[Discuss] Fidelity voice-recognition security?

[Robert Krawitz]

On Thu, 23 Nov 2017 09:38:06 -0500, Richard Pieri wrote:
> On 11/23/2017 7:36 AM, Robert Krawitz wrote:
>> Bit of a difference there, you agree?
>
> Yup. Although the "we have no idea" bit is hyperbole because the reality
> is we do know how unique fingerprints are. Francis Galton did
> substantial scientific research on fingerprints back in the late 1800s.

Which is irrelevant, since this is about voice recognition, not
fingerprints.

>> Meanwhile, as voice synthesis improves in fidelity...
>
> That's only part of it. Even if (when) you can accurately reproduce any
> arbitrary person's voice there is still the playback mechanisms. Voice
> coils are mechanically incapable of exactly reproducing sounds. Even the
> best speakers can be identified as speakers if your hearing is sensitive
> enough and you know what to listen for.

The same applies to microphones.  They aren't perfect and they vary
too.  And there are a lot more variables with voices/microphones and
fingerprints: position of the mic wrt the mouth, ambient noise,
airflow, upper respiratory infections, allergies, exertion, and so
forth.

> On the flip side of that, if you inject the synthesized data stream
> directly into system, bypassing speaker and microphone, it can still be
> detected as a fake because it will lack the analog distortion expected
> from the handset mic.

...except that the synthesized voice can incorporate said analog
distortion.  Decades ago Carver managed to do a pretty good job of
reproducing a much more expensive Mark Levinson amplifier, using
purely analog components; that kind of thing can be done a lot more
easily now.
-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

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