FastTrack is a peer-to-peer (P2P) protocol that was used by the Kazaa,[1][2] Grokster,[3] iMesh[4] and Morpheus file sharing programs.
After selling it to Niklas Zennström from Sweden and Janus Friis from Denmark, it was introduced in March 2001 by their Dutch company Consumer Empowerment.
It appeared during the end of the first generation of P2P networks – Napster shut down in July of that year.
To allow downloading from multiple sources, FastTrack employs the UUHash hashing algorithm.
Many people, as well as the RIAA, have exploited this vulnerability to spread corrupt and fake files on the network.