October 21th, 2009 HGP Team Hyunho Park, Gianni M. Ricciardi, Pierre Alauzet Hyunho Park, Gianni M. Ricciardi, Pierre Alauzet CS642 - Distributed Systems

1. Proposal review 1. Design specifications 1. Next Plan

Park, Ricciardi, Alauzet CS642 - Session key management in a spontaneous network 3 / 11 October 21th, 2009  We are interest in the case of:  Two private spontaneous networks decide to merge together  We wish to find an efficient way for merging multiple private networks in terms of number of messages and size of the message. 1. Proposal review2. Design specifications3. Next plan

Park, Ricciardi, Alauzet CS642 - Session key management in a spontaneous network 4 / 11 October 21th, 2009  In the private networks they are using common session keys for secure communication,  When merging network(s) it needs to manage session keys. Creating a new session key or choosing one of them for the merged network. Share the new session key to all members.  Related works  GKA(Group Key Agreement)-key paper A mechanism to create a common session key for a group of users. Each member provide a public contribution for creating a common session key. It can share a common session key without the use of a secure channel.  Problem  Require creation of a new session key at every times when the network members are changed(join, leave, merge, separating)  Requires 2n messages exchanges for creation and distribution of a new session key.  Each message for exchange a session key is in size of encrypting SizeOfSessionKey*2*n  Ex) if the key size is 256bit, and size of node is 100=> 256*100*2 = bit = 6.4kbytes. 1. Proposal review2. Design specifications3. Next plan

Park, Ricciardi, Alauzet CS642 - Session key management in a spontaneous network 5 / 11 October 21th, 2009  Related works(cont.) 1. Proposal review2. Design specifications3. Next plan Protocol # of messages for creating and sharing a common session key. Size of a message GKAO(N)2*N*sizeOfSessionKey Dynamic Group Diffie- Hellman Key Exchange O(N ^2 )sizeOfSessionKey Scalable Protocols for authenticated Group Key exchange O(N)… Simple and Fault-Tolerant Key Agreement for Dynamic Collaborative Groups O(LogN*(N))… Our Idea O(N) for leave, merging O(1) for join Join, Merge: sizeOfSessionKey Leave: N*sizeOfSessionKey

Park, Ricciardi, Alauzet CS642 - Session key management in a spontaneous network 6 / 11 October 21th, 2009  Elect a leader for creating and distributing a new session key.  Use of a session key independent of members’ context  It doesn’t need to create a new session key when a node request to join.  It allows choosing one among two existing session keys for a new session key when merging two networks. 1. Proposal review2. Design specifications3. Next plan

October 21th, 2009 HGP Team Hyunho Park, Gianni M. Ricciardi, Pierre Alauzet Hyunho Park, Gianni M. Ricciardi, Pierre Alauzet CS642 - Distributed Systems Thank you for your attention ! Any question ? Thank you for your attention ! Any question ?

1. “Establishing trust in pure ad-hoc networks”, Asad Amir Pirzada, Chris McDonald January 2004 ACSC '04: Proceedings of the 27th Australasian conference on Computer science - Volume 26, Volume 26 (ACM Portal) 2. “Spontaneous networks: Trust in a world of equals”, Gilaberte, R.L.; Herrero, L.P.; Networking and Services, ICNS '06. International conference on July 2006 Page(s): (IEEE Xplore) 3. “Security management for ad-hoc networked resource-limited mobile devices” Sedov, I.; Speicher, S.; Cap, C.; Vehicular Technology Conference, VTC2004-Fall IEEE 60th Volume 5, Sept Page(s): Vol. 5 (IEEE Xplore) 4. “Implicit merging of overlapping spontaneous networks [mobile ad hoc networks]”, Legendre, F.; de Amorim, M.D.; Fdida, S.; Vehicular Technology Conference, VTC2004-Fall IEEE 60th Volume 4, Sept Page(s): Vol. 4 (IEEE Xplore) 5. "Spontnet: experiences in configuring and securing small ad hoc networks”, Feeney, L.M.; Ahlgren, B.; Westerlund, A.; Dunkels, A.; Networked Appliances, “A survey on peer-to-peer key management for mobile ad hoc networks.“, van der Merwe, J., Dawoud, D., and McDonald, S ACM Comput. Surv. 39, 1, Article 1 (April 2007)

1. “An Efficient Session Key Generation Protocol”, Chin-Chen Chang, Chi-Yien Chung, Proceedings of ICCTZOO3 2. “An Efficient Group Key Agreement Protocol for Ad hoc Networks” Daniel Augot, Raghav Bhaskar, Val ? rie Issarny and Daniele Sacchetti Proceedings of the First International IEEE WoWMoM Workshop on Trust, Security and Privacy for Ubiquitous Computing - Volume “Self-organised Group Key Management for Ad Hoc Networks”, Ling Luo, Rei Safavi-Naini, Joonsang Baek and Willy Susilo, ASIAN ACM Symposium on Information, Computer and Communications Security archive Proceedings of the 2006 ACM Symposium on Information, computer and communications security Taipei, Taiwan