Hi, On 26.08.2013 00:28, Perry E. Metzger wrote: > We probably don't want any sort of central service running this > network that could be easily disrupted, so identifier to IP address > information should probably be stored in some big honking DHT, signed > in the ID's key. Access to the DHT probably should happen in some > privacy preserving way, possibly through the mix network itself or a > PIR protocol.
Hashing it out in public: Common failure modes of DHT-based anonymity schemes by Andrew Tran, Nicholas Hopper, and Yongdae Kim. In the Proceedings of the Workshop on Privacy in the Electronic Society (WPES 2009), Chicago, IL, USA, November 2009. http://freehaven.net/anonbib/#wpes09-dht-attack "We examine peer-to-peer anonymous communication systems that use Distributed Hash Table algorithms for relay selection. We show that common design flaws in these schemes lead to highly effective attacks against the anonymity provided by the schemes. These at- tacks stem from attacks on DHT routing, and are not mitigated by the well-known DHT security mechanisms due to a fundamental mismatch between the security requirements of DHT routing’s put- get functionality and anonymous routing’s relay selection function- ality. [...] CONCLUSION The anonymity literature, including all of the schemes investi- gated here, is replete with claims that a peer-to-peer architecture is necessary in order to construct a scheme that will work at Internet scale. Distributed Hash Tables offer a scalable architecture for or- ganizing and finding peers, and thus appear to be an obvious choice of peer-to-peer architecture. However, as we have shown there is not a clear bijection between the security and robustness require- ments of a DHT’s put-get interface and an anonymity scheme’s re- lay selection mechanism. This leads to severe vulnerabilities in the existing schemes based on DHTs, limiting the deployability of such schemes. The critical question for future work in this line of research is whether a “DHT-like” algorithm can be designed to meet the specific requirements – in terms of privacy, availability, and correctness – of an anonymity scheme. " _______________________________________________ The cryptography mailing list cryptography@metzdowd.com http://www.metzdowd.com/mailman/listinfo/cryptography