"keyids" Initialization Data Format

W3C Group Note 20 August 2024

Abstract

This specification defines the "keyids" initialization data format for use with the Encrypted Media Extensions [ENCRYPTED-MEDIA].

Note

It defines a stream format-independent format for specifying a list of key ID(s). This type can be used by applications to directly provide information necessary to generate a license request without using media data or constructing container-specific formats.

Status of This Document

This section describes the status of this document at the time of its publication. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at https://www.w3.org/TR/.

This document was published by the Media Working Group as a Group Note using the Note track.

This Group Note is endorsed by the Media Working Group, but is not endorsed by W3C itself nor its Members.

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The format is a JSON object, encoded in UTF-8 as specified in the Encoding specification [encoding], containing the following member:

"kids": An array of key ID(s). Each element of the array is the base64url encoding of the octet sequence containing the key ID value.

Note

See Using base64url.

Note

Applications may encode the JSON string using the TextEncoder interface [encoding].

This section is non-normative.

The following example will generate a license request for two key ID(s). (Line breaks are for readability only.)

Example 1

{
  "kids":
    [
     "LwVHf8JLtPrv2GUXFW2v_A",
     "0DdtU9od-Bh5L3xbv0Xf_A"
    ]
}

As well as sections marked as non-normative, all authoring guidelines, diagrams, examples, and notes in this specification are non-normative. Everything else in this specification is normative.

[encoding]: Encoding Standard. Anne van Kesteren. WHATWG. Living Standard. URL: https://encoding.spec.whatwg.org/
[ENCRYPTED-MEDIA]: Encrypted Media Extensions. Joey Parrish; Greg Freedman. W3C. 7 August 2024. W3C Working Draft. URL: https://www.w3.org/TR/encrypted-media-2/

"keyids" Initialization Data Format

Abstract

Status of This Document

1. Format

2. Example

3. Conformance

A. References

A.1 Normative references