State of the art techniques for Anonymous Authentication? What are the state of the art techniques for Anonymous Authentication? What are the most popular ones? The problem domain I am considering is with respect to different users accessing cloud content; lets say watching movies in Netflix. I am looking for schemes that prevents linkability, and also schemes that allows linkability.

Please let me know if it is too vague to answer, and I would try to narrow it down.
Take a look at the ECDAA protocols. They are implemented in the Trusted Platform Module (TPM 2.0). ECDAA is based on pairings over elliptic curves. In contrast to Idemix, they have the benefit of being far more efficient. In contrast to U-Prove, they have the benefit to be multi-show unlinkable.