Browser Proof Of Work

Abstract

Embodiments are directed to methods and systems for determining the identity of a user as a person or a robot. In some embodiments, the methods and systems engage a web browser to produce a token and calculate a computation cost associated with the token production. The methods and systems use the computation cost to prove that the web browser on a device not handicapped by the computational challenge of producing tokens, which would handicap a robot. In some embodiments, the methods and systems generate a cookie based on a confirmed user purchase, and record the user identity contained in the cookie at a block chain to identify the user as a verified purchaser. The methods and systems may later retrieve the cookie and search the block chain using the user identity contained in the cookie. By locating the user identity in the block chain, the methods and systems know that the user is a verified purchaser, indicating the user to be a person, as robots cannot make purchases.

Dependencies are inferred from the claim text.