Subject: Re: [Speechsc] stealing biometric tokens

From: "Judith Markowitz" <[email-masked]>
Date: Sat, 19 Jul 2008 13:54:36 -0500

I agree that it is difficult to reverse engineer biometric templates/models.
It isn't impossible, but it takes work. 

The article conflates a number of things which reveals some basic
misunderstandings about biometric systems. The start of the article refers
to stealing "biometric scans." That could mean anything - from what is
captured at the device to the stored model/template. Other portions of the
article suggest that the writer is talking about templates. 

If you can capture and reuse raw data then you don't have to deal with
processed data, such as templates. This is not difficult to do. In 2002,
Professor Tsutomu Matsumoto of Yokohama National University conducted a test
in which eleven optical and silicon fingerprint sensors accepted artificial
fingers in at least sixty percent of attempts. Matsumoto’s primary method of
spoofing the systems was to create an impression of an actual fingerprint
using gelatin derived from organic animal material - materials akin to
"gummy bear" candy. A group that opposes the use of fingerprints in German
passports lifted the fingerprint of the German Secretary of the Interior
Wolfgang Schäuble from a drinking glass he used at a restaurant and
published it on the Internet. 

Most criminals won't take the trouble to try to pick up individual
fingerprints. It isn't cost effective. They will go after unprotected
systems to get a lot of data that they can use or sell. This has become big
business. That's why I highlighted the need for encryption and other
security to prevent capture of raw biometric data. 

If an attacker is capturing UNENCRYPTED data from the sensor or the network,
for example, you have a problem. If a database that stores unencrypted raw
data for all ten fingerprints is compromised then you have a big problem.
Unfortunately, a lot of organizations do store raw data and too many of them
don't secure the data. 

Given that the US is now requiring that foreign visitors to enroll all ten
fingerprints theft of raw data for all ten of your fingerprints is not an
entirely unlikely scenario. I can see other countries following the US'
approach. I just went to Japan and had to submit two fingerprints just to
enter the country as a tourist without a visa. These policies have helped
drive the development of "cancelable" biometrics. Voice is inherently
cancelable if you use text-dependent technology so it has some advantages
over some of the other biometrics. 

This gets me back to MRCP V2. I was delighted to see coverage of security in
the draft standard. I would like to see stronger warnings and better
guidance related to security for both speaker biometrics and speech
recognition. Don't forget that speech recognition often transmits sensitive
data, such as account numbers.
 
Judith Markowitz

-----Original Message-----
From: William Meisel [mailto:[email-masked]] 
Sent: Saturday, July 19, 2008 12:52 PM
To: Judith Markowitz; 'Eric Burger'; [email-masked]
Subject: Re: [Speechsc] stealing biometric tokens

Hi, Judith.

I agree that ideally the solution is to provide adequate security for any
authentication data, and I hope solutions that insure every company does so
are eventually adopted.

The cited article really addresses a different subject. It says that
biometric identification, when stolen, is worse than having a PIN stolen
because a PIN can be changed, but a fingerprint can't (or a voice can't).
The article even talks about enrolling a different finger.

I think the basic assumption of the article is flawed. It assumes that one
can steal the stored biometric identifier and use that to authenticate
oneself as another. If the company stores the original image of a
fingerprint or the original recording of a voice, then I guess (with some
effort), the voice or fingerprint could be recreated. However, with speaker
verification and with fingerprints (in fact, with every pattern recognition
application I've been involved with since I wrote a book on it in 1972, the
process of storing "features" of the voice or fingerprint or any other
pattern is highly lossy and can't be reversed,in part because one wants to
identify the pattern in the presence of a lot of variation and thus capture
only largely invariant features. When challenged on the telephone to say a
password, having the features stored by the speaker verification system
wouldn't do one any good.

I hate to to have government agencies and companies left with the
misimpression that storing biometric data is somehow more dangerous (and
possibly creates more liability) than storing PINs.

-- Bill 

Bill Meisel
President, TMA Associates
Publisher & Editor, Speech Strategy News
(818)708-0962
www.tmaa.com

> From: Judith Markowitz <[email-masked]>
> Date: Sat, 19 Jul 2008 11:52:12 -0500
> To: William Meisel <[email-masked]>, 'Eric Burger'
> <[email-masked]>, <[email-masked]>
> Subject: RE: [Speechsc] stealing biometric tokens
> 
> Hi Bill, 
> The attached article presents the picture in about as simplistic and naïve
a
> way as possible. Consequently, it leads the reader to false conclusions.
> 
> Biometrics can be faked (called "spoofing") but it is generally not a
> trivial process and, in most cases, it is done with the raw biometric
data.
> That is, fingerprint or face (etc.) images and voice recordings. It is
much
> harder to re-engineer a biometric model/template, although that is not
> impossible. 
> 
> There are a number of ways to capture raw biometrics. The best way is to
> hack a database that stores them. Other methods involve capture at the
> sensor and on the transmission channel.
> 
> If you look at these approaches to capturing biometrics you can easily see
a
> theme: security. You also see that the security that is needed (and too
> often missing) has nothing really to do with biometrics, itself. It is the
> same kind of security that is missing for PIN and password systems. So, it
> doesn't really help much to have multi-factor authentication if all of
them
> are captured in transit or stolen from a hacked database.
> 
> In short, if government and private industry would take the time and spend
> the money to secure their networks, databases, and other systems many of
> these threats would be eliminated. That's why the data interchange format
> that I'm working on with the American National Standards Institute
includes
> encryption and supports other security.
> 
> Judith Markowitz
> 
> -----Original Message-----
> From: [email-masked] [mailto:[email-masked]] On
Behalf
> Of William Meisel
> Sent: Thursday, July 17, 2008 10:15 PM
> To: Eric Burger; [email-masked]
> Subject: Re: [Speechsc] Just to see if anyone is still out there
> 
> Am I missing something, or does the linked article (and the referenced
> professor) simply misunderstand biometric id? Having the biometric token
(a
> fingerprint is the example) should neither allow the thief to recreate the
> fingerprint (assuming it is features of the fingerprint that are
> encoded--hopefully without announcing what each feature is) nor allow the
> thief to access the system, since they would need to have the finger (not
> the token) to do so. It would not be necessary for the individual to
> reenroll a new finger.
> 
> The same is true of speaker authentication.
> 
> -- Bill 
> 
> Bill Meisel
> President, TMA Associates
> Publisher & Editor, Speech Strategy News
> (818)708-0962
> www.tmaa.com
> 
> 
> 
> 
>> From: Eric Burger <[email-masked]>
>> Date: Thu, 17 Jul 2008 08:07:08 -0400
>> To: <[email-masked]>
>> Subject: [Speechsc] Just to see if anyone is still out there
>> 
>> For the folks who care about biometrics:
>> 
>
http://www.networkworld.com/newsletters/sec/2008/071408sec1.html?nlhtsecstra
> t=
>> ts_071508&nladname=071508securitystrategiesal
>> _______________________________________________
>> Speechsc mailing list
>> [email-masked]
>> https://www.ietf.org/mailman/listinfo/speechsc
>> Supplemental web site:
>> &lt;http://www.standardstrack.com/ietf/speechsc&gt;
> 
> 
> _______________________________________________
> Speechsc mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/speechsc
> Supplemental web site:
> &lt;http://www.standardstrack.com/ietf/speechsc&gt;
> 
> 

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---

From: William Meisel <[email-masked]>
Date: Sat, 19 Jul 2008 10:52:18 -0700

Hi, Judith.

-- Bill 

Bill Meisel

> The attached article presents the picture in about as simplistic and naïve a
> trivial process and, in most cases, it is done with the raw biometric data.
> That is, fingerprint or face (etc.) images and voice recordings. It is much
> If you look at these approaches to capturing biometrics you can easily see a
> doesn't really help much to have multi-factor authentication if all of them
> that I'm working on with the American National Standards Institute includes
> From: [email-masked] [mailto:[email-masked]] On Behalf
> Of William Meisel
> professor) simply misunderstand biometric id? Having the biometric token (a