In the Database As Service(DAS) model, authenticated join processing is more difficult than authenticated range query because the previous approach of authenticated range query, signature on a single relation, can not be used to verify join results directly. In this paper, an authenticated hash join processing algorithm is described in detail, which can take full advantage of database service since most of work is pushed to database service provider. We analyze the performance with respect to cost factors, such as communication cost, server-side cost and client-side cost. Finally, results of experiments validating our approach are also presented.