Research And Implement Of Attribute-Based Task Assignment And Incentive Mechanism In Mobile Crowdsensing

Crowdsensing is a practical example of Internet-of-Things,in which task publishers outsource sensing tasks to workers through crowdsensing server(CS).Workers carry out the task,and then submit the results to its requester.Task assignment and incentive design are two essential parts of crowdsensing.However,due to the semi-honest CS and potential malicious workers,there exist several security and fairness issues during the process of task assignment and worker incentive.First,during task assignment and reward distribution,CS can get the private information of both task publisher and workers such as identity,attributes and so on.Second,malicious workers who are unable to execute tasks can get the details of the task,which leads to privacy leaks.Third,most auction-based incentive mechanism only considers the biddings of workers and ignores the ability of workers,so that the reward paid by the publisher cannot achieve the maximum utility.In response to the aforementioned problems,the main contributions of this paper are summarized as follows:1.This paper proposes a privacy-preserving fine-grained task assignment scheme of mobile crowdsensing.Based on ciphertext-policy attribute-based encryption,the scheme describes the requirements of each task as an access policy and treats each worker as a set of attributes,treats the task assignment problem as an access control problem for workers.It not only achieves the screening of workers,but also guarantees the confidentiality of the task content.2.This paper designs a novel incentive mechanism based on the abilities of workers.First,it screens out suitable workers through attribute-based task assignment scheme above.Then workers decide whether to perform the task after considering his own cost and possible reward.Finally,it quantifies workers' abilities according to their attributes and allocates the reward to workers based on the quantified ability value.This mechanism can ensure fair reward and positive total income of the workers,and workers with high ability get more reward.3.This paper implements a prototype system according to the scheme to verify the accuracy of the scheme,then conducts a security analysis for each component.In terms of performance,this paper compares our task assignment scheme based on attribute encryption with related schemes;in terms of incentive effects,it tests the impact of different worker recruitment strategies and reward calculation methods on worker income.Experimental results prove that the scheme in this paper has a low time cost,can achieve the goal of privacy preservation and has good incentives for workers.