Security issues in public access WLAN architectures March 2002 Security issues in public access WLAN architectures Mats Näslund, Stefan Rommer Ericsson Mats Näslund & Stefan Rommer, Ericsson

Traditional WLAN Environment March 2002 sjkasjhd March 2002 Traditional WLAN Environment Corporate Intranet protected Crypto Protection AP AP - Trusted environment - No charging Mats Näslund & Stefan Rommer, Ericsson John Doe, His Company

Public Access WLAN Environment March 2002 sjkasjhd March 2002 Public Access WLAN Environment HOME AIRPORT WLAN “HOT-SPOTS” 3G Roaming Net HOTEL OFFICE/WORK PUBLIC AREA Mats Näslund & Stefan Rommer, Ericsson John Doe, His Company

Corporate Network or Service Network March 2002 Access Scenario UTRAN RNC Node B SGSN GGSN/FA Gn Iu Gr(MAP) HSS AuC HLR Gi 3GPP Core Network Access Server/HA AAA Subscriber Mgmt Charging/Billing AAA Corporate Network or Service Network Wx (Diameter) IP AP WSN/FA AAA Roaming Partner Signalling and User Data Signalling Data Protection AP WRAN HOTSPOT Could be highly untrusted! Mats Näslund & Stefan Rommer, Ericsson

Security End-points Protected! (Physically secured) Confidentiality March 2002 Security End-points WRAN AP WSN/FA Protected! (Physically secured) AP Confidentiality (soon: integrity) No protection! Could be tampered with. No protection! Robust charging requires at least integrity protection. Mats Näslund & Stefan Rommer, Ericsson

WLAN Public Access Public access is an important WLAN scenario. March 2002 WLAN Public Access Public access is an important WLAN scenario. Security in public scenarios should be important to TGi. How can TGi secure traffic in the AP and the connecting cable? Make it possible to move the security endpoint into the wired network Other (less secure) possibilities AP in tampering-proof box? Make physical access to Ethernet cable impossible? More? Mats Näslund & Stefan Rommer, Ericsson

Moving the security endpoint March 2002 Moving the security endpoint It should be possible to signal the AP not to perform data authentication (a node inside the wired network will check integrity). Optionally, decryption and the whole security association could be moved. Consequences: Higher security in public scenarios. Transparent for RSN-capable mobile nodes. Little point in using OCB, separate MIC preferred. Simpler/legacy APs (without RSN) could be used. Have to be solved: Signaling between AP and network node, fragmentation, etc. Mats Näslund & Stefan Rommer, Ericsson