diff --git a/bn_mp_complement.c b/bn_mp_complement.c
new file mode 100644
index 0000000..256ddea
--- /dev/null
+++ b/bn_mp_complement.c
@@ -0,0 +1,26 @@
+#include "tommath_private.h"
+#ifdef BN_MP_COMPLEMENT_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* b = ~a */
+int mp_complement(const mp_int *a, mp_int *b)
+{
+   int res = mp_neg(a, b);
+   return res == MP_OKAY ? mp_sub_d(b, 1, b) : res;
+}
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
diff --git a/bn_mp_tc_and.c b/bn_mp_tc_and.c
new file mode 100644
index 0000000..0e28ca8
--- /dev/null
+++ b/bn_mp_tc_and.c
@@ -0,0 +1,90 @@
+#include "tommath_private.h"
+#ifdef BN_MP_TC_AND_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* two complement and */
+int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c)
+{
+   int res = MP_OKAY, bits;
+   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
+   mp_int *mx = 0, _mx, acpy, bcpy;
+
+   if (as || bs) {
+      bits = MAX(mp_count_bits(a), mp_count_bits(b));
+      res = mp_init_set_int(&_mx, 1);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      mx = &_mx;
+      res = mp_mul_2d(mx, bits + 1, mx);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      if (as) {
+         res = mp_init(&acpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, a, &acpy);
+         if (res != MP_OKAY) {
+            mp_clear(&acpy);
+            goto end;
+         }
+         a = &acpy;
+      }
+      if (bs) {
+         res = mp_init(&bcpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, b, &bcpy);
+         if (res != MP_OKAY) {
+            mp_clear(&bcpy);
+            goto end;
+         }
+         b = &bcpy;
+      }
+   }
+
+   res = mp_and(a, b, c);
+   s = as & bs;
+
+   if (s && res == MP_OKAY) {
+      res = mp_sub(c, mx, c);
+   }
+
+end:
+   if (a == &acpy) {
+      mp_clear(&acpy);
+   }
+
+   if (b == &bcpy) {
+      mp_clear(&bcpy);
+   }
+
+   if (mx == &_mx) {
+      mp_clear(mx);
+   }
+
+   return res;
+}
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
diff --git a/bn_mp_tc_div_2d.c b/bn_mp_tc_div_2d.c
new file mode 100644
index 0000000..5ea4e38
--- /dev/null
+++ b/bn_mp_tc_div_2d.c
@@ -0,0 +1,36 @@
+#include "tommath_private.h"
+#ifdef BN_MP_TC_DIV_2D_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* two complement right shift */
+int mp_tc_div_2d(const mp_int *a, int b, mp_int *c)
+{
+  int res;
+  if (!mp_isneg(a)) {
+    return mp_div_2d(a, b, c, 0);
+  }
+
+  res = mp_add_d(a, 1, c);
+  if (res != MP_OKAY) {
+    return res;
+  }
+
+  res = mp_div_2d(c, b, c, 0);
+  return res == MP_OKAY ? mp_sub_d(c, 1, c) : res;
+}
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
diff --git a/bn_mp_tc_or.c b/bn_mp_tc_or.c
new file mode 100644
index 0000000..1e7d583
--- /dev/null
+++ b/bn_mp_tc_or.c
@@ -0,0 +1,90 @@
+#include "tommath_private.h"
+#ifdef BN_MP_TC_OR_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* two complement or */
+int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c)
+{
+   int res = MP_OKAY, bits;
+   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
+   mp_int *mx = 0, _mx, acpy, bcpy;
+
+   if (as || bs) {
+      bits = MAX(mp_count_bits(a), mp_count_bits(b));
+      res = mp_init_set_int(&_mx, 1);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      mx = &_mx;
+      res = mp_mul_2d(mx, bits + 1, mx);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      if (as) {
+         res = mp_init(&acpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, a, &acpy);
+         if (res != MP_OKAY) {
+            mp_clear(&acpy);
+            goto end;
+         }
+         a = &acpy;
+      }
+      if (bs) {
+         res = mp_init(&bcpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, b, &bcpy);
+         if (res != MP_OKAY) {
+            mp_clear(&bcpy);
+            goto end;
+         }
+         b = &bcpy;
+      }
+   }
+
+   res = mp_or(a, b, c);
+   s = as | bs;
+
+   if (s && res == MP_OKAY) {
+      res = mp_sub(c, mx, c);
+   }
+
+end:
+   if (a == &acpy) {
+      mp_clear(&acpy);
+   }
+
+   if (b == &bcpy) {
+      mp_clear(&bcpy);
+   }
+
+   if (mx == &_mx) {
+      mp_clear(mx);
+   }
+
+   return res;
+}
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
diff --git a/bn_mp_tc_xor.c b/bn_mp_tc_xor.c
new file mode 100644
index 0000000..be9b9d8
--- /dev/null
+++ b/bn_mp_tc_xor.c
@@ -0,0 +1,90 @@
+#include "tommath_private.h"
+#ifdef BN_MP_TC_XOR_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+
+/* two complement xor */
+int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c)
+{
+   int res = MP_OKAY, bits;
+   int as = mp_isneg(a), bs = mp_isneg(b), s = 0;
+   mp_int *mx = 0, _mx, acpy, bcpy;
+
+   if (as || bs) {
+      bits = MAX(mp_count_bits(a), mp_count_bits(b));
+      res = mp_init_set_int(&_mx, 1);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      mx = &_mx;
+      res = mp_mul_2d(mx, bits + 1, mx);
+      if (res != MP_OKAY) {
+         goto end;
+      }
+
+      if (as) {
+         res = mp_init(&acpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, a, &acpy);
+         if (res != MP_OKAY) {
+            mp_clear(&acpy);
+            goto end;
+         }
+         a = &acpy;
+      }
+      if (bs) {
+         res = mp_init(&bcpy);
+         if (res != MP_OKAY) {
+            goto end;
+         }
+
+         res = mp_add(mx, b, &bcpy);
+         if (res != MP_OKAY) {
+            mp_clear(&bcpy);
+            goto end;
+         }
+         b = &bcpy;
+      }
+   }
+
+   res = mp_xor(a, b, c);
+   s = as ^ bs;
+
+   if (s && res == MP_OKAY) {
+      res = mp_sub(c, mx, c);
+   }
+
+end:
+   if (a == &acpy) {
+      mp_clear(&acpy);
+   }
+
+   if (b == &bcpy) {
+      mp_clear(&bcpy);
+   }
+
+   if (mx == &_mx) {
+      mp_clear(mx);
+   }
+
+   return res;
+}
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
diff --git a/demo/demo.c b/demo/demo.c
index 4f32072..ff67fcc 100644
--- a/demo/demo.c
+++ b/demo/demo.c
@@ -261,6 +261,127 @@ int main(void)
       }
    }
 
+   // test mp_complement
+   printf("\n\nTesting: mp_complement");
+   for (i = 0; i < 1000; ++i) {
+      int l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&a, labs(l));
+      if (l < 0)
+         mp_neg(&a, &a);
+      mp_complement(&a, &b);
+
+      l = ~l;
+      mp_set_int(&c, labs(l));
+      if (l < 0)
+         mp_neg(&c, &c);
+
+      if (mp_cmp(&b, &c) != MP_EQ) {
+         printf("\nmp_complement() bad result!");
+         return EXIT_FAILURE;
+      }
+   }
+
+   // test mp_tc_div_2d
+   printf("\n\nTesting: mp_tc_div_2d");
+   for (i = 0; i < 1000; ++i) {
+      int l, m;
+
+      l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&a, labs(l));
+      if (l < 0)
+         mp_neg(&a, &a);
+
+      m = rand() % 32;
+
+      mp_set_int(&d, labs(l >> m));
+      if ((l >> m) < 0)
+         mp_neg(&d, &d);
+
+      mp_tc_div_2d(&a, m, &b);
+      if (mp_cmp(&b, &d) != MP_EQ) {
+         printf("\nmp_tc_div_2d() bad result!");
+         return EXIT_FAILURE;
+      }
+   }
+
+   // test mp_tc_xor
+   printf("\n\nTesting: mp_tc_or");
+   for (i = 0; i < 1000; ++i) {
+      int l, m;
+
+      l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&a, labs(l));
+      if (l < 0)
+         mp_neg(&a, &a);
+
+      m = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&b, labs(m));
+      if (m < 0)
+         mp_neg(&b, &b);
+
+      mp_set_int(&d, labs(l ^ m));
+      if ((l ^ m) < 0)
+         mp_neg(&d, &d);
+
+      mp_tc_xor(&a, &b, &c);
+      if (mp_cmp(&c, &d) != MP_EQ) {
+         printf("\nmp_tc_xor() bad result!");
+         return EXIT_FAILURE;
+      }
+   }
+
+   // test mp_tc_or
+   printf("\n\nTesting: mp_tc_or");
+   for (i = 0; i < 1000; ++i) {
+      int l, m;
+
+      l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&a, labs(l));
+      if (l < 0)
+         mp_neg(&a, &a);
+
+      m = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&b, labs(m));
+      if (m < 0)
+         mp_neg(&b, &b);
+
+      mp_set_int(&d, labs(l | m));
+      if ((l | m) < 0)
+         mp_neg(&d, &d);
+
+      mp_tc_or(&a, &b, &c);
+      if (mp_cmp(&c, &d) != MP_EQ) {
+         printf("\nmp_tc_or() bad result!");
+         return EXIT_FAILURE;
+      }
+   }
+
+   // test mp_tc_and
+   printf("\n\nTesting: mp_tc_and");
+   for (i = 0; i < 1000; ++i) {
+      int l, m;
+
+      l = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&a, labs(l));
+      if (l < 0)
+         mp_neg(&a, &a);
+
+      m = (rand() * rand() + 1) * (rand() % 1 ? -1 : 1);
+      mp_set_int(&b, labs(m));
+      if (m < 0)
+         mp_neg(&b, &b);
+
+      mp_set_int(&d, labs(l & m));
+      if ((l & m) < 0)
+         mp_neg(&d, &d);
+
+      mp_tc_and(&a, &b, &c);
+      if (mp_cmp(&c, &d) != MP_EQ) {
+         printf("\nmp_tc_and() bad result!");
+         return EXIT_FAILURE;
+      }
+   }
+
    // test mp_get_int
    printf("\n\nTesting: mp_get_int");
    for (i = 0; i < 1000; ++i) {
diff --git a/tommath.h b/tommath.h
index 795cf10..c048777 100644
--- a/tommath.h
+++ b/tommath.h
@@ -292,8 +292,23 @@ int mp_or(const mp_int *a, const mp_int *b, mp_int *c);
 /* c = a AND b */
 int mp_and(const mp_int *a, const mp_int *b, mp_int *c);
 
+/* c = a XOR b (two complement) */
+int mp_tc_xor(const mp_int *a, const mp_int *b, mp_int *c);
+
+/* c = a OR b (two complement) */
+int mp_tc_or(const mp_int *a, const mp_int *b, mp_int *c);
+
+/* c = a AND b (two complement) */
+int mp_tc_and(const mp_int *a, const mp_int *b, mp_int *c);
+
+/* right shift (two complement) */
+int mp_tc_div_2d(const mp_int *a, int b, mp_int *c);
+
 /* ---> Basic arithmetic <--- */
 
+/* b = ~a */
+int mp_complement(const mp_int *a, mp_int *b);
+
 /* b = -a */
 int mp_neg(const mp_int *a, mp_int *b);