Cloud storage service is increasingly important and beneficial to the internet users. Users around the world enjoy the high performance cloud servers that are reliable, cost-effective and highly available. Communication vulnerability is also rising to destroy the confidentiality and integrity of user data and information while accessing via network. To resolve these attacks, cloud service providers offer gateways of secured access to the storage services. Though the existing systems are in reasonable standard, investigating a better approach towards security is always worthy. In this paper, we propose a two-step access control system based on Kerberos authentication protocol implemented using Java based authentication service, JAAS. This system provides a well-built and more powerful encryption process by applying Kerberos in two steps. Finally, we build a real time access control system that implements our proposed system.