Be aware of your leaders LNCS Cohen, Shir Gelashvili, Rati Kokoris Kogias, Eleftherios Li, Zekun Malkhi, Dahlia Sonnino, Alberto Spiegelman, Alexander Advances in blockchains have influenced the State-Machine-Replication (SMR) world and many state-of-the-art blockchain-SMR solutions are based on two pillars: Chaining and Leader-rotation. A predetermined round-robin mechanism used for Leader-rotation, however, has an undesirable behavior: crashed parties become designated leaders infinitely often, slowing down overall system performance. In this paper, we provide a new Leader-Aware SMR framework that, among other desirable properties, formalizes a Leader-utilization requirement that bounds the number of rounds whose leaders are faulty in crash-only executions. We introduce Carousel, a novel, reputation-based Leader-rotation solution to achieve Leader-Aware SMR. The challenge in adaptive Leader-rotation is that it cannot rely on consensus to determine a leader, since consensus itself needs a leader. Carousel uses the available on-chain information to determine a leader locally and achieves Liveness despite this difficulty. A HotStuff implementation fitted with Carousel demonstrates drastic performance improvements: it increases throughput over 2x in faultless settings and provided a 20x throughput increase and 5x latency reduction in the presence of faults. Springer Nature 2022 info:eu-repo/semantics/conferenceObject doc-type:conferenceObject text http://purl.org/coar/resource_type/c_5794 https://research-explorer.ista.ac.at/record/12168 Cohen S, Gelashvili R, Kokoris Kogias E, et al. Be aware of your leaders. In: <i>International Conference on Financial Cryptography and Data Security</i>. Vol 13411. Springer Nature; 2022:279-295. doi:<a href="https://doi.org/10.1007/978-3-031-18283-9_13">10.1007/978-3-031-18283-9_13</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1007/978-3-031-18283-9_13 info:eu-repo/semantics/altIdentifier/issn/0302-9743 info:eu-repo/semantics/altIdentifier/e-issn/1611-3349 info:eu-repo/semantics/altIdentifier/isbn/9783031182822 info:eu-repo/semantics/altIdentifier/e-isbn/9783031182839 info:eu-repo/semantics/altIdentifier/wos/001423640200013 info:eu-repo/semantics/altIdentifier/arxiv/2110.00960 info:eu-repo/semantics/openAccess