In this chapter, we looked at how to secure sensitive data in the Hadoop cluster. We looked at the approaches for encryption of data in motion while block-level encryption for data is at rest. We also looked at the MapReduce processing and ways to enforce data encryption on the input side, intermediate data, and the final results created by the MapReduce program. Encryption causes performance degradation and this has to be carefully evaluated so that only sensitive data is encrypted and secured.
In the next chapter, we will look at how to identify security incidents and events in a secured Hadoop cluster. And we will also look at how to implement auditing and logging of user activities in the Hadoop cluster.
