1. P2P Taxonomy and Security Concerns Ryan Lackey CTO, HavenCo, Ltd. ryan@havenco.com RSA Conference 2002 San Jose 0900 20-02-2002

2. Introduction Variety of P2P systems P2P is not a new thing

3. Types of Systems “Traditional” p2p File Sharing Email Proxies Chat systems Infrastructure systems

4. Major File Systems Napster Gnutella KaZaA/Fasttrack/Morpheus Freenet Mojonation

5. Traditional Email SMTP is peer to peer Deployed with “supernodes” with smtp/pop3 and inter-realm communication via supernodes

6. Cypherpunks-style remailers 35 or so nodes “Onion routing”

7. Chat Systems IRC isn’t really p2p AIM/ICQ with centralized presence Gale, Jabber, IMPP proposals

8. Infrastructure Protocols DNS NTP PKI Certification Authorities

9. Design Comparison Target applications Transport Interactivity Degree of centralization Design/compile-time organization or install/configuration or runtime/evolving Security: traffic encryption, DoS protection, Replication for reliability

10. Implementation Comparison “Official” vs. covert adoption Importance of “network effects” for minimal utility Legal issues (content, copyright controls) Administrative control – what functionality is possible, who exercises it?

11. Security Issues Users provided an incentive to violate security model System not designed to be compatible with non-P2P restrictions Modifies underlying assumptions about connectivity

12. Observations “Old” p2p systems (email, etc.) seem to be designed into security models, so newer systems can emulate Power ultimately wins over security Systems can be re-deployed internally for security

13. Summary Since P2P applications have been popular, and continue to be popular, security practices must take them into account Deployment choices are as important as implementation choices; even unsafe technologies can be wrapped in a security model

14. Q&A