FragDB - ETH Z · 5/11/2007 · FragDB – „Hands-Free“ Access Control Mimics real-world...
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FragDB FragDB Secure Localized Storage Based on S Di t ib t d RFID T I f t t Super-Distributed RFID-Tag Infrastructures M L hi ih Marc Langheinrich Institute for Pervasive Computing, ETH Zurich, Switzerland
Transcript of FragDB - ETH Z · 5/11/2007 · FragDB – „Hands-Free“ Access Control Mimics real-world...
FragDBFragDBSecure Localized Storage Based onS Di t ib t d RFID T I f t tSuper-Distributed RFID-Tag Infrastructures
M L h i i hMarc LangheinrichInstitute for Pervasive Computing, ETH Zurich, Switzerland
L ti b d A C t lLocation-based Access Control
FragDB: A Location-Based Access Control System
Location-Based Access Control in the Real World
Marc‘s Not In
My Office
May 11, 2007 5PALMS 2007 Workshop
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Coffe BreakCafeteria
May 11, 2007 8PALMS 2007 Workshop
h kNo ID Check Here
A Classroom
See What‘s Marc Teaching TodaySee What s Marc Teaching Today
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Examples of „Hands-Free“ Access Control
Information Not Secret“Information Not „SecretBut wouldn‘t want it broadcasted either
L ti B d ALocation-Based AccessIf you‘re in the vicinity, feel free to look
No Management – „Hands-Free“No users, passwords, certificates, policies
May 11, 2007 10PALMS 2007 Workshop
FragDB: A Hands-Free Access Control System
Like Virtual Post-Its
Your Data
A Place
A Visitor
May 11, 2007 12PALMS 2007 Workshop
Basic FragDB Principle: Fingerprinting
Principle: Fingerprinting Place & Time
A VisitorYou
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Principle: Fingerprinting Place & Time
A VisitorYou
Places Change – Fingerprints Should TooPlaces Change Fingerprints Should, TooOtherwise: one visit gives continued accessOld fingerprints fade away“Old fingerprints „fade away
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Fingerprint Requirements
Fluid BoundariesFluid BoundariesTolerate „close enough“ positions
Ti V iTime VarianceFingerprints change over time
Time ContinuityOld fingerprints fade-away slowly
Secure StorageAccess to central server yields no informationy
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Technology Enabler: RFID (Hitachi mu-Chips)
μ-Chip 2005 (Hitachi)
RFID ChipSize: 0 4 x 0 4 mmSize: 0.4 x 0.4 mmCarrier frequency: 2.45 GHzOperating distance: 0-25 cmMemory capacity 128bit ROMMemory capacity: 128bit ROMOperating temperature: -27 to +75ºCAnti-collision: no Response time: 20 msOptional external antenna
May 11, 2007 18PALMS 2007 Workshop
Super-Distributed RFID Tag Infrastructures
A VisitorYou
Bohn Mattern: Super-Distributed RFID TagBohn, Mattern: Super-Distributed RFID Tag Infrastructures. EUSAI 2004, Eindhoven, NL
Passive RFID tags deployed in vast quantities and in aPassive RFID tags deployed in vast quantities and in a highly redundant fashion over large areas or surfaces
May 11, 2007 20PALMS 2007 Workshop
FragDB: Basic Principles
FragDB: Fragmented Database Storage
Each Tag-ID Represents Single Storage CellEach Tag-ID Represents Single Storage CellData is fragmented and stored „in“ tagsCentral storage (encrypted with hashed ID)Central storage (encrypted with hashed ID)
Fl id B d i F d E C ti1. Fluid Boundaries: Forward Error CorrectionData is redundantly stored across several cells
2. Time Variance: Ids Change Over TimeProbabilistic after n readouts (currently simulated)
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4. Secure Storage
Cell Data is Encrypted With Key == Hashed Tag IDNo need for key managementNo need for key management
Storage Cell Location NOT tag ID but Hashed KeyStorage Cell Location NOT tag ID, but Hashed KeyOtherwise: trivial DB-scan attack possibleB t i l t t ll l ti f t IDBut: simple to compute cell location from tag ID
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3. Time ContinuityTag ID Memory
RFID TagsStorage System
C t ID8AF62 54017 03BCA 7843AFile67 - File315 File315, File942
RFID TagsStorage System
C t ID8AF62 54017 03BCA 7843AFile67 - File315 File315, File942
Tag ID-Memory
Current IDCurrent IDF2539
B35F*
8DC12
0439*
948AA
8CC3*
43B21
D132*
File315
File942, File4
File315, File4
File4 File4, File42, …File952
File942 File67
siveFile 4
04DA*
74A**
9DB**
B3EC*
C34**
324**
1231*
BC3**
987**
E321*
DE2**
9E4**
File12, File44
-
File91
File44, File12
File91
-
File44
File91, File12
File14, File74
File44
File91, File12
File74 ally
expe
ns
File 91 9
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98
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9
File14, File15, …
File4856
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4, 74
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-
74
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File32 bina
toric
a9
Tags „remember“ their old IDsOld t d ll l fid lit (i bit )
Com
Old tags gradually loose fidelity (i.e., bits)
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What Can You Do With This?
Classroom Cam
Pass Through Here to Get Lecture Video
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Example: Fingerprinting Road Infrastructures
Continually Fingerprint Road
Store Warning on Previous Segment
Store Warning for Approaching CarsStore Warning for Approaching Cars
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Prototype Implementation
mu-Chip Reader
mu-Chips
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Simulator Control Panel
Virtual Surface
Storage Cells
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Storage Cells
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RFID TagsRFID TagsStorage System
Current ID8AF62
F2539
54017
8DC12
03BCA
948AA
7843A
43B21
File67
File315
-
File315, File4
File315
File942
File315, File942
File67
B35F*
04DA*
0439*
B3EC*
8CC3*
1231*
D132*
E321*
File942, File4
File12, File44
File4 File4, File42, …File952
File44, File12 File44 File44
File 4
74A**
9DB**
89***
C34**
324**
AC***
BC3**
987**
AA***
DE2**
9E4**
12***
-
File91
File14 File15
File91
-
File14 File74
File91, File12
File14, File74
File4856
File91, File12
File74
File14
File 91
May 11, 2007
89
C1***
AC
9C***
AA
84***
12
4E***
File14, File15, …
File4856
File14, File74
File44265
File4856
-
File14
File32
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Summary
FragDB – „Hands-Free“ Access Control
Mimics real-world location-based access controlMimics real-world location-based access controlUseful for many types of semi-public data, e.g., out of office notices lecture materials road conditionsoffice notices, lecture materials, road conditions, …
Principle: Embedded RFIDs & Fragmented StorageFluid BoundariesFluid BoundariesTime VarianceTi C ti itTime ContinuitySecure Storageilt Si l t d t t ( hi )Built Simulator and Prototype (mu-Chips)
May 11, 2007 33PALMS 2007 Workshop
More in the Tech Reportfind it at people inf eth ch/langhein/find it at: people.inf.ethz.ch/langhein/
Effects of ID-fading“Effects of „ID-fadingtime- vs. usage-based updates
St t i f d t hStrategies for data searchesHow to reassemble a file
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S i A tService Announcement
Ubicomp Privacy Workshop 2007Ubicomp Privacy Workshop 2007
Organized ByJohn Canny (UC Berkeley)
Marc Langheinrich (ETH Zurich)Sarah Spiekermann (Humboldt University Berlin)
Technologies, Users, Policy
Keynotes & Contributions by Leading Privacy ExpertsLorrie Cranor Jason Hong John Krumm Serge Guthwirth Paul de Hert
Selected Papers Published in „Personal & Ubiquitous Comp.“
Lorrie Cranor, Jason Hong, John Krumm, Serge Guthwirth, Paul de Hert, …
Submission Deadline: June 1, 2007
May 11, 2007
www.vs.inf.ethz.ch/events/uc7privacy/36PALMS 2007 Workshop
