id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
en-wikipedia-org-8767		Merkle tree - Wikipedia			.html	text/html	2232	309	77	In cryptography and computer science, a hash tree or Merkle tree is a tree in which every leaf node is labelled with the cryptographic hash of a data block, and every non-leaf node is labelled with the cryptographic hash of the labels of its child nodes. Hash trees allow efficient and secure verification of the contents of large data structures. Hash trees are also used in the IPFS, Btrfs and ZFS file systems[4] (to counter data degradation[5]); Dat protocol; Apache Wave protocol;[6] Git and Mercurial distributed revision control systems; the Tahoe-LAFS backup system; Zeronet; the Bitcoin and Ethereum peer-to-peer networks;[7] the Certificate Transparency framework; and a number of NoSQL systems such as Apache Cassandra, Riak, and Dynamo.[8] Tiger tree hash[edit] It uses a binary hash tree (two child nodes under each node), usually has a data block size of 1024 bytes and uses the Tiger hash.[14]	./cache/en-wikipedia-org-8767.html	./txt/en-wikipedia-org-8767.txt