Imagine you’re watching your favorite show on Netflix. You hit play, and within seconds, high-definition video streams seamlessly to your screen. But have you ever wondered—why can’t someone just copy this video and share it for free? Or why does screen recording fail when you try to capture premium content?

Behind the scenes, a highly sophisticated security system is at work, using hardware-backed Trusted Execution Environments (TEEs) and Digital Rights Management (DRM) to prevent piracy and content theft.

Online piracy is a multi-billion dollar problem. Without strong protection, anyone could rip high-quality movies and shows, making them available illegally.

But companies like Netflix, Disney+, and Amazon Prime use a powerful security system that operates beyond software-level encryption—a hardware-based Trusted Execution Environment (TEE) that ensures even the device’s own OS cannot access decrypted video data.

Option 1: How Normal Video Playback Works Without DRM or TEE

The user selects a video on a streaming website/app (e.g., a non-DRM YouTube video), request is sent to the video server. The server sends the unencrypted (raw) video file over HTTP/HTTPS. No DRM or decryption process is needed, HTTPS is not used, attackers can intercept the stream (MITM Attack).

The video file is stored in temporary cache (RAM or disk)*. The CPU/GPU renders the video onto the screen

* Since no TEE or DRM exists, hackers can extract the video from cache

Option 2: Clear key encryption techniques

In clear key encryption without TEE, the decryption process is less secure because the key and decrypted content are exposed to the device’s main memory.

When a user requests DRM-protected video, the encrypted video and a key request URL are sent.The video player fetches the decryption key from the license server after validation. Since there’s no TEE, the key and decrypted data are handled in normal memory, making them vulnerable to interception and piracy.

How Netflix Blocks Screen Recording & Piracy