1. LANMAN2002 Stockholm. Sweden Privacy Enhanced Architecture for Location Based Services (PE-LBS) Alberto Escudero-Pascual Royal Institute of Technology -KTH Sweden

2. LANMAN2002 Stockholm. Sweden About the speaker Researcher in the area of Privacy in mobile Internet, data protection and cybercrime at KTH in Stockholm. Tec. Licentiate –“Anonymous and untraceable communications in mobile Internet”. (2001) Dissertation Proposal –'Privacy in the next generation Internet: Data Protection in the context of European Union Policy’. (2002)

3. LANMAN2002 Stockholm. Sweden Background and definitions Location Based Services (LBS) Privacy Enhanced Technologies (PET) Unlinkability and Location Privacy Chaum’s MIXes (1981) SOAP, XML, RPC, 97/66/EC

4. LANMAN2002 Stockholm. Sweden Location Privacy in a nutshell Someone is somewhere doing something Someone  Identity Management Somewhere  Location Privacy Something  Content Confidentiality

5. LANMAN2002 Stockholm. Sweden PE-LBS Architecture 1. Location Acquisition Hardware 2. XML Location Data Record 3. XML (SOAP) Service Request 4. Transport Service 5. Location Based Service Proxy Server 6. Service Modules XML Location XML ServiceRequest Transport LBS PROXY M1M2 S1S2S3 M3

6. LANMAN2002 Stockholm. Sweden 1. Location Adquisition Hardware Fastrax iTrax02. GPS receiver (iTalk & NMEA)

7. LANMAN2002 Stockholm. Sweden Location Data Records  XML Location Data <loc:SLO xmlns:loc="http://www-nrc.nokia.com/ietf-spatial/2001/05/08/location" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www-nrc.nokia.com/ietf-spatial/2001/05/08/location http://www-nrc.nokia.com/ietf- spatial/2001/05/08/location.xsd"> N59.40.54 E017.94.36 +12.99 010 50 2.5 2001-13-11T12:00:01+02:00 2.0 1 M240 M30 T25 179 $ GP,,,...* $GPGLL,5924.3131,N,01756.5752,E,134703.77,A,A*61 LOCATION DATA RECORDS XML LOCATION DATA

8. LANMAN2002 Stockholm. Sweden SOAP Service Request POST /Temperature HTTP/1.1 Host: www.lbs-proxyserver.com Content-Type: text/xml Content-Length: 357 SOAPAction: "http://weather.org/query#GetTemperature" <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"> <EncryptedData xmlns='http://www.w3.org/2001/04/xmlenc#' Type='http://www.w3.org/2001/04/xmlenc#Content'> KeyID XkIHMHS4ka4CXFWA3yESBqQzIp21D1MHYgeREk3i50BBDrPGPUCkL7bXoC8S9 QlIKbghAkHbZDgrzBI6yvP33

9. LANMAN2002 Stockholm. Sweden Service Modules Publishing location –DNS RRLOC –DNS Update using TSIG Requesting information based on location –Location based Info services –Unlinkability MobileID - Location - InfoRequest

10. LANMAN2002 Stockholm. Sweden Conclusions Using a proxy server between the mobile and the location based services we can hide the location of the mobile device. Using XML Encryption and signatures in Simple Object Access Protocol service requests we can provide both message digest and message authentication (accountability).

11. LANMAN2002 Stockholm. Sweden Conclusions PE-LBS and MIX networks Three benefits of the PE-LBS architecture: –A PE-LBS proxy can act as a “mix” by buffering and changing the sequence of processing SOAP requests. –Chain of PE-LBS can be used as a “mix network”. –All the functionalities are Transport Independent.

12. LANMAN2002 Stockholm. Sweden More info Location Privacy and Mobile Internetworking http://www.it.kth.se/~aep/publications