A Sybil attack is when one actor creates thousands of fake identities to manipulate a system that assumes each identity is a different person. It's the oldest attack on the internet.
AI just made it free.
The name comes from a 1973 case study of a patient with dissociative identity disorder. In 2002, researchers at Microsoft borrowed it to describe a class of attack on distributed systems: one malicious node pretending to be many, gaining disproportionate influence over a network that assumes each node is independent.
The attack predates AI. Fake reviews, coordinated upvotes, sock puppet campaigns, bot armies in elections - all of these are Sybil attacks at different scales. The limiting factor was cost: creating convincing fake identities at scale required time, money, and infrastructure.
AI removed the limiting factor.
A single actor with access to modern language models can now generate thousands of contextually convincing fake identities - complete with posting history, consistent personality, plausible biographical detail - at a cost approaching zero. Every system that aggregates individual signals and assumes those signals come from different people is now vulnerable in a way it wasn't three years ago.
This includes: review platforms, social networks, DAOs and governance systems, prediction markets, academic peer review, community moderation, anywhere reputation is computed from individual inputs.
The only structural defense is proof of unique humanity issued before identity is granted - not after the account is created, not detected from behavior, but verified at the door.
One human, one ID, cryptographically enforced.
That's Alien ID.