Security and Privacy in Location-based MANETs/VANETs 


In many traditional mobile networking scenarios, nodes establish communication on the basis of public identities. However, in some settings, node identities must not be exposed and node movements should not be traceable. Instead, nodes need to communicate on the basis of their current locations. Such scenarios are encountered in mission critical mobile ad-hoc networks (MANETs), Vehicular ad-hoc networks (VANETs) and delay-tolerant-networks (DTNs) and in the near future geo-social mobile networks. In this project, we consider a number of issues arising in such settings by designing anonymous location based routing protocols. We have designed two protocols so far: ALARM and PRISM. ALARM is a link state based protocol which uses nodes' current locations to disseminate and construct topology snapshots. PRISM is a reactive protocol based on AODV which achieves similar goals. With the aid of advanced cryptographic primitives (i.e., group signatures), both protocols provide a mix of security and privacy features, including: node authentication, data integrity, anonymity and untraceability (tracking-resistance). ALARM also offers protection against insider attacks.

Another important issue in location based MANET/VANETs is secure location verification. We propose new techniques to securely verify locations of nodes in group settings using distance bounding protocols (Group Distance Bounding). Our techniques are a generalization of the single prover single verifier distance bounding protocols.

Key differences between MANETs and other wireless networks (Cellular Networks or Wireless LANs) are:

  1. No Fixed Routing/Forwarding Infrastructure:
    Unlike the Internet or other forms of wireless networks (e.g., cellular mobile networks) MANETs don't have a fixed infrastructure that nodes can rely on for forwarding messages. This is the main reason why the design and operation of such networks is challenging. This also raises new security and privacy concerns.

  2. Collaboration:
    Due to the lack of forwarding infrastructure, MANET nodes have to rely on each other in forwarding traffic. This gives attackers who control MANET nodes the ability to drop packets, reroute them. Attackers can also easily impersonate other nodes and/or violate their privacy by tracking their movements.

  3. Untrusted Environment:
    One of the main uses of MANETs is in mission critical networks. Such networks are used in military, law enforcement and search/rescue operations. MANETs may thus be deployed in hostile environments where adversaries will try to disrupt the operation of the network and compromise the security and privacy of the nodes.

  4. No PKI and On-line Security Infrastructure:
    Unlike the Internet or other forms of wireless networks most MANETs don't have a fixed on-line security infrastructure. Any solution relying on on-line trusted third parties will thus be challenging to implement and operate.
  • Gene Tsudik - Professor at the School of Information and Computer Science, University of California Irvine
  • Karim El Defrawy - Ph.D. and M.Sc. student at the School of Information and Computer Science, University of California Irvine (2005-2010)
Cryptographic Tools and Protocols Used
  • Group Signatures: Group signatures can be viewed as traditional public key signatures with additional privacy features. In a group signature scheme, any member of a (potentially large and dynamic) group can sign a message, producing a group signature. A valid group signature can be verified by anyone who has a copy of a constant-length group public key. A valid group signature implies that the signer is a genuine group member. However, given two valid group signatures, it is computationally infeasible to decide whether they are generated by the same or different group member(s). However, if a dispute arises over a group signature, a special off-line entity – called a Group Manager – can “open” a group signature and identify the actual signer. This important feature is referred to as Escrowed Anonymity or, equivalently, Conditional Anonymity.
  • Threshold Signatures: A threshold signature involves a fixed-size quorum (threshold) of signers. Each signer must be a genuine group member with a share of a group secret signing key. A (t,n) threshold signature scheme supports n potential signers, any t of which can on behalf of the group. Threshold signatures reveal nothing about the t signers; no one can trace the identity of the signers (not even a trusted center who have set up the system).
  • Sequential Aggregate Signatures: A sequential aggregate signature (SAS) represents a certain number of signers signing a given message. The number of signers is not fixed and signers identities are evident from a given SAS. An SAS is much shorter (sometimes constant) than the simple collection of individual signatures.

  • Distance Bounding: Distance bounding protocols are cryptographic protocols that enable a verifier (V) to establish an upper bound on the physical distance to a prover (P). Such protocols are based on timing the delay between sending out challenge bits and receiving back the corresponding response bits.


  • Karim El Defrawy, "Security and Privacy in Location-based Mobile Ad-Hoc Networks", Ph.D. Dissertation, Bren School of Information and Computer Science, University of California Irvine. [PDF]


  • Karim El Defrawy, Gene Tsudik, "Anonymous Location Aided Routing in Suspicious MANETs", IEEE Transactions on Mobile Computing (IEEE TMC), Vol. 10 No. 9, September 2011. [PDF]

  • Karim El Defrawy, Gene Tsudik, "Privacy-Preserving Location-Based On-Demand Routing in MANETs", IEEE Journal of Selected Areas of Communication (IEEE JSAC), Vol. 29 No. 10, December 2011. [PDF]


  • Srdjan Capkun, Karim El Defrawy and Gene Tsudik, "Group Distance Bounding Protocols", The 4th International Conference on Trust and Trustworthy Computing (TRUST 2011). [PDF] [Slides] [Full Technical Report]

  • Karim El Defrawy and Gene Tsudik, "PRISM: Privacy-friendly Routing In Suspicious MANETs (and VANETs)", The 2008 IEEE International Conference of Network Protocols (ICNP'08), October 19-22, Florida, USA. [PDF] [Slides]

  • Karim El Defrawy, Gene Tsudik, "ALARM: Anonymous Location Aided Routing in Suspicious MANETS", The 2007 IEEE International Conference of Network Protocols (ICNP'07), October 16-19, Beijing, China. [PDF] [Slides]
Related Work and Literature
  • Secure MANET Routing Protocols (no privacy guarantees):
  1. Yih-Chun Hu and Adrian Perrig, "A survey of secure wireless ad hoc routing" IEEE Security and Privacy, 2(3):28–39, 2004. [PDF]

  2. Gergely Acs, Levente Buttyan, and Istvan Vajda, "Provably secure ondemand source routing in mobile ad hoc networks," IEEE Transactions on Mobile Computing, 5(11):1533–1546, 2006. [PDF]

  3. Yih-Chun Hu, D.B. Johnson, and A. Perrig, "SEAD: Secure efficient distance vector routing for mobile wireless ad hoc networks," In Proceedings of the Fourth IEEE Workshop on Mobile Computing Systems and Applications, pages 3–13, 2002. [PDF]

  4. Yih-Chun Hu, Adrian Perrig, and David B. Johnson, "Ariadne: A secure on-demand routing protocol for ad hoc networks," Wireless Networks, 11(1-2):21–38, 2005. [PDF]

  5. Jihye Kim and Gene Tsudik, "SRDP: Securing route discovery in DSR," The Second Annual International Conference on Mobile and Ubiquitous Systems: Networking and Services (MobiQuitous'05), 2005. [PDF]

  6. P. Papadimitratos and Z.J. Haas, "Secure Data Communication in Mobile Ad Hoc Networks," IEEE Journal on Selected Areas in Communications (JSAC), Special Issue on Security in Wireless Ad Hoc Networks, February 2006. [PDF]

  • Privacy Preserving Routing Protocols (not location-centric):
  1. G. Calandriello, P. Papadimitratos, A. Lioy, and J.-P. Hubaux, "Efficient and Robust Pseudonymous Authentication in VANET," The Fourth ACM Mobicom International Workshop on Vehicular Ad Hoc Networks (VANET), Montréal, QC, Canada, September 2007. [PDF]

  2. SPAAR: S. Carter and A. Yasinsac, "Secure position aided ad hoc routing," Proceedings of the IASTED International Conference on Communications and Computer Networks (CCN02), pages 329–334, 2002. [PDF]

  3. ANODR: J. Kong and X. Hong, "ANODR: anonymous on demand routing with untraceable routes for mobile ad-hoc networks," In Proceedings of the 4th ACM international Symposium on Mobile Ad Hoc Networking &Amp; Computing (Annapolis, Maryland, USA, June 01 - 03, 2003), MobiHoc '03. [PDF]

  4. D-ANODR: Liu Yang, Markus Jakobsson and Susanne Wetzel, "Discount anonymous on demand routing for mobile ad hoc networks," Securecomm'06, 2006. [PDF]

  5. MASK: Yanchao Zhang, Wei Liu, Wenjing Lou, and Yuguang Fang, "MASK: Anonymous on-demand routing in mobile ad hoc networks," IEEE Transactions on Wireless Communications, 5(9):2376–2385, September 2006. [PDF]

  6. ASR: B. Zhu and Z. Wan et al., "Anonymous secure routing in mobile ad-hoc networks," IEEE International Conference on Local Computer Networks, 2004. [PDF]

  7. AO2P: X. Wu and B. Bhargava, "Ao2p: ad hoc on-demand position-based private routing protocol," IEEE Transactions on Mobile Computing, 2005. [PDF]

  8. ARM: S. Seys and B. Preneel, "ARM: Anonymous routing protocol for mobile ad hoc networks," 20th International Conference on Advanced Information Networking and Applications (AINA), 2:133–137, April 2006. [PDF]

  9. ASRP: Y. Cheng and D. Agrawal, "Distributed anonymous secure routing protocol in wireless mobile ad hoc networks," OPNETWORK, 2005. [PDF]

  10. ODAR: Denh Sy, Rex Chen, and Lichun Bao, "ODAR: On-demand anonymous routing in ad hoc networks," IEEE International Conference on Mobile Adhoc and Sensor Systems (MASS), pages 267–276, Oct. 2006. [PDF]

  • Group Signatures (not an exhaustive list):
  1. A more complete collection of links and bibliography on group signatures can be found here and here.

  2. D. Chaum & E van Heyst, "Group Signatures," In Proceedings of EUROCRYPT '91. [PDF]

  3. Jan Camenisch, "Group Signature Schemes and Payment Systems Based on the Discrete Logarithm Problem", PhD Thesis , Vol. 2 of ETH-Series in Information Security an Cryptography,
    ISBN 3-89649-286-1, Hartung-Gorre Verlag, Konstanz, 1998
    . [PS]

  4. G. Ateniese, J. Camenisch, M. Joye, and G. Tsudik, "A Practical and Provably Secure Coalition-Resistant Group Signature Scheme," In Proceedings of the 20th Annual international Cryptology Conference on Advances in Cryptology (August 20 - 24, 2000). [PDF] [Slides]

  5. L. Chen and T. Pederson, "New group signature schemes," In Proceedings of EUROCRYPT '94.[PDF]

  6. D. Boneh, X. Boyen, and H. Shacham, "Short group signatures," In Proceedings of Crypto '04. [PDF]


Last Modified: September,2011.