A
distributed hash table (
DHT) is a class of a decentralized
distributed system that provides a lookup service similar to a
hash table: (
key,
value) pairs are stored in a DHT, and any participating
node can efficiently retrieve the value associated with a given key. Responsibility for maintaining the mapping from keys to values is distributed among the nodes, in such a way that a change in the set of participants causes a minimal amount of disruption. This allows a DHT to
scale to extremely large numbers of nodes and to handle continual node arrivals, departures, and failures.