diff --git a/Editor/Encryption/EncryptInstructionBase.cs b/Editor/Encryption/EncryptInstructionBase.cs
deleted file mode 100644
index be52283..0000000
--- a/Editor/Encryption/EncryptInstructionBase.cs
+++ /dev/null
@@ -1,8 +0,0 @@
-namespace Obfuz.Encryption
-{
-    public abstract class EncryptInstructionBase : IEncryptInstruction
-    {
-        public abstract int Encrypt(int value, int[] secretKey, int salt);
-        public abstract int Decrypt(int value, int[] secretKey, int salt);
-    }
-}
diff --git a/Editor/Encryption/EncryptOpCode.cs b/Editor/Encryption/EncryptionInstructionWithOpCode.cs
similarity index 70%
rename from Editor/Encryption/EncryptOpCode.cs
rename to Editor/Encryption/EncryptionInstructionWithOpCode.cs
index 0a7ef72..c31aa3a 100644
--- a/Editor/Encryption/EncryptOpCode.cs
+++ b/Editor/Encryption/EncryptionInstructionWithOpCode.cs
@@ -1,12 +1,12 @@
 namespace Obfuz.Encryption
 {
-    public class EncryptOpCode
+    public class EncryptionInstructionWithOpCode
     {
         public readonly ushort code;
 
-        public readonly EncryptFunction function;
+        public readonly IEncryptionInstruction function;
 
-        public EncryptOpCode(ushort code, EncryptFunction function)
+        public EncryptionInstructionWithOpCode(ushort code, IEncryptionInstruction function)
         {
             this.code = code;
             this.function = function;
diff --git a/Editor/Encryption/EncryptionVirtualMachine.cs b/Editor/Encryption/EncryptionVirtualMachine.cs
new file mode 100644
index 0000000..d3d1c48
--- /dev/null
+++ b/Editor/Encryption/EncryptionVirtualMachine.cs
@@ -0,0 +1,16 @@
+namespace Obfuz.Encryption
+{
+    public class EncryptionVirtualMachine
+    {
+        public const int SecretKeyLength = 1024;
+
+        public readonly int[] secretKey;
+        public readonly EncryptionInstructionWithOpCode[] opCodes;
+
+        public EncryptionVirtualMachine(int[] secretKey, EncryptionInstructionWithOpCode[] opCodes)
+        {
+            this.secretKey = secretKey;
+            this.opCodes = opCodes;
+        }
+    }
+}
diff --git a/Editor/Encryption/EncryptionVirtualMachineCreator.cs b/Editor/Encryption/EncryptionVirtualMachineCreator.cs
new file mode 100644
index 0000000..c3c4c53
--- /dev/null
+++ b/Editor/Encryption/EncryptionVirtualMachineCreator.cs
@@ -0,0 +1,56 @@
+using Obfuz.Encryption.Instructions;
+using Obfuz.Utils;
+using UnityEngine.Assertions;
+
+namespace Obfuz.Encryption
+{
+    public class EncryptionVirtualMachineCreator
+    {
+        private readonly int[] _vmGenerationSecretKey;
+        private readonly byte[] _encryptionSecretKey;
+        private readonly IRandom _random;
+
+        public const int CodeGenerationSecretKeyLength = 1024;
+
+        public EncryptionVirtualMachineCreator(string vmGenerationSecretKey, byte[] encryptionSecretKey)
+        {
+            _vmGenerationSecretKey = KeyGenerator.ConvertToIntKey(KeyGenerator.GenerateKey(vmGenerationSecretKey, CodeGenerationSecretKeyLength));
+            _encryptionSecretKey = encryptionSecretKey;
+            _random = new RandomWithKey(encryptionSecretKey, 0);
+        }
+
+        private IEncryptionInstruction CreateRandomInstruction(int intSecretKeyLength)
+        {
+            switch (_random.NextInt(3))
+            {
+                case 0:
+                    return new AddInstruction(_random.NextInt(), _random.NextInt(intSecretKeyLength));
+                case 1:
+                    return new XorInstruction(_random.NextInt(), _random.NextInt(intSecretKeyLength));
+                case 2:
+                    return new BitRotateInstruction(_random.NextInt(32), _random.NextInt(intSecretKeyLength));
+                default:
+                throw new System.Exception("Invalid instruction type");
+            }
+        }
+
+        private EncryptionInstructionWithOpCode CreateEncryptOpCode(ushort code)
+        {
+            IEncryptionInstruction inst = CreateRandomInstruction(EncryptionVirtualMachine.SecretKeyLength / sizeof(int));
+            Assert.AreEqual(1234, inst.Decrypt(inst.Encrypt(1234, _vmGenerationSecretKey, 0x12345678), _vmGenerationSecretKey, 0x12345678));
+            return new EncryptionInstructionWithOpCode(code, inst);
+        }
+
+        public EncryptionVirtualMachine CreateVirtualMachine(int opCodeCount)
+        {
+            Assert.IsTrue(opCodeCount > 0);
+            Assert.AreEqual(0, opCodeCount & (opCodeCount - 1));
+            var opCodes = new EncryptionInstructionWithOpCode[opCodeCount];
+            for (int i = 0; i < opCodes.Length; i++)
+            {
+                opCodes[i] = CreateEncryptOpCode((ushort)i);
+            }
+            return new EncryptionVirtualMachine(_vmGenerationSecretKey, opCodes);
+        }
+    }
+}
diff --git a/Editor/Encryption/EncryptionVirtualMachineSimulator.cs b/Editor/Encryption/EncryptionVirtualMachineSimulator.cs
index 8161a3c..119ae93 100644
--- a/Editor/Encryption/EncryptionVirtualMachineSimulator.cs
+++ b/Editor/Encryption/EncryptionVirtualMachineSimulator.cs
@@ -12,15 +12,26 @@ namespace Obfuz.Encryption
 
     public class EncryptionVirtualMachineSimulator : EncryptorBase
     {
-        private readonly EncryptOpCode[] _opCodes;
+        private readonly EncryptionInstructionWithOpCode[] _opCodes;
         private readonly int[] _secretKey;
 
-        public EncryptionVirtualMachineSimulator(EncryptOpCode[] opCodes, int[] secretKey)
+        public EncryptionVirtualMachineSimulator(EncryptionVirtualMachine vm)
         {
-            _opCodes = opCodes;
-            // should be power of 2
-            Assert.AreEqual(0, opCodes.Length ^ (opCodes.Length - 1));
-            _secretKey = secretKey;
+            _opCodes = vm.opCodes;
+            _secretKey = vm.secretKey;
+
+            VerifyInstructions();
+        }
+
+        private void VerifyInstructions()
+        {
+            int value = 0x11223344;
+            for (int i = 0; i < _opCodes.Length; i++)
+            {
+                int encryptedValue = _opCodes[i].Encrypt(value, _secretKey, i);
+                int decryptedValue = _opCodes[i].Decrypt(encryptedValue, _secretKey, i);
+                Assert.AreEqual(value, decryptedValue);
+            }
         }
 
         private List<ushort> DecodeOps(int ops)
diff --git a/Editor/Encryption/IEncryptInstruction.cs b/Editor/Encryption/IEncryptInstruction.cs
deleted file mode 100644
index e2fd265..0000000
--- a/Editor/Encryption/IEncryptInstruction.cs
+++ /dev/null
@@ -1,9 +0,0 @@
-namespace Obfuz.Encryption
-{
-    public interface IEncryptInstruction
-    {
-        int Encrypt(int value, int[] secretKey, int salt);
-
-        int Decrypt(int value, int[] secretKey, int salt);
-    }
-}
diff --git a/Editor/Encryption/IEncryptionInstruction.cs b/Editor/Encryption/IEncryptionInstruction.cs
new file mode 100644
index 0000000..bb3b667
--- /dev/null
+++ b/Editor/Encryption/IEncryptionInstruction.cs
@@ -0,0 +1,15 @@
+namespace Obfuz.Encryption
+{
+    public interface IEncryptionInstruction
+    {
+        int Encrypt(int value, int[] secretKey, int salt);
+
+        int Decrypt(int value, int[] secretKey, int salt);
+    }
+
+    public abstract class EncryptionInstructionBase : IEncryptionInstruction
+    {
+        public abstract int Encrypt(int value, int[] secretKey, int salt);
+        public abstract int Decrypt(int value, int[] secretKey, int salt);
+    }
+}
diff --git a/Editor/Encryption/IVirtualMachineCreator.cs b/Editor/Encryption/IVirtualMachineCreator.cs
deleted file mode 100644
index 6141fb9..0000000
--- a/Editor/Encryption/IVirtualMachineCreator.cs
+++ /dev/null
@@ -1,7 +0,0 @@
-namespace Obfuz.Encryption
-{
-    public interface IVirtualMachineCreator
-    {
-        VirtualMachine CreateVirtualMachine(int opCodeCount);
-    }
-}
diff --git a/Editor/Encryption/AddInstruction.cs b/Editor/Encryption/Instructions/AddInstruction.cs
similarity index 84%
rename from Editor/Encryption/AddInstruction.cs
rename to Editor/Encryption/Instructions/AddInstruction.cs
index 598cc5b..2b3de74 100644
--- a/Editor/Encryption/AddInstruction.cs
+++ b/Editor/Encryption/Instructions/AddInstruction.cs
@@ -1,6 +1,6 @@
-namespace Obfuz.Encryption
+namespace Obfuz.Encryption.Instructions
 {
-    public class AddInstruction : EncryptInstructionBase
+    public class AddInstruction : EncryptionInstructionBase
     {
         private readonly int _addValue;
         private readonly int _opKeyIndex;
diff --git a/Editor/Encryption/BitRotateInstruction.cs b/Editor/Encryption/Instructions/BitRotateInstruction.cs
similarity index 88%
rename from Editor/Encryption/BitRotateInstruction.cs
rename to Editor/Encryption/Instructions/BitRotateInstruction.cs
index 14f41a3..dab8252 100644
--- a/Editor/Encryption/BitRotateInstruction.cs
+++ b/Editor/Encryption/Instructions/BitRotateInstruction.cs
@@ -1,6 +1,6 @@
-namespace Obfuz.Encryption
+namespace Obfuz.Encryption.Instructions
 {
-    public class BitRotateInstruction : EncryptInstructionBase
+    public class BitRotateInstruction : EncryptionInstructionBase
     {
         private readonly int _rotateBitNum;
         private readonly int _opKeyIndex;
diff --git a/Editor/Encryption/EncryptFunction.cs b/Editor/Encryption/Instructions/EncryptFunction.cs
similarity index 75%
rename from Editor/Encryption/EncryptFunction.cs
rename to Editor/Encryption/Instructions/EncryptFunction.cs
index 8e6e398..192e5f1 100644
--- a/Editor/Encryption/EncryptFunction.cs
+++ b/Editor/Encryption/Instructions/EncryptFunction.cs
@@ -3,14 +3,14 @@ using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 
-namespace Obfuz.Encryption
+namespace Obfuz.Encryption.Instructions
 {
 
-    public class EncryptFunction : EncryptInstructionBase
+    public class EncryptFunction : EncryptionInstructionBase
     {
-        private readonly IEncryptInstruction[] _instructions;
+        private readonly IEncryptionInstruction[] _instructions;
 
-        public EncryptFunction(IEncryptInstruction[] instructions)
+        public EncryptFunction(IEncryptionInstruction[] instructions)
         {
             _instructions = instructions;
         }
diff --git a/Editor/Encryption/XorInstruction.cs b/Editor/Encryption/Instructions/XorInstruction.cs
similarity index 84%
rename from Editor/Encryption/XorInstruction.cs
rename to Editor/Encryption/Instructions/XorInstruction.cs
index 2df5a6e..4e8fcc2 100644
--- a/Editor/Encryption/XorInstruction.cs
+++ b/Editor/Encryption/Instructions/XorInstruction.cs
@@ -1,6 +1,6 @@
-namespace Obfuz.Encryption
+namespace Obfuz.Encryption.Instructions
 {
-    public class  XorInstruction : EncryptInstructionBase
+    public class  XorInstruction : EncryptionInstructionBase
     {
         private readonly int _xorValue;
         private readonly int _opKeyIndex;
diff --git a/Editor/Encryption/OpCodeSetFactory.cs b/Editor/Encryption/OpCodeSetFactory.cs
deleted file mode 100644
index 7c4164e..0000000
--- a/Editor/Encryption/OpCodeSetFactory.cs
+++ /dev/null
@@ -1,10 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Obfuz.Encryption
-{
-   
-}
diff --git a/Editor/Encryption/RandomVirtualMachineCreator.cs b/Editor/Encryption/RandomVirtualMachineCreator.cs
deleted file mode 100644
index 422e839..0000000
--- a/Editor/Encryption/RandomVirtualMachineCreator.cs
+++ /dev/null
@@ -1,61 +0,0 @@
-using Obfuz.Utils;
-using UnityEngine.Assertions;
-
-namespace Obfuz.Encryption
-{
-    public class RandomVirtualMachineCreator : IVirtualMachineCreator
-    {
-        private readonly byte[] _byteSecretKey;
-        private readonly int[] _secretKey;
-        private readonly IRandom _random;
-
-        public RandomVirtualMachineCreator(byte[] secretKey)
-        {
-            _byteSecretKey = secretKey;
-            _secretKey = KeyGenerator.ConvertToIntKey(secretKey);
-            _random = new RandomWithKey(secretKey, 0);
-        }
-
-        private IEncryptInstruction CreateRandomInstruction(int secretKeyLength)
-        {
-            switch (_random.NextInt(3))
-            {
-                case 0:
-                    return new AddInstruction(_random.NextInt(), _random.NextInt(secretKeyLength));
-                case 1:
-                    return new XorInstruction(_random.NextInt(), _random.NextInt(secretKeyLength));
-                case 2:
-                    return new BitRotateInstruction(_random.NextInt(32), _random.NextInt(secretKeyLength));
-                default:
-                throw new System.Exception("Invalid instruction type");
-            }
-        }
-
-        private EncryptOpCode CreateEncryptOpCode(ushort code, int opCodeCount)
-        {
-            Assert.IsTrue(code < opCodeCount);
-            var insts = new IEncryptInstruction[opCodeCount];
-            for (int i = 0; i < insts.Length; i++)
-            {
-                IEncryptInstruction inst = CreateRandomInstruction(VirtualMachine.SecretKeyLength);
-                Assert.AreEqual(1234, inst.Decrypt(inst.Encrypt(1234, _secretKey, i), _secretKey, i));
-                insts[i] = CreateRandomInstruction(opCodeCount);
-            }
-            var function = new EncryptFunction(insts);
-            Assert.AreEqual(1234, function.Decrypt(function.Encrypt(1234, _secretKey, code), _secretKey, code));
-            return new EncryptOpCode(code, function);
-        }
-
-        public VirtualMachine CreateVirtualMachine(int opCodeCount)
-        {
-            Assert.IsTrue(opCodeCount > 0);
-            Assert.AreEqual(0, opCodeCount ^ (opCodeCount - 1));
-            var opCodes = new EncryptOpCode[opCodeCount];
-            for (int i = 0; i < opCodes.Length; i++)
-            {
-                opCodes[i] = CreateEncryptOpCode((ushort)i, opCodeCount);
-            }
-            return new VirtualMachine(_byteSecretKey, opCodes);
-        }
-    }
-}
diff --git a/Editor/Encryption/VirtualMachine.cs b/Editor/Encryption/VirtualMachine.cs
deleted file mode 100644
index 2f44983..0000000
--- a/Editor/Encryption/VirtualMachine.cs
+++ /dev/null
@@ -1,16 +0,0 @@
-namespace Obfuz.Encryption
-{
-    public class VirtualMachine
-    {
-        public const int SecretKeyLength = 1024;
-
-        public readonly byte[] secretKey;
-        public readonly EncryptOpCode[] opCodes;
-
-        public VirtualMachine(byte[] secretKey, EncryptOpCode[] opCodes)
-        {
-            this.secretKey = secretKey;
-            this.opCodes = opCodes;
-        }
-    }
-}
diff --git a/Editor/Obfuscator.cs b/Editor/Obfuscator.cs
index d42bd22..ff643d6 100644
--- a/Editor/Obfuscator.cs
+++ b/Editor/Obfuscator.cs
@@ -31,6 +31,7 @@ namespace Obfuz
         private readonly Pipeline _pipeline = new Pipeline();
         private readonly byte[] _secretKey;
         private readonly int _globalRandomSeed;
+        private readonly string _encryptionVmSecretKey;
 
         private ObfuscationPassContext _ctx;
 
@@ -38,10 +39,11 @@ namespace Obfuz
             List<string> notObfuscatedAssemblyNamesReferencingObfuscated,
             List<string> assemblySearchDirs,
             string obfuscatedAssemblyOutputDir,
-            List<IObfuscationPass> obfuscationPasses, string rawSecretKey, int globalRandomSeed)
+            List<IObfuscationPass> obfuscationPasses, string rawSecretKey, int globalRandomSeed, string encryptionVmSecretKey)
         {
-            _secretKey = KeyGenerator.GenerateKey(rawSecretKey, VirtualMachine.SecretKeyLength);
+            _secretKey = KeyGenerator.GenerateKey(rawSecretKey, EncryptionVirtualMachine.SecretKeyLength);
             _globalRandomSeed = globalRandomSeed;
+            _encryptionVmSecretKey = encryptionVmSecretKey;
 
             _toObfuscatedAssemblyNames = toObfuscatedAssemblyNames;
             _notObfuscatedAssemblyNamesReferencingObfuscated = notObfuscatedAssemblyNamesReferencingObfuscated;
@@ -63,13 +65,20 @@ namespace Obfuz
             OnPostObfuscation();
         }
 
+        private IEncryptor CreateEncryptionVirtualMachine()
+        {
+            var vmCreator = new EncryptionVirtualMachineCreator(_encryptionVmSecretKey, _secretKey);
+            var vm = vmCreator.CreateVirtualMachine(1);
+            return new EncryptionVirtualMachineSimulator(vm);
+        }
+
         private void OnPreObfuscation()
         {
             LoadAssemblies();
 
 
             var random = new RandomWithKey(_secretKey, _globalRandomSeed);
-            var encryptor = new NullEncryptor(_secretKey);
+            var encryptor = CreateEncryptionVirtualMachine();
             var rvaDataAllocator = new RvaDataAllocator(random, encryptor);
             var constFieldAllocator = new ConstFieldAllocator(encryptor, random, rvaDataAllocator);
             _ctx = new ObfuscationPassContext
diff --git a/Editor/ObfuscatorBuilder.cs b/Editor/ObfuscatorBuilder.cs
index 04ffcd4..6dc8619 100644
--- a/Editor/ObfuscatorBuilder.cs
+++ b/Editor/ObfuscatorBuilder.cs
@@ -15,6 +15,7 @@ namespace Obfuz
     {
         private string _secretKey;
         private int _globalRandomSeed;
+        private string _encryptionVmGenerationSecretKey;
         private List<string> _toObfuscatedAssemblyNames = new List<string>();
         private List<string> _notObfuscatedAssemblyNamesReferencingObfuscated = new List<string>();
         private List<string> _assemblySearchDirs = new List<string>();
@@ -34,6 +35,12 @@ namespace Obfuz
             set => _globalRandomSeed = value;
         }
 
+        public string EncryptionVmGenerationSecretKey
+        {
+            get => _encryptionVmGenerationSecretKey;
+            set => _encryptionVmGenerationSecretKey = value;
+        }
+
         public List<string> ToObfuscatedAssemblyNames
         {
             get => _toObfuscatedAssemblyNames;
@@ -75,7 +82,7 @@ namespace Obfuz
                 _notObfuscatedAssemblyNamesReferencingObfuscated,
                 _assemblySearchDirs,
                 _obfuscatedAssemblyOutputDir,
-                _obfuscationPasses, _secretKey, _globalRandomSeed);
+                _obfuscationPasses, _secretKey, _globalRandomSeed, _encryptionVmGenerationSecretKey);
         }
 
         public static ObfuscatorBuilder FromObfuzSettings(ObfuzSettings settings, BuildTarget target)
@@ -84,12 +91,17 @@ namespace Obfuz
             {
                 _secretKey = settings.secretKey,
                 _globalRandomSeed = settings.globalRandomSeed,
+                _encryptionVmGenerationSecretKey = settings.encryptionVMSettings.codeGenerationSecretKey,
                 _toObfuscatedAssemblyNames = settings.toObfuscatedAssemblyNames.ToList(),
                 _notObfuscatedAssemblyNamesReferencingObfuscated = settings.notObfuscatedAssemblyNamesReferencingObfuscated.ToList(),
                 _assemblySearchDirs = settings.extraAssemblySearchDirs.ToList(),
                 _obfuscatedAssemblyOutputDir = settings.GetObfuscatedAssemblyOutputDir(target),
             };
             ObfuscationPassType obfuscationPasses = settings.enabledObfuscationPasses;
+            if (obfuscationPasses.HasFlag(ObfuscationPassType.ConstEncrypt))
+            {
+                builder.AddPass(new ConstEncryptPass(settings.constEncryptSettings));
+            }
             if (obfuscationPasses.HasFlag(ObfuscationPassType.FieldEncrypt))
             {
                 builder.AddPass(new FieldEncryptPass(settings.fieldEncryptSettings));
@@ -98,10 +110,6 @@ namespace Obfuz
             {
                 builder.AddPass(new CallObfusPass(settings.callObfusSettings));
             }
-            if (obfuscationPasses.HasFlag(ObfuscationPassType.ConstEncrypt))
-            {
-                builder.AddPass(new ConstEncryptPass(settings.constEncryptSettings));
-            }
             if (obfuscationPasses.HasFlag(ObfuscationPassType.ExprObfus))
             {
                 builder.AddPass(new ExprObfusPass());