CrowdShareSecure Resource Sharing in Mobile Crowds
Stanislaus Stelle
CASED / TU Darmstadt
8th of March 2013 on Moosecon
1
Joined work withAlexandra Dmitrienko | Ahmad-Reza Sadeghi | Elena Reshetova | Thomas Schneider | N. Asokan
Motivation
2
MotivationResource Sharing
3
Motivation
Collaborative workResource Sharing
4
Motivation
Collaborative workResource Sharing
Social Networks
5
Motivation
Collaborative workResource Sharing
Social Networks
6
Mobile
Depends on Carrier
7
4.6 billions without Internet
8
4.6 billions without Internet
9
Focus on Internet Availability
What can weWhat can weWhat can we
do about it
10
Existing Technology: Tethering
Access Point
Participant
Participant
11
Existing Technology: Tethering
Range
Access Point
Participant
Participant
12
Existing Technology: Tethering
Access Point
Participant
Participant
Password
Password
Range
Password Distribution
13
14
Solution: Multihop Resource Sharing
How should this work?
15
16Mesh Network Routing: BATMAN
What aboutsecurity?
17
Link Security
Link Security Access Control
20Link Security Access Control
Anonymity
21Link Security Access Control
Anonymity
Liability
Implementation for Android
Link Security – SSL/VPNAnonymity – Registration with Certs.Liability – Signed Resource RequestsAccess Control – FoF Service
And whataboutliability?
23
Liability
24Has Internet Connection
Internet
Wants to tether
25
Liability
26
Liability
27
Liability
28
LiabilityBound to phone number
Destination IP, Protocol, Port, Timestamp
29
Liability
30
Liability
31
Liability
32
Liability
33
Liability
34
LiabilityLiability
And whataboutaccesscontrol?
35
Friend of Friend Service
Simple alternative
Fancy alternative
36
Simple alternative
37
register
Simple alternative
38
sync
Simple alternative
39
TransmitWhitelists
Fancy alternative
40
Challenges
WiFi in Ad-Hoc modeDynamic Access Control
WiFi and 3G at the same time
WiFi and 3G at the same time
Android prohibits both to be activatedinsmod /system/lib/modules/bcm4329 firmware_path=/system/vendor/firmware/fw_bcm4329.bin
WiFi in Ad-Hoc mode
No System option in Android
iwconfig eth0 channel 11 essid Mesh mode ad-hocifconfig eth0 10.0.0.1 netmask 255.0.0.0 up
Dynamic Access Control
Friend of Friend Service
Liability Feature
Conclusion1) Design of CrowdShare service for secure resource sharing
a. Allows arbitrary people to establish mesh and share resources
b. Enables users to decide what and with whom to share
c. Ensures anonymity, liability, confidentiality, authenticity
2) Implementation for Internet sharing on Android devices
a. Extends Serval
b. Enables internet sharing
c. Brings in a security layer
d. Addresses a number of technical challenges
Thank you
Questions?
