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What exactly is the benefit of HTTP2 for HLS CDN use, particularly? The obvious benefit of not using it is that you don't need your CDN to do TLS, likely to be
by stefan_ 7y ago
What exactly is the benefit of HTTP2 for HLS CDN use, particularly?
The obvious benefit of not using it is that you don't need your CDN to do TLS, likely to be utterly superfluous if video chunks are validated through the secure side-channel of the playlist already.
- otterley 7y agoTLS provides privacy, not merely validity. Some folks don't want others knowing what they watch after connecting to, er, Disney+. (I have no idea why video streaming might be better over HTTP/2 either.)
- brians 7y agoTLS specifically does not prevent a passive eavesdropper from telling what compressed video you’re watching. If they can drop a few packets and force you to rebuffer, they can tell very quickly—plausibly faster than you can tell watching the video start!
- otterley 7y agoThat’s interesting. Do you have a reference to a working example?
- danielparks 7y agoHow does that work?
- nitrogen 7y agoDropping packets is not passive...
- Dylan16807 7y agoOkay so ignore that part. It's a tangent to the actual point.
- danielparks 7y agoCan you point us to some documentation? I’m having trouble seeing how this would work absent a huge vulnerability in TLS.
- Dylan16807 7y agohttps://pdfs.semanticscholar.org/2015/26efeb7206e2704b8db46985e4fcb0b93e55.pdf https://pdfs.semanticscholar.org/2015/26efeb7206e2704b8db469... http://cs.jhu.edu/~cwright/oakland08.pdf http://cs.jhu.edu/~cwright/oakland08.pdf https://www.blackhat.com/docs/us-14/materials/us-14-Niemczyk-Probabilist-Spying-On-Encrypted-Tunnels.pdf https://www.blackhat.com/docs/us-14/materials/us-14-Niemczyk... There's variation in the segment-to-segment sizes of video. Watching the stream of data, you can pretty easily find many of the segment sizes, and from there you just need a lookup table. Figuring out spoken language or which web pages are in packets is fuzzier but still viable.
- danielparks 7y agoAh, thanks. That makes sense.