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+# EME Extension: HDCP Policy Check
+
+## Motivation
+
+A content license can contain a policy that the CDM must enforce. The ability
+of a platform to enforce these policies is a key factor in deciding whether to
+begin streaming media and at what quality (resolution and framerate).
+
+HDCP is a common policy requirement for streaming high resolutions of protected
+content. Currently, applications can only know if this requirements is met
+through key statuses, which are only reported after providing a license. To
+provide a license, applications must: generate a license request, post that
+request to a license server, wait for the response, provide the response to the
+CDM, wait for key status events, and check key statuses.
+
+Application developers would like to know before fetching content if HDCP (and
+what version) can be enforced. This would allow the application to start
+pre-fetching high resolution content rather than starting at a low resolution or
+waiting for the license exchange.
+
+HDCP may be one of many requirements for a content license. The proposed
+dictionary may later be extended to include other requirements as requested by
+application developers. Feature detection can be done by developers by setting
+throwing getters.
+
+
+## Overview
+
+The new API will allow application developers to query the status of a
+hypothetical key associated with an HDCP policy, without the need to create a
+MediaKeySession or fetch a real license. It does not require the MediaKeys to be
+attached to any HTMLMediaElement, either.
+
+If HDCP is available at the specified version, the promise should return
+a MediaKeyStatus of "usable". Otherwise, the promise should return
+a MediaKeyStatus of "output-restricted".  The determination of HDCP status
+should be done in the same way that the CDM would enforce such a restriction
+during playback.  In this way, application developers can get a reasonable hint
+to allow them to optimize what content they fetch to start playback.
+
+A MediaKeyStatus value of "status-pending" must never be returned. Implementers
+must give decisive actionable return values for developers to make decisions
+about what content to fetch.
+
+```
+dictionary MediaKeysPolicy {
+  DOMString minHdcpVersion = "";
+};
+
+partial interface MediaKeys {
+  Promise<MediaKeyStatus> getStatusForPolicy(MediaKeysPolicy policy);
+}
+```
+
+The HDCP versions will be kept in a registry. The initial list will contain:
+```
+ - 1.0
+ - 1.1
+ - 1.2
+ - 1.3
+ - 1.4
+ - 2.0
+ - 2.1
+ - 2.2
+ - 2.3
+
+```
+
+
+## Examples
+
+```js
+video.mediaKeys.getStatusForPolicy({
+  minHdcpVersion: '1.0'
+}).then(status => {
+  if (status === 'usable') {
+    // Pre-fetch HD content.
+  } else {  // such as 'output-restricted' or 'output-downscaled'
+    // Pre-fetch SD content.
+  }
+});
+```
+
+
+## Privacy Considerations
+
+This would allow an application to discover HDCP availability. HDCP is widely
+available on most modern operating systems and display types. It is not expected
+to add much entropy for fingerprinting.
+
+As access to this API is gated by the async `requestMediaKeySystemAccess()` which
+may require user consent, the HDCP privacy concerns are the same as the
+[EME ones](https://w3c.github.io/encrypted-media/#privacy).