Amazon Kinesis Firehose
Developer Guide

Using Server-Side Encryption with Amazon Kinesis Data Firehose

If you have sensitive data, you can enable server-side data encryption when you use Amazon Kinesis Data Firehose. However, this is only possible if you use a Kinesis stream as your data source. When you configure a Kinesis stream as the data source of a Kinesis Data Firehose delivery stream, Kinesis Data Firehose no longer stores the data at rest. Instead, the data is stored in the Kinesis stream.

When you send data from your data producers to your Kinesis stream, the Kinesis Data Streams service encrypts your data using an AWS KMS key before storing it at rest. When your Kinesis Data Firehose delivery stream reads the data from your Kinesis stream, the Kinesis Data Streams service first decrypts the data and then sends it to Kinesis Data Firehose. Kinesis Data Firehose buffers the data in memory based on the buffering hints that you specify and then delivers it to your destinations without storing the unencrypted data at rest.

For information about how to enable server-side encryption for Kinesis Data Streams, see Using Server-Side Encryption.