DAG it off: Latency Prefers No Common Coins

We introduce Black Marlin, the first Directed Acyclic Graph (DAG)-based Byzantine atomic broadcast protocol in a partially synchronous setting that successfully forgoes the reliable broadcast and common coin primitives while delivering transactions every round. Black Marlin achieves the optimal latency of 3 rounds of communication (4.25 with Byzantine faults) while maintaining optimal communication and amortized communication complexities. We present a formal security analysis of the protocol, accompanied by empirical evidence that Black Marlin outperforms state-of-the-art DAG-based protocols in both throughput and latency.