This paper presents a simple and efficient reliable broadcast algorithm for asynchronous message-passing systems made up of n processes, among which up to t < n/5 may behave arbitrarily (Byzantine processes). This algorithm requires two communication steps and n(2) - 1 messages. When compared to Bracha's algorithm, which is resilience optimal (t < n/3) and requires three communication steps and 2n(2) - n - 1 messages, the proposed algorithm shows an interesting tradeoff between communication efficiency and t-resilience.