diff --git a/shadowsocks-csharp/Data/libsscrypto.dll.gz b/shadowsocks-csharp/Data/libsscrypto.dll.gz
index 66a1185e..75fe39ba 100755
Binary files a/shadowsocks-csharp/Data/libsscrypto.dll.gz and b/shadowsocks-csharp/Data/libsscrypto.dll.gz differ
diff --git a/shadowsocks-csharp/Data/libsscrypto2.dll.gz b/shadowsocks-csharp/Data/libsscrypto2.dll.gz
deleted file mode 100644
index 83f7aab1..00000000
Binary files a/shadowsocks-csharp/Data/libsscrypto2.dll.gz and /dev/null differ
diff --git a/shadowsocks-csharp/Encryption/Sodium.cs b/shadowsocks-csharp/Encryption/Sodium.cs
index 14403267..c2c22839 100755
--- a/shadowsocks-csharp/Encryption/Sodium.cs
+++ b/shadowsocks-csharp/Encryption/Sodium.cs
@@ -12,40 +12,14 @@ namespace Shadowsocks.Encryption
     public class Sodium
     {
         const string DLLNAME = "libsscrypto";
-        const string DLLNAME2 = "libsscrypto2";
 
         static Sodium()
-        {
-            LoadSSCryptoLibrary();
-            LoadSSCrypto2Library();
-        }
-
-        static void LoadSSCryptoLibrary()
         {
             string tempPath = Utils.GetTempPath();
             string dllPath = tempPath + "/libsscrypto.dll";
             try
             {
                 FileManager.UncompressFile(dllPath, Resources.libsscrypto_dll);
-                LoadLibrary(dllPath);
-            }
-            catch (IOException)
-            {
-            }
-            catch (Exception e)
-            {
-                Console.WriteLine(e.ToString());
-            }
-        }
-
-        static void LoadSSCrypto2Library()
-        {
-            string tempPath = Utils.GetTempPath();
-            string dllPath = tempPath + "/libsscrypto2.dll";
-            try
-            {
-                FileManager.UncompressFile(dllPath, Resources.libsscrypto2_dll);
-                LoadLibrary(dllPath);
             }
             catch (IOException)
             {
@@ -54,22 +28,23 @@ namespace Shadowsocks.Encryption
             {
                 Console.WriteLine(e.ToString());
             }
+            LoadLibrary(dllPath);
         }
 
         [DllImport("Kernel32.dll")]
         private static extern IntPtr LoadLibrary(string path);
 
         [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
-        public extern static void crypto_stream_salsa20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);
+        public extern static int crypto_stream_salsa20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);
 
         [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
-        public extern static void crypto_stream_chacha20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);
+        public extern static int crypto_stream_chacha20_xor_ic(byte[] c, byte[] m, ulong mlen, byte[] n, ulong ic, byte[] k);
 
-        [DllImport(DLLNAME2, CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
         public extern static int ss_gen_crc(byte[] buf, ref int buf_offset, ref int data_len,
             byte[] crc_buf, ref int crc_idx, int buf_size);
 
-        [DllImport(DLLNAME2, CallingConvention = CallingConvention.Cdecl)]
+        [DllImport(DLLNAME, CallingConvention = CallingConvention.Cdecl)]
         public extern static int ss_onetimeauth(byte[] auth, 
             byte[] msg, int msg_len, 
             byte[] iv, int iv_len,
diff --git a/shadowsocks-csharp/Properties/Resources.Designer.cs b/shadowsocks-csharp/Properties/Resources.Designer.cs
index a5891002..57242844 100644
--- a/shadowsocks-csharp/Properties/Resources.Designer.cs
+++ b/shadowsocks-csharp/Properties/Resources.Designer.cs
@@ -110,16 +110,6 @@ namespace Shadowsocks.Properties {
             }
         }
         
-        /// <summary>
-        ///   查找 System.Byte[] 类型的本地化资源。
-        /// </summary>
-        internal static byte[] libsscrypto2_dll {
-            get {
-                object obj = ResourceManager.GetObject("libsscrypto2_dll", resourceCulture);
-                return ((byte[])(obj));
-            }
-        }
-        
         /// <summary>
         ///   查找 System.Byte[] 类型的本地化资源。
         /// </summary>
diff --git a/shadowsocks-csharp/Properties/Resources.resx b/shadowsocks-csharp/Properties/Resources.resx
index 36dc1386..aa0c2f63 100755
--- a/shadowsocks-csharp/Properties/Resources.resx
+++ b/shadowsocks-csharp/Properties/Resources.resx
@@ -124,9 +124,6 @@
   <data name="cn" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\data\cn.txt;System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089;utf-8</value>
   </data>
-  <data name="libsscrypto2_dll" type="System.Resources.ResXFileRef, System.Windows.Forms">
-    <value>..\Data\libsscrypto2.dll.gz;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
-  </data>
   <data name="libsscrypto_dll" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\data\libsscrypto.dll.gz;System.Byte[], mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </data>
diff --git a/shadowsocks-csharp/shadowsocks-csharp.csproj b/shadowsocks-csharp/shadowsocks-csharp.csproj
index 89389fab..8200aa07 100644
--- a/shadowsocks-csharp/shadowsocks-csharp.csproj
+++ b/shadowsocks-csharp/shadowsocks-csharp.csproj
@@ -205,7 +205,6 @@
     </None>
     <None Include="Data\abp.js.gz" />
     <None Include="Data\libsscrypto.dll.gz" />
-    <None Include="Data\libsscrypto2.dll.gz" />
     <None Include="Data\mgwz.dll.gz" />
     <None Include="Data\privoxy.exe.gz" />
     <None Include="Data\proxy.pac.txt.gz" />