In today’s world the data used by various institutions and organizations is increasing and process petabytes of data per hour. Hence big data storage platform called Apache Hadoop is designed to process large amount of data, but it does not guarantee the security of user stored files in Hadoop. In this paper, a secure HDFS is designed for an efficient and secure data storage model. We encrypt and decrypt client data using RC6 symmetric block cipher. In this research work, Hadoop distributed file system (HDFS) is customized using RC6 which provides transparent end-to-end encryption on user’s data for read as well as write. Our proposed SecHDFS will mitigate several security attacks such as replay attacks, data node impersonating attacks, and brute-force attacks. The proposed model imparts better results than the inbuilt AES symmetric algorithm.