[Clips] Say Hello to Voiceprinting

[coderman]

On 4/14/06, R.A. Hettinga <rah at shipwright.com> wrote:
> ...
>   Say Hello to Voiceprinting
>   Voice biometrics is poised to add more security
>   to phone-based transactions in Europe.

we used a system like this for a retail directory assistance service
called Infone.  the caller could authenticate by pin, by voice, or
both.  the voice enrollment required the caller to say "hello, infone"
three times or until a suitable voice print could be attained.

then when the caller accessed the system they would simply say "hello,
infone" and based on their incoming phone number the print was either
accepted or rejected.

the problem with these systems is that they can only select / identify
an individual from a small group of possibilities and line quality /
head colds can cause false negatives.

for example, if more than 10 people were associated with an account
the user had to enter a PIN to identify them, and then provide the
"hello, infone" voice print for further authentication.

it is also a non-trivial matter to tune the threshold for
success/failure appropriately for a given set of users.  this is all
based on probabilities so you need to set the threshold high enough
that the risk of false positives (impostors) is low enough to keep
security/losses at acceptable limits while also preventing excessive
numbers of false negatives that will annoy and aggravate your
customers.

still, the tech keeps getting (incrementally) better and it does
provide an additional layer of defence.  i'm not sure the currently
excessive costs associated with this technology are worth the benefit
though. (there are basically two companies who specialize in this
stuff (they've bought up all the rest) and they charge a premium for
these services and technologies :)