Stay safe, respect the artists who make the music, and always think twice before running unknown code on your machine.
| Key/Token Name | Role | Where to Find It | | :--- | :--- | :--- | | | Static cryptographic salt. Used to generate a track-specific key. | Hardcoded (obfuscated) in client-side apps and web JS | | Track XOR Key | A unique key for each song. Generated from the Track ID and Master Key. | Dynamically generated at runtime | | ARL (Access Rights Language) Token | User authentication token. Grants access to Deezer's API based on account type. | In browser cookies (Application > Storage tab) | | Gateway Key | Encrypts login parameters for the mobile API. A 16-character static key. | Stored within Android APK assets or iOS binaries | deezer master decryption key work
This approach has been described by reverse engineers as “unique amongst most of the commercial music streaming services,” with many keys stored (often obfuscated) directly in the client. The reasoning appears to be a trade-off: client-side key storage allows for smoother offline playback and faster streaming, but it also introduces a fundamental vulnerability — if a determined user can extract the key, they can decrypt the content. Stay safe, respect the artists who make the
Here is a summary of the technical "paper" (research) regarding how the Deezer decryption keys work: | Hardcoded (obfuscated) in client-side apps and web
There’s an ongoing debate about whether reverse engineering for interoperability or security research constitutes fair use. Some argue that understanding DRM mechanisms is essential for security research, accessibility tools, and archival purposes. Others maintain that any circumvention — regardless of intent — violates both the law and the contractual agreements users accept when signing up for streaming services.