diff --git a/CMakeLists.txt b/CMakeLists.txt
index ff8e3b12c1..2fd234947c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -11,6 +11,8 @@ include(cotire)
 
 add_compile_options(-Wall -Werror -pipe -fvisibility=hidden)
 
+set(CMAKE_CXX_FLAGS_PERFORMANCE "${CMAKE_CXX_FLAGS_RELEASE} -march=native")
+
 if (CMAKE_COMPILER_IS_GNUCXX)
     add_compile_options(-fno-strict-aliasing)
 endif()
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1ec78dd6d9..ae86b6c191 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -74,5 +74,6 @@ set(tfs_SRC
 	${CMAKE_CURRENT_LIST_DIR}/waitlist.cpp
 	${CMAKE_CURRENT_LIST_DIR}/weapons.cpp
 	${CMAKE_CURRENT_LIST_DIR}/wildcardtree.cpp
+	${CMAKE_CURRENT_LIST_DIR}/xtea.cpp
 	PARENT_SCOPE)
 
diff --git a/src/protocol.cpp b/src/protocol.cpp
index 7c2ed2bf92..24598e1fc9 100644
--- a/src/protocol.cpp
+++ b/src/protocol.cpp
@@ -22,6 +22,7 @@
 #include "protocol.h"
 #include "outputmessage.h"
 #include "rsa.h"
+#include "xtea.h"
 
 extern RSA g_RSA;
 
@@ -60,37 +61,14 @@ OutputMessage_ptr Protocol::getOutputBuffer(int32_t size)
 
 void Protocol::XTEA_encrypt(OutputMessage& msg) const
 {
-	const uint32_t delta = 0x61C88647;
-
 	// The message must be a multiple of 8
-	size_t paddingBytes = msg.getLength() % 8;
+	size_t paddingBytes = msg.getLength() % 8u;
 	if (paddingBytes != 0) {
 		msg.addPaddingBytes(8 - paddingBytes);
 	}
 
 	uint8_t* buffer = msg.getOutputBuffer();
-	const size_t messageLength = msg.getLength();
-	size_t readPos = 0;
-	const uint32_t k[] = {key[0], key[1], key[2], key[3]};
-	while (readPos < messageLength) {
-		uint32_t v0;
-		memcpy(&v0, buffer + readPos, 4);
-		uint32_t v1;
-		memcpy(&v1, buffer + readPos + 4, 4);
-
-		uint32_t sum = 0;
-
-		for (int32_t i = 32; --i >= 0;) {
-			v0 += ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
-			sum -= delta;
-			v1 += ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[(sum >> 11) & 3]);
-		}
-
-		memcpy(buffer + readPos, &v0, 4);
-		readPos += 4;
-		memcpy(buffer + readPos, &v1, 4);
-		readPos += 4;
-	}
+	xtea::encrypt(buffer, msg.getLength(), key);
 }
 
 bool Protocol::XTEA_decrypt(NetworkMessage& msg) const
@@ -99,34 +77,11 @@ bool Protocol::XTEA_decrypt(NetworkMessage& msg) const
 		return false;
 	}
 
-	const uint32_t delta = 0x61C88647;
-
 	uint8_t* buffer = msg.getBuffer() + msg.getBufferPosition();
-	const size_t messageLength = (msg.getLength() - 6);
-	size_t readPos = 0;
-	const uint32_t k[] = {key[0], key[1], key[2], key[3]};
-	while (readPos < messageLength) {
-		uint32_t v0;
-		memcpy(&v0, buffer + readPos, 4);
-		uint32_t v1;
-		memcpy(&v1, buffer + readPos + 4, 4);
-
-		uint32_t sum = 0xC6EF3720;
-
-		for (int32_t i = 32; --i >= 0;) {
-			v1 -= ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + k[(sum >> 11) & 3]);
-			sum += delta;
-			v0 -= ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + k[sum & 3]);
-		}
-
-		memcpy(buffer + readPos, &v0, 4);
-		readPos += 4;
-		memcpy(buffer + readPos, &v1, 4);
-		readPos += 4;
-	}
+	xtea::decrypt(buffer, msg.getLength() - 6, key);
 
-	int innerLength = msg.get<uint16_t>();
-	if (innerLength > msg.getLength() - 8) {
+	uint16_t innerLength = msg.get<uint16_t>();
+	if (innerLength + 8 > msg.getLength()) {
 		return false;
 	}
 
diff --git a/src/protocol.h b/src/protocol.h
index 9864a558be..4fa6127b20 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -21,6 +21,7 @@
 #define FS_PROTOCOL_H_D71405071ACF4137A4B1203899DE80E1
 
 #include "connection.h"
+#include "xtea.h"
 
 class Protocol : public std::enable_shared_from_this<Protocol>
 {
@@ -71,8 +72,8 @@ class Protocol : public std::enable_shared_from_this<Protocol>
 		void enableXTEAEncryption() {
 			encryptionEnabled = true;
 		}
-		void setXTEAKey(const uint32_t* key) {
-			memcpy(this->key, key, sizeof(*key) * 4);
+		void setXTEAKey(xtea::key key) {
+			this->key = std::move(key);
 		}
 		void disableChecksum() {
 			checksumEnabled = false;
@@ -95,7 +96,7 @@ class Protocol : public std::enable_shared_from_this<Protocol>
 		OutputMessage_ptr outputBuffer;
 
 		const ConnectionWeak_ptr connection;
-		uint32_t key[4] = {};
+		xtea::key key;
 		bool encryptionEnabled = false;
 		bool checksumEnabled = true;
 		bool rawMessages = false;
diff --git a/src/protocolgame.cpp b/src/protocolgame.cpp
index 4ef047b14f..23e172511f 100644
--- a/src/protocolgame.cpp
+++ b/src/protocolgame.cpp
@@ -252,13 +252,13 @@ void ProtocolGame::onRecvFirstMessage(NetworkMessage& msg)
 		return;
 	}
 
-	uint32_t key[4];
+	xtea::key key;
 	key[0] = msg.get<uint32_t>();
 	key[1] = msg.get<uint32_t>();
 	key[2] = msg.get<uint32_t>();
 	key[3] = msg.get<uint32_t>();
 	enableXTEAEncryption();
-	setXTEAKey(key);
+	setXTEAKey(std::move(key));
 
 	if (operatingSystem >= CLIENTOS_OTCLIENT_LINUX) {
 		NetworkMessage opcodeMessage;
diff --git a/src/protocollogin.cpp b/src/protocollogin.cpp
index eee0cac990..6dadf9096a 100644
--- a/src/protocollogin.cpp
+++ b/src/protocollogin.cpp
@@ -150,13 +150,13 @@ void ProtocolLogin::onRecvFirstMessage(NetworkMessage& msg)
 		return;
 	}
 
-	uint32_t key[4];
+	xtea::key key;
 	key[0] = msg.get<uint32_t>();
 	key[1] = msg.get<uint32_t>();
 	key[2] = msg.get<uint32_t>();
 	key[3] = msg.get<uint32_t>();
 	enableXTEAEncryption();
-	setXTEAKey(key);
+	setXTEAKey(std::move(key));
 
 	if (version < CLIENT_VERSION_MIN || version > CLIENT_VERSION_MAX) {
 		std::ostringstream ss;
diff --git a/src/protocolold.cpp b/src/protocolold.cpp
index cd7f99a576..c9bb819f98 100644
--- a/src/protocolold.cpp
+++ b/src/protocolold.cpp
@@ -59,13 +59,13 @@ void ProtocolOld::onRecvFirstMessage(NetworkMessage& msg)
 		return;
 	}
 
-	uint32_t key[4];
+	xtea::key key;
 	key[0] = msg.get<uint32_t>();
 	key[1] = msg.get<uint32_t>();
 	key[2] = msg.get<uint32_t>();
 	key[3] = msg.get<uint32_t>();
 	enableXTEAEncryption();
-	setXTEAKey(key);
+	setXTEAKey(std::move(key));
 
 	if (version <= 822) {
 		disableChecksum();
diff --git a/src/xtea.cpp b/src/xtea.cpp
new file mode 100644
index 0000000000..855e2ffa70
--- /dev/null
+++ b/src/xtea.cpp
@@ -0,0 +1,140 @@
+/**
+ * The Forgotten Server - a free and open-source MMORPG server emulator
+ * Copyright (C) 2018  Mark Samman <mark.samman@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "otpch.h"
+
+#include "xtea.h"
+
+#include <array>
+#include <assert.h>
+
+namespace xtea {
+
+namespace {
+
+constexpr uint32_t delta = 0x9E3779B9;
+
+template<size_t BLOCK_SIZE>
+void XTEA_encrypt(uint8_t data[BLOCK_SIZE * 8], const key& k)
+{
+    alignas(16) uint32_t left[BLOCK_SIZE], right[BLOCK_SIZE];
+    for (auto i = 0u, j = 0u; i < BLOCK_SIZE; i += 1u, j += 8u) {
+        left[i] = data[j] | data[j+1] << 8u | data[j+2] << 16u | data[j+3] << 24u;
+        right[i] = data[j+4] | data[j+5] << 8u | data[j+6] << 16u | data[j+7] << 24u;
+    }
+
+    uint32_t sum = 0u;
+    for (auto i = 0u; i < 32; ++i) {
+        for (auto j = 0u; j < BLOCK_SIZE; ++j) {
+            left[j] += (((right[j] << 4) ^ (right[j] >> 5)) + right[j]) ^ (sum + k[sum & 3]);
+        }
+        sum += delta;
+        for (auto j = 0u; j < BLOCK_SIZE; ++j) {
+            right[j] += (((left[j] << 4) ^ (left[j] >> 5)) + left[j]) ^ (sum + k[(sum >> 11) & 3]);
+        }
+    }
+
+    for (auto i = 0u, j = 0u; i < BLOCK_SIZE; i += 1u, j += 8u) {
+        data[j] = static_cast<uint8_t>(left[i]);
+        data[j+1] = static_cast<uint8_t>(left[i] >> 8u);
+        data[j+2] = static_cast<uint8_t>(left[i] >> 16u);
+        data[j+3] = static_cast<uint8_t>(left[i] >> 24u);
+        data[j+4] = static_cast<uint8_t>(right[i]);
+        data[j+5] = static_cast<uint8_t>(right[i] >> 8u);
+        data[j+6] = static_cast<uint8_t>(right[i] >> 16u);
+        data[j+7] = static_cast<uint8_t>(right[i] >> 24u);
+    }
+}
+
+template<size_t BLOCK_SIZE>
+void XTEA_decrypt(uint8_t data[BLOCK_SIZE * 8], const key& k)
+{
+    alignas(16) uint32_t left[BLOCK_SIZE], right[BLOCK_SIZE];
+    for (auto i = 0u, j = 0u; i < BLOCK_SIZE; i += 1u, j += 8u) {
+        left[i] = data[j] | data[j+1] << 8u | data[j+2] << 16u | data[j+3] << 24u;
+        right[i] = data[j+4] | data[j+5] << 8u | data[j+6] << 16u | data[j+7] << 24u;
+    }
+
+    uint32_t sum = delta << 5;
+    for (auto i = 0u; i < 32; ++i) {
+        for (auto j = 0u; j < BLOCK_SIZE; ++j) {
+            right[j] -= (((left[j] << 4) ^ (left[j] >> 5)) + left[j]) ^ (sum + k[(sum >> 11) & 3]);
+        }
+        sum -= delta;
+        for (auto j = 0u; j < BLOCK_SIZE; ++j) {
+            left[j] -= (((right[j] << 4) ^ (right[j] >> 5)) + right[j]) ^ (sum + k[(sum) & 3]);
+        }
+    }
+
+    for (auto i = 0u, j = 0u; i < BLOCK_SIZE; i += 1u, j += 8u) {
+        data[j] = static_cast<uint8_t>(left[i]);
+        data[j+1] = static_cast<uint8_t>(left[i] >> 8u);
+        data[j+2] = static_cast<uint8_t>(left[i] >> 16u);
+        data[j+3] = static_cast<uint8_t>(left[i] >> 24u);
+        data[j+4] = static_cast<uint8_t>(right[i]);
+        data[j+5] = static_cast<uint8_t>(right[i] >> 8u);
+        data[j+6] = static_cast<uint8_t>(right[i] >> 16u);
+        data[j+7] = static_cast<uint8_t>(right[i] >> 24u);
+    }
+}
+
+constexpr auto InitialBlockSize =
+#if defined(__AVX512F__)
+      128u;
+#elif defined(__AVX__)
+      32u;
+#elif defined(__SSE__) || defined(__ARM_FEATURE_SIMD32)
+      8u;
+#elif defined(__x86_64__)
+      2u;
+#else
+      1u;
+#endif
+
+template<bool Encrypt, size_t BlockSize>
+struct XTEA {
+    static constexpr auto step = BlockSize * 8u;
+
+    void operator()(uint8_t* input, size_t length, const key& k) const {
+        const auto blocks = (length & ~(step - 1));
+        for (auto i = 0u; i < blocks; i += step) {
+            if (Encrypt) {
+                XTEA_encrypt<BlockSize>(input + i, k);
+            } else {
+                XTEA_decrypt<BlockSize>(input + i, k);
+            }
+        }
+        input += blocks;
+        length -= blocks;
+
+        if (BlockSize != 1) {
+            XTEA<Encrypt, (BlockSize + 1u) / 2u>()(input, length, k);
+        }
+    }
+};
+
+constexpr auto encrypt_v = XTEA<true, InitialBlockSize>();
+constexpr auto decrypt_v = XTEA<false, InitialBlockSize>();
+
+} // anonymous namespace
+
+void encrypt(uint8_t* i, size_t l, const key& k) { encrypt_v(i, l, k); }
+void decrypt(uint8_t* i, size_t l, const key& k) { decrypt_v(i, l, k); }
+
+} // namespace xtea
diff --git a/src/xtea.h b/src/xtea.h
new file mode 100644
index 0000000000..441afd0c6e
--- /dev/null
+++ b/src/xtea.h
@@ -0,0 +1,32 @@
+/**
+ * The Forgotten Server - a free and open-source MMORPG server emulator
+ * Copyright (C) 2018  Mark Samman <mark.samman@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef TFS_XTEA_H
+#define TFS_XTEA_H
+
+namespace xtea {
+
+using key = std::array<uint32_t, 4>;
+
+void encrypt(uint8_t* data, size_t length, const key& k);
+void decrypt(uint8_t* data, size_t length, const key& k);
+
+} // namespace xtea
+
+#endif // TFS_XTEA_H
diff --git a/vc14/theforgottenserver.sln b/vc14/theforgottenserver.sln
index 4c37956c69..b51d0f9f5a 100644
--- a/vc14/theforgottenserver.sln
+++ b/vc14/theforgottenserver.sln
@@ -1,7 +1,7 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.23107.0
+# Visual Studio 15
+VisualStudioVersion = 15.0.27703.2035
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "theforgottenserver", "theforgottenserver.vcxproj", "{A10F9657-129F-0FEF-14CB-CEE0B0E5AA3E}"
 EndProject
@@ -25,4 +25,7 @@ Global
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {81EB239E-6AEB-4015-9915-256C2C90D3FD}
+	EndGlobalSection
 EndGlobal
diff --git a/vc14/theforgottenserver.vcxproj b/vc14/theforgottenserver.vcxproj
index fce4521e8b..8f6ece29fd 100644
--- a/vc14/theforgottenserver.vcxproj
+++ b/vc14/theforgottenserver.vcxproj
@@ -21,7 +21,7 @@
   <PropertyGroup Label="Globals">
     <Keyword>Win32Proj</Keyword>
     <ProjectGuid>{A10F9657-129F-0FEF-14CB-CEE0B0E5AA3E}</ProjectGuid>
-    <WindowsTargetPlatformVersion>10.0.16299.0</WindowsTargetPlatformVersion>
+    <WindowsTargetPlatformVersion>10.0.17134.0</WindowsTargetPlatformVersion>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" Label="Configuration">
@@ -69,15 +69,25 @@
     <Import Project="release.props" />
   </ImportGroup>
   <PropertyGroup Label="UserMacros" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'" />
-  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" />
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <TargetName>$(ProjectName)-$(Platform)</TargetName>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <TargetName>$(ProjectName)-$(Platform)</TargetName>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <TargetName>$(ProjectName)-$(Platform)</TargetName>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <TargetName>$(ProjectName)-$(Platform)</TargetName>
+  </PropertyGroup>
   <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
     <ClCompile>
       <PreprocessorDefinitions>_CONSOLE;$(PREPROCESSOR_DEFS);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <Optimization>Disabled</Optimization>
+      <EnableParallelCodeGeneration>true</EnableParallelCodeGeneration>
+      <EnableEnhancedInstructionSet>AdvancedVectorExtensions2</EnableEnhancedInstructionSet>
     </ClCompile>
     <Link>
       <TargetMachine>MachineX86</TargetMachine>
@@ -89,6 +99,8 @@
     <ClCompile>
       <PreprocessorDefinitions>_CONSOLE;$(PREPROCESSOR_DEFS);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <EnableParallelCodeGeneration>true</EnableParallelCodeGeneration>
+      <EnableEnhancedInstructionSet>AdvancedVectorExtensions2</EnableEnhancedInstructionSet>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -100,6 +112,11 @@
       <PreprocessorDefinitions>NDEBUG;_CONSOLE;$(PREPROCESSOR_DEFS);%(PreprocessorDefinitions)</PreprocessorDefinitions>
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
+      <Optimization>MaxSpeed</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <EnableFiberSafeOptimizations>true</EnableFiberSafeOptimizations>
+      <EnableParallelCodeGeneration>true</EnableParallelCodeGeneration>
+      <EnableEnhancedInstructionSet>AdvancedVectorExtensions2</EnableEnhancedInstructionSet>
     </ClCompile>
     <Link>
       <TargetMachine>MachineX86</TargetMachine>
@@ -115,6 +132,11 @@
       <RuntimeLibrary>MultiThreadedDLL</RuntimeLibrary>
       <DebugInformationFormat>ProgramDatabase</DebugInformationFormat>
       <WarningLevel>Level4</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <EnableFiberSafeOptimizations>true</EnableFiberSafeOptimizations>
+      <EnableParallelCodeGeneration>true</EnableParallelCodeGeneration>
+      <EnableEnhancedInstructionSet>AdvancedVectorExtensions2</EnableEnhancedInstructionSet>
     </ClCompile>
     <Link>
       <GenerateDebugInformation>true</GenerateDebugInformation>
@@ -205,6 +227,7 @@
     <ClCompile Include="..\src\waitlist.cpp" />
     <ClCompile Include="..\src\weapons.cpp" />
     <ClCompile Include="..\src\wildcardtree.cpp" />
+    <ClCompile Include="..\src\xtea.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\src\account.h" />
@@ -290,6 +313,7 @@
     <ClInclude Include="..\src\waitlist.h" />
     <ClInclude Include="..\src\weapons.h" />
     <ClInclude Include="..\src\wildcardtree.h" />
+    <ClInclude Include="..\src\xtea.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">