diff --git a/bose_chaudhuri_hocquenghem_encoder.hh b/bose_chaudhuri_hocquenghem_encoder.hh
index fba9422..282f02a 100644
--- a/bose_chaudhuri_hocquenghem_encoder.hh
+++ b/bose_chaudhuri_hocquenghem_encoder.hh
@@ -11,16 +11,78 @@ Copyright 2018 Ahmet Inan <inan@aicodix.de>
 
 namespace CODE {
 
-template <int NR, int FCR, int MSG, typename GF>
+template <int LEN, int MSG>
 class BoseChaudhuriHocquenghemEncoder
 {
+public:
+	static const int N = LEN, K = MSG, NP = N - K;
+	static const int G = ((NP+1)+7)/8;
+	uint8_t generator[G];
+	BoseChaudhuriHocquenghemEncoder(std::initializer_list<int> minimal_polynomials)
+	{
+		// $generator(x) = \prod_i(minpoly_i(x))$
+		int generator_degree = 1;
+		generator[0] = 1;
+		for (int i = 1; i < G; ++i)
+			generator[i] = 0;
+		for (auto m: minimal_polynomials) {
+			int m_degree = 0;
+			while (m>>m_degree)
+				++m_degree;
+			--m_degree;
+			assert(generator_degree + m_degree <= NP + 1);
+			for (int i = generator_degree; i >= 0; --i) {
+				if (!((generator[i/8]>>(i%8))&1))
+					continue;
+				generator[i/8] &= ~(1<<(i%8));
+				generator[i/8] |= (m&1)<<(i%8);
+				for (int j = 1; j <= m_degree; ++j)
+					generator[(i+j)/8] ^= ((m>>j)&1)<<((i+j)%8);
+			}
+			generator_degree += m_degree;
+		}
+		assert(generator_degree == NP + 1);
+		if (0) {
+			std::cerr << "generator =";
+			for (int i = 0; i <= NP; ++i)
+				std::cerr << " " << int((generator[i/8] >> (i%8))&1);
+			std::cerr << std::endl;
+		}
+	}
+	void operator()(uint8_t *code)
+	{
+		// $code = data * x^{NP} + (data * x^{NP}) \mod{generator}$
+		for (int i = 0; i < NP; ++i)
+			code[(K+i)/8] &= ~(128>>((K+i)%8));
+		for (int i = 0; i < K; ++i) {
+			if (((code[i/8]>>(7-i%8))&1) != ((code[K/8]>>(7-K%8))&1)) {
+				for (int j = 1; j < NP; ++j) {
+					code[(K+j-1)/8] &= ~(128>>((K+j-1)%8));
+					code[(K+j-1)/8] |= (((generator[(NP-j)/8]>>((NP-j)%8))^(code[(K+j)/8]>>(7-(K+j)%8)))&1)<<(7-(K+j-1)%8);
+				}
+				code[(N-1)/8] &= ~(128>>((N-1)%8));
+				code[(N-1)/8] |= (generator[0]&1)<<(7-(N-1)%8);
+			} else {
+				for (int j = 1; j < NP; ++j) {
+					code[(K+j-1)/8] &= ~(128>>((K+j-1)%8));
+					code[(K+j-1)/8] |= ((code[(K+j)/8]>>(7-(K+j)%8))&1)<<(7-(K+j-1)%8);
+				}
+				code[(N-1)/8] &= ~(128>>((N-1)%8));
+			}
+		}
+	}
+};
+
+template <int NR, int FCR, int MSG, typename GF>
+class BoseChaudhuriHocquenghemEncoderReference
+{
 public:
 	typedef typename GF::value_type value_type;
 	typedef typename GF::ValueType ValueType;
 	typedef typename GF::IndexType IndexType;
 	static const int N = GF::N, K = MSG, NP = N - K;
 	ValueType generator[NP+1];
-	BoseChaudhuriHocquenghemEncoder(std::initializer_list<int> minimal_polynomials)
+	BoseChaudhuriHocquenghemEncoderReference(std::initializer_list<int> minimal_polynomials)
 	{
 		// $generator(x) = \prod_i(minpoly_i(x))$
 		int generator_degree = 1;
diff --git a/tests/bch_encoder_test.cc b/tests/bch_encoder_test.cc
index e3bd83c..a6ea9ce 100644
--- a/tests/bch_encoder_test.cc
+++ b/tests/bch_encoder_test.cc
@@ -12,9 +12,43 @@ Copyright 2018 Ahmet Inan <inan@aicodix.de>
 int main()
 {
 	if (1) {
+		// NASA INTRO BCH(15, 5) T=3
+		typedef CODE::BoseChaudhuriHocquenghemEncoder<15, 5> BCH;
+		const int L = (BCH::N + 7) / 8;
+		BCH encode({0b10011, 0b11111, 0b00111});
+		uint8_t code[L] = { 0b11001000 };
+		uint8_t target[L] = { 0b11001000, 0b11110100 };
+		encode(code);
+		for (int i = 0; i < L; ++i)
+			assert(code[i] == target[i]);
+	}
+	if (1) {
+		// DVB-S2 FULL BCH(65535, 65343) T=12
+		typedef CODE::BoseChaudhuriHocquenghemEncoder<65535, 65343> BCH;
+		const int L = (BCH::N + 7) / 8;
+		BCH *encode = new BCH({0b10000000000101101, 0b10000000101110011, 0b10000111110111101, 0b10101101001010101, 0b10001111100101111, 0b11111011110110101, 0b11010111101100101, 0b10111001101100111, 0b10000111010100001, 0b10111010110100111, 0b10011101000101101, 0b10001101011100011});
+		uint8_t *target = new uint8_t[L];
+		for (int i = 0; i < L; ++i)
+			target[i] = 0;
+		for (int i = 0, s = 0; i < BCH::K; ++i, s=(s*(s*s*51767+71287)+35149)&0xffffff)
+			target[i/8] |= ((s^=s>>7)&1) << (7-i%8);
+		uint8_t *code = new uint8_t[L];
+		for (int i = 0; i < L; ++i)
+			code[i] = target[i];
+		bool parity[BCH::NP] = { 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0 };
+		for (int i = 0; i < BCH::NP; ++i)
+			target[(BCH::K+i)/8] |= parity[i] << (7-(BCH::K+i)%8);
+		(*encode)(code);
+		for (int i = 0; i < L; ++i)
+			assert(code[i] == target[i]);
+		delete[] target;
+		delete[] code;
+		delete encode;
+	}
+	if (0) {
 		// NASA INTRO BCH(15, 5) T=3
 		typedef CODE::GaloisField<4, 0b10011, uint8_t> GF;
-		typedef CODE::BoseChaudhuriHocquenghemEncoder<6, 1, 5, GF> BCH;
+		typedef CODE::BoseChaudhuriHocquenghemEncoderReference<6, 1, 5, GF> BCH;
 		GF instance;
 		BCH encode({0b10011, 0b11111, 0b00111});
 		uint8_t code[BCH::N] = { 1, 1, 0, 0, 1 };
@@ -23,10 +57,10 @@ int main()
 		for (int i = 0; i < BCH::N; ++i)
 			assert(code[i] == target[i]);
 	}
-	if (1) {
+	if (0) {
 		// DVB-S2 FULL BCH(65535, 65343) T=12
 		typedef CODE::GaloisField<16, 0b10000000000101101, uint16_t> GF;
-		typedef CODE::BoseChaudhuriHocquenghemEncoder<24, 1, 65343, GF> BCH;
+		typedef CODE::BoseChaudhuriHocquenghemEncoderReference<24, 1, 65343, GF> BCH;
 		GF *instance = new GF();
 		BCH *encode = new BCH({0b10000000000101101, 0b10000000101110011, 0b10000111110111101, 0b10101101001010101, 0b10001111100101111, 0b11111011110110101, 0b11010111101100101, 0b10111001101100111, 0b10000111010100001, 0b10111010110100111, 0b10011101000101101, 0b10001101011100011});
 		uint16_t *code = new uint16_t[BCH::N];