Trust, reputation identity = someone’s collection of attributes
… the Need to remember an object or person’s history and attributes that may change over time = state management
… engineering a reputation or identity system becomes a problem of state management
… for embedded systems and connection oriented protocols, state management is already something we do here, e.g. routing algorithms in P2P nets
… the Web is inherently stateless, so maintaining state requires more work
… for engineering an efficient reputation system, the challenge is in state maintenance and optimising state retrieval.
http://socap.blogspot.com/2008/03/reputation-and-maintaining-state.html