Crazy Little Thing Called Protected HTTP Dynamic Streaming (PHDS)
PHDS is not related to higher education, but is a very powerful option to stream protected content to Flash and Adobe AIR clients. If you don’t have to protect your content, you properly don’t need to read any further – if you do, you should be aware of its functionality, and the benefits for your streaming deployment.
Flash/AIR content protection options
RTMPe is the most popular way to protect content. It’s very easy to turn on, simply switch your rtmp:// URL to rtmpe://, and your server will provide an encrypted streaming channel. In addition, you can lock down the SWF player with SWF verification to make sure only your player consumes the stream.
HDS (or RTMP/PD) with Flash Access
HDS in combination with Flash Access provides high-end content protection. Flash Access is not limited to HDS, and also works with progressive download, or RTMP streaming. The Flash Access setup in this case includes a license server, and provides all the robustness you need.
pRTMP, or protected RTMP, is a new generation of RTMP content protection.
Flash Media Server encrypts on-demand media files and embeds a Flash Access 3.0 license in the DRM metadata of the content. Flash Player and AIR clients communicate with Flash Media Server to play the media. Protected RTMP does not require a license server; the license is embedded in the content metadata and a client receives it along with the media.
Protected RTMP is more secure than RTMPE because it uses Flash Access 3.0 DRM content protection. Protected RTMP encrypts the content whereas RTMPE protects the communication channel. Because data is unencrypted, companies like comScore and Nielsen can measure protected RTMP video. (via Flash Media Server Developer Guide)
PHDS is very similar to pRTMP, but based on HTTP Dynamic Streaming.
Use Flash Media Server 4.5 to serve live and on-demand protected content to Flash Player and AIR over HTTP without using a DRM License Server. When Flash Media Server packages the content, it generates the license and embeds it in the metadata of the content stream. This feature is called Protected HTTP Dynamic Streaming (PHDS). In addition to encrypting content, PHDS also supports SWF verification for HTTP Dynamic Streaming. (via Flash Media Server Developer Guide)
This might sound a bit confusing, therefore here is some guidance:
Best possible protection -> Flash Access (requires Flash Access license server)
Robust RTMP based content protection, better than RTMPe, without license server -> pRTMP
Robust content protection for HDS, without license server -> PHDS
Flash Access will always provide the best content protection, but for certain use cases, e.g. live streaming, it’s more important to have scalability by avoiding license server requests. That’s why it’s important to understand the characteristics and benefits of PHDS.