diff --git a/AyCode.Core/Serializers/AcSerializeBase.cs b/AyCode.Core/Serializers/AcSerializeBase.cs
new file mode 100644
index 0000000..f1d36c0
--- /dev/null
+++ b/AyCode.Core/Serializers/AcSerializeBase.cs
@@ -0,0 +1,30 @@
+using System.Runtime.CompilerServices;
+
+namespace AyCode.Core.Serializers;
+
+/// <summary>
+/// Abstract base class for serialization operations.
+/// Contains serialize-specific logic that may need override capability.
+/// 
+/// Responsibilities:
+/// - Reference scanning (ScanReferences)
+/// - Reference tracking during write (TrackForScanning, ShouldWriteId, MarkAsWritten)
+/// - IId-aware serialization logic
+/// 
+/// Derived classes:
+/// - BinarySerializationContext (or similar) for Binary serialization
+/// - JsonSerializationContext (or similar) for JSON serialization
+/// - ToonSerializationContext for Toon serialization
+/// 
+/// Note: Currently SerializationReferenceTracker remains in AcSerializerCommon.
+/// As patterns emerge, serialize-specific methods can be moved here.
+/// </summary>
+public abstract class AcSerializeBase
+{
+    // Future: Move serialize-specific logic here
+    // - SerializationReferenceTracker (or make it a protected property)
+    // - Virtual ComputeHash method (for IId vs Reference distinction)
+    // - Virtual TrackForScanning method
+    // - Virtual ShouldWriteRef method
+    // - etc.
+}
diff --git a/AyCode.Core/Serializers/AcSerializerCommon.cs b/AyCode.Core/Serializers/AcSerializerCommon.cs
index a59ce38..ed92ead 100644
--- a/AyCode.Core/Serializers/AcSerializerCommon.cs
+++ b/AyCode.Core/Serializers/AcSerializerCommon.cs
@@ -878,23 +878,27 @@ public static class AcSerializerCommon
     
     /// <summary>
     /// Common reference tracking for serialization.
-    /// Used by both JSON and Binary serializers to track multi-referenced objects.
-    /// Supports both ReferenceEquals-based tracking and IId-based tracking.
-    /// Uses int IDs for efficiency (no string allocation).
+    /// Uses unified Bloom filter + HashSet for both IId and Reference tracking.
+    /// - IId objects: hash = Id (positive, DB guarantees uniqueness per entity type)
+    /// - Non-IId objects: hash = RuntimeHelpers.GetHashCode | 0x80000000 (negative)
     /// </summary>
     public sealed class SerializationReferenceTracker
     {
-        private const int InitialReferenceCapacity = 64;
-        private const int InitialMultiRefCapacity = 32;
+        private const int InitialCapacity = 128;
+        
+        // Unified Bloom filter (256 bits = 4 x 64-bit)
+        private ulong _bloom0, _bloom1, _bloom2, _bloom3;
+        
+        // Unified HashSet for seen hashes (both IId and Reference)
+        private HashSet<int>? _seenHashes;
+        
+        // Multi-referenced hashes
+        private HashSet<int>? _multiRefHashes;
+        
+        // Written refs: hash → refId
+        private Dictionary<int, int>? _writtenRefs;
         
-        private Dictionary<object, int>? _scanOccurrences;
-        private Dictionary<object, int>? _writtenRefs;
-        private Dictionary<(Type, object), int>? _iidWrittenRefs;  // IId-based written refs
-        private HashSet<object>? _multiReferenced;
         private int _nextRefId = 1;
-        
-        // IId tracker for same-IId-different-instance deduplication
-        private IIdReferenceTracker? _iidTracker;
 
         /// <summary>
         /// Resets the tracker for reuse.
@@ -902,104 +906,153 @@ public static class AcSerializerCommon
         public void Reset()
         {
             _nextRefId = 1;
-            _scanOccurrences?.Clear();
+            _bloom0 = _bloom1 = _bloom2 = _bloom3 = 0;
+            _seenHashes?.Clear();
+            _multiRefHashes?.Clear();
             _writtenRefs?.Clear();
-            _iidWrittenRefs?.Clear();
-            _multiReferenced?.Clear();
-            _iidTracker?.Reset();
         }
 
         /// <summary>
         /// Ensures internal collections are initialized.
-        /// Call once before scanning when reference handling is enabled.
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void EnsureInitialized()
         {
-            _scanOccurrences ??= new Dictionary<object, int>(InitialReferenceCapacity, ReferenceEqualityComparer.Instance);
-            _writtenRefs ??= new Dictionary<object, int>(InitialReferenceCapacity, ReferenceEqualityComparer.Instance);
-            _iidWrittenRefs ??= new Dictionary<(Type, object), int>(InitialMultiRefCapacity);
-            _multiReferenced ??= new HashSet<object>(InitialMultiRefCapacity, ReferenceEqualityComparer.Instance);
+            _seenHashes ??= new HashSet<int>(InitialCapacity);
+            _multiRefHashes ??= new HashSet<int>();
+            _writtenRefs ??= new Dictionary<int, int>(InitialCapacity);
         }
 
         /// <summary>
-        /// Tracks an object during reference scanning phase.
-        /// Returns true if this is the first occurrence (continue scanning).
-        /// Returns false if already seen (object is multi-referenced, stop scanning this branch).
+        /// Computes the tracking hash for an object.
+        /// IId objects: positive hash from Id
+        /// Non-IId objects: negative hash from RuntimeHelpers.GetHashCode
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static int ComputeHash<TMetadata>(object obj, TMetadata metadata) where TMetadata : TypeMetadataBase
+        {
+            if (metadata.IsIId)
+            {
+                return metadata.IdAccessorType switch
+                {
+                    IdAccessorType.Int32 => metadata.GetIdInt32(obj),
+                    IdAccessorType.Int64 => (int)(metadata.GetIdInt64(obj) ^ (metadata.GetIdInt64(obj) >> 32)),
+                    IdAccessorType.Guid => metadata.GetIdGuid(obj).GetHashCode() & 0x7FFFFFFF,
+                    _ => metadata.IdGetter?.Invoke(obj)?.GetHashCode() ?? 0
+                };
+            }
+            
+            // Non-IId: use RuntimeHelpers identity hash with high bit set (negative)
+            return RuntimeHelpers.GetHashCode(obj) | unchecked((int)0x80000000);
+        }
+
+        /// <summary>
+        /// Tracks an object during reference scanning phase (non-IId version).
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public bool TrackForScanning(object obj)
         {
-            if (_scanOccurrences == null) return true;
-            
-            
-            ref var count = ref System.Runtime.InteropServices.CollectionsMarshal.GetValueRefOrAddDefault(_scanOccurrences, obj, out var exists);
-            if (exists)
-            {
-                count++;
-                _multiReferenced!.Add(obj);
-                return false;
-            }
-            count = 1;
-            return true;
+            var hash = RuntimeHelpers.GetHashCode(obj) | unchecked((int)0x80000000);
+            return TrackHash(hash);
         }
         
         /// <summary>
-        /// Extended tracking with IId support.
-        /// First checks IId match (different instance, same Id), then falls back to ReferenceEquals.
-        /// Returns true if this is the first occurrence (continue scanning children).
-        /// Returns false if already seen (stop scanning this branch).
+        /// Tracks an object during reference scanning phase with IId support.
+        /// Returns true if first occurrence (continue scanning).
+        /// Returns false if already seen (multi-referenced, stop scanning).
         /// </summary>
-        /// <param name="obj">Object to track</param>
-        /// <param name="metadata">Type metadata with IId info</param>
-        /// <param name="existingRefId">If returning false, contains the refId of the existing object (unused, kept for API compatibility)</param>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public bool TrackForScanningWithIId<TMetadata>(object obj, TMetadata metadata, out int existingRefId) 
             where TMetadata : TypeMetadataBase
         {
             existingRefId = 0;
-            if (_scanOccurrences == null) return true;
+            var hash = ComputeHash(obj, metadata);
             
-            // 1. IId check first (different instance, same Id)
-            if (metadata.IsIId && _iidTracker != null && _iidTracker.TryGetOriginalObject(obj, metadata, out var originalObject))
+            // Skip default IId values (Id = 0)
+            if (metadata.IsIId && hash == 0) return true;
+            
+            return TrackHash(hash);
+        }
+        
+        /// <summary>
+        /// Core tracking logic using Bloom filter + HashSet.
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private bool TrackHash(int hash)
+        {
+            // Bloom filter check - fast "definitely new" detection
+            var segment = (hash >> 6) & 3;
+            var bit = hash & 63;
+            var mask = 1UL << bit;
+            
+            var bloomHit = segment switch
             {
-                // Same IId already seen → mark BOTH original and current as multi-referenced
-                _multiReferenced!.Add(originalObject!);  // Original object
-                _multiReferenced.Add(obj);                // Current object (duplicate)
-                return false;
+                0 => (_bloom0 & mask) != 0,
+                1 => (_bloom1 & mask) != 0,
+                2 => (_bloom2 & mask) != 0,
+                _ => (_bloom3 & mask) != 0
+            };
+            
+            if (!bloomHit)
+            {
+                // Definitely new - add to bloom and set
+                switch (segment)
+                {
+                    case 0: _bloom0 |= mask; break;
+                    case 1: _bloom1 |= mask; break;
+                    case 2: _bloom2 |= mask; break;
+                    default: _bloom3 |= mask; break;
+                }
+                _seenHashes ??= new HashSet<int>(InitialCapacity);
+                _seenHashes.Add(hash);
+                return true;
             }
             
-            // 2. ReferenceEquals check (same instance)
-            ref var count = ref System.Runtime.InteropServices.CollectionsMarshal.GetValueRefOrAddDefault(_scanOccurrences, obj, out var exists);
-            if (exists)
+            // Possible duplicate - check HashSet
+            _seenHashes ??= new HashSet<int>(InitialCapacity);
+            if (!_seenHashes.Add(hash))
             {
-                count++;
-                _multiReferenced!.Add(obj);
+                // Already seen - multi-referenced!
+                _multiRefHashes ??= new HashSet<int>();
+                _multiRefHashes.Add(hash);
                 return false;
             }
-            count = 1;
-            
-            // 3. Register IId for future lookups
-            if (metadata.IsIId)
-            {
-                _iidTracker ??= new IIdReferenceTracker();
-                _iidTracker.Register(obj, metadata);
-            }
             
             return true;
         }
 
         /// <summary>
         /// Checks if object needs a reference ID during serialization.
-        /// Returns true if object is multi-referenced and hasn't been written yet.
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public bool ShouldWriteId(object obj, out int refId)
         {
-            if (_multiReferenced != null && _multiReferenced.Contains(obj) && !_writtenRefs!.ContainsKey(obj))
+            var hash = RuntimeHelpers.GetHashCode(obj) | unchecked((int)0x80000000);
+            return ShouldWriteIdForHash(hash, out refId);
+        }
+        
+        /// <summary>
+        /// Checks if object needs a reference ID (IId-aware version).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool ShouldWriteIdForIId<TMetadata>(object obj, TMetadata metadata, out int refId)
+            where TMetadata : TypeMetadataBase
+        {
+            var hash = ComputeHash(obj, metadata);
+            return ShouldWriteIdForHash(hash, out refId);
+        }
+        
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private bool ShouldWriteIdForHash(int hash, out int refId)
+        {
+            if (_multiRefHashes != null && _multiRefHashes.Contains(hash))
             {
-                refId = _nextRefId++;
-                return true;
+                _writtenRefs ??= new Dictionary<int, int>(InitialCapacity);
+                if (!_writtenRefs.ContainsKey(hash))
+                {
+                    refId = _nextRefId++;
+                    return true;
+                }
             }
             refId = 0;
             return false;
@@ -1011,22 +1064,20 @@ public static class AcSerializerCommon
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void MarkAsWritten(object obj, int refId)
         {
-            var type = obj.GetType();
-            var idInfo = JsonUtilities.GetIdInfo(type);
-            
-            // IId típus → IId alapján tároljuk
-            if (idInfo.IsId && idInfo.IdType != null)
-            {
-                var key = GetIIdKey(obj, type, idInfo.IdType);
-                if (key.HasValue)
-                {
-                    _iidWrittenRefs![key.Value] = refId;
-                    return;
-                }
-            }
-            
-            // Nem IId → ReferenceEquals alapján
-            _writtenRefs![obj] = refId;
+            var hash = RuntimeHelpers.GetHashCode(obj) | unchecked((int)0x80000000);
+            _writtenRefs![hash] = refId;
+        }
+        
+        /// <summary>
+        /// Marks object as written (IId-aware version).
+        /// </summary>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void MarkAsWrittenForIId<TMetadata>(object obj, TMetadata metadata, int refId)
+            where TMetadata : TypeMetadataBase
+        {
+            var hash = ComputeHash(obj, metadata);
+            _writtenRefs ??= new Dictionary<int, int>(InitialCapacity);
+            _writtenRefs[hash] = refId;
         }
 
         /// <summary>
@@ -1035,42 +1086,30 @@ public static class AcSerializerCommon
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public bool TryGetExistingRef(object obj, out int refId)
         {
-            var type = obj.GetType();
-            var idInfo = JsonUtilities.GetIdInfo(type);
-            
-            // IId típus → IId alapján keresünk
-            if (idInfo.IsId && idInfo.IdType != null && _iidWrittenRefs != null)
-            {
-                var key = GetIIdKey(obj, type, idInfo.IdType);
-                if (key.HasValue && _iidWrittenRefs.TryGetValue(key.Value, out refId))
-                {
-                    return true;
-                }
-            }
-            
-            // Nem IId → ReferenceEquals alapján
-            if (_writtenRefs != null && _writtenRefs.TryGetValue(obj, out refId))
-            {
-                return true;
-            }
-            
-            refId = 0;
-            return false;
+            var hash = RuntimeHelpers.GetHashCode(obj) | unchecked((int)0x80000000);
+            return TryGetExistingRefForHash(hash, out refId);
         }
         
         /// <summary>
-        /// Gets the (Type, Id) key for IId-based lookup.
+        /// Tries to get existing reference ID (IId-aware version).
         /// </summary>
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        private static (Type, object)? GetIIdKey(object obj, Type type, Type idType)
+        public bool TryGetExistingRefForIId<TMetadata>(object obj, TMetadata metadata, out int refId)
+            where TMetadata : TypeMetadataBase
         {
-            var idProp = type.GetProperty("Id");
-            if (idProp == null) return null;
-            
-            var id = idProp.GetValue(obj);
-            if (id == null || JsonUtilities.IsDefaultValue(id, idType)) return null;
-            
-            return (type, id);
+            var hash = ComputeHash(obj, metadata);
+            return TryGetExistingRefForHash(hash, out refId);
+        }
+        
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private bool TryGetExistingRefForHash(int hash, out int refId)
+        {
+            if (_writtenRefs != null && _writtenRefs.TryGetValue(hash, out refId))
+            {
+                return true;
+            }
+            refId = 0;
+            return false;
         }
     }
 
diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializationException.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializationException.cs
new file mode 100644
index 0000000..c3fbaac
--- /dev/null
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializationException.cs
@@ -0,0 +1,17 @@
+namespace AyCode.Core.Serializers.Binaries;
+
+/// <summary>
+/// Exception thrown when binary deserialization fails.
+/// </summary>
+public class AcBinaryDeserializationException : Exception
+{
+    public int Position { get; }
+    public Type? TargetType { get; }
+
+    public AcBinaryDeserializationException(string message, int position = 0, Type? targetType = null, Exception? innerException = null)
+        : base(message, innerException)
+    {
+        Position = position;
+        TargetType = targetType;
+    }
+}
\ No newline at end of file
diff --git a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
index a6ef251..57fda80 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinaryDeserializer.cs
@@ -12,22 +12,6 @@ using static AyCode.Core.Helpers.JsonUtilities;
 
 namespace AyCode.Core.Serializers.Binaries;
 
-/// <summary>
-/// Exception thrown when binary deserialization fails.
-/// </summary>
-public class AcBinaryDeserializationException : Exception
-{
-    public int Position { get; }
-    public Type? TargetType { get; }
-
-    public AcBinaryDeserializationException(string message, int position = 0, Type? targetType = null, Exception? innerException = null)
-        : base(message, innerException)
-    {
-        Position = position;
-        TargetType = targetType;
-    }
-}
-
 /// <summary>
 /// High-performance binary deserializer matching AcBinarySerializer.
 /// Features:
@@ -1412,21 +1396,4 @@ public static partial class AcBinaryDeserializer
     #endregion
 }
 
-/// <summary>
-/// Cached type conversion info. Using readonly struct to avoid heap allocation.
-/// </summary>
-readonly struct TypeConversionInfo
-{
-    public readonly Type UnderlyingType;
-    public readonly TypeCode TypeCode;
-    public readonly bool IsEnum;
-
-    public TypeConversionInfo(Type underlyingType, TypeCode typeCode, bool isEnum)
-    {
-        UnderlyingType = underlyingType;
-        TypeCode = typeCode;
-        IsEnum = isEnum;
-    }
-}
-
 // Implementation moved to AcBinaryDeserializer.TypeConversionInfo.cs
diff --git a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
index c9a3a0e..d28775b 100644
--- a/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
+++ b/AyCode.Core/Serializers/Binaries/AcBinarySerializer.BinarySerializationContext.cs
@@ -47,7 +47,7 @@ public static partial class AcBinarySerializer
     /// <summary>
     /// Binary serialization context. Public for generated serializers.
     /// </summary>
-    internal sealed class BinarySerializationContext : IDisposable
+    internal sealed class BinarySerializationContext : AcSerializeBase, IDisposable
     {
         private const int MinBufferSize = 256;
         private const int PropertyIndexBufferMaxCache = 512;
diff --git a/AyCode.Core/Serializers/Binaries/TypeConversionInfo.cs b/AyCode.Core/Serializers/Binaries/TypeConversionInfo.cs
new file mode 100644
index 0000000..65e7fbf
--- /dev/null
+++ b/AyCode.Core/Serializers/Binaries/TypeConversionInfo.cs
@@ -0,0 +1,18 @@
+namespace AyCode.Core.Serializers.Binaries;
+
+/// <summary>
+/// Cached type conversion info. Using readonly struct to avoid heap allocation.
+/// </summary>
+readonly struct TypeConversionInfo
+{
+    public readonly Type UnderlyingType;
+    public readonly TypeCode TypeCode;
+    public readonly bool IsEnum;
+
+    public TypeConversionInfo(Type underlyingType, TypeCode typeCode, bool isEnum)
+    {
+        UnderlyingType = underlyingType;
+        TypeCode = typeCode;
+        IsEnum = isEnum;
+    }
+}
\ No newline at end of file
diff --git a/AyCode.Core/Serializers/Jsons/AcJsonDeserializationException.cs b/AyCode.Core/Serializers/Jsons/AcJsonDeserializationException.cs
new file mode 100644
index 0000000..4fea839
--- /dev/null
+++ b/AyCode.Core/Serializers/Jsons/AcJsonDeserializationException.cs
@@ -0,0 +1,17 @@
+namespace AyCode.Core.Serializers.Jsons;
+
+/// <summary>
+/// Exception thrown when JSON deserialization fails.
+/// </summary>
+public class AcJsonDeserializationException : Exception
+{
+    public string? Json { get; }
+    public Type? TargetType { get; }
+
+    public AcJsonDeserializationException(string message, string? json = null, Type? targetType = null, Exception? innerException = null)
+        : base(message, innerException)
+    {
+        Json = json?.Length > 500 ? json[..500] + "..." : json;
+        TargetType = targetType;
+    }
+}
\ No newline at end of file
diff --git a/AyCode.Core/Serializers/Jsons/AcJsonDeserializer.cs b/AyCode.Core/Serializers/Jsons/AcJsonDeserializer.cs
index f1e78d4..60aec2b 100644
--- a/AyCode.Core/Serializers/Jsons/AcJsonDeserializer.cs
+++ b/AyCode.Core/Serializers/Jsons/AcJsonDeserializer.cs
@@ -9,22 +9,6 @@ using static AyCode.Core.Helpers.JsonUtilities;
 
 namespace AyCode.Core.Serializers.Jsons;
 
-/// <summary>
-/// Exception thrown when JSON deserialization fails.
-/// </summary>
-public class AcJsonDeserializationException : Exception
-{
-    public string? Json { get; }
-    public Type? TargetType { get; }
-
-    public AcJsonDeserializationException(string message, string? json = null, Type? targetType = null, Exception? innerException = null)
-        : base(message, innerException)
-    {
-        Json = json?.Length > 500 ? json[..500] + "..." : json;
-        TargetType = targetType;
-    }
-}
-
 /// <summary>
 /// High-performance custom JSON deserializer optimized for IId&lt;T&gt; reference handling.
 /// Uses Utf8JsonReader for streaming deserialization when possible (STJ approach).
diff --git a/AyCode.Core/Serializers/Jsons/AcJsonSerializer.JsonSerializationContext.cs b/AyCode.Core/Serializers/Jsons/AcJsonSerializer.JsonSerializationContext.cs
index 95e25df..07013f8 100644
--- a/AyCode.Core/Serializers/Jsons/AcJsonSerializer.JsonSerializationContext.cs
+++ b/AyCode.Core/Serializers/Jsons/AcJsonSerializer.JsonSerializationContext.cs
@@ -35,7 +35,7 @@ public static partial class AcJsonSerializer
         }
     }
 
-    private sealed class JsonSerializationContext : IDisposable
+    private sealed class JsonSerializationContext : AcSerializeBase, IDisposable
     {
         private readonly ArrayBufferWriter<byte> _buffer;
         public Utf8JsonWriter Writer { get; private set; }
diff --git a/AyCode.Core/Serializers/Toons/AcToonSerializer.ToonSerializationContext.cs b/AyCode.Core/Serializers/Toons/AcToonSerializer.ToonSerializationContext.cs
index ae6420d..4e064cd 100644
--- a/AyCode.Core/Serializers/Toons/AcToonSerializer.ToonSerializationContext.cs
+++ b/AyCode.Core/Serializers/Toons/AcToonSerializer.ToonSerializationContext.cs
@@ -47,7 +47,7 @@ public static partial class AcToonSerializer
     /// Pooled context for Toon serialization.
     /// Handles output building, indentation, and reference tracking.
     /// </summary>
-    private sealed class ToonSerializationContext
+    private sealed class ToonSerializationContext : AcSerializeBase
     {
         private readonly StringBuilder _builder;
         private Dictionary<object, int>? _scanOccurrences;