diff --git a/include/fc/crypto/aes.hpp b/include/fc/crypto/aes.hpp
index 70fdc7c..f0c7616 100644
--- a/include/fc/crypto/aes.hpp
+++ b/include/fc/crypto/aes.hpp
@@ -37,12 +37,12 @@ namespace fc {
          fc::fwd<impl,96> my;
     };
 
-    int aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
-                    unsigned char *iv, unsigned char *ciphertext);
-    int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
-                    unsigned char *iv, unsigned char *plaintext);
-    int aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
-                    unsigned char *iv, unsigned char *plaintext);
+    unsigned aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
+                         unsigned char *iv, unsigned char *ciphertext);
+    unsigned aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+                         unsigned char *iv, unsigned char *plaintext);
+    unsigned aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+                             unsigned char *iv, unsigned char *plaintext);
 
     std::vector<char> aes_encrypt( const fc::sha512& key, const std::vector<char>& plain_text  );
     std::vector<char> aes_decrypt( const fc::sha512& key, const std::vector<char>& cipher_text );
diff --git a/include/fc/io/varint.hpp b/include/fc/io/varint.hpp
index 3536d4e..e289f87 100644
--- a/include/fc/io/varint.hpp
+++ b/include/fc/io/varint.hpp
@@ -19,12 +19,21 @@ struct unsigned_int {
     
     uint32_t value;
 
-    friend bool operator==( const unsigned_int& i, const uint32_t& v ) { return v == i.value; }
-    friend bool operator!=( const unsigned_int& i, const uint32_t& v ) { return v != i.value; }
-    friend bool operator<( const unsigned_int& i, const uint32_t& v ) { return v < i.value; }
-    friend bool operator>=( const unsigned_int& i, const uint32_t& v ) { return v >= i.value; }
-    friend bool operator<( const unsigned_int& i, const unsigned_int& v ) { return v < i.value; }
-    friend bool operator>=( const unsigned_int& i, const unsigned_int& v ) { return v >= i.value; }
+    friend bool operator==( const unsigned_int& i, const uint32_t& v )     { return i.value == v; }
+    friend bool operator==( const uint32_t& i, const unsigned_int& v )     { return i       == v.value; }
+    friend bool operator==( const unsigned_int& i, const unsigned_int& v ) { return i.value == v.value; }
+
+    friend bool operator!=( const unsigned_int& i, const uint32_t& v )     { return i.value != v; }
+    friend bool operator!=( const uint32_t& i, const unsigned_int& v )     { return i       != v.value; }
+    friend bool operator!=( const unsigned_int& i, const unsigned_int& v ) { return i.value != v.value; }
+
+    friend bool operator<( const unsigned_int& i, const uint32_t& v )      { return i.value < v; }
+    friend bool operator<( const uint32_t& i, const unsigned_int& v )      { return i       < v.value; }
+    friend bool operator<( const unsigned_int& i, const unsigned_int& v )  { return i.value < v.value; }
+
+    friend bool operator>=( const unsigned_int& i, const uint32_t& v )     { return i.value >= v; }
+    friend bool operator>=( const uint32_t& i, const unsigned_int& v )     { return i       >= v.value; }
+    friend bool operator>=( const unsigned_int& i, const unsigned_int& v ) { return i.value >= v.value; }
 };
 
 /**
@@ -41,6 +50,22 @@ struct signed_int {
     signed_int& operator++(){ ++value; return *this; }
 
     int32_t value;
+
+    friend bool operator==( const signed_int& i, const int32_t& v )    { return i.value == v; }
+    friend bool operator==( const int32_t& i, const signed_int& v )    { return i       == v.value; }
+    friend bool operator==( const signed_int& i, const signed_int& v ) { return i.value == v.value; }
+
+    friend bool operator!=( const signed_int& i, const int32_t& v )    { return i.value != v; }
+    friend bool operator!=( const int32_t& i, const signed_int& v )    { return i       != v.value; }
+    friend bool operator!=( const signed_int& i, const signed_int& v ) { return i.value != v.value; }
+
+    friend bool operator<( const signed_int& i, const int32_t& v )     { return i.value < v; }
+    friend bool operator<( const int32_t& i, const signed_int& v )     { return i       < v.value; }
+    friend bool operator<( const signed_int& i, const signed_int& v )  { return i.value < v.value; }
+
+    friend bool operator>=( const signed_int& i, const int32_t& v )    { return i.value >= v; }
+    friend bool operator>=( const int32_t& i, const signed_int& v )    { return i       >= v.value; }
+    friend bool operator>=( const signed_int& i, const signed_int& v ) { return i.value >= v.value; }
 };
 
 class variant;
@@ -64,4 +89,13 @@ namespace std
             return std::hash<int32_t>()(a.value);
          }
    };
+   template<>
+   struct hash<fc::unsigned_int>
+   {
+       public:
+         size_t operator()(const fc::signed_int &a) const 
+         {
+            return std::hash<uint32_t>()(a.value);
+         }
+   };
 }
diff --git a/include/fc/signals.hpp b/include/fc/signals.hpp
index 35f9a60..632f4f4 100644
--- a/include/fc/signals.hpp
+++ b/include/fc/signals.hpp
@@ -8,6 +8,8 @@ namespace fc {
 #if !defined(BOOST_NO_TEMPLATE_ALIASES) 
    template<typename T>
    using signal = boost::signals2::signal<T>;
+
+   using scoped_connection = boost::signals2::scoped_connection;
 #else
   /** Workaround for missing Template Aliases feature in the VS 2012.
       \warning Class defined below cannot have defined constructor (even base class has it)
diff --git a/src/crypto/aes.cpp b/src/crypto/aes.cpp
index 8e51519..1c2a036 100644
--- a/src/crypto/aes.cpp
+++ b/src/crypto/aes.cpp
@@ -157,13 +157,13 @@ uint32_t aes_decoder::final_decode( char* plaintext )
 
 
 /** example method from wiki.opensslfoundation.com */
-int aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
-              unsigned char *iv, unsigned char *ciphertext)
+unsigned aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
+                     unsigned char *iv, unsigned char *ciphertext)
 {
     evp_cipher_ctx ctx( EVP_CIPHER_CTX_new() );
 
     int len = 0;
-    int ciphertext_len = 0;
+    unsigned ciphertext_len = 0;
 
     /* Create and initialise the context */
     if(!ctx)
@@ -206,12 +206,12 @@ int aes_encrypt(unsigned char *plaintext, int plaintext_len, unsigned char *key,
     return ciphertext_len;
 }
 
-int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
-              unsigned char *iv, unsigned char *plaintext)
+unsigned aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+                     unsigned char *iv, unsigned char *plaintext)
 {
     evp_cipher_ctx ctx( EVP_CIPHER_CTX_new() );
     int len = 0;
-    int plaintext_len = 0;
+    unsigned plaintext_len = 0;
 
     /* Create and initialise the context */
     if(!ctx) 
@@ -255,12 +255,12 @@ int aes_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *ke
     return plaintext_len;
 }
 
-int aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
-              unsigned char *iv, unsigned char *plaintext)
+unsigned aes_cfb_decrypt(unsigned char *ciphertext, int ciphertext_len, unsigned char *key,
+                         unsigned char *iv, unsigned char *plaintext)
 {
     evp_cipher_ctx ctx( EVP_CIPHER_CTX_new() );
     int len = 0;
-    int plaintext_len = 0;
+    unsigned plaintext_len = 0;
 
     /* Create and initialise the context */
     if(!ctx)
@@ -308,8 +308,8 @@ std::vector<char> aes_encrypt( const fc::sha512& key, const std::vector<char>& p
 {
     std::vector<char> cipher_text(plain_text.size()+16);
     auto cipher_len = aes_encrypt( (unsigned char*)plain_text.data(), plain_text.size(),  
-                                 (unsigned char*)&key, ((unsigned char*)&key)+32,
-                                 (unsigned char*)cipher_text.data() );
+                                   (unsigned char*)&key, ((unsigned char*)&key)+32,
+                                   (unsigned char*)cipher_text.data() );
     FC_ASSERT( cipher_len <= cipher_text.size() );
     cipher_text.resize(cipher_len);
     return cipher_text;
diff --git a/src/crypto/elliptic.cpp b/src/crypto/elliptic.cpp
index dd3c4cb..ed38ad2 100644
--- a/src/crypto/elliptic.cpp
+++ b/src/crypto/elliptic.cpp
@@ -265,7 +265,7 @@ namespace fc { namespace ecc {
     std::string public_key::to_base58() const
     {
       public_key_data key = serialize();
-      uint32_t check = sha256::hash(key.data, sizeof(key))._hash[0];
+      uint32_t check = (uint32_t)sha256::hash(key.data, sizeof(key))._hash[0];
       assert(key.size() + sizeof(check) == 37);
       array<char, 37> data;
       memcpy(data.data, key.begin(), key.size());
@@ -280,7 +280,7 @@ namespace fc { namespace ecc {
         FC_ASSERT( s == sizeof(data) );
 
         public_key_data key;
-        uint32_t check = sha256::hash(data.data, sizeof(key))._hash[0];
+        uint32_t check = (uint32_t)sha256::hash(data.data, sizeof(key))._hash[0];
         FC_ASSERT( memcmp( (char*)&check, data.data + sizeof(key), sizeof(check) ) == 0 );
         memcpy( (char*)key.data, data.data, sizeof(key) );
         return public_key(key);