You can now utilize upgraded versions of Apache Spark (1.6.1),Apache Hadoop (2.7.2), and an upgraded sandbox release of Presto (0.140) on Amazon EMR release 4.5.0. Spark 1.6.1 was released in the community on March 9th, or it contains several bug fixes and updates to the Dataset API. Additionally,the EMR Filesystem (EMRFS) can now read objects from and write objects to Amazon S3 with S3 server-side encryption with AWS Key Management Service keys (SSE-KMS). Previously, EMRFS supported S3 server-side encryption with S3 managed keys (SSE-S3) and S3 client-side encryption with AWS KMS keys or custom keys.
Source: amazon.com