, "Making RSA keys." );
            Worker.ReportProgress( 0, "Bits size is: " + ShowBits.ToString());

            // ulong Loops = 0;
            while( true )
              {
              if( Worker.CancellationPending )
            return;

              Thread.Sleep( 1 ); // Give up the time slice.  Let other things on the server run.

              // Make two prime factors.
              // Normally you'd only make new primes when you pay the Certificate
              // Authority for a new certificate.
              if( !MakeAPrime( PrimeP, PrimeIndex, 20 ))
            return;

              IntegerBase TestP = new IntegerBase();
              IntegerBaseMath IntBaseMath = new IntegerBaseMath( IntMath );
              string TestS = IntMath.ToString10( PrimeP );
              IntBaseMath.SetFromString( TestP, TestS );
              string TestS2 = IntBaseMath.ToString10( TestP );
              if( TestS != TestS2 )
            throw( new Exception( "TestS != TestS2 for IntegerBase." ));

              if( Worker.CancellationPending )
            return;

              if( !MakeAPrime( PrimeQ, PrimeIndex, 20 ))
            return;

              if( Worker.CancellationPending )
            return;

              // This is extremely unlikely.
              Integer Gcd = new Integer();
              IntMath.GreatestCommonDivisor( PrimeP, PrimeQ, Gcd );
              if( !Gcd.IsOne())
            {
            Worker.ReportProgress( 0, "They had a GCD: " + IntMath.ToString10( Gcd ));
            continue;
            }

              if( Worker.CancellationPending )
            return;

              // This would never happen since the public key exponent used here
              // is one of the small primes in the array in IntegerMath that it
              // was checked against.  But it does show here in the code that
              // they have to be co-prime to each other.  And in the future it
              // might be found that the public key exponent has to be much larger
              // than the one used here.
              IntMath.GreatestCommonDivisor( PrimeP, PubKeyExponent, Gcd );
              if( !Gcd.IsOne())
            {
            Worker.ReportProgress( 0, "They had a GCD with PubKeyExponent: " + IntMath.ToString10( Gcd ));
            continue;
            }

              if( Worker.CancellationPending )
            return;

              IntMath.GreatestCommonDivisor( PrimeQ, PubKeyExponent, Gcd );
              if( !Gcd.IsOne())
            {
            Worker.ReportProgress( 0, "2) They had a GCD with PubKeyExponent: " + IntMath.ToString10( Gcd ));
            continue;
            }

              // For Modular Reduction.  This only has to be done
              // once, when P and Q are made.
              IntMathNewForP.SetupGeneralBaseArray( PrimeP );
              IntMathNewForQ.SetupGeneralBaseArray( PrimeQ );

              PrimePMinus1.Copy( PrimeP );
              IntMath.SubtractULong( PrimePMinus1, 1 );
              PrimeQMinus1.Copy( PrimeQ );
              IntMath.SubtractULong( PrimeQMinus1, 1 );

              // These checks should be more thorough.

              if( Worker.CancellationPending )
            return;

              Worker.ReportProgress( 0, "The Index of Prime P is: " + PrimeP.GetIndex().ToString() );
              Worker.ReportProgress( 0, "Prime P:" );
              Worker.ReportProgress( 0, IntMath.ToString10( PrimeP ));
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "Prime Q:" );
              Worker.ReportProgress( 0, IntMath.ToString10( PrimeQ ));
              Worker.ReportProgress( 0, " " );

              PubKeyN.Copy( PrimeP );
              IntMath.Multiply( PubKeyN, PrimeQ );

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "PubKeyN:" );
              Worker.ReportProgress( 0, IntMath.ToString10( PubKeyN ));
              Worker.ReportProgress( 0, " " );

              // Euler's Theorem:
              // https://en.wikipedia.org/wiki/Euler's_theorem
              // if x ≡ y (mod φ(n)),
              // then a^x ≡ a^y (mod n).

              // Euler's Phi function (aka Euler's Totient function) is calculated
              // next.

              // PhiN is made from the two factors: (P - 1)(Q - 1)
              // PhiN is: (P - 1)(Q - 1) = PQ - P - Q + 1
              // If I add (P - 1) to PhiN I get:
              // PQ - P - Q + 1 + (P - 1) = PQ - Q.
              // If I add (Q - 1) to that I get:
              // PQ - Q + (Q - 1) = PQ - 1.
              // (P - 1)(Q - 1) + (P - 1) + (Q - 1) = PQ - 1

              // If (P - 1) and (Q - 1) had a larger GCD then PQ - 1 would have
              // that same factor too.

              IntMath.GreatestCommonDivisor( PrimePMinus1, PrimeQMinus1, Gcd );
              Worker.ReportProgress( 0, "GCD of PrimePMinus1, PrimeQMinus1 is: " + IntMath.ToString10( Gcd ));

              if( !Gcd.IsULong())
            {
            Worker.ReportProgress( 0, "This GCD number is too big: " + IntMath.ToString10( Gcd ));
            continue;
            }
              else
            {
            ulong TooBig = Gcd.GetAsULong();
            // How big of a GCD is too big?
            if( TooBig > 1234567 )
              {
              // (P - 1)(Q - 1) + (P - 1) + (Q - 1) = PQ - 1
              Worker.ReportProgress( 0, "This GCD number is bigger than 1234567: " + IntMath.ToString10( Gcd ));
              continue;
              }
            }

              Integer Temp1 = new Integer();

              PhiN.Copy( PrimePMinus1 );
              Temp1.Copy( PrimeQMinus1 );
              IntMath.Multiply( PhiN, Temp1 );

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "PhiN:" );
              Worker.ReportProgress( 0, IntMath.ToString10( PhiN ));
              Worker.ReportProgress( 0, " " );
              if( Worker.CancellationPending )
            return;

              // In RFC 2437 there are commonly used letters/symbols to represent
              // the numbers used.  So the number e is the public exponent.
              // The number e that is used here is called PubKeyExponentUint = 65537.
              // In the RFC the private key d is the multiplicative inverse of
              // e mod PhiN.  Which is mod (P - 1)(Q - 1).  It's called
              // PrivKInverseExponent here.

              if( !IntMath.IntMathNew.FindMultiplicativeInverseSmall( PrivKInverseExponent, PubKeyExponent, PhiN, Worker ))
            return;

              if( PrivKInverseExponent.IsZero())
            continue;

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "PrivKInverseExponent: " + IntMath.ToString10( PrivKInverseExponent ));

              if( Worker.CancellationPending )
            return;

              // In RFC 2437 it defines a number dP which is the multiplicative
              // inverse, mod (P - 1) of e.  That dP is named PrivKInverseExponentDP here.
              Worker.ReportProgress( 0, " " );
              if( !IntMath.IntMathNew.FindMultiplicativeInverseSmall( PrivKInverseExponentDP, PubKeyExponent, PrimePMinus1, Worker ))
            return;

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "PrivKInverseExponentDP: " + IntMath.ToString10( PrivKInverseExponentDP ));
              if( PrivKInverseExponentDP.IsZero())
            continue;

              // PrivKInverseExponentDP is PrivKInverseExponent mod PrimePMinus1.
              Integer Test1 = new Integer();
              Test1.Copy( PrivKInverseExponent );
              IntMath.Divide( Test1, PrimePMinus1, Quotient, Remainder );
              Test1.Copy( Remainder );
              if( !Test1.IsEqual( PrivKInverseExponentDP ))
            throw( new Exception( "Bug. This does not match the definition of PrivKInverseExponentDP." ));

              if( Worker.CancellationPending )
            return;

              // In RFC 2437 it defines a number dQ which is the multiplicative
              // inverse, mod (Q - 1) of e.  That dQ is named PrivKInverseExponentDQ here.
              Worker.ReportProgress( 0, " " );
              if( !IntMath.IntMathNew.FindMultiplicativeInverseSmall( PrivKInverseExponentDQ, PubKeyExponent, PrimeQMinus1, Worker ))
            return;

              if( PrivKInverseExponentDQ.IsZero())
            continue;

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "PrivKInverseExponentDQ: " + IntMath.ToString10( PrivKInverseExponentDQ ));
              if( Worker.CancellationPending )
            return;

              Test1.Copy( PrivKInverseExponent );
              IntMath.Divide( Test1, PrimeQMinus1, Quotient, Remainder );
              Test1.Copy( Remainder );
              if( !Test1.IsEqual( PrivKInverseExponentDQ ))
            throw( new Exception( "Bug. This does not match the definition of PrivKInverseExponentDQ." ));

              // Make a random number to test encryption/decryption.
              Integer ToEncrypt = new Integer();
              int HowManyBytes = PrimeIndex * 4;
              byte[] RandBytes = MakeRandomBytes( HowManyBytes );
              if( RandBytes == null )
            {
            Worker.ReportProgress( 0, "Error making random bytes in MakeRSAKeys()." );
            return;
            }

              if( !ToEncrypt.MakeRandomOdd( PrimeIndex - 1, RandBytes ))
            {
            Worker.ReportProgress( 0, "Error making random number ToEncrypt." );
            return;
            }

              Integer PlainTextNumber = new Integer();
              PlainTextNumber.Copy( ToEncrypt );

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "Before encrypting number: " + IntMath.ToString10( ToEncrypt ));
              Worker.ReportProgress( 0, " " );

              IntMath.IntMathNew.ModularPower( ToEncrypt, PubKeyExponent, PubKeyN, false );
              if( Worker.CancellationPending )
            return;

              Worker.ReportProgress( 0, IntMath.GetStatusString() );

              Integer CipherTextNumber = new Integer();
              CipherTextNumber.Copy( ToEncrypt );

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "Encrypted number: " + IntMath.ToString10( CipherTextNumber ));
              Worker.ReportProgress( 0, " " );

              ECTime DecryptTime = new ECTime();
              DecryptTime.SetToNow();
              IntMath.IntMathNew.ModularPower( ToEncrypt, PrivKInverseExponent, PubKeyN, false );
              Worker.ReportProgress( 0, "Decrypted number: " + IntMath.ToString10( ToEncrypt ));

              if( !PlainTextNumber.IsEqual( ToEncrypt ))
            {
            throw( new Exception( "PlainTextNumber not equal to unencrypted value." ));
            // Because P or Q wasn't really a prime?
            // Worker.ReportProgress( 0, "PlainTextNumber not equal to unencrypted value." );
            // continue;
            }

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "Decrypt time seconds: " + DecryptTime.GetSecondsToNow().ToString( "N2" ));
              Worker.ReportProgress( 0, " " );
              if( Worker.CancellationPending )
            return;

              // Test the standard optimized way of decrypting:
              if( !ToEncrypt.MakeRandomOdd( PrimeIndex - 1, RandBytes ))
            {
            Worker.ReportProgress( 0, "Error making random number in MakeRSAKeys()." );
            return;
            }

              PlainTextNumber.Copy( ToEncrypt );
              IntMath.IntMathNew.ModularPower( ToEncrypt, PubKeyExponent, PubKeyN, false );
              if( Worker.CancellationPending )
            return;

              CipherTextNumber.Copy( ToEncrypt );

              // QInv is the multiplicative inverse of PrimeQ mod PrimeP.
              if( !IntMath.MultiplicativeInverse( PrimeQ, PrimeP, QInv, Worker ))
            throw( new Exception( "MultiplicativeInverse() returned false." ));

              if( QInv.IsNegative )
            throw( new Exception( "This is a bug. QInv is negative." ));

              Worker.ReportProgress( 0, "QInv is: " + IntMath.ToString10( QInv ));

              DecryptWithQInverse( CipherTextNumber,
                           ToEncrypt, // Decrypt it to this.
                           PlainTextNumber, // Test it against this.
                           PubKeyN,
                           PrivKInverseExponentDP,
                           PrivKInverseExponentDQ,
                           PrimeP,
                           PrimeQ,
                           Worker );

              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, "Found the values:" );
              Worker.ReportProgress( 0, "Seconds: " + StartTime.GetSecondsToNow().ToString( "N0" ));
              Worker.ReportProgress( 0, " " );

              Worker.ReportProgress( 1, "Prime1: " + IntMath.ToString10( PrimeP ));
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 1, "Prime2: " + IntMath.ToString10( PrimeQ ));
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 1, "PubKeyN: " + IntMath.ToString10( PubKeyN ));
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 1, "PrivKInverseExponent: " + IntMath.ToString10( PrivKInverseExponent ));

              /*
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, " " );
              Worker.ReportProgress( 0, " " );
              DoCRTTest( PrivKInverseExponent );
              Worker.ReportProgress( 0, "Finished CRT test." );
              Worker.ReportProgress( 0, " " );
              */

              return; // Comment this out to just leave it while( true ) for testing.
              }
        }
Example #3
0
        private void CheckTimer_Tick(object sender, EventArgs e)
        {
            // This timer event only gets called when the server isn't otherwise busy.
            // Even though the timer interval is set to once every 50 milliseconds it
            // doesn't mean it will get called that often.
            // It has TestTime to check on how busy it is.

            if( !IsEnabled )
              return;

            CheckTimer.Stop();
            try // for finally
            {

            try // for catch
            {
            ECTime TestTime = new ECTime();
            TestTime.SetToNow();

            // 100 clients queued up per timer tick is 2,000 per second max,
            // assuming the server isn't busy and the timer events get called that often.
            // But if there were that many clients connecting you'd need more front end
            // servers to handle the I/O.  Or it's a denial of service attack, and you'd
            // need to deal with that.
            for( int Count = 0; Count < 100; Count++ )
              {
              if( !IsEnabled )
            return;

              if( Listener.Pending() )
            QueueConnectedClient();
              else
            break;

              }

            CloseTimedOut();
            if( !IsEnabled )
              return;

            FreeClosed();
            if( !IsEnabled )
              return;

            ProcessOuterMessages();
            if( !IsEnabled )
              return;

            double Seconds = TestTime.GetSecondsToNow();
            if( Seconds > 1.0 )
              {
              ShowStatus( " " );
              ShowStatus( "**************************************************" );
              ShowStatus( "TLS Listener Test time seconds: " + Seconds.ToString( "N0" ));
              ShowStatus( "Test time:: " + TestTime.ToLocalTimeString());
              ShowStatus( "**************************************************" );
              ShowStatus( " " );
              }
            }
            catch( Exception Except )
              {
              ShowStatus( "Exception in CheckTimerTick: \r\n" + Except.Message );
              return;
              }

            }
            finally
              {
              CheckTimer.Start();
              }
        }
Example #4
0
        internal bool DecryptWithQInverse( Integer EncryptedNumber,
                                     Integer DecryptedNumber,
                                     Integer TestDecryptedNumber,
                                     Integer PubKeyN,
                                     Integer PrivKInverseExponentDP,
                                     Integer PrivKInverseExponentDQ,
                                     Integer PrimeP,
                                     Integer PrimeQ,
                                     BackgroundWorker Worker )
        {
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, "Top of DecryptWithQInverse()." );

            // QInv and the dP and dQ numbers are normally already set up before
            // you start your listening socket.
            ECTime DecryptTime = new ECTime();
            DecryptTime.SetToNow();

            // See section 5.1.2 of RFC 2437 for these steps:
            // http://tools.ietf.org/html/rfc2437
            //      2.2 Let m_1 = c^dP mod p.
            //      2.3 Let m_2 = c^dQ mod q.
            //      2.4 Let h = qInv ( m_1 - m_2 ) mod p.
            //      2.5 Let m = m_2 + hq.

            Worker.ReportProgress( 0, "EncryptedNumber: " + IntMath.ToString10( EncryptedNumber ));

            //      2.2 Let m_1 = c^dP mod p.
            TestForDecrypt.Copy( EncryptedNumber );
            IntMathNewForP.ModularPower( TestForDecrypt, PrivKInverseExponentDP, PrimeP, true );
            if( Worker.CancellationPending )
              return false;

            M1ForInverse.Copy( TestForDecrypt );

            //      2.3 Let m_2 = c^dQ mod q.
            TestForDecrypt.Copy( EncryptedNumber );
            IntMathNewForQ.ModularPower( TestForDecrypt, PrivKInverseExponentDQ, PrimeQ, true );

            if( Worker.CancellationPending )
              return false;

            M2ForInverse.Copy( TestForDecrypt );

            //      2.4 Let h = qInv ( m_1 - m_2 ) mod p.

            // How many is optimal to avoid the division?
            int HowManyIsOptimal = (PrimeP.GetIndex() * 3);
            for( int Count = 0; Count < HowManyIsOptimal; Count++ )
              {
              if( M1ForInverse.ParamIsGreater( M2ForInverse ))
            M1ForInverse.Add( PrimeP );
              else
            break;

              }

            if( M1ForInverse.ParamIsGreater( M2ForInverse ))
              {
              M1M2SizeDiff.Copy( M2ForInverse );
              IntMath.Subtract( M1M2SizeDiff, M1ForInverse );
              // Unfortunately this long Divide() has to be done.
              IntMath.Divide( M1M2SizeDiff, PrimeP, Quotient, Remainder );
              Quotient.AddULong( 1 );
              Worker.ReportProgress( 0, "The Quotient for M1M2SizeDiff is: " + IntMath.ToString10( Quotient ));
              IntMath.Multiply( Quotient, PrimeP );
              M1ForInverse.Add( Quotient );
              }

            M1MinusM2.Copy( M1ForInverse );
            IntMath.Subtract( M1MinusM2, M2ForInverse );

            if( M1MinusM2.IsNegative )
              throw( new Exception( "This is a bug. M1MinusM2.IsNegative is true." ));

            if( QInv.IsNegative )
              throw( new Exception( "This is a bug. QInv.IsNegative is true." ));

            HForQInv.Copy( M1MinusM2 );
            IntMath.Multiply( HForQInv, QInv );

            if( HForQInv.IsNegative )
              throw( new Exception( "This is a bug. HForQInv.IsNegative is true." ));

            if( PrimeP.ParamIsGreater( HForQInv ))
              {
              IntMath.Divide( HForQInv, PrimeP, Quotient, Remainder );
              HForQInv.Copy( Remainder );
              }

            //      2.5 Let m = m_2 + hq.
            DecryptedNumber.Copy( HForQInv );
            IntMath.Multiply( DecryptedNumber, PrimeQ );
            DecryptedNumber.Add( M2ForInverse );
            if( !TestDecryptedNumber.IsEqual( DecryptedNumber ))
              throw( new Exception( "!TestDecryptedNumber.IsEqual( DecryptedNumber )." ));

            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, "DecryptedNumber: " + IntMath.ToString10( DecryptedNumber ));
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, "TestDecryptedNumber: " + IntMath.ToString10( TestDecryptedNumber ));
            Worker.ReportProgress( 0, " " );
            Worker.ReportProgress( 0, "Decrypt with QInv time seconds: " + DecryptTime.GetSecondsToNow().ToString( "N2" ));
            Worker.ReportProgress( 0, " " );
            return true;
        }