diff --git a/wolfcrypt/src/sp_int.c b/wolfcrypt/src/sp_int.c
index 4ec6e2339..d983e1ed2 100644
--- a/wolfcrypt/src/sp_int.c
+++ b/wolfcrypt/src/sp_int.c
@@ -653,10 +653,17 @@ void sp_rshb(sp_int* a, int n, sp_int* r)
 {
     int i;
     int j;
+    int s = n % SP_WORD_SIZE;
 
-    for (i = n / SP_WORD_SIZE, j = 0; i < a->used-1; i++, j++)
-        r->dp[i] = (a->dp[j] >> n) | (a->dp[j+1] << (SP_WORD_SIZE - n));
-    r->dp[i] = a->dp[j] >> n;
+    if (s == 0) {
+        for (i = n / SP_WORD_SIZE, j = 0; i < a->used-1; i++, j++)
+            r->dp[j] = a->dp[i];
+    }
+    else {
+        for (i = n / SP_WORD_SIZE, j = 0; i < a->used-1; i++, j++)
+            r->dp[j] = (a->dp[i] >> s) | (a->dp[i+1] << (SP_WORD_SIZE - s));
+    }
+    r->dp[j] = a->dp[i] >> s;
     r->used = j + 1;
     sp_clamp(r);
 }
@@ -688,6 +695,59 @@ static void _sp_mul_d(sp_int* a, sp_int_digit n, sp_int* r, int o)
     sp_clamp(r);
 }
 
+/* Divide a two digit number by a digit number and return. (hi | lo) / d
+ *
+ * hi  SP integer digit. High digit.
+ * lo  SP integer digit. Lower digit.
+ * d   SP integer digit. Number to divide by.
+ * returns the division result.
+ */
+static WC_INLINE sp_int_digit sp_div_word(sp_int_digit hi, sp_int_digit lo,
+                                          sp_int_digit d)
+{
+#ifdef WOLFSSL_SP_DIV_WORD_HALF
+    sp_int_digit div = d >> SP_HALF_SIZE;
+    sp_int_digit r;
+    sp_int_digit r2;
+    sp_int_word w = ((sp_int_word)hi << SP_WORD_SIZE) | lo;
+    sp_int_word trial;
+
+    r = hi / div;
+    if (r > SP_HALF_MAX) {
+        r = SP_HALF_MAX;
+    }
+    r <<= SP_HALF_SIZE;
+    trial = r * (sp_int_word)d;
+    while (trial > w) {
+        r -= (sp_int_digit)1 << SP_HALF_SIZE;
+        trial -= (sp_int_word)d << SP_HALF_SIZE;
+    }
+    w -= trial;
+    r2 = ((sp_int_digit)(w >> SP_HALF_SIZE)) / div;
+    trial = r2 * (sp_int_word)d;
+    while (trial > w) {
+        r2--;
+        trial -= d;
+    }
+    w -= trial;
+    r += r2;
+    r2 = ((sp_int_digit)w) / d;
+    r += r2;
+
+    return r;
+#else
+    sp_int_word w;
+    sp_int_digit r;
+
+    w = ((sp_int_word)hi << SP_WORD_SIZE) | lo;
+    w /= d;
+    r = (sp_int_digit)w;
+
+    return r;
+#endif
+}
+
+
 /* Divide a by d and return the quotient in r and the remainder in rem.
  *   r = a / d; rem = a % d
  *
@@ -705,9 +765,6 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
     int done = 0;
     int i;
     int s;
-#ifndef WOLFSSL_SP_DIV_32
-    sp_int_word w = 0;
-#endif
     sp_int_digit dt;
     sp_int_digit t;
 #ifdef WOLFSSL_SMALL_STACK
@@ -721,38 +778,53 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
     sp_int tr[1];
     sp_int trial[1];
 #endif
+#ifdef WOLFSSL_SP_SMALL
+    int c;
+#else
+    int j, o;
+    sp_int_word tw;
+    sp_int_sword sw;
+#endif
 
     if (sp_iszero(d))
         err = MP_VAL;
 
-    ret = sp_cmp(a, d);
-    if (ret == MP_LT) {
-        if (rem != NULL) {
-            sp_copy(a, rem);
+    if (err == MP_OKAY) {
+        ret = sp_cmp(a, d);
+        if (ret == MP_LT) {
+            if (rem != NULL) {
+                sp_copy(a, rem);
+            }
+            if (r != NULL) {
+                sp_set(r, 0);
+            }
+            done = 1;
         }
-        if (r != NULL) {
-            sp_set(r, 0);
+        else if (ret == MP_EQ) {
+            if (rem != NULL) {
+                sp_set(rem, 0);
+            }
+            if (r != NULL) {
+                sp_set(r, 1);
+            #ifdef WOLFSSL_SP_INT_NEGATIVE
+                r->sign = aSign;
+            #endif
+            }
+            done = 1;
         }
-        done = 1;
-    }
-    else if (ret == MP_EQ) {
-        if (rem != NULL) {
-            sp_set(rem, 0);
+        else if (sp_count_bits(a) == sp_count_bits(d)) {
+            /* a is greater than d but same bit length */
+            if (rem != NULL) {
+                sp_sub(a, d, rem);
+            }
+            if (r != NULL) {
+                sp_set(r, 1);
+            #ifdef WOLFSSL_SP_INT_NEGATIVE
+                r->sign = aSign;
+            #endif
+            }
+            done = 1;
         }
-        if (r != NULL) {
-            sp_set(r, 1);
-        }
-        done = 1;
-    }
-    else if (sp_count_bits(a) == sp_count_bits(d)) {
-        /* a is greater than d but same bit length */
-        if (rem != NULL) {
-            sp_sub(a, d, rem);
-        }
-        if (r != NULL) {
-            sp_set(r, 1);
-        }
-        done = 1;
     }
 
 #ifdef WOLFSSL_SMALL_STACK
@@ -790,79 +862,94 @@ static int sp_div(sp_int* a, sp_int* d, sp_int* r, sp_int* rem)
         sp_clear(tr);
         tr->used = sa->used - d->used + 1;
         dt = d->dp[d->used-1];
-#ifndef WOLFSSL_SP_DIV_32
-        for (i = sa->used - 1; i >= d->used; ) {
-            if (sa->dp[i] > dt) {
-                t = (sp_int_digit)-1;
+
+        for (i = d->used - 1; i > 0; i--) {
+            if (sa->dp[sa->used - d->used + i] != d->dp[i]) {
+                break;
+            }
+        }
+        if (sa->dp[sa->used - d->used + i] >= d->dp[i]) {
+            i = sa->used;
+            o = sa->used - d->used;
+            sp_lshb(d, o * SP_WORD_SIZE);
+            sp_sub(sa, d, sa);
+            sp_rshb(d, o * SP_WORD_SIZE, d);
+            sa->used = i;
+            if (r != NULL) {
+                tr->dp[o] = 1;
+            }
+        }
+        for (i = sa->used - 1; i >= d->used; i--) {
+            if (sa->dp[i] == dt) {
+                t = (sp_digit)-1;
             }
             else {
-                w = ((sp_int_word)sa->dp[i] << SP_WORD_SIZE) | sa->dp[i-1];
-                w /= dt;
-                if (w > (sp_int_digit)-1) {
-                    t = (sp_int_digit)-1;
-                }
-                else {
-                    t = (sp_int_digit)w;
-                }
+                t = sp_div_word(sa->dp[i], sa->dp[i-1], dt);
             }
 
-            if (t > 0) {
+#ifdef WOLFSSL_SP_SMALL
+            do {
                 _sp_mul_d(d, t, trial, i - d->used);
-                while (sp_cmp(trial, sa) == MP_GT) {
+                c = _sp_cmp_abs(trial, sa);
+                if (c == MP_GT) {
                     t--;
-                    _sp_mul_d(d, t, trial, i - d->used);
                 }
-                sp_sub(sa, trial, sa);
-                tr->dp[i - d->used] += t;
-                if (tr->dp[i - d->used] < t)
-                    tr->dp[i + 1 - d->used]++;
             }
-            i = sa->used - 1;
-        }
+            while (c == MP_GT);
+
+            sp_sub(sa, trial, sa);
+            tr->dp[i - d->used] += t;
+            if (tr->dp[i - d->used] < t) {
+                tr->dp[i + 1 - d->used]++;
+            }
 #else
-     {
-        sp_int_digit div = (dt >> (SP_WORD_SIZE / 2)) + 1;
-        for (i = sa->used - 1; i >= d->used; ) {
-            t = sa->dp[i] / div;
-            if ((t > 0) && (t << (SP_WORD_SIZE / 2) == 0))
-                t = (sp_int_digit)-1;
-            t <<= SP_WORD_SIZE / 2;
-            if (t == 0) {
-               t = sa->dp[i] << (SP_WORD_SIZE / 2);
-               t += sa->dp[i-1] >> (SP_WORD_SIZE / 2);
-               t /= div;
-            }
-
-            if (t > 0) {
-                _sp_mul_d(d, t, trial, i - d->used);
-                while (sp_cmp(trial, sa) == MP_GT) {
-                    t--;
-                    _sp_mul_d(d, t, trial, i - d->used);
+            o = i - d->used;
+            do {
+                tw = 0;
+                for (j = 0; j < d->used; j++) {
+                    tw += (sp_int_word)d->dp[j] * t;
+                    trial->dp[j] = (sp_int_digit)tw;
+                    tw >>= SP_WORD_SIZE;
+                }
+                trial->dp[j] = (sp_int_digit)tw;
+
+                for (j = d->used; j > 0; j--) {
+                    if (trial->dp[j] != sa->dp[j + o]) {
+                        break;
+                    }
+                }
+                if (trial->dp[j] > sa->dp[j + o]) {
+                    t--;
                 }
-                sp_sub(sa, trial, sa);
-                tr->dp[i - d->used] += t;
-                if (tr->dp[i - d->used] < t)
-                    tr->dp[i + 1 - d->used]++;
             }
-            i = sa->used - 1;
-        }
+            while (trial->dp[j] > sa->dp[j + o]);
 
-        while (sp_cmp(sa, d) != MP_LT) {
-            sp_sub(sa, d, sa);
-            sp_add_d(tr, 1, tr);
-        }
-    }
+            sw = 0;
+            for (j = 0; j <= d->used; j++) {
+                sw += sa->dp[j + o];
+                sw -= trial->dp[j];
+                sa->dp[j + o] = (sp_digit)sw;
+                sw >>= SP_WORD_SIZE;
+            }
+
+            tr->dp[o] += t;
+            if (tr->dp[o] < t) {
+                tr->dp[o + 1]++;
+            }
 #endif
-
-        sp_clamp(tr);
+        }
+        sa->used = i + 1;
 
         if (rem != NULL) {
             if (s != SP_WORD_SIZE)
                 sp_rshb(sa, s, sa);
             sp_copy(sa, rem);
+            sp_clamp(rem);
         }
-        if (r != NULL)
+        if (r != NULL) {
             sp_copy(tr, r);
+            sp_clamp(r);
+        }
     }
 
 #ifdef WOLFSSL_SMALL_STACK
diff --git a/wolfssl/wolfcrypt/sp_int.h b/wolfssl/wolfcrypt/sp_int.h
index df963951c..e3cc191be 100644
--- a/wolfssl/wolfcrypt/sp_int.h
+++ b/wolfssl/wolfcrypt/sp_int.h
@@ -60,6 +60,7 @@
     typedef int32 sp_digit;
     typedef uint32 sp_int_digit;
     typedef uint64 sp_int_word;
+    typedef int64 sp_int_sword;
     #undef SP_WORD_SIZE
     #define SP_WORD_SIZE 32
 #elif !defined(WOLFSSL_SP_ASM)
@@ -67,6 +68,7 @@
     typedef int32_t sp_digit;
     typedef uint32_t sp_int_digit;
     typedef uint64_t sp_int_word;
+    typedef int64_t sp_int_sword;
   #elif SP_WORD_SIZE == 64
     typedef int64_t sp_digit;
     typedef uint64_t sp_int_digit;
@@ -78,6 +80,7 @@
       typedef long int128_t __attribute__ ((mode(TI)));
     #endif
     typedef uint128_t sp_int_word;
+    typedef int128_t sp_int_sword;
   #else
     #error Word size not defined
   #endif
@@ -86,6 +89,7 @@
     typedef uint32_t sp_digit;
     typedef uint32_t sp_int_digit;
     typedef uint64_t sp_int_word;
+    typedef int64_t sp_int_sword;
   #elif SP_WORD_SIZE == 64
     typedef uint64_t sp_digit;
     typedef uint64_t sp_int_digit;
@@ -97,6 +101,7 @@
       typedef long int128_t __attribute__ ((mode(TI)));
     #endif
     typedef uint128_t sp_int_word;
+    typedef int128_t sp_int_sword;
   #else
     #error Word size not defined
   #endif