Keystroke Biometric System

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Keystroke Biometric System
Client Dr. Mary VillaniInstructor Dr. Charles
Tappert

• Team 4 Members Michael Wuench Mingfei Bi
  Evelin Urbaez Shaji Mary Varghese Michael
  Tevnan

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Contents
1. Introduction
2. New System
3. Experimental Results
4. Conclusion
5. Future Studies
6. Demo
3
Introduction

• Previous Work
• Pace University has 5 years in keystroke
  biometrics research.
• Built a complex system of interworking JAVA and
  PHP programs to support academic research in
  biometrics.
• System can successfully identify and authenticate
  individuals with a relatively high degree of
  accuracy especially during same time periods.

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Current Study

• Objectives
• Modifies the existing systems toward practical
  usage.
• Attempts to verify users taking an online test
  based on the characteristics of their typing.
• Analyze results on new input data.
• Present possible methods for determining instant
  authentication.

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New System Overview
Subject Registration
Keystroke Entry
Test Taker Applet
Feature Extractor (BioFeature)
Classifier (BAS)
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New System

• New System consists of the following
• 1. A PHP Website registers the user.
• 2. A modified Java applet captures 300 keystrokes
  and produces two files a raw data file and a
  text file.
• 3. A Java program, BioFeature, extracts 239
  feature measurements.
• 4. A Java program, Biometric Authentication
  System (BAS), performs authentication tests.

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Test-Taker Authentication System

• Feature Extraction BioFeature
• Extracts 239 features from raw data collected
  from applets
• Ex. Features file
• Authentication Classifier
• Uses 2 features files
• One is trained-on and the other is tested-on.
• Returns False Acceptance Rate (FAR), False
  Rejection Rate (FRR) combined performance
• Ex. BAS results (html file)

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Authentication Classifier

• Authentication Transformation

feature space (left)
feature distance space (right)
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Experimental Design Data Sets

• 1. Team member Data
• 5 samples of free text using enrollment applet
  (650 keystrokes)
• 5 samples of free text data using test-taker
  applet (300 keystrokes)
• 2. Outsider Sample
• 5 samples of free text data using test-taker
  applet (300 keystrokes)
• 3. Original 36 subjects from 2006 Study
• 5 samples of laptop free text using enrollment
  applet (650 keystrokes)

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Experimental Results
Study 1 Fall 2008 Team with Outsider
Test Train
FRR
FAR
Performance
5 5
0.0(0/50)
4.8(12/250)
96.0(288/300)
1
5 5
6.0(3/50)
1.2(3/250)
98.0(294/300)
2
6 5
0.0(0/60)
11.2(42/375)
90.3(393/435)
3
5 6
12.0(6/50)
0.4(1/250)
97.7(293/300)
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Biometric Authentication System (BAS) results
using test and enrollment samples (5 per subject)
collected in the fall of 2008
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Study 1 Conclusions

• Performance is high (at least 95) with same
  subject testing
• No significant difference in results due to
  keystroke length (300 vs 650)
• Immediate drop in performance when an subject
  that is not enrolled is used.
• Increased number of subjects is recommended

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Study 2 (partial)
Study 2 Original-36 Training-on Tests
Test Train FRR FAR Performance
10 5 0.0 (0/225) 27.7 (277/1000) 77.4 (948/1225)
10 10 8.4 (19/225) 8.5 (85/1000) 91.5 (1121/1225)
10 15 7.1 (16/225) 5.9 (59/1000) 93.9 (1150/1225)
10 20 25.3 (57/225) 1.8 (18/1000) 93.9 (1150/1225)
10 25 29.3 (66/225) 1.4 (14/1000) 93.5 (1145/1225)
10 30 44.0 (99/225) 0.9 (9/1000) 91.2 (1117/1225)
10 36 39.6 (89/225) 0.6 (6/1000) 92.2 (1130/1225)
Testing on combined fall 2008 enrollment and
test-taker samples (10 per subject) and training
on original-36 subject samples (5 per subject).
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Study 2 Conclusions

• Again, keystroke length has little effect on
  results.
• When the number of subject is large (30), it
  produces a very low FAR (should be as low as
  possible for maximum security).
• Performance increases (above 90), FAR decreases,
  and FRR increases as of subject is 10 or more.

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Study 3 (partial)
Study 3 Original-36 Testing-on Tests
Test Train FRR FAR Performance
5 10 10.0 (5/50) 11.2 (28/250) 89.0 (267/300)
10 10 3.0 (3/100) 23.2 (232/1000) 78.6 (865/1100)
15 10 2.7 (4/150) 21.6 (216/1000) 80.8 (930/1150)
20 10 5.0 (10/200) 57.5 (575/1000) 51.3 (615/1200)
25 10 2.0 (5/250) 68.1 (681/1000) 45.1 (564/1250)
30 10 1.3 (4/300) 72.0 (720/1000) 44.3 (576/1300)
36 10 0.3 (1/360) 78.5 (785/1000) 42.2 (574/1360)
Testing on original 36 subject samples (5 per
subject) and training on combined fall 2008
enrollment and test-taker samples (10 per
subject).
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Study 3 Conclusions

• Yet again, keystroke length has little effect on
  results.
• Overall poor performance indicates that system
  requires adequate training data.
• FAR increases substantially, and FRR decreases as
  of subject is 10 or more.
• Study 2 and Study 3 hint that 30 or more subjects
  will yield a more reliable authentication.

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Future Studies

• Convert the current Java programs to web
  applications using J2EE or PHP.
• Further testing should be done with at least 30
  enrolled subjects.
• Use the test taker applet as individual samples
  to test against a large enrollment database.
• Continue to modify the Authentication Classifier
  (BAS) to implement the proposed
  k-nearest-neighbor procedure. (NEXT)

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Simple k-nearest-neighbor procedure
K 10 (the 10 nearest neighbors) W within
(accept) class B between (reject)
W
B
Matching sets W B B W B B W W B B W W B W W
W W W B W W B W W B B W W W W
4
6
1
8
2
2
7
3
3
19gtAccept
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Totals
Proposed authentication using k-nearest-neighbor
procedure.
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Demo Test-Taker Authentication System

• How to access the system
• (Taking the Test )
• User must first enroll into the system.
• Click on the Web Link (http//utopia.csis.pace.edu
  /cs691/2008-2009/team4/testtakersite).
• The enter same name you enrolled with and take
  the test in the applet

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Demo Taking the Test

• Presented with five questions and must provide
  five answers.
• Answer should be more than 50 words, based on the
  assumption that words are approximately 6
  keystrokes in length.
• Once completed, click on Submit
• If 50 words are not meet, user will be presented
  with an error.

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Demo New Online Test SystemLogging In
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New Online Test System
Test Applet
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New Online Test System
Test Applet (continued)
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New Online Test System
User reached at least 300 keystrokes
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Demo Test Applet
User did reach or surpass the 300 keystrokes
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QA Thank You!
Pace University