This paper describes the first constructions of identity-based broadcast encryption (IBBE) using Type-3 pairings which can be proved secure against adaptive-identity attacks based on the SXDH assumption (which is a static, if not a standard, assumption) achieving a security degradation which is not exponential in the size of the target identity set. The constructions are obtained by extending the currently known most efficient identity-based encryption scheme proposed by Jutla and Roy in 2013. The new constructions fill both a practical and a theoretical gap in the literature on efficient IBBE schemes.Index Terms-broadcast encryption, identity-based broadcast encryption, Type-3 pairings, dual-system encryption, standard assumptions.0018-9448 (c)