International Association for Cryptologic Research (IACR)
Abstract
In attribute-based signatures, each signer receives a signing key from the authority,
which is associated with the signer\u27s attribute,
and using the signing key, the signer can issue a signature on any message under a predicate,
if his attribute satisfies the predicate.
One of the ultimate goals in this area
is to support a wide class of predicates,
such as the class of \emph{arbitrary circuits},
with \emph{practical efficiency} from \emph{a simple assumption},
since these three aspects determine the usefulness of the scheme.
We present an attribute-based signature scheme
which allows us to use an arbitrary circuit as the predicate
with practical efficiency from the symmetric external Diffie-Hellman assumption.
We achieve this by combining the efficiency of Groth-Sahai proofs,
which allow us to prove algebraic equations efficiently,
and the expressiveness of Groth-Ostrovsky-Sahai proofs,
which allow us to prove any NP relation via circuit satisfiability
