Lowering security overhead in link state routing1
Section snippets
Introduction: security of routing protocols
As both the complexity and diversity of today's networks and internetworks grow, so does the need for new, more versatile and more efficient routing protocols. Since routing is a critical network function, security of routing protocols is naturally very important. This has been widely recognized by the designers of many routing protocols both past and present. Sound security, however, comes at a high price which translates into processing, bandwidth and storage overhead. Consequently, it is
Secure link state routing
Network routing has received a lot of attention in the last three decades as evidenced by the enormous amount of literature in the field. Dijkstra's Shortest Path [7] and Ford/Fulkerson's Max Flow algorithms [6] gave rise to link state and distance vector routing protocols, respectively. In distance vector protocols, nodes keep tables of the best paths and associated metrics for all possible destinations and periodically exchange the contents of the tables with neighbors. In contrast, link
Requirements
Before attempting to construct solutions we briefly examine the requirements for LSU security:
- 1.
Origin authentication,
- 2.
Non-repudiation,6
- 3.
Data integrity,
- 4.
Timeliness and ordering.
Building blocks
We use two basic tools in our construction of secure LSU distribution: public key-based digital signatures and one-way hash functions. Signatures can be computed using any well-known public key cryptosystem: RSA, DSS, El Gamal, Schnorr, etc. A number of (conjectured) strong one-way functions have been proposed, e.g., MD4, MD5, 8-pass SNEFRU and SHA 1, 2, 5, 12.
We also take advantage of a simple and elegant technique of constructing hash chains similar to that utilized in S/KEY one-time
Stable link state
In this section we describe a simple technique for reducing cryptographic costs associated with LSU processing. This scheme, referred to as SLS (Stable Link State), is effective when network links and nodes are fairly stable and LSUs are triggered either by time or by explicit requests.
It has been observed that a large percentage (50%, by some estimates) of LSUs are simply re-statements of previous LSUs. In other words, an LSU often carries no new information other than its timing since links
Fluctuating link state
The SLS scheme is not very effective if links and nodes fluctuate. However, it is precisely under such conditions when the cost of processing LSUs is particularly felt. In this section we outline a technique called FLS (Fluctuating Link State) aimed at a more dynamic routing environment.
The basic technique in FLS is similar to that in SLS. However, instead of one, each router generates distinct hash chains forming a hash table. (Where n is the number of steps in the chain and k is the
Applications in ad hoc networks
It has been one of our implicit assumptions thus far that the underlying network is fixed. Obviously, any kind of node mobility complicates not only SLS/FLS but, much more importantly, the functioning of the routing protocol itself. Therefore, it might seem that techniques such as SLS/FLS are much less suitable for mobile networks than for their fixed counterparts. Surprisingly, this is not the case for at least some mobile networks.
At the extreme of mobility are the networks often referred to
Summary and future directions
In conclusion, this paper presented two techniques for efficient and secure generation and processing of updates in link state routing protocols. The first technique (SLS) is geared towards relatively stable network environments where node and link outages are infrequent. The second, more involved, technique (FLS) is designed with more volatile environments in mind. However, neither technique is particularly suitable for the worst-case scenario of arbitrary failures. Work is on-going to
Acknowledgements
The authors would like to acknowledge Michael Steiner, Hilarie Orman, Kannan Varadhan, Michael Waidner and anonymous referees for their valuable comments on the earlier drafts of this paper.
Ralf Hauser is currently a Senior Associate with McKinsey & Company. Before joining McKinsey in 1995 he was a Researcher at IBM Research (Zurich Laboratory) since 1992. He obtained his Ph.D. (1995) from the University of Zurich and M.S. in Computer Science (1992) from the University of Toronto, and B.S./B.B.A (1990) from the University of Zurich. Ralf Hauser has published in the areas of computer security and electronic commerce and his research interests include network security, electronic
References (19)
- R. Rivest, The MD5 Message-Digest Algorithm, Internet RFC 1321, April...
- R. Rivest, The MD4 Message-Digest Algorithm, Internet RFC 1320, April...
- J. Moy, OSPF Version 2, Internet RFC 2178, July...
- R. Perlman, Network layer protocols with byzantine robustness, Ph.D. Dissertation, MIT LCS TR-429, October...
- R. Merkle, One-way hash functions and DES, Proc. CRYPTO 89, August...
- L. Ford, D. Fulkerson, Flows in Networks, Princeton University Press, Princeton, NJ,...
- E. Dijkstra, Self-stabilization in spite of distributed control, Communications of the ACM, November...
- N. Asokan, G. Tsudik, M. Waidner, Server-supported signatures, 1996 European Symp. on Research in Computer Security,...
- R. Hauser, G. Tsudik, On shopping incognito, 2nd USENIX Workshop on Electronic Commerce, November...
Cited by (36)
Routing path authentication in link-state routing protocols
2012, Network SecurityEvaluation of efficient security for BGP route announcements using parallel simulation
2004, Simulation Modelling Practice and TheoryCitation Excerpt :In the following section we propose an optimization that offers the hope of achieving nearly the convergence of ordinary BGP, but without the overhead and uncertainty of caching. Questions related to reducing the cost of cryptography in the routing context have been raised before, e.g. [9,35]. Such methods typically work to reduce the cost by reducing the dependence on public-key methods, i.e. develop different ways of authentication.
A formal treatment of efficient byzantine routing against fully byzantine adversary
2018, NCA 2018 - 2018 IEEE 17th International Symposium on Network Computing and ApplicationsQuality of Service in Mobile Ad Hoc Networks
2017, The Handbook of Ad Hoc Wireless NetworksCryptanalysis of secure routing among authenticated nodes in MANETs
2017, Advances in Intelligent Systems and Computing
Ralf Hauser is currently a Senior Associate with McKinsey & Company. Before joining McKinsey in 1995 he was a Researcher at IBM Research (Zurich Laboratory) since 1992. He obtained his Ph.D. (1995) from the University of Zurich and M.S. in Computer Science (1992) from the University of Toronto, and B.S./B.B.A (1990) from the University of Zurich. Ralf Hauser has published in the areas of computer security and electronic commerce and his research interests include network security, electronic commerce, and knowledge management. Email: [email protected].
Antoni Przygienda is currently a Research Staff Member at High Speed Networks Research at Bell Labs, Lucent where he is working on architecture and implementation of IP routing protocols. Before coming to Bell Labs, he was with Fore Systems, Inc. working on PNNI and other ATM related standards and their implementation since 1995, and with IBM Research (Zurich Laboratory) as a Research Staff Member since 1992. He obtained his Ph.D. (1995) and M.S. in Computer Science (1992) from Swiss Federal Institute of Technology. Antoni Przygienda has published in the areas of quality-of-service routing, security and directory services. Email: [email protected]
Gene Tsudik is currently a Project Leader and Senior Research Scientist at the University of Southern California, Information Sciences Institute (USC/ISI). Before coming to USC/ISI in 1996 he was a Research Staff Member at IBM Research (Zurich Laboratory) since 1991. He obtained his Ph.D. (1991) and M.S. (1987) from the University of Southern California, and B.S. (1985) from the University of Houston. Gene Tsudik has published in the areas of internetworking and computer security and his research interests include network security, multicast communication, electronic commerce, mobile computing, fault-tolerant protocols and internetwork routing. Email: [email protected]
- 1
An earlier version of this paper [19] was presented at the ISOC (Symposium on Network and Distributed System Security), February 1997, San Diego, CA, USA.
- 2
E-mail: [email protected].
- 3
E-mail: [email protected].