Most existing blockchain sharding systems suffer from load imbalance, which affects overall performance. To achieve load balance among shards, we use ML to predict load variations for each shard and dynamically allocate accounts through secure and efficient cross-shard account migration. Download PDF

Existing blockchain sharding systems usually set up large shard sizes to guarantee the security of each shard, which limits the transaction concurrency.We set up a large number of small yet corruptible shards to improve concurrency. At the same time, to guarantee the security of the system, we design Consensus on Consensus among the shards. Download PDF

We propose a novel blockchain sharding system that can efficiently process smart contract transactions. We orchestrate the state storage, logic storage, and execution of smart contracts, and propose a “network-wide logic storage” mechanism and an “orthogonal lattice structure” mechanism to achieve efficient processing of smart contracts in blockchain sharding. Download PDF

We propose a spatial crowdsourcing task assignment system that can protect users’ location privacy in a fully distributed scenario. We leverage homomorphic encryption to protect the location information of workers and task requesters. We propose a “wait-and-decide” and a “proportional-backoff” mechanism to improve the quality of task assignment in such a fully distributed scenario. Download PDF

We propose a new account assignment algorithm based on matching theory in IoT sharding blockchain systems which considers the features of the shards and accounts. We model the accounts assignment problem as a many-to-one matching model with externalities and propose an iterative algorithm to find a stable matching. Download PDF

We explore the problem of how much computational power would miners contribute to different kinds of committees in the view of game theory. We model the game as a two-stage hierarchical game. In the first stage, miners compete for the seat of the directory service (DS) committee and then in the second stage, those who are not DS committees members play games for rest shards formation. We prove the existence of the Nash equilibrium and obtain it in the simulation. Download PDF