How does it work?

The FileSystemRepository was introduced in NiFi 0.2.1 and provided the only persistent content repository implementation. The encrypted version wraps that implementation with functionality to return to the Session (usually StandardProcessSession) a special OutputStream/InputStream which encrypt and decrypt the serialized bytes respectively. This allows all components to continue interacting with the content repository interface in the same way as before and continue operating on content data in a streaming manner, without requiring any changes to handle the data protection.

The fully qualified class org.apache.nifi.content.EncryptedFileSystemRepository is specified as the content repository implementation in as the value of nifi.content.repository.implementation. In addition, new properties must be populated to allow successful initialization.