Abstract

P eer-to-peer systems are distributed systemsthat operate without centralized organiza-tion or control. To find a particular piece of data within the network, P2P systems explicit-ly or implicitly provide a lookup mechanism, or locator function, that matches a given string, or key, to one or more network nodes responsible for the value associated with that key. P2P nodes interoperate by using the same software or the same set of network-based APIs. Current Internet P2P applications typically provide locator functions using time-to-live (TTL) controlled-flooding mechanisms. With this approach, the querying node wraps the query in a single message and sends it to all known neigh-bors. The neighbors then check to see whether they can reply to the query by matching it to keys