1. A method for revoking delegatable anonymous credentials, comprising: receiving, in a processor, a request to revoke an anonymous credential representative of an ability to prove non-membership in an accumulator for a first entity, wherein the anonymous credential is delegated from the first entity to a second entity; revoking the anonymous credential from the first entity in response to the request to revoke the anonymous credential; and revoking the anonymous credential from the second entity in response to the request to revoke the anonymous credential, wherein revoking the anonymous credential from the second entity comprises revoking a delegated descendant of the anonymous credential.