Key Management for Onion Routing in a True Peer to Peer Setting
Onion routing is a technique for anonymous and privacy preserving communication at the base of popular Internet anonymity tools such as Tor. In onion routing, traffic is relayed by a number of intermediary nodes (called relays) before it reaches the intended destination. To guarantee privacy and prevent tampering, each packet is encrypted multiple times in a layered manner, using the public keys of the relays. Therefore, this mechanism makes two important assumptions: first, that the relays are able to communicate with each other; second, that the user knows the list of available relays and their respective public keys. Tor implements therefore a distributed directory listing the relays and their keys. When a user is not able to communicate with relays directly, he has to use special bridge servers to connect to the onion network.
This construction, however, does not work in a fully peer to peer setting, where each peer only knows a limited number of other peers and may not be able to communicate with some of them due, for instance, to NAT or firewalls. In this paper we propose a key management scheme for onion routing that overcomes these problems. The proposed solution does not need a directory system and does not imply knowledge of all active relays, while it guarantees the secure distribution of public keys. We also present an alternative strategy for building circuit of relays based on bloom filters. The proposed construction overcomes some of the structural inefficiencies of the Tor design, and opens the way for implementing onion routing over a true peer to peer overlay network.
KeywordsKey Management Onion Routing Peer to Peer
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- 3.Bennett, K., Grothoff, C., Horozov, T., Patrascu, I., Stef, T.: The GNet whitepaper. Tech. rep., Purdue University (2002)Google Scholar
- 5.Chung, K.-I., Sohn, K., Yung, M. (eds.): WISA 2008. LNCS, vol. 5379. Springer, Heidelberg (2009)Google Scholar
- 7.Dingledine, R., Mathewson, N., Syverson, P.F.: Tor: The second-generation onion router. In: USENIX Security Symposium, pp. 303–320. USENIX (2004)Google Scholar
- 8.Isdal, T., Piatek, M., Krishnamurthy, A., Anderson, T.E.: Privacy-preserving p2p data sharing with oneswarm. In: SIGCOMM, pp. 111–122. ACM (2010)Google Scholar
- 9.Landsiedel, O., Pimenidis, L., Wehrle, K., Niedermayer, H., Carle, G.: Dynamic multipath onion routing in anonymous peer-to-peer overlay networks. In: GLOBECOM, pp. 64–69. IEEE (2007)Google Scholar
- 12.McLachlan, J., Tran, A., Hopper, N., Kim, Y.: Scalable onion routing with torsk. In: ACM CCS, pp. 590–599 (2009)Google Scholar
- 13.van der Merwe, J., Dawoud, D.S., McDonald, S.: A survey on peer-to-peer key management for mobile ad hoc networks. ACM Comput. Surv. 39(1) (2007)Google Scholar
- 14.Michéle, B.: Using Onion Routing in Well-Established P2P Networks to Provide Anonymity. Master’s thesis, Technische Universität Berlin (December 2008)Google Scholar
- 15.Mittal, P., Borisov, N.: Shadowwalker: peer-to-peer anonymous communication using redundant structured topologies. In: ACM CCS, pp. 161–172 (2009)Google Scholar
- 16.Naranjo, J.A.M., López-Ramos, J.A., Casado, L.G.: Key management schemes for peer-to-peer multimedia streaming overlay networks. In: Markowitch, O., Bilas, A., Hoepman, J.-H., Mitchell, C.J., Quisquater, J.-J. (eds.) WISTP 2009. LNCS, vol. 5746, pp. 128–142. Springer, Heidelberg (2009)CrossRefGoogle Scholar
- 18.Saboori, E., Mohammadi, S.: Anonymous communication in peer-to-peer networks for providing more privacy and security. CoRR abs/1208.3192 (2012)Google Scholar
- 20.Syverson, P.F., Goldschlag, D.M., Reed, M.G.: Anonymous connections and onion routing. In: IEEE Symposium on Security and Privacy, pp. 44–54. IEEE (1997)Google Scholar
- 21.Wang, Q., Mittal, P., Borisov, N.: In search of an anonymous and secure lookup: attacks on structured peer-to-peer anonymous communication systems. In: ACM CCS, pp. 308–318. ACM (2010)Google Scholar
- 22.Wen, Z., Zhang Niu, S., Cheng Zou, J.: A Key Management Mechanism for DHT Networks. In: IIH-MSP, pp. 339–342. IEEE (2012)Google Scholar