IP Address Location Privacy and Mobile IPv6 draft-koodli-mip6-location-privacy-00.txt draft-koodli-mip6-location-privacy-solutions-00.txt

Introduction Mobile IP defines two IP addresses Home Address (HoA) The MN’s fixed identifier Visible in all packets the MN uses whether on its home network or a visited network Care of Address (CoA) The MN’s routable address on a visited network Visible in all packets sent from the visited network

The problem Roaming problem: HoA on a visited network reveals user roaming to an on-looker CoA reveals user roaming to a correspondent Profiling problem: As with any IPv6 address, an HoA or a CoA can be profiled for activity

Profiling problem Care of Address: Can use privacy extensions to IPv6 (RFC 3041) Could introduce additional Mobile IPv6 signaling Home Address: Using RFC 3041 addresses introduces DNS and IPsec considerations: DNS: DNS update Mobility Option in BU Frequent updates (more than static HoA, and dynamic HoA) DNS TTL has to be small IPsec: Since the MN – HA SA is keyed on HoA, frequent re-keying is necessary Uses HoA as phase 2 identity (IKEv1) or Traffic-Selector- initiator (IKEv2)

Roaming Problem Knowledge of CoA to a correspondent Reverse-tunnel data packets Knowledge of HoA to an on-looker Reverse-tunneling: ESP tunnel between MN and HA carries all traffic including Binding Update and Binding Acknowledgment Route Optimization: Replace HoA with a Label in both Binding Update and data packets Packet formats in the solutions draft

Privacy Label Computation HoA should be recoverable from the Label Label should be computable without HoA, since HoA should not be visible in any route-optimized packets (including BU) sent from the MN to CN If BU is reverse-tunneled, the HoA is visible in the HA – CN path, but Label computation can include HoA If BU is sent route-optimized, HoA is not visible at all, but needs addition of a bit to the HOTI message

Label Computation Privacy Label = String XOR HoA String = First (128, HMAC_SHA1 (K pm, (CoA | Home Nonce Index | Care-of Nonce Index))) K pm = K bm for reverse-tunneled BU K pm = First (64, Kcn (HoA set to all zeros | nonce | 0))

Related Work draft-qiu-mip6-hiding-movement-00.txt draft-zhao-mip6-rr-ext-01.txt draft-dupont-mip6-privacyext-00.html Others?