Cloud computing is an emerging technology in modern society. In recent years mobile users and cloud service providers are increased rapidly. In the cloud or any other distributed environment, if the users increased then security risks also increase parallelly. Many security problems are still unclear even after the advanced security measures have been taken. Security of stored data in the server is one of the most challenging issues in the cloud-based environment. Only authorized users should access the stored data of the server. Authentication plays a significant role in providing authorization. Therefore, in cloud computing, authentication is the primary measure to protect the data and the server from an unauthorized user. In this paper, an efficient authentication scheme using the smart card in the cloud environment is proposed. In the proposed scheme, with the help of a single private key, the user can access many cloud services. Also, the proposed scheme resists all security attacks. Through the simulation using the AVISPA tool, it is proved that the proposed scheme is robust and suitable for practical implementation.