diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index b07753a..6573f89 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4613,17 +4613,17 @@
 #if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
 static int ecp_mod_p192k1(mbedtls_mpi *);
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p192k1(mbedtls_mpi *);
+int mbedtls_ecp_mod_p192k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
 static int ecp_mod_p224k1(mbedtls_mpi *);
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p224k1(mbedtls_mpi *);
+int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 static int ecp_mod_p256k1(mbedtls_mpi *);
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *);
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #endif
 
 #if defined(ECP_LOAD_GROUP)
@@ -5532,7 +5532,7 @@
  * Fast quasi-reduction modulo P = 2^s - R,
  * with R about 33 bits, used by the Koblitz curves.
  *
- * Write N as A0 + 2^224 A1, return A0 + R * A1.
+ * Write X as A0 + 2^224 A1, return A0 + R * A1.
  */
 #define P_KOBLITZ_R     (8 / sizeof(mbedtls_mpi_uint))            // Limbs in R
 
@@ -5629,81 +5629,95 @@
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t expected_width = 2 * ((192 + biL - 1) / biL);
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, expected_width));
-    ret = mbedtls_ecp_mod_p192k1(N);
+    ret = mbedtls_ecp_mod_p192k1_raw(N->p, expected_width);
 
 cleanup:
     return ret;
 }
 
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p192k1(mbedtls_mpi *N)
+int mbedtls_ecp_mod_p192k1_raw(mbedtls_mpi_uint *X, size_t X_limbs)
 {
     static mbedtls_mpi_uint Rp[] = {
-        MBEDTLS_BYTES_TO_T_UINT_8(0xC9, 0x11, 0x00, 0x00, 0x01, 0x00, 0x00,
-                                  0x00)
+        MBEDTLS_BYTES_TO_T_UINT_8(0xC9, 0x11, 0x00, 0x00,
+                                  0x01, 0x00, 0x00, 0x00)
     };
 
-    return ecp_mod_koblitz(N->p, N->n, Rp, 192);
+    if (X_limbs != 2 * ((192 + biL - 1) / biL)) {
+        return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+
+    return ecp_mod_koblitz(X, X_limbs, Rp, 192);
 }
 
 #endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
 
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
 
+/*
+ * Fast quasi-reduction modulo p224k1 = 2^224 - R,
+ * with R = 2^32 + 2^12 + 2^11 + 2^9 + 2^7 + 2^4 + 2 + 1 = 0x0100001A93
+ */
 static int ecp_mod_p224k1(mbedtls_mpi *N)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t expected_width =  2 * 224 / biL;
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, expected_width));
-    ret = mbedtls_ecp_mod_p224k1(N);
+    ret = mbedtls_ecp_mod_p224k1_raw(N->p, expected_width);
 
 cleanup:
     return ret;
 }
 
-/*
- * Fast quasi-reduction modulo p224k1 = 2^224 - R,
- * with R = 2^32 + 2^12 + 2^11 + 2^9 + 2^7 + 2^4 + 2 + 1 = 0x0100001A93
- */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p224k1(mbedtls_mpi *N)
+int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs)
 {
     static mbedtls_mpi_uint Rp[] = {
-        MBEDTLS_BYTES_TO_T_UINT_8(0x93, 0x1A, 0x00, 0x00, 0x01, 0x00, 0x00,
-                                  0x00)
+        MBEDTLS_BYTES_TO_T_UINT_8(0x93, 0x1A, 0x00, 0x00,
+                                  0x01, 0x00, 0x00, 0x00)
     };
 
-    return ecp_mod_koblitz(N->p, N->n, Rp, 224);
+    if (X_limbs != 2 * 224 / biL) {
+        return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+
+    return ecp_mod_koblitz(X, X_limbs, Rp, 224);
 }
 
 #endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
 
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 
+/*
+ * Fast quasi-reduction modulo p256k1 = 2^256 - R,
+ * with R = 2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1 = 0x01000003D1
+ */
 static int ecp_mod_p256k1(mbedtls_mpi *N)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t expected_width = 2 * ((256 + biL - 1) / biL);
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, expected_width));
-    ret = mbedtls_ecp_mod_p256k1(N);
+    ret = mbedtls_ecp_mod_p256k1_raw(N->p, expected_width);
 
 cleanup:
     return ret;
 }
 
-/*
- * Fast quasi-reduction modulo p256k1 = 2^256 - R,
- * with R = 2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1 = 0x01000003D1
- */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N)
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs)
 {
     static mbedtls_mpi_uint Rp[] = {
-        MBEDTLS_BYTES_TO_T_UINT_8(0xD1, 0x03, 0x00, 0x00, 0x01, 0x00, 0x00,
-                                  0x00)
+        MBEDTLS_BYTES_TO_T_UINT_8(0xD1, 0x03, 0x00, 0x00,
+                                  0x01, 0x00, 0x00, 0x00)
     };
-    return ecp_mod_koblitz(N->p, N->n, Rp, 256);
+
+    if (X_limbs != 2 * ((256 + biL - 1) / biL)) {
+        return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+    }
+
+    return ecp_mod_koblitz(X, X_limbs, Rp, 256);
 }
+
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
 
 #if defined(MBEDTLS_TEST_HOOKS)
diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index 68187ac..aadcdbc 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -171,25 +171,73 @@
 
 #if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
 
-/*
- * Fast quasi-reduction modulo p192k1 = 2^192 - R,
- * with R = 2^32 + 2^12 + 2^8 + 2^7 + 2^6 + 2^3 + 1 = 0x0100001119
+/** Fast quasi-reduction modulo p192k1 = 2^192 - R,
+ * with R = 2^32 + 2^12 + 2^8 + 2^7 + 2^6 + 2^3 + 1 = 0x01000011C9
+ *
+ * \param[in,out]   X       The address of the MPI to be converted.
+ *                          Must have exact limb size that stores a 384-bit MPI
+ *                          (double the bitlength of the modulus).
+ *                          Upon return holds the reduced value which is
+ *                          in range `0 <= X < 2 * N` (where N is the modulus).
+ *                          The bitlength of the reduced value is the same as
+ *                          that of the modulus (192 bits).
+ * \param[in]       X_limbs The length of \p X in limbs.
+ *
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if \p X does not have
+ *                  twice as many limbs as the modulus.
+ * \return          #MBEDTLS_ERR_ECP_ALLOC_FAILED if memory allocation failed.
  */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p192k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p192k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
+
 #if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
 
+/** Fast quasi-reduction modulo p224k1 = 2^224 - R,
+ * with R = 2^32 + 2^12 + 2^11 + 2^9 + 2^7 + 2^4 + 2 + 1 = 0x0100001A93
+ *
+ * \param[in,out]   X       The address of the MPI to be converted.
+ *                          Must have exact limb size that stores a 448-bit MPI
+ *                          (double the bitlength of the modulus).
+ *                          Upon return holds the reduced value which is
+ *                          in range `0 <= X < 2 * N` (where N is the modulus).
+ *                          The bitlength of the reduced value is the same as
+ *                          that of the modulus (224 bits).
+ * \param[in]       X_limbs The length of \p X in limbs.
+ *
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if \p X does not have
+ *                  twice as many limbs as the modulus.
+ * \return          #MBEDTLS_ERR_ECP_ALLOC_FAILED if memory allocation failed.
+ */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p224k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
 
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 
+/** Fast quasi-reduction modulo p256k1 = 2^256 - R,
+ * with R = 2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1 = 0x01000003D1
+ *
+ * \param[in,out]   X       The address of the MPI to be converted.
+ *                          Must have exact limb size that stores a 512-bit MPI
+ *                          (double the bitlength of the modulus).
+ *                          Upon return holds the reduced value which is
+ *                          in range `0 <= X < 2 * N` (where N is the modulus).
+ *                          The bitlength of the reduced value is the same as
+ *                          that of the modulus (256 bits).
+ * \param[in]       X_limbs The length of \p X in limbs.
+ *
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if \p X does not have
+ *                  twice as many limbs as the modulus.
+ * \return          #MBEDTLS_ERR_ECP_ALLOC_FAILED if memory allocation failed.
+ */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
 
diff --git a/scripts/mbedtls_dev/ecp.py b/scripts/mbedtls_dev/ecp.py
index 5f0efcf..c9fb5e5 100644
--- a/scripts/mbedtls_dev/ecp.py
+++ b/scripts/mbedtls_dev/ecp.py
@@ -494,8 +494,8 @@
                    EcpTarget):
     """Test cases for ECP P192K1 fast reduction."""
     symbol = "-"
-    test_function = "ecp_mod_p192k1"
-    test_name = "ecp_mod_p192k1"
+    test_function = "ecp_mod_p_generic_raw"
+    test_name = "ecp_mod_p192k1_raw"
     input_style = "fixed"
     arity = 1
     dependencies = ["MBEDTLS_ECP_DP_SECP192K1_ENABLED"]
@@ -557,13 +557,17 @@
     def is_valid(self) -> bool:
         return True
 
+    def arguments(self):
+        args = super().arguments()
+        return  ["MBEDTLS_ECP_DP_SECP192K1"] + args
+
 
 class EcpP224K1Raw(bignum_common.ModOperationCommon,
                    EcpTarget):
     """Test cases for ECP P224 fast reduction."""
     symbol = "-"
-    test_function = "ecp_mod_p224k1"
-    test_name = "ecp_mod_p224k1"
+    test_function = "ecp_mod_p_generic_raw"
+    test_name = "ecp_mod_p224k1_raw"
     input_style = "fixed"
     arity = 1
     dependencies = ["MBEDTLS_ECP_DP_SECP224K1_ENABLED"]
@@ -582,7 +586,7 @@
         # 2^224 - 1
         "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
 
-        # Maximum canonical P224 multiplication result
+        # Maximum canonical P224K1 multiplication result
         ("fffffffffffffffffffffffffffffffffffffffffffffffdffffcad8"
          "00000000000000000000000000000000000000010000352802c26590"),
 
@@ -626,13 +630,17 @@
     def is_valid(self) -> bool:
         return True
 
+    def arguments(self):
+        args = super().arguments()
+        return  ["MBEDTLS_ECP_DP_SECP224K1"] + args
+
 
 class EcpP256K1Raw(bignum_common.ModOperationCommon,
                    EcpTarget):
     """Test cases for ECP P256 fast reduction."""
     symbol = "-"
-    test_function = "ecp_mod_p256k1"
-    test_name = "ecp_mod_p256k1"
+    test_function = "ecp_mod_p_generic_raw"
+    test_name = "ecp_mod_p256k1_raw"
     input_style = "fixed"
     arity = 1
     dependencies = ["MBEDTLS_ECP_DP_SECP256K1_ENABLED"]
@@ -651,9 +659,13 @@
         # 2^256 - 1
         "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
 
-        # Maximum canonical P256 multiplication result
-        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffdfffff85c0"
-         "00000000000000000000000000000000000000000000001000007a4000e9844"),
+        # Maximum canonical P256K1 multiplication result
+        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffdfffff85c"
+         "000000000000000000000000000000000000000000000001000007a4000e9844"),
+
+        # Test case for overflow during addition
+        ("0000fffffc2f000e90a0c86a0a63234e5ba641f43a7e4aecc4040e67ec850562"
+         "00000000000000000000000000000000000000000000000000000000585674fd"),
 
         # Test case for overflow during addition
         ("0000fffffc2f000e90a0c86a0a63234e5ba641f43a7e4aecc4040e67ec850562"
@@ -694,6 +706,10 @@
     def is_valid(self) -> bool:
         return True
 
+    def arguments(self):
+        args = super().arguments()
+        return  ["MBEDTLS_ECP_DP_SECP256K1"] + args
+
 
 class EcpP448Raw(bignum_common.ModOperationCommon,
                  EcpTarget):
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index e5dddc4..250efcc 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1328,6 +1328,27 @@
             curve_func = &mbedtls_ecp_mod_p521_raw;
             break;
 #endif
+#if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
+        case MBEDTLS_ECP_DP_SECP192K1:
+            limbs = 2 * limbs_N;
+            curve_bits = 192;
+            curve_func = &mbedtls_ecp_mod_p192k1_raw;
+            break;
+#endif
+#if defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
+        case MBEDTLS_ECP_DP_SECP224K1:
+            limbs = 448 / biL;
+            curve_bits = 224;
+            curve_func = &mbedtls_ecp_mod_p224k1_raw;
+            break;
+#endif
+#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
+        case MBEDTLS_ECP_DP_SECP256K1:
+            limbs = 2 * limbs_N;
+            curve_bits = 256;
+            curve_func = &mbedtls_ecp_mod_p256k1_raw;
+            break;
+#endif
         default:
             mbedtls_test_fail("Unsupported curve_id", __LINE__, __FILE__);
             goto exit;
@@ -1355,123 +1376,6 @@
 }
 /* END_CASE */
 
-/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_SECP192K1_ENABLED */
-void ecp_mod_p192k1(char *input_N,
-                    char *input_X,
-                    char *result)
-{
-    mbedtls_mpi X;
-    mbedtls_mpi N;
-    mbedtls_mpi res;
-
-    mbedtls_mpi_init(&X);
-    mbedtls_mpi_init(&N);
-    mbedtls_mpi_init(&res);
-
-    TEST_EQUAL(mbedtls_test_read_mpi(&X,   input_X), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&N,   input_N), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&res, result),  0);
-
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, X.p, X.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, N.p, N.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, res.p, res.n));
-
-    size_t limbs = N.n;
-    size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
-
-    TEST_EQUAL(X.n, 2 * limbs);
-    TEST_EQUAL(res.n, limbs);
-
-    TEST_EQUAL(mbedtls_ecp_mod_p192k1(&X), 0);
-    TEST_EQUAL(mbedtls_mpi_mod_mpi(&X, &X, &N), 0);
-    TEST_LE_U(mbedtls_mpi_core_bitlen(X.p, X.n), 192);
-    ASSERT_COMPARE(X.p, bytes, res.p, bytes);
-
-exit:
-    mbedtls_mpi_free(&X);
-    mbedtls_mpi_free(&N);
-    mbedtls_mpi_free(&res);
-}
-/* END_CASE */
-
-/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_SECP224K1_ENABLED */
-void ecp_mod_p224k1(char *input_N,
-                    char *input_X,
-                    char *result)
-{
-    mbedtls_mpi X;
-    mbedtls_mpi N;
-    mbedtls_mpi res;
-
-    mbedtls_mpi_init(&X);
-    mbedtls_mpi_init(&N);
-    mbedtls_mpi_init(&res);
-
-    TEST_EQUAL(mbedtls_test_read_mpi(&X,   input_X), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&N,   input_N), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&res, result),  0);
-
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, X.p, X.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, N.p, N.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, res.p, res.n));
-
-    size_t limbs = N.n;
-    size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
-
-    TEST_LE_U(X.n, 448 / biL);
-    TEST_EQUAL(res.n, limbs);
-
-    TEST_EQUAL(mbedtls_ecp_mod_p224k1(&X), 0);
-    TEST_EQUAL(mbedtls_mpi_mod_mpi(&X, &X, &N), 0);
-    TEST_LE_U(mbedtls_mpi_core_bitlen(X.p, X.n), 224);
-    ASSERT_COMPARE(X.p, bytes, res.p, bytes);
-
-exit:
-    mbedtls_mpi_free(&X);
-    mbedtls_mpi_free(&N);
-    mbedtls_mpi_free(&res);
-}
-/* END_CASE */
-
-/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_SECP256K1_ENABLED */
-void ecp_mod_p256k1(char *input_N,
-                    char *input_X,
-                    char *result)
-{
-    mbedtls_mpi X;
-    mbedtls_mpi N;
-    mbedtls_mpi res;
-
-    mbedtls_mpi_init(&X);
-    mbedtls_mpi_init(&N);
-    mbedtls_mpi_init(&res);
-
-    TEST_EQUAL(mbedtls_test_read_mpi(&X,   input_X), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&N,   input_N), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&res, result),  0);
-
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, X.p, X.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, N.p, N.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, res.p, res.n));
-
-    size_t limbs = N.n;
-    size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
-
-    TEST_LE_U(X.n, 2 * limbs);
-    TEST_EQUAL(res.n, limbs);
-
-    TEST_EQUAL(mbedtls_ecp_mod_p256k1(&X), 0);
-    TEST_EQUAL(mbedtls_mpi_mod_mpi(&X, &X, &N), 0);
-    TEST_LE_U(mbedtls_mpi_core_bitlen(X.p, X.n), 256);
-    ASSERT_COMPARE(X.p, bytes, res.p, bytes);
-
-exit:
-    mbedtls_mpi_free(&X);
-    mbedtls_mpi_free(&N);
-    mbedtls_mpi_free(&res);
-}
-/* END_CASE */
-
 /* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_CURVE448_ENABLED */
 void ecp_mod_p448(char *input_N,
                   char *input_X,