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Protected Streaming〔("Using the Adobe Access Server for Protected Streaming" )〕 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 RTE 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. == Encryption == 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. 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. Adobe fixed the security issue in January 2009, but did not fix the security holes in the design of the RTMPE algorithm itself.〔(【引用サイトリンク】title=RTMPE Specification and Analysis )〕 Analysis of the algorithm shows that it relies on security through obscurity. For example, this renders RTMPE vulnerable to Man in the Middle attacks. 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.〔(【引用サイトリンク】title=Adobe has issued a DMCA removal request for rtmpdump )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Protected Streaming」の詳細全文を読む スポンサード リンク
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