Embodiments of the present disclosure include systems and methods for upload and/or download streaming encryption to/from an online service, or cloud-based platform or environment. The encryption process includes the following parts: Upload encryption, download decryption, and a central piece of infrastructure called the Interval Key Server (IKS). During both upload and download, the encryption and decryption processes are performed while the files are being uploaded/downloaded, (e.g., the files are being encrypted/decrypted as they are being streamed).