Computing resources are made available for rent under the Infrastructure as a Service (IaaS) model of cloud computing. Users are hesitant to utilise it because they do not have faith in the leased computing resources, even if it provides a costeffective answer to virtual network needs. There is multitenancy, which allows computing resources to be pooled in order to save costs. Security and privacy concerns arise due to the sharing of communication channels and other computing resources. Users remain anonymous, so it's impossible to tell which of them may be a reliable flatmate. The responsibility of assigning reliable co-tenants to the user rests on the Cloud Provider (CP). However, making the most of its resources is what the CP wants. Users' actions have no effect on the maximum co-tenancy it permits. In order to prevent resource sharing in a federated cloud, we provide a strong reputation management method that motivates CPs to identify fraudulent users and allocate