Hadoop is a software paradigm which is designed on MapReduce architecture. MapReduce executes the job parallely in two phases that is map and reduce.The main focus will be the performance analysis of Hadoop to find out how it handles big data, whether it is feasible or not, How Hadoop reacts with increase in size of the data set. Furthermore, Hadoop does not come with any security features. So we have proposed an asymmetric key cryptosystem to apply encryption to files before storing it in Hadoop.