Patent ID: 7606915

Claim:
A method of preventing automated access to a service provided by a server coupled to a data communication network, said method comprising: delivering a first test to a client coupled to the data communication network for rendering to a user in response to the user requesting access to the service via the client, said first test being a human interaction proof test; delivering a second test to the client as an alternative to the first test, said second test being a human interaction proof test; delivering a third test to the client as an alternative to the first and second tests, said third test including a computational puzzle to be solved by the client, said first, second, and third tests each having a different correct solution, at least one of said first, second, and third tests being elected by the user; receiving, via the client, a response to the at least one of the tests elected by the user; and granting access to the service via the client if the received response is the correct solution to the at least one of the tests elected by the user.