Proof of Life
Daniel explains that in a hostage negotiation, the first step is to authenticate who the hostage takers are and if the person is still alive. This is done by asking key questions that only the hostage can answer, which proves that the communication is authentic. Without this authentication, it's impossible to move forward with any rescue plan.In this clip
From this podcast

The Jordan Harbinger Show
617: Daniel Levin | Finding a Missing Person in the Middle East
Related Questions
What insights can be gained from kidnapping negotiations?
What negotiation tactics are effective in the episode 617: Daniel Levin | Finding a Missing Person in the Middle East and the clip Trusting Militant Groups from the episode 617: Daniel Levin | Finding a Missing Person in the Middle East, as well as the clip Negotiating Hostage Situations?