EPiC Series in Computing Volume 89, 2022, Pages 62–71 Proceedings of 35th International Conference on Computer Applications in Industry and Engineering Efficient Secured Public-Key based Data Lookup and Multicast Protocols with Anonymity in RC-Based Two-level Hierarchical Structured P2P Network Indranil Roy 1 , Nick Rahimi 2 , Reshmi Mitra 1 , and Swathi Kaluvakuri 3 1 Southeast Missouri State University, Cape Girardeau, Missouri, U.S.A iroy@semo.edu , rmitra@semo.edu 2 University of Southern Mississippi, Hattiesburg, Mississippi, U.S.A. nick.rahimi@usm.edu 3 Southern Illinois University, Carbondale, Carbondale,Illinois, U.S.A swathi.kaluvakuri@siu.edu Abstract Because peer-to-peer networks are inherently insecure, they provide a special chal- lenge in terms of network security. In this study, we have considered a recently described non-DHT-based 2-level structured P2P network. It is an architecture built on interests. Utilizing RC, a modular arithmetic-based residue class, the overlay topology has been achieved. This design was chosen because it allows for minimal latency in both intra and inter-group communications. In the present study, we provide efficient schemes for public- key cryptographic security of existing communication protocols. We have also extended these approaches to include anonymity. 1 Introduction Due to their capacity to offer computational and data resource sharing in a scalable, self- organizing, distributed manner, peer-to-peer (P2P) overlay networks are widely used in dis- tributed systems. P2P networks are divided into two categories: unstructured networks and structured networks. Peers in unstructured systems [2] are arranged in any random topology. For data lookup, flooding is necessary. In unstructured systems, problems brought on by fre- quent peer joining and leaving the system, or ”churn,” are effectively handled. However, this compromises the effectiveness of data querying and the crucial flexibility. Lookups are not guar- anteed in unstructured networks. On the other hand, structured overlay networks offer deter- ministic limits on data discovery. They create scalable network overlays based on a distributed data structure that truly allows deterministic data lookup behavior. The usage of distributed hash tables (DHTs) is a recent trend in the design of structured overlay systems [6, 10, 19]. Overlay designs of this type can provide efficient, flexible, and resilient service [6, 10, 12, 19, 20]. However, maintaining DHTs is a complicated operation that requires significant effort to ad- dress the churn issue. As a result, the main difficulty for such designs is reducing this amount Y. Shi, G. Hu, K. Kambhampaty and T. Goto (eds.), CAINE 2022 (EPiC Series in Computing, vol. 89), pp. 62–71