{"ID":2868765,"CreatedAt":"2026-06-01T04:54:23.091178241Z","UpdatedAt":"2026-06-01T04:54:23.091178241Z","DeletedAt":null,"paper_url":"https://arxiv.org/abs/2509.15847","arxiv_id":"2509.15847","title":"Angelfish: Leader, DAG, or Anywhere in Between","abstract":"To maximize performance, many modern blockchain systems rely on eventually-synchronous, Byzantine fault-tolerant (BFT) consensus protocols. Two protocol designs have emerged in this space: protocols that minimize latency using a leader that drives both data dissemination and consensus, and protocols that maximize throughput using a separate, asynchronous data dissemination layer. Recent protocols such as Partially-Synchronous Bullshark and Sailfish combine elements of both approaches by using a DAG to enable parallel data dissemination and a leader that paces DAG formation. This improves latency while achieving state-of-the-art throughput. However, the DAG-formation process of those protocols imposes overheads that prevent matching the latency possible with a leader-based protocol. We present Angelfish, a hybrid protocol that adapts smoothly across this design space, from leader-based to DAG-based consensus. Angelfish lets a dynamically-adjusted subset of parties use best-effort broadcast to issue lightweight votes instead of using a costlier reliably broadcast to create DAG vertices. This reduces communication, tolerates more lagging nodes, and lowers latency in practice compared to prior DAG-based protocols. Our empirical evaluation shows that Angelfish attains state-of-the-art peak throughput while matching the latency of leader-based protocols under moderate throughput, delivering the best of both worlds. The implementation is open-sourced and publicly available.","short_abstract":"To maximize performance, many modern blockchain systems rely on eventually-synchronous, Byzantine fault-tolerant (BFT) consensus protocols. Two protocol designs have emerged in this space: protocols that minimize latency using a leader that drives both data dissemination and consensus, and protocols that maximize throu...","url_abs":"https://arxiv.org/abs/2509.15847","url_pdf":"https://arxiv.org/pdf/2509.15847v2","authors":"[\"Qianyu Yu\",\"Giuliano Losa\",\"Nibesh Shrestha\",\"Xuechao Wang\"]","published":"2025-09-19T10:30:25Z","proceeding":"cs.DC","tasks":"[\"cs.DC\",\"cs.CR\"]","methods":"[]","has_code":false}