diff --git a/src/ed25519.h b/src/ed25519.h
index 4fea9ad..906ed82 100644
--- a/src/ed25519.h
+++ b/src/ed25519.h
@@ -1,8 +1,10 @@
 #ifndef ED25519_H
 #define ED25519_H
 
-int ed25519_sign(unsigned char *signature, const unsigned char *message, unsigned int message_len, const unsigned char *sign_key);
-int ed25519_verify(const unsigned char *signature, const unsigned char *message, unsigned int message_len, const unsigned char *verify_key);
+#include <stddef.h>
+
+int ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *sign_key);
+int ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *verify_key);
 int ed25519_create_keypair(unsigned char *verify_key, unsigned char *sign_key, unsigned char *seed);
 
 #ifndef ED25519_NO_SEED
diff --git a/src/fe.c b/src/fe.c
index 37f4fc7..f05e8ff 100644
--- a/src/fe.c
+++ b/src/fe.c
@@ -1,5 +1,4 @@
 #include "fixedint.h"
-
 #include "fe.h"
 
 
diff --git a/src/ge.c b/src/ge.c
index 4eed5fc..3c342b1 100644
--- a/src/ge.c
+++ b/src/ge.c
@@ -1,6 +1,5 @@
 #include "ge.h"
-
-#include "base_precomp_data.h"
+#include "precomp_data.h"
 
 
 /*
diff --git a/src/ge.h b/src/ge.h
index 5c04e17..17fde2d 100644
--- a/src/ge.h
+++ b/src/ge.h
@@ -1,6 +1,9 @@
 #ifndef GE_H
 #define GE_H
 
+#include "fe.h"
+
+
 /*
 ge means group element.
 
@@ -15,8 +18,6 @@ Representations:
   ge_precomp (Duif): (y+x,y-x,2dxy)
 */
 
-#include "fe.h"
-
 typedef struct {
   fe X;
   fe Y;
diff --git a/src/base_precomp_data.h b/src/precomp_data.h
similarity index 100%
rename from src/base_precomp_data.h
rename to src/precomp_data.h
diff --git a/src/sc.c b/src/sc.c
index 3c2c860..bc288a6 100644
--- a/src/sc.c
+++ b/src/sc.c
@@ -1,5 +1,5 @@
-#include "sc.h"
 #include "fixedint.h"
+#include "sc.h"
 
 static uint64_t load_3(const unsigned char *in) {
     uint64_t result;
diff --git a/src/seed.txt b/src/seed.txt
index e08137d..d6b84d2 100644
Binary files a/src/seed.txt and b/src/seed.txt differ
diff --git a/src/sha512.c b/src/sha512.c
index baa859d..b5677a4 100644
--- a/src/sha512.c
+++ b/src/sha512.c
@@ -9,8 +9,6 @@
  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  */
 
-#include <string.h>
- 
 #include "fixedint.h"
 #include "sha512.h"
 
@@ -170,7 +168,8 @@ return 0;
 */
 int sha512_update (sha512_context * md, const unsigned char *in, size_t inlen)               
 {                                                                                           
-    size_t n;                                                                        
+    size_t n;
+    size_t i;                                                                        
     int           err;     
     if (md == NULL) return 1;  
     if (in == NULL) return 1;                                                              
@@ -186,8 +185,13 @@ int sha512_update (sha512_context * md, const unsigned char *in, size_t inlen)
            in             += 128;                                                    
            inlen          -= 128;                                                    
         } else {                                                                            
-           n = MIN(inlen, (128 - md->curlen));                           
-           memcpy(md->buf + md->curlen, in, (size_t)n);              
+           n = MIN(inlen, (128 - md->curlen));
+
+           for (i = 0; i < n; i++) {
+            md->buf[i + md->curlen] = in[i];
+           }
+
+
            md->curlen += n;                                                     
            in             += n;                                                             
            inlen          -= n;                                                             
diff --git a/src/sign.c b/src/sign.c
index 478ecdd..502e344 100644
--- a/src/sign.c
+++ b/src/sign.c
@@ -4,29 +4,35 @@
 #include "sc.h"
 
 
-int ed25519_sign(unsigned char *signature, const unsigned char *message, unsigned int message_len, const unsigned char *sign_key) {
+int ed25519_sign(unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *sign_key) {
     unsigned char az[64];
     unsigned char r[64];
     unsigned char hram[64];
     ge_p3 R;
     sha512_context hash;
+
     sha512(sign_key, 32, az);
     az[0] &= 248;
     az[31] &= 63;
     az[31] |= 64;
+
     sha512_init(&hash);
     sha512_update(&hash, az + 32, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, r);
+
     sc_reduce(r);
     ge_scalarmult_base(&R, r);
     ge_p3_tobytes(signature, &R);
+
     sha512_init(&hash);
     sha512_update(&hash, signature, 32);
     sha512_update(&hash, sign_key + 32, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, hram);
+
     sc_reduce(hram);
     sc_muladd(signature + 32, hram, az, r);
+    
     return 0;
 }
diff --git a/src/verify.c b/src/verify.c
index e2853a2..4999b63 100644
--- a/src/verify.c
+++ b/src/verify.c
@@ -44,7 +44,7 @@ static int consttime_equal(const unsigned char *x, const unsigned char *y) {
     return !r;
 }
 
-int ed25519_verify(const unsigned char *signature, const unsigned char *message, unsigned int message_len, const unsigned char *verify_key) {
+int ed25519_verify(const unsigned char *signature, const unsigned char *message, size_t message_len, const unsigned char *verify_key) {
     unsigned char h[64];
     unsigned char checker[32];
     sha512_context hash;
@@ -64,6 +64,7 @@ int ed25519_verify(const unsigned char *signature, const unsigned char *message,
     sha512_update(&hash, verify_key, 32);
     sha512_update(&hash, message, message_len);
     sha512_final(&hash, h);
+    
     sc_reduce(h);
     ge_double_scalarmult_vartime(&R, h, &A, signature + 32);
     ge_tobytes(checker, &R);