Abstract. This paper presents a novel use of pairing-based cryptography to improve circuit construction in onion routing anonymity networks. Instead of iteratively and interactively constructing circuits with a telescoping method, our approach builds a circuit with a single pass. The cornerstone of the improved protocol is a new pairing-based privacypreserving non-interactive key exchange. Compared to previous singlepass designs, our algorithm provides practical forward secrecy and leads to a reduction in the required amount of authenticated directory information. In addition, it requires significantly less computation and communication than the telescoping mechanism used by Tor. These properties suggest that pairing-based onion routing is a practical way to allow anonymity networks to scale gracefully.
Aniket Kate, Gregory M. Zaverucha, Ian Goldberg