# L1 Research: Aptos/Sui - Monolithic protocol - Share Tx data as part of consensus - Sui - DAG-based mempool + Tusk consensus algo - [DAG](https://www.twblogs.net/a/5ee05d26cd139eebd77e968e) - Exploited at execution layer for parallelization - DAG - 有向無環圖，從一個頂點前進，但永遠不會回到原點 - DAG - 安全問題：雙花、影子鏈 - Narwhal - DAG mempool, separate the dissemination and ordering transactions - Tusk - a zero-message overhead protocol for maintaining Narwhal’s liveness - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2Fn4d9GE-zrk.png?alt=media&token=0485e5a9-9a96-4f6d-8abd-d021f8552c52) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2FY6O3S_Kv3j.png?alt=media&token=aed6b701-693c-4384-8499-00d021b9a302) - 每個節點有很多工人，每個工人各自收到一筆交易，接著送到其他平行時空的同一號工人，同時每個時空有各自的工頭，每個工人在處理完自己的工作後，會把收據交給工頭 - Both Narwhal and Tusk protocol create a BFT protocol to reach consensus on blocks metadata - Object - Owned/shared, Mutable/immutable - Reliable broadcast for non-shared object - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2F7xrXcApyfg.png?alt=media&token=e412e232-6a0e-4ee2-a7c0-89cc2cd3dcfc) - Aptos - BlockSTM + DiemBFT(Hotstuff Variant) - It uses the 4th iteration of DiemBFT, a variant of HotStuff, which is one of the leading consensus protocols. - [BlockSTM](https://www.youtube.com/watch?v=fK_V9Z1q10U) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2FZaxBNfFAjS.png?alt=media&token=890d2630-a2a7-4b2c-8aee-b9697b6f81a0) - Optimistic concurrency control - Multi-version data structure - Dynamic dependency estimation - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2F1QL34vDgMW.png?alt=media&token=c8ff7fd3-b6e3-43a6-9bd0-1fffa55b7fb5) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2FMxIb6_YLF_.png?alt=media&token=562faf00-ea40-4f14-bcab-64ff0850258f) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2Fiv3jAFS0PS.png?alt=media&token=bac4d0df-ad53-434b-8151-f3b678749f55) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2F7-yfMUlNiX.png?alt=media&token=930cd157-a7cf-4379-a527-dd5406849aa1) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2FnNwWRZXH6o.png?alt=media&token=01daf9da-45d6-4bd9-8201-3ad30f7fd194) - ![](https://firebasestorage.googleapis.com/v0/b/firescript-577a2.appspot.com/o/imgs%2Fapp%2FProtocol-Research%2FTvtBNMUu0F.png?alt=media&token=8b56462e-35d3-4965-a3ae-0251a84c89bc) - https://arxiv.org/pdf/2105.11827.pdf