There are always stories, for example the recent account of a wayward princess who was black-bagged, where someone demands proof that the kidnap victim is still alive.
I wonder, short of producing the person, what proof, if any, would be convincing? A written statement? A video of them reading the morning newspaper? Could be faked.
Can voice prints be faked with a computer? If not, you could have the captive read the headlines from today’s paper. The voice print comparison would prove their identity (assuming you had an earlier recording to compare it to) and the material being read would prove the time when it was made.
Of course it is possible to fake voice prints with a computer. I do not know what is the state of the art, but for example this story dated January 24, 2020 says
In an online poll of 100 participants conducted by the researchers, 55 percent of generated videos were rated as “real.”
It is probably still not trivial to fool UN experts with a fake video cobbled together in only a couple of hours [also NB distinguishing real camera footage from CGI is also a thing].
These computer-generated fakes are good enough to fool a human listener. But can they stand up to a technological analysis? I think (although I’ll admit I’m not sure) a good analysis would detect the splices in the recording.
Short of a live phone call or videocall, I don’t see how it could be proven. And the victim’s family would ideally ask questions that only the victim could answer convincingly and the captors couldn’t fake.
A couple of days ago I watched the Denzel Washington movie, Man on Fire. His character, seeking to prove that a kidnapped child is alive, asks the kidnapper to ask her the name of her teddy bear.
A live, but non-interactive video would probably be sufficient. They could put a TV in the background tuned to CNN or whatever. It would be tough to fake this in real-time without giveaways.
Not that an interactive live stream is that hard to pull off. Just use Twitch or some other streaming service via VPN. Pretty much untraceable as long as the criminals aren’t dumb enough to put something obvious in the background.
I mean, if you have access to the victim’s DNA, a nice fresh ear or finger would prove they have been alive within the past x hours - I assume it would be relatively simple to determine if the tissue had been frozen or cold stored.
Have them send an e-mail from their personal account, or add Gone With the Wind to their Amazon shopping cart, or something where they need to log in with a password.
I like the live video idea better. No reason to assume a person’s e-mail can’t be compromised, and there are known cases of killers sending messages from their murder victim’s phone.
Pfftt. A finger? I can get you a finger by 3 o’clock this afternoon.