By the analysis of the reason of using a trust model in UC (Universally Composable) secure computation, overseas existing trust models were researched and their merits and demerits were indicated. Then based on Divided Bi-Trapdoor, a trust model named DBT that has the flavor of a “public-key infrastructure” was proposed, and as an experiment, a UC secure commitment protocol was implemented in this model. The DBT model has the complementary benefits of the existing models, and especially supports the full-simulation of protocols.
