"Hi, my name is Werner Brandes. My voice is my passport. Verify Me."
I LOVED the movie Sneakers as a kid and it had a huge influence on me. Long before Stephen Tobolowsky was playing the Hooli and Pied Piper CEO and holding business meetings in front of mating horses, his Werner character was the quintessential 90s Dilbert-style engineer.
Liveness testing would be one way to prevent the voice recognition service from being foiled so easily.
The premise of this movie is solid and even more relevant today. With quantum computing having the potential to destroy even the strongest encryption, it could mean that all secrets will be revealable.