Introduction to DRM Decryption
What is DRM? Learn Widevine, PlayReady, CDM Levels, PSSH, MPD, Decryption Tools
This section is transparent, verified, and constantly tested, created to protect the streaming and DRM community from scams.
💡 We invite all members to contribute valuable tools: scripts from providers, decryption software, private/public CDMs, key generation methods, MPD links, and automation scripts.
🔓 All resources will be reviewed and published publicly, helping others stay safe and informed.
👉 Let’s build the largest open DRM knowledge base together.
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🔐 What is DRM and How Does Decryption Work?
DRM (Digital Rights Management) is a content protection system that ensures only authorized users can access and play digital media like movies, TV shows, or sports events. Two of the most common systems in the streaming industry are Widevine (by Google) and PlayReady (by Microsoft).
These systems use encryption, licenses, tokens, and specialized secure environments called CDMs (Content Decryption Modules) to lock media playback.
🧠 CDM Levels: L1, L2, L3 Explained
A CDM is a secure software module that requests licenses from a DRM server and decrypts content locally.
| Level | Description |
|---|---|
| L1 | Highest level, hardware-secured (used in certified mobile chips or TVs) |
| L2 | Partially hardware-based, some operations done in TEE |
| L3 | Software-only CDM (can run on Android emulators, browsers, etc.) |
✅ CDM L3 can be extracted for research purposes from:
- Android Emulators (e.g., MEmu, Nox)
- Real Android Devices using Frida
- Files needed:
device.wvd,device_client_id_blob,device_private_key
⚙️ What is a Decryption Script?
DRM Decryption Scripts are tools written in Python or JavaScript that:
- Parse MPD streams
- Extract PSSH data
- Send license requests
- Retrieve decryption keys automatically
Popular tools include:
- PyWidevine – Python-based automation for license retrieval
- WKS-KEYS / widevine_keys – script-based key extraction tools
- Browser extensions (Chrome/Firefox) for pen-testing to intercept CDM requests and extract keys (for testing only)
📦 What is a .MPD file and PSSH?
MPD (Media Presentation Description) is a manifest XML file used by DASH streaming. It tells the player where video/audio segments are and how they are encrypted.
Inside the MPD or the init segments, we find PSSH (Protection System Specific Header), which contains DRM info like:
- DRM system ID (e.g., Widevine)
- License server URL
- KID (Key ID)
- Content metadata
🧪 Full Test Example: Real Working Widevine Stream
Let’s break down this real test stream:
- MPD URL:
https://cdn.bitmovin.com/content/assets/art-of-motion_drm/mpds/11331.mpd - PSSH Base64:
AAAAW3Bzc2gAAAAA7e+LqXnWSs6jyCfc1R0h7QAAADsIARIQ62dqu8s0Xpa7z2FmMPGj2hoNd2lkZXZpbmVfdGVzdCIQZmtqM2xqYVNkZmFsa3IzaioCSEQyAA==- License Server:
https://cwip-shaka-proxy.appspot.com/no_auth - Decryption Keys:
--key ccbf5fb4c2965be7aa130ffb3ba9fd73:9cc0c92044cb1d69433f5f5839a159df
--key 9bf0e9cf0d7b55aeb4b289a63bab8610:90f52fd8ca48717b21d0c2fed7a12ae1
--key eb676abbcb345e96bbcf616630f1a3da:100b6c20940f779a4589152b57d2dacb
--key 0294b9599d755de2bbf0fdca3fa5eab7:3bda2f40344c7def614227b9c0f03e26
--key 639da80cf23b55f3b8cab3f64cfa5df6:229f5f29b643e203004b30c4eaf348f4
🔁 How the Decryption Process Works
- MPD is loaded by the player
- It detects encryption → extracts the PSSH block
- Player or script sends a license challenge (request) to the license server with
KID+ device info - License server checks the device's CDM authenticity
- If valid, server sends back a license (response) containing the decryption keys
- The CDM receives & unpacks the license → extracts the actual decryption keys
- Keys are used to decrypt the video/audio segments and enable playback
This process is handled securely inside a browser or app – but automation tools replicate the same logic using valid CDM data and license interactions.