Definition: DHT

(Distributed Hash Table) A method for storing hash tables in geographically distributed locations in order to provide a failsafe lookup mechanism for distributed computing. Various algorithms have been explored that provide the right balance and speed for storing parts of the tables in different locations. Having been used in the early and mid-1990s for local area network storage, after the turn of the century, DHTs were brought into focus for peer-to-peer computing over the Internet. A DHT provides a fault tolerant storage interface on top of which is layered an application such as music sharing, file sharing or distributed backup.

In 2002, the National Science Foundation awarded a grant to the IRIS Project (Infrastructure for Resilient Internet Systems) to develop failure-proof lookup tables for data storage. Five universities and research institutes were involved (for more information, visit http://iris.lcs.mit.edu).