Digital non-transferable anonymous credentials allow individuals in aparticular group to remain anonymous while demonstrating group membership.An analogous credential in the real world is a hand stamp one mightobtain upon entering an establishment that serves alcohol, afterdemonstrating that he is of legal drinking age. The individual later useshis stamp to prove to the bartender that he is old enough to purchasealcohol, but the stamp alone does not reveal the individual's identity.Furthermore, this credential cannot be transferred to a differentindividual. In this talk, we address the challenges of achieving this type ofcredential in the digital world, and present a solution based oncryptography and secure hardware. No prior knowledge of cryptography orsecurity is required. This talk describes joint work with RussellImpagliazzo from UCSD.