4 ms·

Is protecting user privacy really the primary focus of this initiative? It seems to be another step in the multi-front battle between Netflix and ISPs: 1) Expo

by nrb 10y ago

Is protecting user privacy really the primary focus of this initiative? It seems to be another step in the multi-front battle between Netflix and ISPs: 1) Expose ISPs who limit your bandwidth to the service. 2) Protect against manipulation/degradation of the video stream quality.

brianwawok 10y ago
Does this really solve the ISP identifying the traffic? I suspect netflix still has limited source IPs. If you see netflix like steady bandwidth from a known netflix IP, pretty sure it would be trivial to throttle.
- CaptSpify 10y ago
  Aren't there ISP's using other traffic-shaping techniques than simply throttling? I'm guessing this is meant to also impede those.
- ejcx 10y ago
  No it would not, you're right, but there's more too it. Most ISPs, it's just easier to get an OCA in their data center that going through the process of throttling traffic or whatever else they want to do with it. TLS SNI is still a way that an ISP could identify the traffic when it's routing folks on the net to an OCA in a different AS.
- samplonius 10y ago
  It is not that Netflix is being access, but what on Netflix is being accessed. Netflix does not publish viewership information. But a large ISP could run DPI on Netflix traffic to determine what content is being viewed. And since many ISPs have their own TV product, they would be really interested in that information themselves. But if Netflix streams at TLSed, then good luck figuring out Archer from The Lust of the Dead.
  - tveita 10y ago
    > good luck figuring out Archer from The Lust of the Dead. Not necessarily that hard. TLS won't hide the sizes of the files being downloaded. You may even be able to estimate the size of each segment as they're downloaded, which should give you a pretty accurate fingerprint. You'd need to spend resources to play each movie with different devices and bandwidths and record the traffic pattern, which raises the bar a fair bit.
    - angry_octet 10y ago
      The traffic pattern would be more specific to the playback device than the content. There might be more spread in duration, but even so, television networks like shows to go for specific times for ease of programming. As for encoding rates, it is quite possible they use CBR. Even if they use VBR they may choose different playout sources depending on the consuming devices and network conditions. On the whole I doubt you would have a high probability of identifying any specific show. Even if you are able to cull 75% of the possibilities (i.e. 4 bits of entropy) that still leaves lots of shows (total ~1000 tv series and ~5000 movies by one source), plus all the noise of people pausing/switching, skipping credits, etc.
      - repsilat 10y ago
        How big is a show, sent compressed? A gigabyte an episode? I guess the range is more relevant, say plus or minus ten megs to be conservative. I don't know how big packets are, maybe 4k is too small? 10M/4k=2.5k, not bad, but not great if you want to avoid birthday collisions, you'd only get maybe 60 uniques if they're uniformly distributed. CBR does kill it, though, and "uniformly distributed" is too big an ask. Off topic, but an interesting thought: you know the HBO intro? With the static? That static is the hardest thing in the world to compress, and also the thing that viewers care the least about having compressed accurately. That's weird, I wonder how true it is across the board -- certainly artifacts can be jarring in flat shaded cartoons...
        angry_octet 10y ago
kakarot 10y ago
I guess it solves both problems, so it's probably a smart move.
fred256 10y ago
There may be another angle to this: Netflix does not publish viewership ratings of its shows, but there have been a few attempts by various companies to infer the ratings by traffic analysis. Encrypting the traffic makes it harder to do so.
- deleted 10y ago
  [deleted]

by nrb 10y ago

brianwawok 10y ago

Does this really solve the ISP identifying the traffic? I suspect netflix still has limited source IPs. If you see netflix like steady bandwidth from a known netflix IP, pretty sure it would be trivial to throttle.

CaptSpify 10y ago
Aren't there ISP's using other traffic-shaping techniques than simply throttling? I'm guessing this is meant to also impede those.
ejcx 10y ago
No it would not, you're right, but there's more too it. Most ISPs, it's just easier to get an OCA in their data center that going through the process of throttling traffic or whatever else they want to do with it. TLS SNI is still a way that an ISP could identify the traffic when it's routing folks on the net to an OCA in a different AS.
samplonius 10y ago
It is not that Netflix is being access, but what on Netflix is being accessed. Netflix does not publish viewership information. But a large ISP could run DPI on Netflix traffic to determine what content is being viewed. And since many ISPs have their own TV product, they would be really interested in that information themselves. But if Netflix streams at TLSed, then good luck figuring out Archer from The Lust of the Dead.
- tveita 10y ago
  > good luck figuring out Archer from The Lust of the Dead. Not necessarily that hard. TLS won't hide the sizes of the files being downloaded. You may even be able to estimate the size of each segment as they're downloaded, which should give you a pretty accurate fingerprint. You'd need to spend resources to play each movie with different devices and bandwidths and record the traffic pattern, which raises the bar a fair bit.
  - angry_octet 10y ago
    The traffic pattern would be more specific to the playback device than the content. There might be more spread in duration, but even so, television networks like shows to go for specific times for ease of programming. As for encoding rates, it is quite possible they use CBR. Even if they use VBR they may choose different playout sources depending on the consuming devices and network conditions. On the whole I doubt you would have a high probability of identifying any specific show. Even if you are able to cull 75% of the possibilities (i.e. 4 bits of entropy) that still leaves lots of shows (total ~1000 tv series and ~5000 movies by one source), plus all the noise of people pausing/switching, skipping credits, etc.
    - repsilat 10y ago
      How big is a show, sent compressed? A gigabyte an episode? I guess the range is more relevant, say plus or minus ten megs to be conservative. I don't know how big packets are, maybe 4k is too small? 10M/4k=2.5k, not bad, but not great if you want to avoid birthday collisions, you'd only get maybe 60 uniques if they're uniformly distributed. CBR does kill it, though, and "uniformly distributed" is too big an ask. Off topic, but an interesting thought: you know the HBO intro? With the static? That static is the hardest thing in the world to compress, and also the thing that viewers care the least about having compressed accurately. That's weird, I wonder how true it is across the board -- certainly artifacts can be jarring in flat shaded cartoons...
      - angry_octet 10y ago

kakarot 10y ago

I guess it solves both problems, so it's probably a smart move.

fred256 10y ago

There may be another angle to this: Netflix does not publish viewership ratings of its shows, but there have been a few attempts by various companies to infer the ratings by traffic analysis. Encrypting the traffic makes it harder to do so.

deleted 10y ago
[deleted]