DEFCON Authenticator

Targus

PA460U

• Targus DEFCON Authenticator
• Yellow Warning Sheet: contains instructions for users who are installing SecureSuite onto a system that does not have a network client or Internet protocol installed.
• Installation Guide
• Software CD

"This equipment generates, uses, and can radiate radio frequency energy and if not installed and used in accordance with the instructions, may cause harmful interference with radio communication."

Plug the device into the computer's USB port when prompted during software installation.

Authentec Entrepad AES 4000 silicon sensor (Radio Frequency Sensor)

• Size: 2.7" x 1.9" x 0.8"
• Weight: 5.0 oz

• Incorporates 2 port USB hub
• Thicker protective surface coatings
• Higher electrostatic discharge (ESD) resistance
• Higher scratch and abrasion resistance
• Exceptional resistance to chemical and environmental hazards

SecureSuite Software Version 3.1

Software

• Windows 98/ME/2000

• Intel Pentium processor (or compatible)
• 64 MB of RAM

For the Targus finger authenticator, SecureSuite v3.1 is installed. This is the same software installation as the Authenticam. The user must have administrator privileges on the local machine before installation. For details about this software please refer to the Authenticam. Note that PrivateID is not installed this time, since it is used only for iris capture.

Number of Templates
During the enrollment process, 3 fingerprint templates are created.

Creation of Template
Image Capture
The sensor uses a radio frequency (RF) imaging technique that allows the sensor to generate an image of the shape of the live layer of the skin that is buried beneath the surface of the finger. The physics behind this is that when the finger touches the sensing surface, the conductive plate (surface) will follow the shape of the conductive boundary defined by the electrically conductive live cells underneath the dead skin which behaves like an dielectric. Then the equipotential surfaces between the sensor plates will take on the shapes that are an attenuated form of the shape of the conducting plate. This live subsurface layer has the shape of the fingerprint ridge and valley pattern, in fact it is the source of the fingerprint pattern, and it is rarely affected by damage or wear to the finger surface. Below is a diagram that illustrate this image capture process.

Template Creation
The available documentation does not specify which type of features are extracted from the fingerprint image, but it appears to be a combination of global and minutia features. What is clear is that a template is created by composing several views of the finger. Each view is characterized by their relative position to each other and by the features that each contains. Below is a table of data extraction provided by AuthenTec.

The orange circles contain macro features such as core, delta and scars. The green circles contain classical ridge minutia.	This shows the generalized pattern of the fingerprint.	This shows the specific ridge pattern of the fingerprint	The orange circles contain the lateral ridge shape and the purple circles contain pores (sweat glands).

Authentication Process
The general process is very similar to the Puppy and U.are.U devices. A claimant finger is compared to an enrolled template. In this case the live image of the finger is compared to each view that composed the enrolled template, and a score generated as a statistical combination of each evaluation. The program sets a default threshold, and all the values above a certain score is granted access to the computer.

Several problems are encountered during enrollment:

Small Sensor
The sensor is about the size of a penny and it does not capture the complete fingerprint. When the tester attempted to register her thumbs on both hands it was impossible to capture a full fingerprint. The application rejected the image for enrollment because the tester keept on enrolling with the same finger position, and therefore the template could not be created due to the incompleteness of the fingerprint. The tester then read the documentation on the usage of the device, and it was recommended to roll or to position the finger differently. The tester followed the recommendation of the manufacturer and successfully enrolled her thumb.

The AuthenTec company claims that the size of the image is compensated by the use of higher density, small-scale feature information captured in high quality and the use of template composition to store areas of finger skin larger than the sensor itself. In the template composition process, multiple images acquired from enrollment are logically interconnected to create a larger template. The diagram below illustrates this process.

Affordance of Fingers
The device's contours do not easily accomodate placement of all the fingers, especially the index finger. Please refer to the U.are.U for details about this problem.

Enrollment Wizard
The enrollment wizard of this program is well designed with instant visual feedback. All the registered fingers are highlighted (at the nail position). All ten fingers can be registered by each user. Below is a screen capture of the enrollment wizard, and the user feedback.

Please refer to the Authenticam.

Please refer to the Authenticam, this device uses the same software, and has the same software interface.