DHTnil: An Approach to Publish and Lookup Nilsimsa Digests in DHT

Nilsimsa algorithm plays an important role in the digest-based anti-spam technique. Based on the research about Nilsimsa digest, we propose an approach to publish and lookup for Nilsimsa digests inDHT: DHTnil. In this paper, we discuss DHTnil´s publication and lookup algorithm in detail, and evaluate the effectiveness of DHTnil through simulation experiments. For random generated digests, DHTnil can guarantee that the publication of a group of similar Nilsimsa digests involves no more than 3% of all subspaces, and the similar lookup of a digest involves no more than 3.5% of all subspaces to guarantee a recall rate of 80%. For real junk email samples collected from Internet, DHTnil has an even better performance.