Provably Secure and Practical Onion Routing

The onion routing network Tor is undoubtedly the most widely employed technology for anonymous web access. Although the underlying onion routing (OR) protocol appears satisfactory, a comprehensive analysis of its security guarantees is still lacking. This has also resulted in a significant gap between research work on OR protocols and existing OR anonymity analyses. In this work, we address both issues with onion routing by defining a provably secure OR protocol, which is practical for deployment in the next generation Tor network. We start off by presenting a security definition (an ideal functionality) for the OR methodology in the universal composability (UC) framework. We then determine the exact security properties required for OR cryptographic primitives (onion construction and processing algorithms, and a key exchange protocol) to achieve a provably secure OR protocol. We show that the currently deployed onion algorithms with slightly strengthened integrity properties can b...

• Type: Journal
• Year: 2012
• Where: CSFW
• Authors: Michael Backes, Ian Goldberg, Aniket Kate, Esfandiar Mohammadi
• Keywords: Cryptographic Primitives, CSFW 2012, Integrity Properties, Onion Routing Network, Security Privacy