diff --git a/src/crypto/crypto-ops.c b/src/crypto/crypto-ops.c
index 5cc3b572..8bc86a2f 100644
--- a/src/crypto/crypto-ops.c
+++ b/src/crypto/crypto-ops.c
@@ -12,14 +12,14 @@ DISABLE_VS_WARNINGS(4146 4244)
 
 /* Predeclarations */
 
-static void fe_mul(fe, const fe, const fe);
-static void fe_sq(fe, const fe);
-static void fe_tobytes(unsigned char *, const fe);
+void fe_mul(fe, const fe, const fe);
+void fe_sq(fe, const fe);
+void fe_tobytes(unsigned char *, const fe);
 static void ge_madd(ge_p1p1 *, const ge_p3 *, const ge_precomp *);
 static void ge_msub(ge_p1p1 *, const ge_p3 *, const ge_precomp *);
 static void ge_p2_0(ge_p2 *);
 static void ge_p3_dbl(ge_p1p1 *, const ge_p3 *);
-static void ge_sub(ge_p1p1 *, const ge_p3 *, const ge_cached *);
+void ge_sub(ge_p1p1 *, const ge_p3 *, const ge_cached *);
 static void fe_divpowm1(fe, const fe, const fe);
 
 /* Common functions */
@@ -48,7 +48,7 @@ static uint64_t load_4(const unsigned char *in)
 h = 0
 */
 
-static void fe_0(fe h) {
+void fe_0(fe h) {
   h[0] = 0;
   h[1] = 0;
   h[2] = 0;
@@ -232,7 +232,7 @@ static void fe_copy(fe h, const fe f) {
 
 /* From fe_invert.c */
 
-static void fe_invert(fe out, const fe z) {
+void fe_invert(fe out, const fe z) {
   fe t0;
   fe t1;
   fe t2;
@@ -351,7 +351,7 @@ Can get away with 11 carries, but then data flow is much deeper.
 With tighter constraints on inputs can squeeze carries into int32.
 */
 
-static void fe_mul(fe h, const fe f, const fe g) {
+void fe_mul(fe h, const fe f, const fe g) {
   int32_t f0 = f[0];
   int32_t f1 = f[1];
   int32_t f2 = f[2];
@@ -631,7 +631,7 @@ Postconditions:
 See fe_mul.c for discussion of implementation strategy.
 */
 
-static void fe_sq(fe h, const fe f) {
+void fe_sq(fe h, const fe f) {
   int32_t f0 = f[0];
   int32_t f1 = f[1];
   int32_t f2 = f[2];
@@ -1005,7 +1005,7 @@ Proof:
   so floor(2^(-255)(h + 19 2^(-25) h9 + 2^(-1))) = q.
 */
 
-static void fe_tobytes(unsigned char *s, const fe h) {
+void fe_tobytes(unsigned char *s, const fe h) {
   int32_t h0 = h[0];
   int32_t h1 = h[1];
   int32_t h2 = h[2];
@@ -1398,7 +1398,7 @@ void ge_p2_dbl(ge_p1p1 *r, const ge_p2 *p) {
 
 /* From ge_p3_0.c */
 
-static void ge_p3_0(ge_p3 *h) {
+void ge_p3_0(ge_p3 *h) {
   fe_0(h->X);
   fe_1(h->Y);
   fe_1(h->Z);
@@ -1565,7 +1565,7 @@ void ge_scalarmult_base(ge_p3 *h, const unsigned char *a) {
 r = p - q
 */
 
-static void ge_sub(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q) {
+void ge_sub(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q) {
   fe t0;
   fe_add(r->X, p->Y, p->X);
   fe_sub(r->Y, p->Y, p->X);
@@ -2963,3 +2963,53 @@ int sc_isnonzero(const unsigned char *s) {
     s[18] | s[19] | s[20] | s[21] | s[22] | s[23] | s[24] | s[25] | s[26] |
     s[27] | s[28] | s[29] | s[30] | s[31]) - 1) >> 8) + 1;
 }
+
+// see implmentation of ge_frombytes_vartime above
+void fe_frombytes(fe h, const unsigned char *s)
+{
+  /* From fe_frombytes.c */
+
+  int64_t h0 = load_4(s);
+  int64_t h1 = load_3(s + 4) << 6;
+  int64_t h2 = load_3(s + 7) << 5;
+  int64_t h3 = load_3(s + 10) << 3;
+  int64_t h4 = load_3(s + 13) << 2;
+  int64_t h5 = load_4(s + 16);
+  int64_t h6 = load_3(s + 20) << 7;
+  int64_t h7 = load_3(s + 23) << 5;
+  int64_t h8 = load_3(s + 26) << 4;
+  int64_t h9 = (load_3(s + 29) & 8388607) << 2;
+  int64_t carry0;
+  int64_t carry1;
+  int64_t carry2;
+  int64_t carry3;
+  int64_t carry4;
+  int64_t carry5;
+  int64_t carry6;
+  int64_t carry7;
+  int64_t carry8;
+  int64_t carry9;
+
+  carry9 = (h9 + (int64_t)(1 << 24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
+  carry1 = (h1 + (int64_t)(1 << 24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
+  carry3 = (h3 + (int64_t)(1 << 24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
+  carry5 = (h5 + (int64_t)(1 << 24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
+  carry7 = (h7 + (int64_t)(1 << 24)) >> 25; h8 += carry7; h7 -= carry7 << 25;
+
+  carry0 = (h0 + (int64_t)(1 << 25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
+  carry2 = (h2 + (int64_t)(1 << 25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
+  carry4 = (h4 + (int64_t)(1 << 25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
+  carry6 = (h6 + (int64_t)(1 << 25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
+  carry8 = (h8 + (int64_t)(1 << 25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
+
+  h[0] = h0;
+  h[1] = h1;
+  h[2] = h2;
+  h[3] = h3;
+  h[4] = h4;
+  h[5] = h5;
+  h[6] = h6;
+  h[7] = h7;
+  h[8] = h8;
+  h[9] = h9;
+}
diff --git a/src/crypto/crypto-ops.h b/src/crypto/crypto-ops.h
index c29c100d..138db1d2 100644
--- a/src/crypto/crypto-ops.h
+++ b/src/crypto/crypto-ops.h
@@ -104,13 +104,17 @@ void ge_scalarmult(ge_p2 *, const unsigned char *, const ge_p3 *);
 void ge_scalarmult_p3(ge_p3 *, const unsigned char *, const ge_p3 *);
 void ge_double_scalarmult_precomp_vartime(ge_p2 *, const unsigned char *, const ge_p3 *, const unsigned char *, const ge_dsmp);
 void ge_mul8(ge_p1p1 *, const ge_p2 *);
+void ge_fromfe_frombytes_vartime(ge_p2 *, const unsigned char *);
+void ge_p3_0(ge_p3 *h);
+void ge_sub(ge_p1p1 *, const ge_p3 *, const ge_cached *);
+
 extern const fe fe_ma2;
 extern const fe fe_ma;
 extern const fe fe_fffb1;
 extern const fe fe_fffb2;
 extern const fe fe_fffb3;
 extern const fe fe_fffb4;
-void ge_fromfe_frombytes_vartime(ge_p2 *, const unsigned char *);
+
 void sc_0(unsigned char *);
 void sc_reduce32(unsigned char *);
 void sc_add(unsigned char *, const unsigned char *, const unsigned char *);
@@ -118,3 +122,9 @@ void sc_sub(unsigned char *, const unsigned char *, const unsigned char *);
 void sc_mulsub(unsigned char *, const unsigned char *, const unsigned char *, const unsigned char *);
 int sc_check(const unsigned char *);
 int sc_isnonzero(const unsigned char *); /* Doesn't normalize */
+
+void fe_sq(fe h, const fe f);
+void fe_mul(fe, const fe, const fe);
+void fe_frombytes(fe h, const unsigned char *s);
+void fe_invert(fe out, const fe z);
+void fe_tobytes(unsigned char *s, const fe h);
diff --git a/src/crypto/crypto.h b/src/crypto/crypto.h
index f6a3aebf..64df2444 100644
--- a/src/crypto/crypto.h
+++ b/src/crypto/crypto.h
@@ -288,7 +288,7 @@ namespace crypto {
     uint8_t* const  m_p_data;
     size_t          m_data_used;
     bool            m_ready;
-  };
+  }; // class stream_cn_hash
 
 } // namespace crypto
 
diff --git a/src/currency_core/account.cpp b/src/currency_core/account.cpp
index 85c5ba7f..4f8e9320 100644
--- a/src/currency_core/account.cpp
+++ b/src/currency_core/account.cpp
@@ -226,6 +226,11 @@ namespace currency
     return true;
   }
   //-----------------------------------------------------------------
+  bool account_base::is_seed_tracking(const std::string& seed_phrase)
+  {
+    return seed_phrase.find(':') != std::string::npos;
+  }
+  //-----------------------------------------------------------------
   bool account_base::is_seed_password_protected(const std::string& seed_phrase, bool& is_password_protected)
   {
     //cut the last timestamp word from restore_dats
diff --git a/src/currency_core/account.h b/src/currency_core/account.h
index ba723670..305b02e3 100644
--- a/src/currency_core/account.h
+++ b/src/currency_core/account.h
@@ -79,6 +79,7 @@ namespace currency
     static std::string vector_of_chars_to_string(const std::vector<unsigned char>& v) { return std::string(v.begin(), v.end()); }
     static std::vector<unsigned char> string_to_vector_of_chars(const std::string& v) { return std::vector<unsigned char>(v.begin(), v.end()); }
     static bool is_seed_password_protected(const std::string& seed_phrase, bool& is_password_protected);
+    static bool is_seed_tracking(const std::string& seed_phrase);
 
     BEGIN_KV_SERIALIZE_MAP()
       KV_SERIALIZE(m_keys)
diff --git a/src/wallet/wallet_helpers.h b/src/wallet/wallet_helpers.h
index 12355011..8e37d856 100644
--- a/src/wallet/wallet_helpers.h
+++ b/src/wallet/wallet_helpers.h
@@ -27,27 +27,39 @@ namespace tools
   inline std::string get_seed_phrase_info(const std::string& seed_phrase, const std::string& seed_password, view::seed_phrase_info& result)
   {
     //cut the last timestamp word from restore_dats
-    try{
-      result.syntax_correct = currency::account_base::is_seed_password_protected(seed_phrase, result.require_password);
+    try
+    {
+      //restore_from_tracking_seed
+      bool is_tracking = currency::account_base::is_seed_tracking(seed_phrase);
+      if (is_tracking)
+      {
+        currency::account_base acc;
+        result.require_password = false;
+        result.hash_sum_matched = false;
+        result.syntax_correct = acc.restore_from_tracking_seed(seed_phrase);
+      }
+      else
+      {
+        result.syntax_correct = currency::account_base::is_seed_password_protected(seed_phrase, result.require_password);
+        if (result.syntax_correct && result.require_password)
+        {
+          if (seed_password.size())
+          {
+            currency::account_base acc;
+            result.hash_sum_matched = acc.restore_from_seed_phrase(seed_phrase, seed_password);
+          }
+          else
+          {
+            result.hash_sum_matched = false;
+          }
+        }
+      }
+      return API_RETURN_CODE_OK;
     }
     catch (...)
     {
       result.syntax_correct = false;
       return API_RETURN_CODE_OK;
     }
-
-    if (result.syntax_correct && result.require_password)
-    {
-      if (seed_password.size())
-      {
-        currency::account_base acc;
-        result.hash_sum_matched = acc.restore_from_seed_phrase(seed_phrase, seed_password);
-      }
-      else 
-      {
-        result.hash_sum_matched = false;
-      }
-    }
-    return API_RETURN_CODE_OK;
   }
 }
\ No newline at end of file
diff --git a/src/wallet/wallets_manager.cpp b/src/wallet/wallets_manager.cpp
index ec07c3b2..eb101997 100644
--- a/src/wallet/wallets_manager.cpp
+++ b/src/wallet/wallets_manager.cpp
@@ -1060,16 +1060,22 @@ std::string wallets_manager::is_pos_allowed()
 }
 std::string wallets_manager::is_valid_brain_restore_data(const std::string& seed_phrase, const std::string& seed_password)
 {
+  
   currency::account_base acc;
-  if (acc.restore_from_seed_phrase(seed_phrase, seed_password))
-    return API_RETURN_CODE_TRUE;
-
-  currency::account_public_address addr;
-  crypto::secret_key view_sec_key;
-  uint64_t ts;
-  if (currency::parse_tracking_seed(seed_phrase, addr, view_sec_key, ts))
-    return API_RETURN_CODE_TRUE;
+  if (!currency::account_base::is_seed_tracking(seed_phrase))
+  {
+    if (acc.restore_from_seed_phrase(seed_phrase, seed_password))
+      return API_RETURN_CODE_TRUE;
+  }
+  else
+  {
+    currency::account_public_address addr = AUTO_VAL_INIT(addr);
+    crypto::secret_key view_sec_key = AUTO_VAL_INIT(view_sec_key);
+    uint64_t ts = 0;
+    if (currency::parse_tracking_seed(seed_phrase, addr, view_sec_key, ts))
+      return API_RETURN_CODE_TRUE;
 
+  }
   return API_RETURN_CODE_FALSE;
 }
 #ifndef MOBILE_WALLET_BUILD
@@ -1115,8 +1121,8 @@ std::string wallets_manager::restore_wallet(const std::wstring& path, const std:
   currency::account_base acc;
   try
   {
-    bool auditable_watch_only = seed_phrase.find(':') != std::string::npos;
-    w->restore(path, password, seed_phrase, auditable_watch_only, seed_password); 
+    bool is_tracking = currency::account_base::is_seed_tracking(seed_phrase);
+    w->restore(path, password, seed_phrase, is_tracking, seed_password);
     //owr.seed = w->get_account().get_seed_phrase();
   }
   catch (const tools::error::file_exists&)
diff --git a/tests/unit_tests/crypto_tests.cpp b/tests/unit_tests/crypto_tests.cpp
new file mode 100644
index 00000000..366a1145
--- /dev/null
+++ b/tests/unit_tests/crypto_tests.cpp
@@ -0,0 +1,803 @@
+// Copyright (c) 2020 Zano Project
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#define USE_INSECURE_RANDOM_RPNG_ROUTINES // turns on random manupulation for tests
+#include "gtest/gtest.h"
+#include "crypto/crypto.h"
+
+extern "C" {
+#include "crypto/crypto-ops.h"
+void fe_reduce(fe u, const fe h)
+{
+  /* From fe_frombytes.c */
+
+  // loading changed
+
+  int64_t h0 = h[0];
+  int64_t h1 = h[1];
+  int64_t h2 = h[2];
+  int64_t h3 = h[3];
+  int64_t h4 = h[4];
+  int64_t h5 = h[5];
+  int64_t h6 = h[6];
+  int64_t h7 = h[7];
+  int64_t h8 = h[8];
+  int64_t h9 = h[9];
+  int64_t carry0;
+  int64_t carry1;
+  int64_t carry2;
+  int64_t carry3;
+  int64_t carry4;
+  int64_t carry5;
+  int64_t carry6;
+  int64_t carry7;
+  int64_t carry8;
+  int64_t carry9;
+
+  carry9 = (h9 + (int64_t)(1 << 24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25;
+  carry1 = (h1 + (int64_t)(1 << 24)) >> 25; h2 += carry1; h1 -= carry1 << 25;
+  carry3 = (h3 + (int64_t)(1 << 24)) >> 25; h4 += carry3; h3 -= carry3 << 25;
+  carry5 = (h5 + (int64_t)(1 << 24)) >> 25; h6 += carry5; h5 -= carry5 << 25;
+  carry7 = (h7 + (int64_t)(1 << 24)) >> 25; h8 += carry7; h7 -= carry7 << 25;
+
+  carry0 = (h0 + (int64_t)(1 << 25)) >> 26; h1 += carry0; h0 -= carry0 << 26;
+  carry2 = (h2 + (int64_t)(1 << 25)) >> 26; h3 += carry2; h2 -= carry2 << 26;
+  carry4 = (h4 + (int64_t)(1 << 25)) >> 26; h5 += carry4; h4 -= carry4 << 26;
+  carry6 = (h6 + (int64_t)(1 << 25)) >> 26; h7 += carry6; h6 -= carry6 << 26;
+  carry8 = (h8 + (int64_t)(1 << 25)) >> 26; h9 += carry8; h8 -= carry8 << 26;
+
+  u[0] = h0;
+  u[1] = h1;
+  u[2] = h2;
+  u[3] = h3;
+  u[4] = h4;
+  u[5] = h5;
+  u[6] = h6;
+  u[7] = h7;
+  u[8] = h8;
+  u[9] = h9;
+
+  /* End fe_frombytes.c */
+
+}
+
+
+void sc_mul(unsigned char *s, const unsigned char *a, const unsigned char *b)
+{
+  unsigned char c[32];
+  unsigned char neg_a[32];
+  sc_0(c);
+  sc_sub(neg_a, c, a);
+  // s = c - ab
+  sc_mulsub(s, neg_a, b, c);
+}
+
+} // extern "C"
+
+
+unsigned char Lm2[32] = { 0xeb, 0xd3, 0xf5, 0x5c, 0x1a, 0x63, 0x12, 0x58, 0xd6, 0x9c, 0xf7, 0xa2, 0xde, 0xf9, 0xde, 0x14, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x10 };
+
+// out = z ^ s (mod l)
+void sc_exp(unsigned char* out, const unsigned char* z, const unsigned char* s)
+{
+  sc_0(out);
+  out[0] = 1;
+  if (sc_isnonzero(s) == 0)
+  {
+    return;
+  }
+
+  // calc position of the most significant bit of s
+  size_t msb_s = 0;
+  for (size_t i = 31; i != SIZE_MAX; --i)
+  {
+    if (s[i] != 0)
+    {
+      msb_s = 8 * i;
+      uint8_t t = s[i] >> 1;
+      while (t)
+      {
+        t >>= 1;
+        ++msb_s;
+      }
+      break;
+    }
+  }
+
+  //memcpy(out, z, sizeof(crypto::ec_scalar));
+
+  for (size_t i = msb_s; i != SIZE_MAX; --i)
+  {
+    sc_mul(out, out, out);
+    std::cout << "sc_mul(out, out, out);" << std::endl;
+    uint8_t bit = (s[i / 8] >> (i % 8)) & 1;
+    if (bit)
+    {
+      sc_mul(out, out, z);
+      std::cout << "sc_mul(out, out, z);" << std::endl;
+    }
+  }
+}
+
+void sc_invert(unsigned char* out, const unsigned char* z)
+{
+  memcpy(out, z, sizeof(crypto::ec_scalar));
+  for(size_t i = 0; i < 128; ++i)
+    sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+  sc_mul(out, out, out);
+  sc_mul(out, out, z);
+}
+
+
+
+
+template<class pod_t>
+std::string pod_to_hex_big_endian(const pod_t &h)
+{
+  constexpr char hexmap[] = "0123456789abcdef";
+  const char* data = reinterpret_cast<const char*>(&h);
+  size_t len = sizeof h;
+
+  std::string s(len * 2, ' ');
+  for (size_t i = 0; i < len; ++i) {
+    s[2 * i]     = hexmap[(data[len - 1 - i] & 0xF0) >> 4];
+    s[2 * i + 1] = hexmap[(data[len - 1 - i] & 0x0F)];
+  }
+
+  return s;
+}
+
+
+int fe_cmp(const fe a, const fe b)
+{
+  for (size_t i = 9; i != SIZE_MAX; --i)
+  {
+    if (reinterpret_cast<const uint32_t&>(a[i]) < reinterpret_cast<const uint32_t&>(b[i])) return -1;
+    if (reinterpret_cast<const uint32_t&>(a[i]) > reinterpret_cast<const uint32_t&>(b[i])) return 1;
+  }
+  return 0;
+}
+
+static const fe scalar_L_fe = { 16110573, 10012311, -6632702, 16062397, 5471207, 0, 0, 0, 0, 4194304 };
+
+
+__declspec(align(32))
+struct scalar_t
+{
+  //fe m_fe; // 40 bytes, array 10 * 4, optimized form
+  union
+  {
+    uint64_t      m_u64[4];
+    unsigned char m_s[32];
+  };
+  // DONE! consider 1) change to aligned array of unsigned chars
+  // consider 2) add 32 byte after to speed up sc_reduce by decreasing num of copy operations
+
+  scalar_t()
+  {}
+
+  scalar_t(uint64_t a0, uint64_t a1, uint64_t a2, uint64_t a3)
+  {
+    m_u64[0] = a0;
+    m_u64[1] = a1;
+    m_u64[2] = a2;
+    m_u64[3] = a3;
+  }
+
+  scalar_t(int64_t v)
+  {
+    zero();
+    if (v == 0)
+    {
+      return;
+    }
+    //unsigned char bytes[32] = {0};
+    reinterpret_cast<int64_t&>(m_s) = v;
+    //fe_frombytes(m_fe, bytes);
+    // do not need to call reduce as 2^64 < L
+  }
+
+  unsigned char* data()
+  {
+    return &m_s[0];
+  }
+
+  const unsigned char* data() const
+  {
+    return &m_s[0];
+  }
+
+  operator crypto::secret_key() const
+  {
+    crypto::secret_key result;
+    memcpy(result.data, &m_s, sizeof result.data);
+    //fe_tobytes(reinterpret_cast<unsigned char*>(&result), m_fe);
+    return result;
+  }
+
+  bool from_secret_key(const crypto::secret_key& sk)
+  {
+    //fe_frombytes(m_fe, reinterpret_cast<const unsigned char*>(&sk));
+    return false;
+  }
+
+  void zero()
+  {
+    //fe_0(m_fe);
+    m_u64[0] = 0;
+    m_u64[1] = 0;
+    m_u64[2] = 0;
+    m_u64[3] = 0;
+    //memset(&m_s, 0, sizeof m_s);
+  }
+
+  void make_random()
+  {
+    unsigned char tmp[64];
+    crypto::generate_random_bytes(64, tmp);
+    sc_reduce(tmp);
+    memcpy(&m_s, tmp, 32);
+  }
+
+  bool is_zero() const
+  {
+    return sc_isnonzero(&m_s[0]) == 0;
+  }
+
+  scalar_t operator+(const scalar_t& v) const
+  {
+    scalar_t result;
+    sc_add(reinterpret_cast<unsigned char*>(&result), reinterpret_cast<const unsigned char*>(&m_s), reinterpret_cast<const unsigned char*>(&v));
+    return result;
+  }
+
+  scalar_t operator-(const scalar_t& v) const
+  {
+    scalar_t result;
+    sc_sub(reinterpret_cast<unsigned char*>(&result), reinterpret_cast<const unsigned char*>(&m_s), reinterpret_cast<const unsigned char*>(&v));
+    return result;
+  }
+
+  scalar_t operator*(const scalar_t& v) const
+  {
+    scalar_t result;
+    sc_mul(reinterpret_cast<unsigned char*>(&result), reinterpret_cast<const unsigned char*>(&m_s), reinterpret_cast<const unsigned char*>(&v));
+    return result;
+  }
+
+  scalar_t reciprocal() const
+  {
+    /*unsigned char bytes[32] = {2};
+    fe t;
+    fe_frombytes(t, (unsigned char*)&bytes);
+    fe r;
+    fe_invert(r, t);
+    fe m;
+    fe_mul(m, r, t);
+
+
+    fe r2;
+    my_fe_invert(r2, t);
+    fe m2;
+    fe_mul(m2, r2, t);
+
+    scalar_t result;
+    fe v_f;
+    fe result_f;
+    fe_frombytes(v_f, reinterpret_cast<const unsigned char*>(&m_s));
+    my_fe_invert(result_f, v_f);
+    fe_tobytes(reinterpret_cast<unsigned char*>(&result), result_f);
+    //sc_reduce(reinterpret_cast<unsigned char*>(&result));
+    fe result_check;
+    fe_frombytes(result_check, reinterpret_cast<unsigned char*>(&result));
+    fe v_check;
+    fe_invert(v_check, result_check);
+    //sc_reduce(reinterpret_cast<unsigned char*>(&result));
+    return result;*/
+
+    scalar_t result;
+    fe v_f;
+    fe result_f;
+    fe_frombytes(v_f, reinterpret_cast<const unsigned char*>(&m_s));
+    fe_invert(result_f, v_f);
+
+    /*fe x2;
+    fe_mul(x2, result_f, v_f);
+
+    fe_reduce(result_f, result_f);
+    if (fe_cmp(result_f, scalar_L_fe) > 0)
+    {
+      // result_f > L
+      fe_sub(result_f, result_f, scalar_L_fe);
+      if (fe_cmp(result_f, scalar_L_fe) >= 0)
+        return false; // fail
+    }*/
+    unsigned char tmp[64] = { 0 };
+    fe_tobytes(reinterpret_cast<unsigned char*>(&tmp), result_f);
+    sc_reduce(tmp);
+    memcpy(&result, &tmp, sizeof result);
+    return result;
+  }
+
+  scalar_t operator/(const scalar_t& v) const
+  {
+    return operator*(v.reciprocal());
+  }
+
+  bool operator==(const scalar_t& rhs) const
+  {
+    return
+      m_u64[0] == rhs.m_u64[0] &&
+      m_u64[1] == rhs.m_u64[1] &&
+      m_u64[2] == rhs.m_u64[2] &&
+      m_u64[3] == rhs.m_u64[3];
+  }
+
+  bool operator<(const scalar_t& rhs) const
+  {
+    if (m_u64[3] < rhs.m_u64[3]) return true;
+    if (m_u64[3] > rhs.m_u64[3]) return false;
+    if (m_u64[2] < rhs.m_u64[2]) return true;
+    if (m_u64[2] > rhs.m_u64[2]) return false;
+    if (m_u64[1] < rhs.m_u64[1]) return true;
+    if (m_u64[1] > rhs.m_u64[1]) return false;
+    if (m_u64[0] < rhs.m_u64[0]) return true;
+    if (m_u64[0] > rhs.m_u64[0]) return false;
+    return false;
+  }
+
+  bool operator>(const scalar_t& rhs) const
+  {
+    if (m_u64[3] < rhs.m_u64[3]) return false;
+    if (m_u64[3] > rhs.m_u64[3]) return true;
+    if (m_u64[2] < rhs.m_u64[2]) return false;
+    if (m_u64[2] > rhs.m_u64[2]) return true;
+    if (m_u64[1] < rhs.m_u64[1]) return false;
+    if (m_u64[1] > rhs.m_u64[1]) return true;
+    if (m_u64[0] < rhs.m_u64[0]) return false;
+    if (m_u64[0] > rhs.m_u64[0]) return true;
+    return false;
+  }
+
+  friend std::ostream& operator<<(std::ostream& ss, const scalar_t &v)
+  {
+    return ss << "0x" << pod_to_hex_big_endian(v);
+  }
+  
+}; // struct scalar_t
+
+//__declspec(align(32))
+struct point_t
+{
+  // A point(x, y) is represented in extended homogeneous coordinates (X, Y, Z, T)
+  // with x = X / Z, y = Y / Z, x * y = T / Z.
+  ge_p3 m_p3;
+
+  point_t()
+  {
+  }
+
+  void zero()
+  {
+    ge_p3_0(&m_p3);
+  }
+
+  bool from_public_key(const crypto::public_key& pk)
+  {
+    return ge_frombytes_vartime(&m_p3, reinterpret_cast<const unsigned char*>(&pk)) == 0;
+  }
+
+  operator crypto::public_key()
+  {
+    crypto::public_key result;
+    ge_p3_tobytes((unsigned char*)&result, &m_p3);
+    return result;
+  }
+
+  point_t operator+(const point_t& rhs)
+  {
+    point_t result;
+    ge_cached rhs_c;
+    ge_p1p1 t;
+    ge_p3_to_cached(&rhs_c, &rhs.m_p3);
+    ge_add(&t, &m_p3, &rhs_c);
+    ge_p1p1_to_p3(&result.m_p3, &t);
+    return result;
+  }
+
+  point_t operator-(const point_t& rhs)
+  {
+    point_t result;
+    ge_cached rhs_c;
+    ge_p1p1 t;
+    ge_p3_to_cached(&rhs_c, &rhs.m_p3);
+    ge_sub(&t, &m_p3, &rhs_c);
+    ge_p1p1_to_p3(&result.m_p3, &t);
+    return result;
+  }
+
+  friend point_t operator*(const scalar_t& lhs, const point_t& rhs)
+  {
+    point_t result;
+    ge_scalarmult_p3(&result.m_p3, reinterpret_cast<const unsigned char*>(&lhs), &rhs.m_p3);
+    return result;
+  }
+
+  friend bool operator==(const point_t& lhs, const point_t& rhs) 
+  {
+    // convert to xy form, then compare components (because (z, y, z, t) representation is not unique)
+    fe lrecip, lx, ly;
+    fe rrecip, rx, ry;
+
+    fe_invert(lrecip, lhs.m_p3.Z);
+    fe_invert(rrecip, rhs.m_p3.Z);
+
+    fe_mul(lx, lhs.m_p3.X, lrecip);
+    fe_mul(rx, rhs.m_p3.X, rrecip);
+    if (memcmp(&lx, &rx, sizeof lx) != 0)
+      return false;
+
+    fe_mul(ly, lhs.m_p3.Y, lrecip);
+    fe_mul(ry, rhs.m_p3.Y, rrecip);
+    if (memcmp(&ly, &ry, sizeof ly) != 0)
+      return false;
+
+    return true;
+  };
+}; // struct point_t
+
+struct point_g_t : public point_t
+{
+  point_g_t()
+  {
+
+  }
+
+  friend point_t operator*(const scalar_t& lhs, const point_g_t&)
+  {
+    point_t result;
+    ge_scalarmult_base(&result.m_p3, reinterpret_cast<const unsigned char*>(&lhs));
+    return result;
+  }
+
+  /*friend point_t operator*(const int64_t lhs, const point_g_t& rhs)
+  {
+    return operator*(scalar_t)
+  }*/
+
+  static_assert(sizeof(crypto::public_key) == 32, "size error");
+
+}; // struct point_g_t
+
+static const point_g_t point_G;
+
+static const scalar_t scalar_L     = { 0x5812631a5cf5d3ed, 0x14def9dea2f79cd6, 0x0,                0x1000000000000000 };
+static const scalar_t scalar_Lm1   = { 0x5812631a5cf5d3ec, 0x14def9dea2f79cd6, 0x0,                0x1000000000000000 };
+static const scalar_t scalar_P     = { 0xffffffffffffffed, 0xffffffffffffffff, 0xffffffffffffffff, 0x7fffffffffffffff };
+static const scalar_t scalar_Pm1   = { 0xffffffffffffffec, 0xffffffffffffffff, 0xffffffffffffffff, 0x7fffffffffffffff };
+static const scalar_t scalar_256m1 = { 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff };
+
+
+/* temporary disable in order not to break the compilation
+TEST(crypto, scalar_basics)
+{
+  scalar_t zero = 0;
+  ASSERT_TRUE(zero.is_zero());
+  scalar_t one = 1;
+  ASSERT_FALSE(one.is_zero());
+  ASSERT_TRUE(one > zero);
+  scalar_t z = 0;
+  for (size_t j = 0; j < 1000; ++j)
+  {
+    z.make_random();
+    ASSERT_FALSE(z.is_zero());
+    ASSERT_GT(z, z - 1);
+    ASSERT_LT(z, z + 1);
+  }
+
+  ASSERT_TRUE(scalar_L > 0 && !(scalar_L < 0));
+  ASSERT_TRUE(scalar_Lm1 > 0 && !(scalar_Lm1 < 0));
+  ASSERT_TRUE(scalar_Lm1 < scalar_L);
+  ASSERT_FALSE(scalar_Lm1 > scalar_L);
+  ASSERT_TRUE(scalar_P > scalar_Pm1);
+  ASSERT_FALSE(scalar_P < scalar_Pm1);
+
+  std::cout << "0   = " << zero << std::endl;
+  std::cout << "1   = " << one << std::endl;
+  std::cout << "L   = " << scalar_L << std::endl;
+  std::cout << "Lm1 = " << scalar_Lm1 << std::endl;
+  std::cout << "P   = " << scalar_P << std::endl;
+  std::cout << "Pm1 = " << scalar_Pm1 << std::endl;
+
+  // check rolling over L for scalars arithmetics
+  ASSERT_EQ(scalar_Lm1 + 1, 0);
+  ASSERT_EQ(scalar_t(0) - 1, scalar_Lm1);
+  ASSERT_EQ(scalar_Lm1 * 2, scalar_Lm1 - 1); // (L - 1) * 2 = L + L - 2 = (L - 1) - 1  (mod L)
+  ASSERT_EQ(scalar_Lm1 * 100, scalar_Lm1 - 99);
+  ASSERT_EQ(scalar_Lm1 * scalar_Lm1, 1);     // (L - 1) * (L - 1) = L*L - 2L + 1 = 1 (mod L)
+
+  std::cout << std::endl;
+
+
+
+  fe L_fe;
+  fe_frombytes(L_fe, &scalar_L.m_s[0]);
+
+  fe Pm1_fe;
+  fe_frombytes(Pm1_fe, &scalar_Pm1.m_s[0]);
+
+  fe r;
+  fe f_1 = { 1 };
+  fe_add(r, Pm1_fe, f_1);
+
+
+
+  while(true)
+  {
+    static int ti = 2;
+    static int pi = 3;
+    scalar_t t = ti;
+    scalar_t p = pi;
+    scalar_t r = 0;
+    //sc_exp(r.data(), t.data(), Lm2);
+
+    sc_invert(r.data(), t.data());
+
+    std::cout << ti << " ^ L-2" << " = " << r << std::endl;
+
+    r = r * 6;
+    std::cout << r << std::endl;
+  }
+
+
+
+  scalar_t a = 2;
+  a = a / 2;
+  std::cout << "2 / 2       = " << a << std::endl;
+  a = scalar_Lm1 / 2;
+  std::cout << "L-1 / 2     = " << a << std::endl;
+  a = a * 2;
+  std::cout << "L-1 / 2 * 2 = " << a << std::endl;
+
+}
+
+TEST(crypto, point_basics)
+{
+  scalar_t s = 4;
+  point_t E = s * point_G;
+  point_t X = 4 * E;
+  point_t K = 193847 * point_G;
+  point_t C = E + K;
+
+  ASSERT_TRUE(X == 16 * point_G);
+  ASSERT_TRUE(C - K == E);
+  ASSERT_TRUE(C - E == K);
+  ASSERT_TRUE(C == 193851 * point_G);
+}
+
+TEST(crypto, scalar_reciprocal)
+{
+  int64_t test_nums[] = {1, 2, 10};
+
+  for (size_t i = 0; i < sizeof test_nums / sizeof test_nums[0]; ++i)
+  {
+    scalar_t s = test_nums[i];
+    scalar_t z = s - s;
+    ASSERT_TRUE(z.is_zero());
+  }
+
+  scalar_t s = 20;
+  scalar_t d = 5;
+  scalar_t e = s / d;
+  scalar_t m = e * d;
+
+  ASSERT_TRUE(m == s);
+}
+
+
+TEST(crypto, scalars)
+{
+  scalar_t s = 20;
+  scalar_t d = 5;
+  scalar_t e = s / d;
+  scalar_t m = e * d;
+
+  ASSERT_TRUE(m == s);
+}
+
+*/
\ No newline at end of file