In this paper, we study a new type of spatial crowdsourcing, namely competitive detour tasking, where workers can make detours from their original travel paths to perform multiple tasks, and each worker is allowed to compete for preferred tasks by strategically claiming his/her detour costs. The objective is to make suitable task assignment by maximizing the social welfare of crowdsourcing systems and protecting workers’ private sensitive information. We first model the task assignment problem as a reverse auction process. We formalize the winning bid selection of reverse auction as an $n$n-to-one weighted bipartite graph matching problem with multiple 0-1 knapsack constraints. Since this problem is NP-hard, we design an approximation algorithm to select winning bids and determine corresponding payments. Based on this, a Secure Reverse Auction (SRA) protocol is proposed for this novel spatial crowdsourcing. We analyze the approximation performance of the proposed protocol and prove that it has some desired properties, including truthfulness, individual rationality, computational efficiency, and security. To the best of our knowledge, this is the first theoretically provable secure auction protocol for spatial crowdsourcing systems. In addition, we also conduct extensive simulations on a real trace to verify the performance of the proposed protocol.

中文翻译：

---

SRA：空间众包中任务分配的安全反向拍卖

在本文中，我们研究了一种新型的空间众包，即竞争性绕道任务，其中工人可以从原来的旅行路径绕道执行多项任务，并且每个工人都可以通过战略性地要求他/她的绕道来竞争首选任务。成本。目标是通过最大化众包系统的社会福利和保护工人的私人敏感信息来做出合适的任务分配。我们首先将任务分配问题建模为反向拍卖过程。我们将反向拍卖的中标选择正式化为$n$n具有多个 0-1 背包约束的一对一加权二分图匹配问题。由于这个问题是 NP-hard，我们设计了一个近似算法来选择中标并确定相应的付款。基于此，针对这种新颖的空间众包提出了一种安全反向拍卖（SRA）协议。我们分析了所提出协议的近似性能，并证明它具有一些理想的特性，包括真实性、个体合理性、计算效率和安全性。据我们所知，这是第一个理论上可证明的空间众包系统安全拍卖协议。此外，我们还对真实轨迹进行了广泛的模拟，以验证所提出协议的性能。