A new variant of 3GPP-MAC with provable security and higher efficiency

3GPP-MAC, also called f9, is an integr ity schem e adopted by Univer sal M obile Telecommunication System as a standard for the 3rd generation wireless communications. In this paper, we investigate the feasibility of improving its efficiency, with the precondition that its security would not be com promised. As we show, the newly proposed f9^- enjoys provable security under t he s olo P RP a ssumption; m ore i mportantly, f9^- removes the last block- cipher invocation of f9, which m eans it needs less tim e and resources to compute MACs than f9, offering higher efficiency in practice. Furthermore, f9^- keeps the main structure of f9 almost unchanged, making it easy to update f9 to f9^- in reality.