RSL Encrypted Media Standard (EMS) ​

Version 1.0 Draft. Last updated: 2025-07-03.

RSL enables client applications to securely license and access proprietary digital assets, including paywalled web content, images, videos, books, and datasets, by using Encrypted Media Standard (EMS) files. Encrypted content files are identified by the encrypted="true" attribute on the <content> element in an RSL license.

To access the content of an EMS file, a client application must first obtain a license from the designated RSL License Server, and then retrieve the corresponding decryption key via the RSL Key Management Protocol. This ensures that only authorized clients can decrypt and access the content.

The choice of cryptographic algorithms and the implementation of encryption and decryption for EMS files are out of scope for this specification and are left to individual license server operators.

Example Code ​

Below is an example RSL license file for an encrypted asset.

xml
<rsl xmlns="https://rslstandard.org/rsl">
  <content url="https://example.com/books/example_book.epub.enc" 
           encrypted="true" server="https://api.rslcollective.org">
    <license>
      <permits type="usage">ai-train</permits>
      <payment>
        <custom>https://example.com/contact.html</custom>
      </payment>
    </license>
  </content>
</rsl>