Minimizing unwanted traffic in a global messaging system. Spam, denial-of-service-attacks, and edacious subscribers

The main purpose of this paper is to illuminate two types of unwanted traffic in a publish/subscribe system -- malicious (spam, DoS attacks) and vain (unused events) -- and suggest a general mechanism for minimizing their effects. We do this by augmenting the classic publish/subscribe interface with volume-limiting parameters -- a combination of attributes assigned to events by publishers and thresholds specified by subscribers -- and consider the implications of this interface on the unwanted traffic and on the routing infrastructure. Notably, we observe that this mechanism can minimize unwanted traffic without total access control if the routing substrate supports two properties: flow control and routing integrity.