A Cross-platform Errand Service Application for Campus with a Dual-user Identity Model

With the development of the food delivery industry and the impact of the global Covid-19 pandemic in recent years, the demand for errand service platform has been progressively growing. However, due to crowd control policies during epidemics in China, off-campus personnel are unable to enter the campus, resulting in the current public errand service application invalid in campus. In this circumstance, students who need the errand service can only post the errand requests in chatting groups or use the mini-programs embedded in WeChat. Both approaches, however, have significant flaws. Therefore, a specific errand service application for campus is desired. In this paper, an errand services application named AoAoRun is developed for university students and faculties on campus using a dual-user identity model, making it possible for both students and faculties to become the service provider and the service recipients. It integrates and organizes the needs of errand services, providing a safe and user-friendly platform. In addition, unlike current errand service platforms, this application uses blockchain technology for data backup and credit scores system. This credit system gives higher priority to orders posted by users with higher credit scores. Finally, 53 volunteers participate in the user testing of the application. The test results show that AoAoRun greatly improves the utilization of resources and increases the efficiency of students' study and life. © 2022 IEEE.

A Blockchain based Human-to-Infrastructure Contact Tracing Approach for COVID-19

In a post-pandemic era with personal precautions and vaccination, the emergence of COVID-19 variants with higher transmissibility and the socio-economic reopening have raised new challenges to existing human-to-human digital contact tracing systems, where privacy, efficiency and energy consumption issues are major concerns. In this paper, we propose a novel blockchain based human-to-infrastructure contact tracing framework for the post-pandemic era. Specifically, our approach collects and records the interaction information between persons and pre-deployed anchor nodes to trace the possible contacts with confirmed patients, so as to capture the indirect contacts and reduces the energy consumption of users. To address the privacy leakage and reliability issues in contact tracing, we introduce a Self-Sovereign Identity (SSI) model-based blockchain which enables users to gain full control of their own identities and eliminate the linkage between the identity and location information in interaction records. To further preserve the privacy of confirmed patients, we introduce the Private Set Intersection Cardinality (PSI-CA) protocol to estimate the risk of infection by only counting the number of encounters between users and confirmed patients. Two self-executed smart contracts are deployed on the SSI blockchain to perform contact tracing, which guarantees the robustness of the system. The performance analysis validates the effectiveness of our approach. IEEE