A _Merkle Tree_ is a data structure created by Ralph Merkle used for efficiently summarizing and verifying the integrity of large sets of data. Merkle Trees are binary trees containing cryptographic hashes. When N data elements are hashed and summarized in a Merkle Tree, you can check to see if any one data element is included in the tree with at most +log(N)+ calculations, making this a very efficient data structure.
[[simple_merkle]]
.Calculating the nodes in a Merkle Tree
image::images/MerkleTree.png["merkle_tree"]
[[merkle_tree_odd]]
.An even number of data elements, by duplicating one data element