diff --git a/rsa/rsa_basic.c b/rsa/rsa_basic.c
index 3e536b8..d152be2 100644
--- a/rsa/rsa_basic.c
+++ b/rsa/rsa_basic.c
@@ -29,8 +29,55 @@ void rsa_enc(bigint_t* data, rsa_publickey_t* key){
 	bigint_expmod_u(data, data, key->exponent, key->modulus);
 }
 
-void rsa_dec(bigint_t* data, rsa_privatekey_t* key){
-	bigint_expmod_u(data, data, key->exponent, key->modulus);
+/*
+(p,q,dp,dq,qinv)
+m1 = c**dp % p
+m2 = c**dq % q
+h = (m1 - m2) * qinv % p
+m = m2 + q * h
+*/
+
+uint8_t rsa_dec_crt_mono(bigint_t* data, rsa_privatekey_t* key){
+	bigint_t m1, m2;
+	m1.wordv = malloc(key->components[0]->length_B * sizeof(bigint_word_t));
+	m2.wordv = malloc(key->components[1]->length_B * sizeof(bigint_word_t));
+	if(!m1.wordv || !m2.wordv){
+		free(m1.wordv);
+		free(m2.wordv);
+		return 1;
+	}
+	bigint_expmod_u(&m1, data, key->components[2], key->components[0]);
+	bigint_expmod_u(&m2, data, key->components[3], key->components[1]);
+	bigint_sub_s(&m1, &m1, &m2);
+	while(BIGINT_NEG_MASK & m1.info){
+		bigint_add_s(&m1, &m1, key->components[0]);
+	}
+	bigint_reduce(&m1, key->components[0]);
+	bigint_mul_u(data, &m1, key->components[4]);
+	bigint_reduce(data, key->components[0]);
+	bigint_mul_u(data, data, key->components[1]);
+	bigint_add_u(data, data, &m2);
+	free(m1.wordv);
+	free(m2.wordv);
+	return 0;
+}
+
+uint8_t rsa_dec(bigint_t* data, rsa_privatekey_t* key){
+	if(key->n == 1){
+		bigint_expmod_u(data, data, key->components[0], key->modulus);
+		return 0;
+	}
+	if(key->n == 5){
+		if (rsa_dec_crt_mono(data, key)){
+			return 3;
+		}
+		return 0;
+	}
+	if(key->n<8 || (key->n-5)%3 != 0){
+		return 1;
+	}
+	//rsa_dec_crt_multi(data, key, (key->n-5)/3);
+	return 2;
 }
 
 void rsa_os2ip(bigint_t* dest, const void* data, uint32_t length_B){
diff --git a/rsa/rsa_basic.h b/rsa/rsa_basic.h
index a8a2dc8..4dc705d 100644
--- a/rsa/rsa_basic.h
+++ b/rsa/rsa_basic.h
@@ -28,20 +28,20 @@ typedef struct {
 } rsa_publickey_t;
 
 typedef struct {
-	bigint_t* exponent;
+	uint8_t n;
 	bigint_t* modulus;
+	bigint_t** components;
 } rsa_privatekey_t;
 
 
 typedef struct {
-	bigint_t* public_exponent;
-	bigint_t* private_exponent;
-	bigint_t* modulus;
+	rsa_privatekey_t priv;
+	rsa_publickey_t  pub;
 } rsa_fullkey_t;
 
 
 void rsa_enc(bigint_t* data, rsa_publickey_t* key);
-void rsa_dec(bigint_t* data, rsa_privatekey_t* key);
+uint8_t rsa_dec(bigint_t* data, rsa_privatekey_t* key);
 void rsa_os2ip(bigint_t* dest, const void* data, uint32_t length_B);
 void rsa_i2osp(void* dest, bigint_t* src, uint16_t* out_length_B);
 
diff --git a/rsa/rsa_pkcs15.c b/rsa/rsa_pkcs15.c
index 781c9ba..359801e 100644
--- a/rsa/rsa_pkcs15.c
+++ b/rsa/rsa_pkcs15.c
@@ -69,7 +69,9 @@ uint8_t rsa_decrypt_pkcs15(void* dest, uint16_t* out_length, const void* src,
 	uint16_t m_length, pad_length=0, idx=0;
 	x.wordv = dest;
 	rsa_os2ip(&x, src, length_B);
+	cli_putstr("\r\ncalling rsa_dec() ...");
 	rsa_dec(&x, key);
+	cli_putstr("\r\nfinished rsa_dec() ...");
 	rsa_i2osp(NULL, &x, &m_length);
 	while(((uint8_t*)x.wordv)[idx]==0 && idx<m_length){
 		++idx;
diff --git a/test_src/main-rsa-test.c b/test_src/main-rsa-test.c
index 7f571cc..c2465ae 100644
--- a/test_src/main-rsa-test.c
+++ b/test_src/main-rsa-test.c
@@ -63,6 +63,42 @@ const uint8_t private_exponent[] = {
 	0xb7, 0x8a, 0xd8, 0x84, 0xf8, 0x4d, 0x5b, 0xeb, 0x04, 0x72, 0x4d, 0xc7, 0x36, 0x9b, 0x31, 0xde,
 	0xf3, 0x7d, 0x0c, 0xf5, 0x39, 0xe9, 0xcf, 0xcd, 0xd3, 0xde, 0x65, 0x37, 0x29, 0xea, 0xd5, 0xd1
 };
+
+const uint8_t p[] = {
+	0xd3, 0x27, 0x37, 0xe7, 0x26, 0x7f, 0xfe, 0x13, 0x41, 0xb2, 0xd5, 0xc0, 0xd1, 0x50, 0xa8, 0x1b,
+	0x58, 0x6f, 0xb3, 0x13, 0x2b, 0xed, 0x2f, 0x8d, 0x52, 0x62, 0x86, 0x4a, 0x9c, 0xb9, 0xf3, 0x0a,
+	0xf3, 0x8b, 0xe4, 0x48, 0x59, 0x8d, 0x41, 0x3a, 0x17, 0x2e, 0xfb, 0x80, 0x2c, 0x21, 0xac, 0xf1,
+	0xc1, 0x1c, 0x52, 0x0c, 0x2f, 0x26, 0xa4, 0x71, 0xdc, 0xad, 0x21, 0x2e, 0xac, 0x7c, 0xa3, 0x9d
+};
+
+const uint8_t q[] = {
+	0xcc, 0x88, 0x53, 0xd1, 0xd5, 0x4d, 0xa6, 0x30, 0xfa, 0xc0, 0x04, 0xf4, 0x71, 0xf2, 0x81, 0xc7,
+	0xb8, 0x98, 0x2d, 0x82, 0x24, 0xa4, 0x90, 0xed, 0xbe, 0xb3, 0x3d, 0x3e, 0x3d, 0x5c, 0xc9, 0x3c,
+	0x47, 0x65, 0x70, 0x3d, 0x1d, 0xd7, 0x91, 0x64, 0x2f, 0x1f, 0x11, 0x6a, 0x0d, 0xd8, 0x52, 0xbe,
+	0x24, 0x19, 0xb2, 0xaf, 0x72, 0xbf, 0xe9, 0xa0, 0x30, 0xe8, 0x60, 0xb0, 0x28, 0x8b, 0x5d, 0x77
+};
+
+const uint8_t dp[] = {
+	0x0e, 0x12, 0xbf, 0x17, 0x18, 0xe9, 0xce, 0xf5, 0x59, 0x9b, 0xa1, 0xc3, 0x88, 0x2f, 0xe8, 0x04,
+	0x6a, 0x90, 0x87, 0x4e, 0xef, 0xce, 0x8f, 0x2c, 0xcc, 0x20, 0xe4, 0xf2, 0x74, 0x1f, 0xb0, 0xa3,
+	0x3a, 0x38, 0x48, 0xae, 0xc9, 0xc9, 0x30, 0x5f, 0xbe, 0xcb, 0xd2, 0xd7, 0x68, 0x19, 0x96, 0x7d,
+	0x46, 0x71, 0xac, 0xc6, 0x43, 0x1e, 0x40, 0x37, 0x96, 0x8d, 0xb3, 0x78, 0x78, 0xe6, 0x95, 0xc1
+};
+
+const uint8_t dq[] = {
+	0x95, 0x29, 0x7b, 0x0f, 0x95, 0xa2, 0xfa, 0x67, 0xd0, 0x07, 0x07, 0xd6, 0x09, 0xdf, 0xd4, 0xfc,
+	0x05, 0xc8, 0x9d, 0xaf, 0xc2, 0xef, 0x6d, 0x6e, 0xa5, 0x5b, 0xec, 0x77, 0x1e, 0xa3, 0x33, 0x73,
+	0x4d, 0x92, 0x51, 0xe7, 0x90, 0x82, 0xec, 0xda, 0x86, 0x6e, 0xfe, 0xf1, 0x3c, 0x45, 0x9e, 0x1a,
+	0x63, 0x13, 0x86, 0xb7, 0xe3, 0x54, 0xc8, 0x99, 0xf5, 0xf1, 0x12, 0xca, 0x85, 0xd7, 0x15, 0x83
+};
+
+const uint8_t qinv[] = {
+	0x4f, 0x45, 0x6c, 0x50, 0x24, 0x93, 0xbd, 0xc0, 0xed, 0x2a, 0xb7, 0x56, 0xa3, 0xa6, 0xed, 0x4d,
+	0x67, 0x35, 0x2a, 0x69, 0x7d, 0x42, 0x16, 0xe9, 0x32, 0x12, 0xb1, 0x27, 0xa6, 0x3d, 0x54, 0x11,
+	0xce, 0x6f, 0xa9, 0x8d, 0x5d, 0xbe, 0xfd, 0x73, 0x26, 0x3e, 0x37, 0x28, 0x14, 0x27, 0x43, 0x81,
+	0x81, 0x66, 0xed, 0x7d, 0xd6, 0x36, 0x87, 0xdd, 0x2a, 0x8c, 0xa1, 0xd2, 0xf4, 0xfb, 0xd8, 0xe1,
+};
+
 /*
 # PKCS#1 v1.5 encryption of 20 random messages with random seeds
 # ---------------------------------------------------------------------------
@@ -94,72 +130,172 @@ const uint8_t encrypted[] = {
 	0xcd, 0xa0, 0x7b, 0xf2, 0x64, 0x89, 0x31, 0x0b, 0xcd, 0x23, 0xb5, 0x28, 0xce, 0xab, 0x3c, 0x31
 };
 
+const uint8_t message1[] = {
+	0x75, 0x0c, 0x40, 0x47, 0xf5, 0x47, 0xe8, 0xe4, 0x14, 0x11, 0x85, 0x65, 0x23, 0x29, 0x8a, 0xc9,
+	0xba, 0xe2, 0x45, 0xef, 0xaf, 0x13, 0x97, 0xfb, 0xe5, 0x6f, 0x9d, 0xd5,
+};
+
+const uint8_t seed1[] = {
+	0xac, 0x47, 0x28, 0xa8, 0x42, 0x8c, 0x1e, 0x52, 0x24, 0x71, 0xa8, 0xdf, 0x73, 0x5a, 0x8e, 0x92,
+	0x92, 0xaf, 0x0d, 0x55, 0xbc, 0xb7, 0x3a, 0x12, 0xac, 0x32, 0xc2, 0x64, 0xf3, 0x88, 0x1c, 0x7c,
+	0x8a, 0x71, 0x0f, 0x70, 0xfe, 0xb1, 0x04, 0x85, 0xc8, 0x37, 0x0f, 0x78, 0x1f, 0xff, 0xd0, 0x21,
+	0x81, 0x6f, 0x05, 0x87, 0x39, 0x76, 0x6d, 0xa0, 0xa9, 0xc9, 0xdb, 0x0e, 0xae, 0x7e, 0x9a, 0x25,
+	0xb6, 0xc4, 0x33, 0x18, 0xd0, 0xca, 0xac, 0x23, 0x65, 0x22, 0xca, 0x31, 0x0f, 0x17, 0xfc, 0x52,
+	0xad, 0x42, 0x29, 0xc8, 0x3a, 0x24, 0xe9, 0xe5, 0x45, 0xeb, 0x35, 0xe9, 0x82, 0x6d, 0x55, 0x9f,
+	0x57
+};
+
+const uint8_t message2[] = {
+0xd9, 0x4a, 0xe0, 0x83, 0x2e, 0x64, 0x45, 0xce, 0x42, 0x33, 0x1c, 0xb0, 0x6d, 0x53, 0x1a, 0x82,
+0xb1, 0xdb, 0x4b, 0xaa, 0xd3, 0x0f, 0x74, 0x6d, 0xc9, 0x16, 0xdf, 0x24, 0xd4, 0xe3, 0xc2, 0x45,
+0x1f, 0xff, 0x59, 0xa6, 0x42, 0x3e, 0xb0, 0xe1, 0xd0, 0x2d, 0x4f, 0xe6, 0x46, 0xcf, 0x69, 0x9d,
+0xfd, 0x81, 0x8c, 0x6e, 0x97, 0xb0, 0x51
+};
+
+const uint8_t seed2[] = {
+0xdd, 0x2d, 0x60, 0xa5, 0xe0, 0x08, 0xeb, 0xe1, 0xd0, 0xbe, 0x6f, 0x60, 0xdb, 0xc4, 0x3f, 0x29,
+0x62, 0xef, 0x50, 0xbf, 0xde, 0x54, 0x2b, 0xbb, 0xe9, 0x8f, 0xed, 0xd1, 0xfe, 0xac, 0x05, 0x7e,
+0x77, 0x1c, 0xf1, 0x5f, 0xc6, 0x32, 0xc8, 0xdb, 0x27, 0x2e, 0x28, 0xd2, 0x9b, 0x57, 0x93, 0xea,
+0x6a, 0xb8, 0x06, 0x21, 0x8c, 0x53, 0x82, 0x39, 0xb9, 0x3a, 0x93, 0x5e, 0x65, 0xd2, 0x44, 0x16,
+0xec, 0x6c, 0x6e, 0x99, 0xae, 0x04
+};
+
+const uint8_t message3[] = {
+0x52, 0xe6, 0x50, 0xd9, 0x8e, 0x7f, 0x2a, 0x04, 0x8b, 0x4f, 0x86, 0x85, 0x21, 0x53, 0xb9, 0x7e,
+0x01, 0xdd, 0x31, 0x6f, 0x34, 0x6a, 0x19, 0xf6, 0x7a, 0x85
+};
+
+const uint8_t seed3[] = {
+0x26, 0x29, 0xa7, 0xaa, 0xc0, 0xc3, 0x90, 0x5e, 0x83, 0x1e, 0xb6, 0x02, 0x38, 0x8c, 0x54, 0x5a,
+0xf5, 0x54, 0xb9, 0x6b, 0x2a, 0xe5, 0x15, 0x32, 0xe9, 0xcc, 0xdb, 0x89, 0x72, 0xef, 0x30, 0xb6,
+0x4a, 0x2f, 0x98, 0xc6, 0x95, 0x29, 0x7a, 0x01, 0xc5, 0x81, 0x2a, 0x2c, 0x40, 0x15, 0x82, 0xf3,
+0x7b, 0x14, 0x4a, 0x3e, 0x90, 0xe5, 0x9d, 0x81, 0xb6, 0x90, 0x39, 0xc6, 0x4b, 0x84, 0x4b, 0x02,
+0x8c, 0x10, 0x5c, 0x8e, 0x68, 0x36, 0x15, 0xaf, 0xb6, 0x58, 0xb6, 0xc4, 0xd9, 0xf3, 0x82, 0x38,
+0xa7, 0x63, 0x01, 0xbb, 0x14, 0x44, 0x91, 0x13, 0xb6, 0x9d, 0xe1, 0x26, 0x04, 0x5e, 0x26, 0xf1,
+0x3e, 0xe6, 0xd7
+};
+
 rsa_publickey_t pub_key;
 rsa_privatekey_t priv_key;
 
+void load_priv_conventional(void){
+	bigint_t *epriv;
+	epriv = malloc(sizeof(bigint_t));
+	if(!epriv){
+		cli_putstr("\r\nERROR: OOM!");
+		return;
+	}
+	epriv->length_B = (sizeof(private_exponent) + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
+	epriv->wordv =  malloc(epriv->length_B * sizeof(bigint_word_t));
+	if(!epriv->wordv){
+		cli_putstr("\r\nERROR: OOM!");
+		return;
+	}
+	memcpy(epriv->wordv, private_exponent, sizeof(private_exponent));
+	priv_key.components = malloc(sizeof(bigint_t*));
+	priv_key.components[0] = epriv;
+	priv_key.n = 1;
+	bigint_changeendianess(epriv);
+	bigint_adjust(epriv);
+}
+
+
+void load_priv_crt_mono(void){
+	bigint_t **v;
+	const uint8_t *bv[5] = {p,q,dp,dq,qinv};
+	uint16_t sv[5] = {sizeof(p), sizeof(q), sizeof(dp), sizeof(dq), sizeof(qinv)};
+	uint8_t i;
+	v = malloc(5 * sizeof(bigint_t));
+	if(!v){
+		cli_putstr("\r\nERROR: OOM!");
+		return;
+	}
+	priv_key.components = malloc(5*sizeof(bigint_t*));
+	if(!priv_key.components){
+		cli_putstr("\r\nERROR: OOM!");
+		return;
+	}
+	priv_key.n = 5;
+	for(i=0; i<5; ++i){
+		v[i] = malloc(sizeof(bigint_t));
+		v[i]->info = 0;
+		v[i]->length_B = (sv[i] + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
+		v[i]->wordv = calloc(v[i]->length_B , sizeof(bigint_word_t));
+		if(!v[i]->wordv){
+			cli_putstr("\r\nERROR: OOM!");
+			return;
+		}
+		memcpy(v[i]->wordv, bv[i], sv[i]);
+		bigint_changeendianess(v[i]);
+		bigint_adjust(v[i]);
+		priv_key.components[i] = v[i];
+	}
+}
+
+
 void load_fix_rsa(void){
-	bigint_t *m, *epub, *epriv;
+	bigint_t *m, *epub;
 	m = malloc(sizeof(bigint_t));
 	epub = malloc(sizeof(bigint_t));
-	epriv = malloc(sizeof(bigint_t));
-	if(!m || !epub || !epriv){
+	if(!m || !epub){
 		cli_putstr("\r\nOOM!\r\n");
 		return;
 	}
 
 	m->length_B = (sizeof(modulus) + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
 	epub->length_B = (sizeof(public_exponent) + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
-	epriv->length_B = (sizeof(private_exponent) + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
 
 	m->wordv = malloc(m->length_B * sizeof(bigint_word_t));
 	epub->wordv = malloc(epub->length_B * sizeof(bigint_word_t));
-	epriv->wordv =  malloc(epriv->length_B * sizeof(bigint_word_t));
 
-	if(!m->wordv || !epub->wordv || !epriv->wordv){
+	if(!m->wordv || !epub->wordv){
 		cli_putstr("\r\nOOM!\r\n");
 		return;
 	}
 
 	memcpy(m->wordv, modulus, sizeof(modulus));
 	memcpy(epub->wordv, public_exponent, sizeof(public_exponent));
-	memcpy(epriv->wordv, private_exponent, sizeof(private_exponent));
 
 	pub_key.modulus = priv_key.modulus = m;
 	pub_key.exponent = epub;
-	priv_key.exponent = epriv;
 
 	bigint_changeendianess(m);
 	bigint_adjust(m);
 	bigint_changeendianess(epub);
 	bigint_adjust(epub);
-	bigint_changeendianess(epriv);
-	bigint_adjust(epriv);
 
+//	load_priv_conventional();
+	load_priv_crt_mono();
 }
 
+
+#define MSG message3
+#define SEED seed3
+
 void quick_test(void){
 	uint8_t *ciphertext, *plaintext, rc;
 	uint16_t clen, plen;
 	ciphertext = malloc(clen = pub_key.modulus->length_B * sizeof(bigint_word_t));
 	plaintext = malloc(pub_key.modulus->length_B * sizeof(bigint_word_t));
-	memcpy(ciphertext, message, sizeof(message));
-	cli_putstr("\r\nplaintext:\r\n");
-	cli_hexdump_block(ciphertext, sizeof(message), 4, 8);
-	rc = rsa_encrypt_pkcs15(ciphertext, &clen, message, sizeof(message), &pub_key, seed);
+//	memcpy(ciphertext, message1, sizeof(message1));
+	cli_putstr("\r\nplaintext:");
+	cli_hexdump_block(MSG, sizeof(MSG), 4, 8);
+	rc = rsa_encrypt_pkcs15(ciphertext, &clen, MSG, sizeof(MSG), &pub_key, SEED);
 	if(rc){
 		cli_putstr("\r\nERROR: rsa_encrypt_pkcs15 returned: ");
 		cli_hexdump_byte(rc);
 		return;
 	}
-	cli_putstr("\r\nciphertext:\r\n");
+	cli_putstr("\r\n\r\nciphertext:");
 	cli_hexdump_block(ciphertext, clen, 4, 8);
+	uart_flush(0);
 	rc = rsa_decrypt_pkcs15(plaintext, &plen, ciphertext, clen, &priv_key, NULL);
 	if(rc){
 		cli_putstr("\r\nERROR: rsa_encrypt_pkcs15 returned: ");
 		cli_hexdump_byte(rc);
 		return;
 	}
-	cli_putstr("\r\nplaintext:\r\n");
+	cli_putstr("\r\n\r\nplaintext:");
 	cli_hexdump_block(plaintext, plen, 4, 8);
 	free(ciphertext);
 	free(plaintext);