Protected Streaming
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Protected Streaming[1] is a DRM technology by Adobe. The aim of the technology is to protect digital content (video or audio) from unauthorized use.
Protected Streaming consists of many different techniques; basically there are two main components: encryption and SWF verification.
This technique is used by the Hulu desktop player and the RTÉ Player. Fifa.com also uses this technique to serve the videos on the official site. Some videos on YouTube also use RTMPE, including those uploaded there by BBC Worldwide.
Streamed content is encrypted by the Flash Media Server "on the fly", so that the source file itself does not need to be encrypted (a significant difference from Microsoft's DRM). For transmission ("streaming"), a special protocol is required, either RTMPE or RTMPS.[citation needed]
RTMPS uses SSL-encryption. In contrast, RTMPE is designed to be simpler than RTMPS, by removing the need to acquire a SSL Certificate. RTMPE makes use of well-known industry standard cryptographic primitives, consisting of Diffie–Hellman key exchange and HMACSHA256, generating a pair of RC4 keys, one of which is then used to encrypt the media data sent by the server (the audio or video stream), while the other key is used to encrypt any data sent to the server. RTMPE caused less CPU-load than RTMPS on the Flash Media Server.[citation needed]
Tools which have a copy of the well-known constants extracted from the Adobe Flash Player are able to capture RTMPE streams, a form of the trusted client problem. Adobe issued DMCA takedowns on RTMPE recording tools, including rtmpdump, to try to limit their distribution. In the case of rtmpdump, however, this led to a Streisand effect.[2]
