AsynchronousByzantine Fault Tolerance(BFT) consensus protocols are gaining attention for their resilience against network attacks. Among them,Multi-valued Byzantine Agreement(MVBA) protocols play a critical role, which accepts input values from each replica and returns a consistent output. The state-of-the-art MVBA protocol, sMVBA, has a good-case latency of$6\delta$and an expected bad-case latency of$12\delta$, with$\delta$representing the network delay. Additionally, sMVBA exhibits a communication of$O(n^{2})$in both good and bad cases. Although it outperforms other MVBA protocols, sMVBA still lags behind partially-synchronous counterparts. For instance, PBFT achieves a good-case latency of$3\delta$, and HotStuff boasts a good-case communication of$O(n)$. This paper introduces a novel MVBA protocol, Pako, aiming for performance comparable to partially-synchronous protocols. Pako leverages an existing MVBA protocol as a black box and introduces an additional view with an optimistic path to commit values efficiently. Two Pako variants, Pako1 and Pako2, provide a trade-off between latency and communication. To be more specific, Pako1 achieves a good-case latency of$3\delta$with$O(n^{2})$communication, while Pako2 reduces the communication to$O(n)$with a slightly higher good-case latency of$5\delta$. A series of experiments demonstrate Pako's significant outperformance of counterparts.

Standing as a foundational element within blockchain systems, theByzantine Fault Tolerant(BFT) consensus has garnered significant attention over the past decade. The introduction of aDirected Acyclic Directed(DAG) structure into BFT consensus design, termed DAG-based BFT, has emerged to bolster throughput. However, prevalent DAG-based protocols grapple with substantial latency issues, suffering from a latency gap compared to non-DAG protocols. For instance, leading-edge DAG-based protocols named GradedDAG and BullShark exhibit a good-case latency of$4$and$6$communication rounds, respectively. In contrast, the non-DAG protocol, exemplified by PBFT, attains a latency of$3$rounds in favorable conditions. To bridge this latency gap, we propose Remora, a novel DAG-based BFT protocol. Remora achieves a reduced latency of$3$rounds by incorporating optimistic paths. At its core, Remora endeavors to commit blocks through the optimistic path initially, facilitating low latency in favorable situations. Conversely, in unfavorable scenarios, Remora seamlessly transitions to a pessimistic path to ensure liveness. Various experiments validate Remora's feasibility and efficiency, highlighting its potential as a robust solution in the realm of BFT consensus protocols.

To improve the throughput of Byzantine Fault Tolerance (BFT) consensus protocols, the Directed Acyclic Graph (DAG) topology has been introduced to parallel data processing, leading to the development of DAG-based BFT consensus. However, existing DAG-based works heavily rely on Reliable Broadcast (RBC) protocols for block broadcasting, which introduces significant latency due to the three communication steps involved in each RBC. For instance, DAGRider, a representative DAG-based protocol, exhibits the best latency of 12 steps, considerably higher than non-DAG protocols like PBFT, which only requires 3 steps. To tackle this issue, we propose LightDAG, which replaces RBC with lightweight broadcasting protocols such as Consistent Broadcast (CBC) and Plain Broadcast (PBC). Since CBC and PBC can be implemented in two and one communication steps, respectively, LightDAG achieves low latency.In our proposal, we present two variants of LightDAG, namely LightDAG1 and LightDAG2, each providing a trade-off between the best latency and the expected worst latency. In LightDAG1, every block is broadcast using CBC, which exhibits a best latency of 5 steps and an expected worst latency of 14 steps. Since CBC cannot guarantee the totality property, we design a block retrieval mechanism in LightDAG1 to assist replicas in retrieving missing blocks. LightDAG2 utilizes a combination of PBC and CBC for block broadcasting, resulting in the best latency of 4 steps and an expected worst latency of 12(t+1) steps, where t represents the number of actual Byzantine replicas. Since a Byzantine replica may equivocate through PBC, LightDAG2 prohibits blocks from directly referencing contradictory blocks. To ensure liveness, we propose a mechanism to identify and exclude Byzantine replicas if they engage in equivocation attacks. Extensive experiments have been conducted to evaluate LightDAG, and the results demonstrate its feasibility and efficiency.

The rapid development of network freight platforms has directly increased the level of social logistics resource collaboration and improved both the efficiency and quality of logistics industry services. As a bilateral platform that connects freight shippers and freight carriers, the organizational structure and operational mode of network freight platforms differ substantially from those of traditional logistics service providers. In this paper, a tripartite evolutionary game model is constructed in which a network freight platform, freight shipper, and freight carrier are considered, and the evolutionary stability strategies of the parties and the tripartite system are dynamically analyzed. The reliability of the model is verified through a numerical case, and several countermeasures have been proposed to improve the stability of the system based on the sensitivity analysis of important parameters. This paper helps standardize the principal behavior of all parties under the network freight mode, reduce the default risk of all parties, and improve the overall cooperation stability of the logistics service supply chain.