In cryptography

Cryptography

Cryptography is the practice and study of techniques for secure communication in the presence of third parties...

 and computer science

Computer science

Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

 Hash trees or Merkle trees are a type of data structure

Data structure

In computer science, a data structure is a particular way of storing and organizing data in a computer so that it can be used efficiently.Different kinds of data structures are suited to different kinds of applications, and some are highly specialized to specific tasks...

which contains a tree

Tree (data structure)

In computer science, a tree is a widely-used data structure that emulates a hierarchical tree structure with a set of linked nodes.Mathematically, it is an ordered directed tree, more specifically an arborescence: an acyclic connected graph where each node has zero or more children nodes and at...

 of summary information about a larger piece of data – for instance a file – used to verify its contents. Hash trees are a combination of hash list

Hash list

In computer science, a hash list is typically a list of hashes of the data blocks in a file or set of files. Lists of hashes are used for many different purposes, such as fast table lookup and distributed databases...

s and hash chain

Hash chain

A hash chain is the successive application of a cryptographic hash function to a piece of data. In computer security, a hash chain is a method to produce many one-time keys from a single key or password...

ing, which in turn are extensions of hash

Hash function

A hash function is any algorithm or subroutine that maps large data sets to smaller data sets, called keys. For example, a single integer can serve as an index to an array...

ing. Hash trees in which the underlying hash function is Tiger are often called Tiger trees or Tiger tree hashes.
Hash trees can be used to verify any kind of data stored, handled and transferred in and between computers.