Assentication: User De-Authentication and Lunch Time Attack - - PDF document

assentication user de authentication and lunch time
SMART_READER_LITE
LIVE PREVIEW

Assentication: User De-Authentication and Lunch Time Attack - - PDF document

5/25/2019 Assentication: User De-Authentication and Lunch Time Attack Mitigation with Seated Posture Biometric University of California, Irvine Tyler Kaczmarek , Ercan Ozturk, Gene Tsudik { tkaczmar , ercano, gtsudik}@uci.edu 1 Overview


slide-1
SLIDE 1

5/25/2019 1

Assentication: User De-Authentication and Lunch Time Attack Mitigation with Seated Posture Biometric

University of California, Irvine Tyler Kaczmarek, Ercan Ozturk, Gene Tsudik {tkaczmar, ercano, gtsudik}@uci.edu

1

Overview

  • Introduction, Motivation and Background
  • Assentication Biometric
  • Adversarial Model
  • Assentication Prototype Setup and User Study
  • Conclusion/Future Work

2

slide-2
SLIDE 2

5/25/2019 2

Authentication

  • Effective user authentication critical for meaningful security system

Modern systems typically use 2 factors:

  • What you know (password/PIN)
  • What you have (physical token)
  • What you are / how you behave (biometrics)
  • Can be biological or behavioral
  • Confirms legitimate user present at session start

3

Workplace Activities

[A1]: Work while providing continuous input [A2]: Take a quick seated nap or meditation break [A3]: Read some printed material [A4]: Use a personal device other than your computer [A5]: Turn away from one's desk to talk [A6]: Consume media without using any input devices [A7]: Take part in an audio or video conference [A8]: Get up momentarily without leaving [A9]: Leave the workplace

4

slide-3
SLIDE 3

5/25/2019 3

The Lunch Time Attack

  • Careless user walks away

without logging out

  • Adversary moves in and hijacks

session

  • Difficult to repudiate
  • Need to periodically

reauthenticate users

5

Continuous Authentication/De-authentication

  • Continuous Authentication
  • Confirm legitimate user presence
  • De-authentication
  • Special case
  • Confirm user absence

6

slide-4
SLIDE 4

5/25/2019 4

Continuous Authentication Goals

  • Correctly identify [A9]
  • Quickly detect circumvention attempts
  • Minimize FRR
  • Confusing [A1]-[A8] for [A9]
  • Minimize FAR
  • Confusing [A9] for [A1]-[A8]
  • Confusing illegitimate users for authorized ones
  • Minimize obtrusiveness
  • Both user burden and extra equipment

7

Default De-authentication: Inactivity Timeouts

  • Lock session if user inactive for given time limit
  • Reduces activities to [A1], and NOT [A1]
  • FRR high for [A2]-[A8]
  • FAR high for non-legitimate users
  • Timeout duration public knowledge

8

slide-5
SLIDE 5

5/25/2019 5

Modern De-authentication Techniques: Keystroke Dynamics and Zebra

  • Keystroke Dynamics [TC 2014]
  • Can detect inauthentic users
  • Requires active input
  • Defaults to inactivity timeout in NOT [A1]
  • Zebra [S&P 2014]
  • Uses wrist device to track arm movements
  • Matches movements to observed input
  • Vulnerable to imitation attack [NDSS 2016]

9

Modern De-authentication Techniques: Gaze Tracking and FADEWITCH

  • Gaze Tracking [NDSS 2015]
  • Follows user eye patterns
  • Detects inauthentic users in 40 sec
  • De-authenticates if user looks away
  • Requires extremely expensive equipment
  • FADEWITCH [ICDCS 2017]
  • Detects presence through RSSI changes on wireless sensors
  • Cannot discriminate impostors from legitimate users

10

slide-6
SLIDE 6

5/25/2019 6

Overview

  • Introduction, Motivation and Background
  • Assentication Biometric
  • Adversarial Model
  • Assentication Prototype Setup and User Study
  • Conclusion/Future Work

11

Assentication Biometric

  • Physical
  • Hip width
  • Weight
  • Leg length
  • Behavioral
  • Posture patterns

12

slide-7
SLIDE 7

5/25/2019 7

Assentication Advantages

  • Passive
  • Not easily circumventable
  • Liveness is implicit
  • No alteration in user behavior
  • Office workers sit >75% of the week
  • Very little specialized hardware
  • Works well with [A1]-[A7]

13

Assentication Disadvantages

  • Incompatible with edge-case office arrangements
  • Yoga balls
  • Standing desks
  • Confuse [A8] for [A9]
  • Day-to-Day stability questionable
  • Weight shifts
  • Posture linked to mood

14

slide-8
SLIDE 8

5/25/2019 8

Overview

  • Introduction, Motivation and Background
  • Assentication Biometric
  • Adversarial Model
  • Assentication Prototype Setup and User Study
  • Conclusion/Future Work

15

Adversarial Model

  • Insider attacks responsible for 28% of crimes in industry
  • Disgruntled employee with physical access
  • Doesn’t want to be linked to attack

16

slide-9
SLIDE 9

5/25/2019 9

Casual Adversary

  • Aware of Assentication
  • Tries to physically imitate posture
  • Does not use extra equipment

17

Determined Adversary

  • Aware of Assentication
  • Access to sensor data
  • Access to precise victim measurements
  • Constructs a physical victim model
  • Constructs pneumatic/hydraulic contraption

18

slide-10
SLIDE 10

5/25/2019 10

Overview

  • Introduction, Motivation and Background
  • Assentication Biometric
  • Adversarial Model
  • Assentication Prototype Setup and User Study
  • Conclusion/Future Work

19

Prototype Design

20

  • 2003/2004 Hon Mid-Back Task Chair
  • 16 Tekscan Flexiforce A401 Large Force Sensing Resistors
  • 2 Arduino 101 modules
  • Total instrumentation cost - $275
  • Under $150 at 30-user scale
slide-11
SLIDE 11

5/25/2019 11

Prototype Construction

21

User Study

  • 30 subjects
  • 10 female
  • 20 male
  • Brought prototype to subjects in their office environment
  • Each user spent 10 minutes seated on prototype
  • Measurements collected every 0.5 seconds

22

slide-12
SLIDE 12

5/25/2019 12

Raw Data: Posture shift

23

Identification Results – True Positive Rates

24

slide-13
SLIDE 13

5/25/2019 13

Identification Results – False Positive Rates

25

Results – Continuous Authentication

  • Anomaly detector
  • Trains 5 minutes
  • Checks every 1.5 seconds
  • 3 0.5 second frames
  • Classifies each frame as “extreme” or not
  • If all 3 are “extreme” user rejected
  • 0% of legitimate users rejected
  • 91% of impostor data rejected after first 1.5 seconds
  • 100% of rejected by 45 seconds

26

slide-14
SLIDE 14

5/25/2019 14

Overview

  • Introduction, Motivation and Background
  • Assentication Biometric
  • Adversarial Model
  • Assentication Prototype Setup and User Study
  • Conclusion/Future Work

27

Conclusions

  • Assentication biometric can be used for de-authentication
  • 94.2% accuracy for identification
  • 100% accuracy for continuous authentication
  • Casual impersonation unlikely
  • 90% imposters immediately rejected
  • 100% imposters rejected by 45 seconds
  • Determined impersonation logistically difficult

28

slide-15
SLIDE 15

5/25/2019 15

Future Work

  • Longitudinal study
  • Understand longevity of Posture Patterns
  • Workplace evaluation
  • Adversarial study
  • Both casual and determined

29

References

  • S. Eberz, K. B. Rasmussen, V. Lenders, and I. Martinovic, Preventing lunchtime attacks: Fighting insider

threats with eye movement biometrics." in Network and Distributed System Security Symposium 2015 (NDSS), Internet Society, San Diego, 2015.

  • A. A. Ahmed and I. Traore, “Biometric recognition based on free-text keystroke dynamics,“ in IEEE

Transactions on cybernetics, vol. 44, no. 4, pp. 458-472, 2014.

  • M. Conti, G. Lovisotto, I. Martinovic, and G. Tsudik, Fadewich: Fast deauthentication over the wireless

channel," in 2017 IEEE 37th International Conference on Distributed Computing Systems (ICDCS). IEEE, 2017,

  • pp. 2294-2301.
  • S. Mare, A. M. Markham, C. Cornelius, R. Peterson, and D. Kotz, Zebra: zero-effort bilateral recurring

authentication," in 2014 IEEE Symposium on Security and Privacy (S&P). IEEE, 2014, pp. 705-720.

  • Huhta , O , Shrestha , P , Udar , S , Juuti , M , Saxena , N & Asokan , N 2016 , Pitfalls in Designing Zero-Effort

Deauthentication: Opportunistic Human Observation Attacks . in Network and Distributed System Security Symposium 2016 (NDSS). Internet Society , San Diego , pp. 1-14 , Network and Distributed System Security Symposium , San Diego , United States , 21/02/2016 . DOI: 10.14722/ndss.2016.23199

30