New Delhi, Feb. 2 -- Here we are in the third decade of the 21st century, and the internet has an identity crisis. For years, we worried about anonymity, privacy and whether our passwords were strong enough. Now the more awkward question is whether the replies we get online are from a person at all.

Generative AI systems can write posts, argue politics, flirt, invest, complain and even scam us with unnerving fluency. Digital avatars are eerily human. The result is an online world where trust is evaporating because the basic assumption of a human on the other side of an interaction no longer holds.

Proof-of-personhood has emerged as an attempt to fix this problem by giving the internet a way to distinguish humans from machines without tu...