diff --git a/SHAMap.h b/SHAMap.h
new file mode 100644
index 0000000000..62d2d1bea3
--- /dev/null
+++ b/SHAMap.h
@@ -0,0 +1,88 @@
+#ifndef __SHAMAP__
+#define __SHAMAP__
+
+#include "uint256.h"
+
+class SHAMapNodeID
+{
+public:
+	int	mDepth;
+	uint256	mNodeID;
+	
+        bool operator<(const Transaction &) const;
+        bool operator>(const Transaction &) const;
+        bool operator==(const Transaction &) const;
+        bool operator!=(const Transaction &) const;
+        bool operator<=(const Transaction &) const;
+        bool operator>=(const Transaction &) const;
+};
+
+class SHAMapLeafNode
+{
+private:
+	uint256			mNodeID;
+	std::list<uint256>	mHashes;
+	uint256			mNodeHash;
+
+public:
+	SHAMapLeafNode(const uint256& NodeID);
+
+	const uint256& GetNodeID(void) const { return mNodeID; }
+	bool HasHash(const uint256& Hash) const;
+
+	uint256& GetNodeHash();
+
+	bool AddHash(const uint256& Hash);
+	bool DelHash(const uint256& Hash);
+};
+
+typedef boost::shared_ptr<SHAMapLeafNode> pointer;
+
+class SHAMapInnerNode
+{
+private:
+	int		mDepth;
+	uint256		mNodeID;
+	uint256		mHash;
+	uint256[32]	mHashes;
+
+public:
+	SHAMapInnerNode(int Depth, const uint256 &NodeID);
+
+	int GetDepth() const { return mDepth; }
+	const uint256& GetNodeID() const { return mNodeID; }
+	const uint256& GetChildHash(int m) const;
+	const uint256& GetNodeHash() const;
+
+	bool IsRootNode() const { return mDepth==0; }
+	bool IsLastInnerNode() const { return mDepth==9; }
+
+	uint256 GetChildNodeID(int m) const;
+	void SetChildHash(int m, const uint256& Hash);
+	void SetChildHash(const SHAMapInnerNode &mChild);
+	void SetChildHash(const SHAMapLeafNode &mLeaf);
+};
+
+typedef boost::shared_ptr<SHAMapInnerNode> pointer;
+
+// Not all nodes need to be resident in memory, the class can hold subsets
+// This class does not handle any inter-node logic because that requires reads/writes
+
+class SHAMap
+{
+private:
+	boost::mutex mLock;
+	std::map<SHAMapNodeID, SHAMapLeafNode> mLeaves
+	std::multimap<SHAMapNodeID, SHAMapInnerNode> mInnerNodes;
+
+public:
+	SHAMap();
+
+	bool HasInnerNode(int m, const uint160 &nodeID);
+	bool GiveInnerNode(SHAMapInnerNode::pointer);
+	SHAMapInnerNode::pointer GetInnerNode(int m, const uint160 &nodeID);
+
+	bool HasLeafNode(int m, const uint160 &nodeID);
+	bool GiveLeafNode(SHAMapLeafNode::pointer);
+	SHAMapLeafNode::pointer GetLeafNode(int m, const uint160 &nodeID);
+};