Cryptography Reference
In-Depth Information
The use of these systems can be very convenient. One company (
www.
cognitec-systems.de
) showed me a screen saver that locks the screen
automatically after a set time of inactivity. To unlock the screen, the right
person either sits down and briefly looks into the camera or enters a pass-
word. This is a huge step forward against 'sloppy daily routines' at work!
In addition, this system cannot be fooled by showing it a photo, because it
detects changes in the perspective and shadows that always occur in the real
world. The two error values FAR and FRR (see below) can achieve about
1 % with this system.
Nevertheless, this screen saver was not well accepted. A decent technical
concept alone does not convince users; there has to also be a demand for
using it (this is why the company prefers to use their
FaceVACS
system in
airports). Problems in facial recognition are the high demand in computational
performance, aging, and lighting conditions (outdoor recognition can reach
error rates of up to 50 %).
•
Iris scan:
The pattern of the iris, just as unique as a fingerprint, is captured
by a camera. Problems can arise from its uncomfortable use, in its present
form, and due to eye or eyelid injuries, cataracts, eyeglasses, and contact
lenses. Iris scanning is not cheap. This alone seems to be barring it from
wide use despite its excellent FAR and FRR values.
•
Retinal scan:
This system scans the retina via infrared. The same problems as
with iris scan systems can arise here, too, and the wait times are considerable
(I know of systems with roughly a 1-minute wait time).
•
Signature recognition:
This system electronically detects a signature. You
probably know of a simple system: the one used by UPS where you have to
use a special pen to sign for receipt in a small screen.
A much more sophisticated system appears to be
Smartpen
(
www.
smartpen.net
). It lets you use a special pen to write on a regular sheet
of paper on a regular base. Sensors in the pen acquire all sorts of writing
characteristics, such as trait, dynamics, pressure, and pausing as well as the
angle of tilt. Signature forgers would get nowhere with data acquired like this.
Such pens would be ideally suited for ATMs if it weren't for the problem
that they can be easily stolen, which is certainly significant considering their
rather high price. A less elegant but cheaper system is offered by
Softpro
(
www.softpro.de
), for example, where a simple graphics tablet serves as
the writing base.
Figure 6.11:
(
continued
)
