diff --git a/ImageBase.HashBase.UnitTests/HashBaseUnitTests.cs b/ImageBase.HashBase.UnitTests/HashBaseUnitTests.cs
new file mode 100644
index 0000000..5ef24d0
--- /dev/null
+++ b/ImageBase.HashBase.UnitTests/HashBaseUnitTests.cs
@@ -0,0 +1,220 @@
+using System.Collections.Generic;
+using System.Linq;
+using Xunit;
+
+namespace ImageBase.HashBase.UnitTests
+{
+    public class HashBaseUnitTests
+    {
+        public static IEnumerable<object[]> Strings =>
+            new List<object[]>
+            {
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {
+                            new HashItem() { ObjectId = 1, Hash = 1 },
+                            new HashItem() { ObjectId = 2, Hash = 3 },
+                            new HashItem() { ObjectId = 3, Hash = 7 },
+                            new HashItem() { ObjectId = 4, Hash = 37 },
+                            new HashItem() { ObjectId = 5, Hash = 53 },
+                            new HashItem() { ObjectId = 6, Hash = 63 },
+                            new HashItem() { ObjectId = 7, Hash = 127 },
+                            new HashItem() { ObjectId = 8, Hash = 255 },
+                            new HashItem() { ObjectId = 9, Hash = 511},
+                            new HashItem() { ObjectId = 10, Hash = 512},
+                            new HashItem() { ObjectId = 11, Hash = 500},
+                        },
+                        37, 2, 10,new List<long>() { 1, 3, 4, 5 }
+                    },
+
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {
+                            new HashItem() { ObjectId = 1, Hash = 1 },
+                            new HashItem() { ObjectId = 2, Hash = 3 },
+                            new HashItem() { ObjectId = 3, Hash = 7 },
+                            new HashItem() { ObjectId = 4, Hash = 37 },
+                            new HashItem() { ObjectId = 5, Hash = 53 },
+                            new HashItem() { ObjectId = 6, Hash = 63 },
+                            new HashItem() { ObjectId = 7, Hash = 127 },
+                            new HashItem() { ObjectId = 8, Hash = 255 },
+                            new HashItem() { ObjectId = 9, Hash = 511},
+                            new HashItem() { ObjectId = 10, Hash = 512},
+                            new HashItem() { ObjectId = 11, Hash = 500},
+                        },
+                        511, 2, 10,new List<long>() { 7, 8, 9 } },
+
+                    new object[] {
+                        new List<HashItem>()
+                        {
+                            new HashItem() { ObjectId = 1, Hash = 1 },
+                            new HashItem() { ObjectId = 2, Hash = 3 },
+                            new HashItem() { ObjectId = 3, Hash = 7 },
+                            new HashItem() { ObjectId = 4, Hash = 37 },
+                            new HashItem() { ObjectId = 5, Hash = 53 },
+                            new HashItem() { ObjectId = 6, Hash = 63 },
+                            new HashItem() { ObjectId = 7, Hash = 127 },
+                            new HashItem() { ObjectId = 8, Hash = 255 },
+                            new HashItem() { ObjectId = 9, Hash = 511},
+                            new HashItem() { ObjectId = 10, Hash = 512},
+                            new HashItem() { ObjectId = 11, Hash = 500},
+                        },
+                        31, 3, 10,new List<long>() { 2, 3, 5, 6, 7, 8 } },
+
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {                                                 //Hashes
+                            new HashItem() { ObjectId = 1, Hash = 1 },    //1
+                            new HashItem() { ObjectId = 2, Hash = 3 },    //11
+                            new HashItem() { ObjectId = 3, Hash = 7 },    //11
+                            new HashItem() { ObjectId = 4, Hash = 15 },   //111
+                            new HashItem() { ObjectId = 5, Hash = 31 },   //1111
+                            new HashItem() { ObjectId = 6, Hash = 63 },   //11111
+                            new HashItem() { ObjectId = 7, Hash = 127 },  //111111
+                            new HashItem() { ObjectId = 8, Hash = 255 },  //1111111
+                            new HashItem() { ObjectId = 9, Hash = 511},   //11111111
+                            new HashItem() { ObjectId = 10, Hash = 1023 },//111111111
+                            new HashItem() { ObjectId = 11, Hash = 2047 },//1111111111
+                            new HashItem() { ObjectId = 12, Hash = 4095 },//11111111111
+                            new HashItem() { ObjectId = 13, Hash = 8191 },//111111111111
+                        },
+                        511, 1, 100,new List<long>() { 8, 9, 10 },
+                    },
+
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {                                                 //Hashes
+                            new HashItem() { ObjectId = 1, Hash = 1 },    //1
+                            new HashItem() { ObjectId = 2, Hash = 3 },    //11
+                            new HashItem() { ObjectId = 3, Hash = 7 },    //11
+                            new HashItem() { ObjectId = 4, Hash = 15 },   //111
+                            new HashItem() { ObjectId = 5, Hash = 31 },   //1111
+                            new HashItem() { ObjectId = 6, Hash = 63 },   //11111
+                            new HashItem() { ObjectId = 7, Hash = 127 },  //111111
+                            new HashItem() { ObjectId = 8, Hash = 255 },  //1111111
+                            new HashItem() { ObjectId = 9, Hash = 511},   //11111111
+                            new HashItem() { ObjectId = 10, Hash = 1023 },//111111111
+                            new HashItem() { ObjectId = 11, Hash = 2047 },//1111111111
+                            new HashItem() { ObjectId = 12, Hash = 4095 },//11111111111
+                            new HashItem() { ObjectId = 13, Hash = 8191 },//111111111111
+                        },
+                        511, 2, 100,new List<long>() { 7, 8, 9, 10, 11 }
+                    },
+
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {                                                 //Hashes
+                            new HashItem() { ObjectId = 1, Hash = 1 },    //1
+                            new HashItem() { ObjectId = 2, Hash = 3 },    //11
+                            new HashItem() { ObjectId = 3, Hash = 7 },    //11
+                            new HashItem() { ObjectId = 4, Hash = 15 },   //111
+                            new HashItem() { ObjectId = 5, Hash = 31 },   //1111
+                            new HashItem() { ObjectId = 6, Hash = 63 },   //11111
+                            new HashItem() { ObjectId = 7, Hash = 127 },  //111111
+                            new HashItem() { ObjectId = 8, Hash = 255 },  //1111111
+                            new HashItem() { ObjectId = 9, Hash = 511},   //11111111
+                            new HashItem() { ObjectId = 10, Hash = 1023 },//111111111
+                            new HashItem() { ObjectId = 11, Hash = 2047 },//1111111111
+                            new HashItem() { ObjectId = 12, Hash = 4095 },//11111111111
+                            new HashItem() { ObjectId = 13, Hash = 8191 },//111111111111
+                        },
+                        31, 4, 100,new List<long>() { 1, 2, 3, 4, 5, 6, 7, 8, 9 }
+                    },
+
+                    new object[]
+                    {
+                        new List<HashItem>()
+                        {                                                 //Hashes
+                            new HashItem() { ObjectId = 1, Hash = 1 },    //1
+                            new HashItem() { ObjectId = 2, Hash = 3 },    //11
+                            new HashItem() { ObjectId = 3, Hash = 7 },    //11
+                            new HashItem() { ObjectId = 4, Hash = 15 },   //111
+                            new HashItem() { ObjectId = 5, Hash = 31 },   //1111
+                            new HashItem() { ObjectId = 6, Hash = 63 },   //11111
+                            new HashItem() { ObjectId = 7, Hash = 127 },  //111111
+                            new HashItem() { ObjectId = 8, Hash = 255 },  //1111111
+                            new HashItem() { ObjectId = 9, Hash = 511},   //11111111
+                            new HashItem() { ObjectId = 10, Hash = 1023 },//111111111
+                            new HashItem() { ObjectId = 11, Hash = 2047 },//1111111111
+                            new HashItem() { ObjectId = 12, Hash = 4095 },//11111111111
+                            new HashItem() { ObjectId = 13, Hash = 8191 },//111111111111
+                        },
+                        31, 4, 3,new List<long>() { 4, 5, 6 }
+                    },
+
+                new object[]
+                {
+                    new List<HashItem>()
+                    {
+                        //Hashes
+                        new HashItem() {ObjectId = 1, Hash = 1}, //1
+                        new HashItem() {ObjectId = 2, Hash = 3}, //11
+                        new HashItem() {ObjectId = 3, Hash = 7}, //11
+                        new HashItem() {ObjectId = 4, Hash = 15}, //111
+                        new HashItem() {ObjectId = 5, Hash = 31}, //1111
+                        new HashItem() {ObjectId = 6, Hash = 63}, //11111
+                        new HashItem() {ObjectId = 7, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 14, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 15, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 16, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 17, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 8, Hash = 255}, //1111111
+                        new HashItem() {ObjectId = 9, Hash = 511}, //11111111
+                        new HashItem() {ObjectId = 10, Hash = 1023}, //111111111
+                        new HashItem() {ObjectId = 11, Hash = 2047}, //1111111111
+                        new HashItem() {ObjectId = 12, Hash = 4095}, //11111111111
+                        new HashItem() {ObjectId = 13, Hash = 8191}, //111111111111
+                    },
+                    127, 4, 100, new List<long>() {3, 4, 5, 6, 7, 8, 9, 10, 11, 14, 15, 16, 17}
+                },
+
+                new object[]
+                {
+                    new List<HashItem>()
+                    {
+                        //Hashes
+                        new HashItem() {ObjectId = 1, Hash = 1}, //1
+                        new HashItem() {ObjectId = 2, Hash = 3}, //11
+                        new HashItem() {ObjectId = 3, Hash = 7}, //11
+                        new HashItem() {ObjectId = 4, Hash = 15}, //111
+                        new HashItem() {ObjectId = 5, Hash = 31}, //1111
+                        new HashItem() {ObjectId = 6, Hash = 63}, //11111
+                        new HashItem() {ObjectId = 7, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 14, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 15, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 16, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 17, Hash = 127}, //111111
+                        new HashItem() {ObjectId = 8, Hash = 255}, //1111111
+                        new HashItem() {ObjectId = 9, Hash = 511}, //11111111
+                        new HashItem() {ObjectId = 10, Hash = 1023}, //111111111
+                        new HashItem() {ObjectId = 11, Hash = 2047}, //1111111111
+                        new HashItem() {ObjectId = 12, Hash = 4095}, //11111111111
+                        new HashItem() {ObjectId = 18, Hash = 4095}, //11111111111
+                        new HashItem() {ObjectId = 13, Hash = 8191}, //111111111111
+                    },
+                    8191, 6, 100, new List<long>() {7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18}
+                },
+            };
+
+        [Theory]
+        [MemberData(nameof(Strings))]
+        public void CalculatesForSearch(IEnumerable<HashItem> hashesInput, long hashSearch, int searchRadius, int limit, List<long> expectedIDs)
+        {
+            //check 100 times because vantage index can be different
+            for (int i = 0; i < 100; i++)
+            {
+                VPTreeHashBase vpTreeHashBase = new VPTreeHashBase();
+                vpTreeHashBase.CreateIndex(hashesInput);
+
+                var result = vpTreeHashBase.Search(hashSearch, searchRadius, limit).OrderBy(x => x);
+
+                Assert.Equal(expectedIDs, result);
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/ImageBase.HashBase.UnitTests/ImageBase.HashBase.UnitTests.csproj b/ImageBase.HashBase.UnitTests/ImageBase.HashBase.UnitTests.csproj
new file mode 100644
index 0000000..d306a09
--- /dev/null
+++ b/ImageBase.HashBase.UnitTests/ImageBase.HashBase.UnitTests.csproj
@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.5.0" />
+    <PackageReference Include="xunit" Version="2.4.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
+    <PackageReference Include="coverlet.collector" Version="1.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ImageBase.HashBase\ImageBase.HashBase.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/ImageBase.HashBase/HashComparer.cs b/ImageBase.HashBase/HashComparer.cs
new file mode 100644
index 0000000..e9aa898
--- /dev/null
+++ b/ImageBase.HashBase/HashComparer.cs
@@ -0,0 +1,23 @@
+using System.Collections.Generic;
+using ImageBase.Common;
+
+namespace ImageBase.HashBase
+{
+    public class HashComparer : IComparer<HashItem>
+    {
+        private readonly long vantagePointHash;
+
+        public HashComparer(HashItem vantagePoint)
+        {
+            this.vantagePointHash = vantagePoint.Hash;
+        }
+
+        public int Compare(HashItem x, HashItem y)
+        {
+            var result = HammingDistance.Calculate(x.Hash, vantagePointHash)
+                .CompareTo(HammingDistance.Calculate(y.Hash, vantagePointHash));
+
+            return result;
+        }
+    }
+}
\ No newline at end of file
diff --git a/ImageBase.HashBase/HashItem.cs b/ImageBase.HashBase/HashItem.cs
new file mode 100644
index 0000000..0252b5e
--- /dev/null
+++ b/ImageBase.HashBase/HashItem.cs
@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace ImageBase.HashBase
+{
+    public struct HashItem
+    {
+        /// <summary>
+        /// id for object in database
+        /// </summary>
+        public long ObjectId { get; set; }
+
+        public long Hash { get; set; }
+    }
+}
diff --git a/ImageBase.HashBase/IHashBase.cs b/ImageBase.HashBase/IHashBase.cs
new file mode 100644
index 0000000..d96e428
--- /dev/null
+++ b/ImageBase.HashBase/IHashBase.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace ImageBase.HashBase
+{
+    interface IHashBase
+    {
+        /// <summary>
+        /// Creates in memory VP-Tree for specified hashes.
+        /// </summary>
+        /// <param name="items"></param>
+        void CreateIndex(IEnumerable<HashItem> items);
+
+        /// <summary>
+        /// Returns list of objects IDs
+        /// </summary>
+        /// <param name="hash"></param>
+        /// <param name="radius"></param>
+        /// <param name="limit"></param>
+        /// <returns></returns>
+        IReadOnlyList<long> Search(long hash, int radius, int limit); 
+    }
+}
diff --git a/ImageBase.HashBase/ImageBase.HashBase.csproj b/ImageBase.HashBase/ImageBase.HashBase.csproj
index 9f5c4f4..53a73c7 100644
--- a/ImageBase.HashBase/ImageBase.HashBase.csproj
+++ b/ImageBase.HashBase/ImageBase.HashBase.csproj
@@ -1,7 +1,11 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>netstandard2.0</TargetFramework>
+    <TargetFramework>netstandard2.1</TargetFramework>
   </PropertyGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\ImageBase.Common\ImageBase.Common.csproj" />
+  </ItemGroup>
+
 </Project>
diff --git a/ImageBase.HashBase/VPTree.cs b/ImageBase.HashBase/VPTree.cs
new file mode 100644
index 0000000..d5044d8
--- /dev/null
+++ b/ImageBase.HashBase/VPTree.cs
@@ -0,0 +1,84 @@
+using ImageBase.Common;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace ImageBase.HashBase
+{
+    public class VPTree
+    {
+        public VPTree(IEnumerable<HashItem> items)
+        {
+            itemsList = items.ToList();
+
+            startIndex = 0;
+            endIndex = itemsList.Count() - 1;
+
+            CreateNode();
+        }
+
+        private VPTree(List<HashItem> items, int startIndex, int endIndex)
+        {
+            itemsList = items;
+            this.startIndex = startIndex;
+            this.endIndex = endIndex;
+
+            CreateNode();
+        }
+
+        /// <summary>
+        /// A vantage point chosen from data
+        /// </summary>
+        public HashItem VantagePoint { get; private set; }
+
+        /// <summary>
+        /// A radius value defining the range of the node
+        /// </summary>
+        public int Radius { get; private set; }
+
+        /// <summary>
+        /// The left subtree
+        /// </summary>
+        public VPTree Inside { get; private set; }
+
+        /// <summary>
+        /// The right subtree
+        /// </summary>
+        public VPTree Outside { get; private set; }
+
+        private readonly int startIndex;
+        private readonly int endIndex;
+        private readonly List<HashItem> itemsList;
+
+        private void CreateNode()
+        {
+            int childrenCount = endIndex - startIndex;
+
+            int vantagePointIndex = new Random().Next(startIndex, endIndex);
+            VantagePoint = itemsList[vantagePointIndex];
+
+            SwapItems(itemsList, startIndex, vantagePointIndex);
+
+            if (childrenCount < 1)
+                return;
+
+            int median = (endIndex + startIndex) / 2;
+
+            itemsList.Sort(startIndex + 1, childrenCount, new HashComparer(VantagePoint));
+
+            Radius = HammingDistance.Calculate(itemsList[median].Hash, VantagePoint.Hash);
+
+            if (median - startIndex > 0)
+                Inside = new VPTree(itemsList, startIndex + 1, median);
+
+            Outside = new VPTree(itemsList, median + 1, endIndex);
+        }
+
+        private void SwapItems(List<HashItem> items, int index1, int index2)
+        {
+            var temp = items[index1];
+            items[index1] = VantagePoint;
+            items[index2] = temp;
+        }
+    }
+}
diff --git a/ImageBase.HashBase/VPTreeHashBase.cs b/ImageBase.HashBase/VPTreeHashBase.cs
new file mode 100644
index 0000000..35d4eca
--- /dev/null
+++ b/ImageBase.HashBase/VPTreeHashBase.cs
@@ -0,0 +1,73 @@
+using ImageBase.Common;
+using System.Collections.Generic;
+
+namespace ImageBase.HashBase
+{
+    public class VPTreeHashBase : IHashBase
+    {
+        private VPTree root;
+
+        public void CreateIndex(IEnumerable<HashItem> items)
+        {
+            root = new VPTree(items);
+        }
+
+        public IReadOnlyList<long> Search(long hash, int radius, int limit)
+        {
+            var allItems = new List<HashItem>();
+
+            var resultIDs = new List<long>(limit);
+
+            SearchAllIDs(root, allItems, hash, radius);
+
+            allItems.Sort(new HashComparer(new HashItem() { Hash = hash }));
+
+            for (int i = 0; i < limit && i < allItems.Count; i++)
+            {
+                resultIDs.Add(allItems[i].ObjectId);
+            }
+
+            return resultIDs;
+        }
+
+        private void SearchAllIDs(VPTree node, List<HashItem> resultIDs, long hash, int radius)
+        {
+            int centerToPointDistance = HammingDistance.Calculate(node.VantagePoint.Hash, hash);
+
+            if ((centerToPointDistance - radius) > node.Radius)
+            {
+                if (node.Outside != null)
+                {
+                    SearchAllIDs(node.Outside, resultIDs, hash, radius);
+                }
+                return;
+            }
+
+            if ((centerToPointDistance + radius) < node.Radius)
+            {
+                if (node.Inside != null)
+                {
+                    SearchAllIDs(node.Inside, resultIDs, hash, radius);
+                }
+                if (centerToPointDistance <= radius)
+                {
+                    resultIDs.Add(node.VantagePoint);
+                }
+                return;
+            }
+
+            if (node.Outside != null)
+            {
+                SearchAllIDs(node.Outside, resultIDs, hash, radius);
+            }
+            if (node.Inside != null)
+            {
+                SearchAllIDs(node.Inside, resultIDs, hash, radius);
+            }
+            if (centerToPointDistance <= radius)
+            {
+                resultIDs.Add(node.VantagePoint);
+            }
+        }
+    }
+}
diff --git a/imagebase.sln b/imagebase.sln
index 24d2884..4483588 100644
--- a/imagebase.sln
+++ b/imagebase.sln
@@ -15,7 +15,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ImageBase.Common.UnitTests"
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ImageBase.WebApp.UnitTests", "ImageBase.WebApp.UnitTests\ImageBase.WebApp.UnitTests.csproj", "{0B6BEB91-7E92-4848-949E-99633DB4A54B}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ImageBase.ImageHash.UnitTests", "ImageBase.ImageHash.Tests\ImageBase.ImageHash.UnitTests.csproj", "{9B5EFF94-E990-4828-A424-490F31EA3289}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ImageBase.ImageHash.UnitTests", "ImageBase.ImageHash.Tests\ImageBase.ImageHash.UnitTests.csproj", "{9B5EFF94-E990-4828-A424-490F31EA3289}"
+EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "ImageBase.HashBase.UnitTests", "ImageBase.HashBase.UnitTests\ImageBase.HashBase.UnitTests.csproj", "{34EC7522-24B2-4206-B3C1-DA33B9485F2B}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -51,6 +53,10 @@ Global
 		{9B5EFF94-E990-4828-A424-490F31EA3289}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{9B5EFF94-E990-4828-A424-490F31EA3289}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{9B5EFF94-E990-4828-A424-490F31EA3289}.Release|Any CPU.Build.0 = Release|Any CPU
+		{34EC7522-24B2-4206-B3C1-DA33B9485F2B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{34EC7522-24B2-4206-B3C1-DA33B9485F2B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{34EC7522-24B2-4206-B3C1-DA33B9485F2B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{34EC7522-24B2-4206-B3C1-DA33B9485F2B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE