1. Reputation Systems Thomas Choi COMP 5104 March 5, 2008

2. Trust Lack of trust blamed for many security issues today Limited trust = Reduced effectiveness of distributed OS Issue with trust can be traced to weakness in reputation Reputation describes entity’s trustworthiness Require means for effective and easy to deploy machine-to-machine trust model

3. Related Work PGP Web of Trust: Establish level of trust through trusted third party attestation PKI: Trust established through central certificate authority E-bay Reputation System: Trust established from history of user transactions

4. Proposed Research Use anti-spam DNS-based reputation systems to establish machine-to-machine trust –Lists compromised machines –Populated using a large honeypot/spamtrap Machine queries DNS to determine reputation score of remote host Effective performance and simple to use Technology is not new but applying it to distributed OS to establish trust is new