TinMan: Eliminating Confidential Mobile Data Exposure with Security Oriented Offloading
Yubin Xia, Yutao Liu, Cheng Tan, Mingyang Ma, Haibing Guan, Binyu Zang, Haibo Chen
IPADS, Shanghai Jiao Tong University (http://ipads.se.sjtu.edu.cn)
Yubin Xia. [email protected]
Goals & Threat Model
Problem & Motivation
Main Idea
• Offload all c ors accesses to a trusted node
Confidential Record (cor) Exposure
• E.g., password, bank account, social security number
• Such c ritical data remain on a device for long time [1]
• These data might be stolen from a phone
Goals: Nothing to lose!
• Zero exposure of cors on the device at any time
• Support existing apps • Small overhead on both performance and power
Threat Model
• Not trust the software stack on the mobile device
• Only trust the trusted n ode, which maybe a private cloud, a PC at home, etc.
Our Solution: TinMan
1:
Evaluation
Security-oriented Offloading
Latency of PayPal login latency
Caffeinemark
8000
18
Original system
TinMan (symmetric-taint)
TinMan (asymmetric-taint)
7000
CaffeineMark 3.0 Score
Offload cor accesses to a trusted node
• Use tainting to track c or data flow on the client
• Store a placeholder for each cor
Multiple levels of migration
• Ensure no plaintext of a cor exists on the client device
• Make the offloading transparent to applications
6000
12.3
12
5000
4000
3000
9.6%
20.1%
2000
9.4
9
9.2
7.1
6
3
1000
0
Original login
On-demand offload
SSL/TCP offload
15
Elapsed Time (Seconds)
Design Overall
• Using security-‐oriented offloading mechanism to seamlessly support existing applications
On-‐demand Offloading
• Java DSM offloading engine based on COMET [2]
• Track dataflow of placeholders of cors on the client
SSL Offloading: Session Injection
• Migrate a part of an SSL session from
mobile device to the trusted node
• Different transferred metadata based on different encryption methods used by SSL
TCP Offloading: Payload Replacement
• Trusted node replaces the payload of the packet with the cor, and then sends it out
Asymmetric Tainting
• Adopt lightweight tainting on the mobile device
• Adopt full-‐fledged tainting on the trusted node
Sieve
Loop
Logic
String
Float
Method Overall Score
0
Orig TinM
inal
an
WIFI
Orig TinM
inal
an
Configurations
3G
1. Y. Tang, P. Ames, S. Bhamidipati, A. Bijlani, R. Geambasu, and N . Sarda. Cleanos: Limiting mobile data exposure with idle eviction. I n O SDI, 2012.
2. M. S. Gordon, D. A. Jamshidi, S. Mahlke, Z. M. Mao, and X. Chen. Comet: code offload b y migrating execution trans-‐ parently. I n OSDI, 2012.
This is a conference paper poster. The paper will be presented on Session 8, 09:00 -‐ 10:15 on 24 April.