Although TESLA can provide the crucial broadcast authentication, it also introduces large verification delay that limit its application in a large wireless sensor network. In this paper, we present two localized broadcast authentication protocols that reduce verification delay via using a few trusted nodes. These trusted nodes divide sensor nodes in a large sensor network into several subsets, and coordinate broadcast authentication in the subsets. Thereby, all sensor nodes can verify a broadcast message as if they were in a small network. One of the proposed protocols, L-TESLA, is developed to identify the subsets according to the deployment of the trusted nodes. However, the delay reduction of L-TESLA is at the expense of increasing broadcast overhead due to updating localization information. To address the problem, we propose LD-TESLA to incorporate the technique of dominating nodes in broadcast authentication. The simulation results illustrate that both protocols significantly reduce the average verification delay. At the same time, they provide tradeoff between verification delay and broadcast overhead, and thus can work as alternative broadcast authentication protocols serving different applications.