Is this kind of key rotation considered in gpac drm packaging?
Segment files may have PSSH(playready pro object, els key object) table.

**Key rotation with ROOT/LEAF keys** 
_Changing the encryption keys frequently—scalable key rotation_ 
https://docs.microsoft.com/en-us/playready/packaging/content-packaging-and-delivery
https://github.com/MicrosoftDocs/PlayReady/blob/main/Docs/Packaging/how-to-package-mp4-based.md

> 
> There is an advanced mechanism in PlayReady called scalable key rotation (as opposed to license rotation). This method stores an Embedded License Store (ELS) in the stream of the actual content. In this mechanism, the key used to encrypt the A2 segment itself is called the leaf key {kidA2, ckA2}, and is delivered in the ELS of the segment A2, being itself encrypted with a separate key that is the same for all the segments of track A, called the root key {kidRA, ckRA}. 
> 
> Let's say this asset is live linear TV. When the client attempts playback, it finds kidRA in the PlayReady Header of the stream manifest, and requests a license for kidRA. The License Server returns a root license for the root key {kidRA, ckRA}. Then the client parses segment A1 and discovers the ELS in the header of the segment. Parsing this ELS, it finds the leaf license {kidA1, ckA1} in this ELS. Using the root key {kidRA, ckRA} and the leaf license {kidA1, ckA1}, it can get the value of ckA1, and decrypt and render the segment A1. 
Key rotation with ROOT/LEAF keys instead of new <Period> on each new keyID
This is a GitHub Issue
repo:gpac
owner:gpac
Title : Key rotation with ROOT/LEAF keys instead of new <Period> on each new keyID
Issue date:

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Is this kind of key rotation considered in gpac drm packaging?
Segment files may have PSSH(playready pro object, els key object) table.

**Key rotation with ROOT/LEAF keys** 
_Changing the encryption keys frequently—scalable key rotation_ 
https://docs.microsoft.com/en-us/playready/packaging/content-packaging-and-delivery
https://github.com/MicrosoftDocs/PlayReady/blob/main/Docs/Packaging/how-to-package-mp4-based.md

> 
> There is an advanced mechanism in PlayReady called scalable key rotation (as opposed to license rotation). This method stores an Embedded License Store (ELS) in the stream of the actual content. In this mechanism, the key used to encrypt the A2 segment itself is called the leaf key {kidA2, ckA2}, and is delivered in the ELS of the segment A2, being itself encrypted with a separate key that is the same for all the segments of track A, called the root key {kidRA, ckRA}. 
> 
> Let's say this asset is live linear TV. When the client attempts playback, it finds kidRA in the PlayReady Header of the stream manifest, and requests a license for kidRA. The License Server returns a root license for the root key {kidRA, ckRA}. Then the client parses segment A1 and discovers the ELS in the header of the segment. Parsing this ELS, it finds the leaf license {kidA1, ckA1} in this ELS. Using the root key {kidRA, ckRA} and the leaf license {kidA1, ckA1}, it can get the value of ckA1, and decrypt and render the segment A1. 
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