1. Re-thinking Security in Network Mobility Jukka Ylitalo Ericsson Research NomadicLab NDSS '05 Workshop - February 2

2. Outline ● Nodes in the Architecture ● Problem description ● Identifier – locator split in HIP ● Identifier multiplexed locator translation ● Signaling delegation between identifiers ● Conclusions

3. Nodes in the Architecture Mobile Router (MR) Access Router (AR) Internet Correspondent Node (CN) Mobile network Mobile Node (MN) MR Nested mobile network Rendezvous Server (RS)

4. Problem Statement ● How to inform peers about MN's new location in a secure and efficient way? ● How to sustain optimal routing? MN MR AR CN ? ● Address Binding Update (BU) ● Challenge-response Test

5. Related Problems ● Signaling explosion in highly populated networks. ● Suboptimal routing. ● Authorizing MR to signal on behalf of the MN. ● Address assignment inside mobile network.

6. Identifier - Locator Split in HIP ● A new public-key based Host Identifier (HI) name space ● Sockets bound to HIs, not to IP addresses. ● HIs translated to IP addresses by kernel Process Transport Host Identity IP Layer Link Layer Host ID IP Address Dynamic binding

7. Advantage of Cryptographic HIs ● Public-key based end-point identifiers (HIs) vs. untrustworthy IP addresses. ● Possible to authorize and delegate signaling rights between HIs in a secure way. ● Possible to use authorization certificates, e.g., SPKI certificates.

8. HI multiplexed Locator Translation ● MN registers its HI and local unicast address to MR. ● MN learns MR's HI during the registration. ● MR implements HI multiplexed locator translation. MN MR Internet Registration Local unicast address space

9. Authorizing MR to send BUs ● MR hides the network mobility from MNs. ● MNs authorize MR to send Binding Update messages on behalf of them to CNs. AR CN RS AR BU signaling from MR MN MR MN MR MN-CoA1 MR-CoA1MR-CoA2 Authorization

10. Delegating Rights to Signaling Proxy ● MR may delegate the signaling rights to a trusted signaling proxy. MN MR Signaling proxy Delegation AR Authorization Internet

11. Optimizing MR-to-CNs Signaling ● The signaling proxy sends BUs on behalf of the MNs to CNs. AR RS CN BU signaling from Sig. Proxy MN MR MN MR Signaling proxy AR Single BU from MR CoA2CoA1 Internet

12. Reach-ability Test ● The peer nodes must verify that the MN is in the MR’s location where the signaling proxy claims the MN to be. AR RS CN Challenge-Response MN MR MN MR Signaling proxy AR CoA2CoA1 Internet

13. Optimizing CNs-to-MR Signaling ● The signaling proxy may hide the regional mobility, acting as an on-the-path Mobility Anchor Point (MAP). AR RS CN MN MR MN MR Signaling proxy & MAP AR Single BU from MR Internet MAP Domain

14. Many Roles of a Mobile Router ● Access router (AR) ● HI multiplexed locator translation device ● Mobility Anchor Point (MAP) ● Mobility signaling proxy

15. Conclusions ● The solution is based on the HIP and signaling rights delegation between public-key based HIs. ● Optimized over-the-air mobility signaling inside a mobile network, and between the mobile network and the Internet. ● Optimized routing between MNs and peer nodes.

16. Thank You! Questions, comments?