diff --git a/src/crypto/crypto-ops.c b/src/crypto/crypto-ops.c
index 2ab08dc2..caf20a07 100644
--- a/src/crypto/crypto-ops.c
+++ b/src/crypto/crypto-ops.c
@@ -4110,209 +4110,66 @@ void sc_muladd(unsigned char* s, const unsigned char* a,
   s[31] = s11 >> 17;
 }
 
-
-// out = z ^ -1 (= z ^ (L - 2) according to Fermat little theorem)
-void sc_invert(unsigned char* out, const unsigned char* z)
+/* libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c */
+void sc_sqmul(unsigned char s[32], const int n, const unsigned char a[32])
 {
-  memcpy(out, z, 32);
-  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);
+  int i;
+  for (i = 0; i < n; ++i)
+    sc_mul(s, s, s);
+  sc_mul(s, s, a);
+}
+
+/* libsodium/crypto_core/ed25519/ref10/ed25519_ref10.c */
+void sc_invert(unsigned char* recip, const unsigned char* s)
+{
+  unsigned char _10[32], _100[32], _1000[32], _10000[32], _100000[32],
+    _1000000[32], _10010011[32], _10010111[32], _100110[32], _1010[32],
+    _1010000[32], _1010011[32], _1011[32], _10110[32], _10111101[32],
+    _11[32], _1100011[32], _1100111[32], _11010011[32], _1101011[32],
+    _11100111[32], _11101011[32], _11110101[32];
+
+  sc_mul(_10, s, s);
+  sc_mul(_11, s, _10);
+  sc_mul(_100, s, _11);
+  sc_mul(_1000, _100, _100);
+  sc_mul(_1010, _10, _1000);
+  sc_mul(_1011, s, _1010);
+  sc_mul(_10000, _1000, _1000);
+  sc_mul(_10110, _1011, _1011);
+  sc_mul(_100000, _1010, _10110);
+  sc_mul(_100110, _10000, _10110);
+  sc_mul(_1000000, _100000, _100000);
+  sc_mul(_1010000, _10000, _1000000);
+  sc_mul(_1010011, _11, _1010000);
+  sc_mul(_1100011, _10000, _1010011);
+  sc_mul(_1100111, _100, _1100011);
+  sc_mul(_1101011, _100, _1100111);
+  sc_mul(_10010011, _1000000, _1010011);
+  sc_mul(_10010111, _100, _10010011);
+  sc_mul(_10111101, _100110, _10010111);
+  sc_mul(_11010011, _10110, _10111101);
+  sc_mul(_11100111, _1010000, _10010111);
+  sc_mul(_11101011, _100, _11100111);
+  sc_mul(_11110101, _1010, _11101011);
+
+  sc_mul(recip, _1011, _11110101);
+
+  sc_sqmul(recip, 126, _1010011);
+
+  sc_sqmul(recip, 9, _10);
+  sc_mul(recip, recip, _11110101);
+  sc_sqmul(recip, 7, _1100111);
+  sc_sqmul(recip, 9, _11110101);
+  sc_sqmul(recip, 11, _10111101);
+  sc_sqmul(recip, 8, _11100111);
+  sc_sqmul(recip, 9, _1101011);
+  sc_sqmul(recip, 6, _1011);
+  sc_sqmul(recip, 14, _10010011);
+  sc_sqmul(recip, 10, _1100011);
+  sc_sqmul(recip, 9, _10010111);
+  sc_sqmul(recip, 10, _11110101);
+  sc_sqmul(recip, 8, _11010011);
+  sc_sqmul(recip, 8, _11101011);
 }
 
 /*
diff --git a/tests/functional_tests/crypto_tests.cpp b/tests/functional_tests/crypto_tests.cpp
index 775e9b93..ba4313fd 100644
--- a/tests/functional_tests/crypto_tests.cpp
+++ b/tests/functional_tests/crypto_tests.cpp
@@ -80,56 +80,208 @@ sc_sqmul(unsigned char s[32], const int n, const unsigned char a[32])
   sc_mul(s, s, a);
 }
 
-void sc_invert2(unsigned char* recip, const unsigned char* s)
+// out = z ^ -1 (= z ^ (L - 2) according to Fermat little theorem)
+void sc_invert2(unsigned char* out, const unsigned char* z)
 {
-  unsigned char _10[32], _100[32], _1000[32], _10000[32], _100000[32],
-    _1000000[32], _10010011[32], _10010111[32], _100110[32], _1010[32],
-    _1010000[32], _1010011[32], _1011[32], _10110[32], _10111101[32],
-    _11[32], _1100011[32], _1100111[32], _11010011[32], _1101011[32],
-    _11100111[32], _11101011[32], _11110101[32];
-
-  sc_mul(_10, s, s);
-  sc_mul(_11, s, _10);
-  sc_mul(_100, s, _11);
-  sc_mul(_1000, _100, _100);
-  sc_mul(_1010, _10, _1000);
-  sc_mul(_1011, s, _1010);
-  sc_mul(_10000, _1000, _1000);
-  sc_mul(_10110, _1011, _1011);
-  sc_mul(_100000, _1010, _10110);
-  sc_mul(_100110, _10000, _10110);
-  sc_mul(_1000000, _100000, _100000);
-  sc_mul(_1010000, _10000, _1000000);
-  sc_mul(_1010011, _11, _1010000);
-  sc_mul(_1100011, _10000, _1010011);
-  sc_mul(_1100111, _100, _1100011);
-  sc_mul(_1101011, _100, _1100111);
-  sc_mul(_10010011, _1000000, _1010011);
-  sc_mul(_10010111, _100, _10010011);
-  sc_mul(_10111101, _100110, _10010111);
-  sc_mul(_11010011, _10110, _10111101);
-  sc_mul(_11100111, _1010000, _10010111);
-  sc_mul(_11101011, _100, _11100111);
-  sc_mul(_11110101, _1010, _11101011);
-
-  sc_mul(recip, _1011, _11110101);
-
-  sc_sqmul(recip, 126, _1010011);
-
-  sc_sqmul(recip, 9, _10);
-  sc_mul(recip, recip, _11110101);
-  sc_sqmul(recip, 7, _1100111);
-  sc_sqmul(recip, 9, _11110101);
-  sc_sqmul(recip, 11, _10111101);
-  sc_sqmul(recip, 8, _11100111);
-  sc_sqmul(recip, 9, _1101011);
-  sc_sqmul(recip, 6, _1011);
-  sc_sqmul(recip, 14, _10010011);
-  sc_sqmul(recip, 10, _1100011);
-  sc_sqmul(recip, 9, _10010111);
-  sc_sqmul(recip, 10, _11110101);
-  sc_sqmul(recip, 8, _11010011);
-  sc_sqmul(recip, 8, _11101011);
+  memcpy(out, z, 32);
+  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);
 }
 
 extern void *sha3(const void *in, size_t inlen, void *md, int mdlen);