16 ms·
Game of Thrones leak and watermark: a stupid tracking system
- fredley 11y ago...or just use steganography. Steganography in videos can be made to be invisible to the naked eye, and extremely robust - even to video compression. It's also difficult to detect, and even more difficult to remove/tamper with. What the author of the article is proposing is actually a kind of steganography, albeit a rather crude one, and probably rather difficult to implement (since scene timings will be different for each episode, and you'll need to keep a separate log of exactly which timings correspond to each person you've distributed the file to), compared to running a video through a process that embeds a steganographically hidden id pattern at each keyframe.
- NoMoreNicksLeft 11y agoHow will that survive transcoding? What if you bump it down to 477p resolution?
- fredley 11y agoThere will be a limit to how much compression it can take, but some methods e.g. Echo Hiding are extremely compression resistant (I've implemented this over a phoneline - it works).
- mitchell_h 11y agoWouldn't a simple re-encode break any sort of stenography?
- fredley 11y agoNo. There are algorithms out there that can survive compression[1] by encoding statistically over an image instead of just bit manipulation. You can also embed data in the audio channel by alternating between two imperceptible echo kernels for 1/0[2]. This is extremely compression resistant. 1: http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumber=4428921&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4428921 http://ieeexplore.ieee.org/xpl/articleDetails.jsp?tp=&arnumb... 2: http://www.slidefinder.net/a/audio_steganography_echo_data_hiding/jeff_england_audio_steganography/24367218 http://www.slidefinder.net/a/audio_steganography_echo_data_h...
- psk 11y agoSurely it would be possible to create encoding resistant stenography. Will the stenography be affected, sure, but it should be possible to create error-resistant stenography up to a certain point.
- dTal 11y agoStenography: encode information such that it is below the human detection threshold. Lossy compression: discard all sub-threshold information. Thus, in the general case it's fundamentally impossible. You can make a scheme that will survive certain known encoders and bitrates, but you can't make one that will survive all lossy compression.
- llimllib 11y agoOf course we have no idea if they used steganography or not, right? He bases the article on the idea that they have no tracking info except the watermark, but I don't see any evidence that they don't know more.
- fredley 11y agoTo be honest, when I heard that the files were protected with a watermark, I assumed that they actually meant a steganographic watermark. I thought that this tech had been adopted into the industry ages ago, I'm rather surprised if it isn't the case, given the arms-race between the media and illegal distribution.
- bru 11y agoSame here. I was really surprised. That's why I thought that my very simple idea warranted writing a post.
- rlx0x 11y agoYour initial assumption was correct, it is widely deployed in the industry, there are multiple vendors that provide fingerprinting technology that is orders of magnitude more advanced then what the article suggests. The visible fingerprint might just have been there to deter the clueless. In any case even with a fingerprint its hard to proof without a doubt, the individual who actually stole it.
- jjoonathan 11y agoThe visible fingerprint might also be there to prove intent or add circumvention charges in court. I don't think they need to prove that a certain individual stole it. The party which received the advanced copies likely had to take on liability, so HBO can go after them. Of course, that doesn't mean they won't turn around and lean on the actual culprit, but whether or not they catch someone HBO will have their due.
- anigbrowl 11y ago
- marquis 11y agoIt it were a full-screen steganograph it would need to be subtle as to not interfere with viewing. So could that be combatted by re-compressing with another codec?
- DanBC 11y ago> it would need to be subtle as to not interfere with viewing Pre-release screeners often have big ugly on-screen watermarks. Almost anything is better than a scrolling mid-screen line of text "PROPERTY OF STUDIO NAME DO NOT PIRATE THIS FILM".
- markbnj 11y agoCame in to say this. It's the obvious answer, and presumably the IP owners know about it even if the author of the article does not. It's also obvious that the author doesn't understand video encoding if he is proposing measuring millisecond differences in the length of specific scenes.
- URSpider94 11y agoThis. The minimum difference in scene length allowable would be a single frame.
- jjoonathan 11y agoDo you actually know that or are you speculating? I wouldn't be surprised if MP4 (or other video formats) provided a mechanism for tweaking the timing of a given frame. Of course, if you're using such a primitive watermark you might as well just add a note in the metadata...
- ianferrel 11y agoBut wouldn't it be trivial to notice that in the reencoding step and throw it away? "Huh, this frame is supposed to be delayed by 3ms. Ah, screw it, [checks 'force to 23.97 fps' button]."
- HelloNurse 11y agoYes, we know that. Video playback has physical constraints; a file format where image elements are sampled at irregular time intervals is obviously possible and useful for very "scientific" purposes like measuring when images are acquired and interpolating the raw data, but not reasonable for playing back on a screen with good compression and easy decompression.
- mappu 11y agoHuh? VC-1 in WMV and H.264 in MKV both support VFR. It's not uncommon for handheld video cameras or some anime sources.
- est 11y ago> and extremely robust - even to video compression. It's also difficult to detect, and even more difficult to remove/tamper with. Split & merge frame by frame, in random, from multiple video sources. Visually they will be the same, but steganography has a high chance of been broken.
- royjacobs 11y agoAny steganography solution on the market today that is worth its salt would actually be robust against this. The amount of different sources you would have to combine to protect against this is higher than you'd realistically be able to find. Disclaimer: I used to work at one of the leading companies in this field.
- est 11y agothe algorithm could tell exactly which sources are used in the final video? impressive!
- fluidcruft 11y agoAre you being sardonic? There are extremely obvious ways to do this particularly since they've got both space, color, sound and particularly time to play with. Unmixing signals isn't rocket science, especially if you've provided the signals that are getting mixed.
- Strilanc 11y agoThat's very interesting. I always assumed averaging (maybe with varying weights across frames and time), or applying a few rounds of other steganography, would degrade the encoded message into noise. Could you link to some papers? If you try to encode lots and lots of messages with different keys into the video, does it ruin the quality before ruining previous messages?
- royjacobs 11y agoI'm not sure in how much details I can go since a lot of this is behind patents and NDAs and whatnot, but just googling for "video watermarking" should already yield quite a few interesting details for you.
- edoloughlin 11y agoWhat the author of the article is proposing is actually a kind of steganography, albeit a rather crude one, and probably rather difficult to implement ...but easy to explain (and sell?) to the entertainment industry, who have shown themselves to be mostly technically illiterate. Some cynical, unscrupulous hacker could probably extract a lot of money from them for such a service...
- bru 11y agoAuthor here. That's my goal, but I don't have their email address so I simply wrote it down there.
- madaxe_again 11y agoWhile stego might be a route, blurring the watermark may not be enough to obscure the source. Given a known frame, they could blur the same portion of the same frame on all watermarked copies, and the one with a matching output is your culprit. Blurring loses information, but is more akin to a hash than a deletion, as it's a deterministic process. Edit: this sort of thing. http://dheera.net/projects/blur http://dheera.net/projects/blur
- peeters 11y agoIt's a deterministic process, but it still has inputs. You'd have to know those inputs or test for every possible set of inputs to whatever blurring method was used.
- spb 11y agoI imagine HBO knows every reviewer they gave a watermarked copy to.
- darkmighty 11y agoIt depends on the blurring method. If you do a gaussian blur, for example, you might be able to do a pretty good inverse blur by finding black frames and performing blind deconvolution. If I were at risk I'd use a nonlinear injective filter instead, to make sure information is lost (linear filtering is not only deterministic but perfectly without noise and no frequency response nulls).
- sorokod 11y agoSteganography (which may or may not have been used) wouldn't have any effect whatsoever on the number of downloads
- jamesrom 11y agoI don't see anyone anywhere claim that it would. It would only aid in tracing the source of the leak.
- sorokod 11y agoTrue - and then what? The leaked episodes may have been stolen or can be claimed to have been stolen. Anyway, the horses have bolted and the damage is done.
- cpeterso 11y agoYes, but the leaker would be blacklisted from all future HBO (and possibly partner) pre-release materials.
- tbabb 11y agoAnd probably sued into oblivion.
- sorokod 11y agoDo you know for a fact that the leaker is the same person (organisation?) that has received the official HBO material? Maybe it is more like this: http://www.ibtimes.co.uk/expendables-3-online-leak-two-arrested-over-damaging-pre-release-movie-piracy-1476498 http://www.ibtimes.co.uk/expendables-3-online-leak-two-arres...
- c22 11y agoMaybe so, but HBO isn't obligated to prove guilt beyond reasonable doubt. Arguably if someone can't keep the screener secured from internet thieves they're still not a trustworthy guardian of the content.
- DrJokepu 11y agoThis might be a very naive suggestion (I know nothing about the subject) but couldn't you just take two copies, XOR them and blank out the difference to defeat such signatures?
- darkmighty 11y agoWe're talking about images, so if you take the pixels for example they're just {0,...,255}^n, integers. You can if you have the original file, but then what's the point? Otherwise, take image a=original+f1, image b=original+f2. Then if you e.g. average them you still have c=original+f1/2+f2/2 -- so both signatures are kept (theoretically if either you have a large number of sources you could average the signals out of existence, or perhaps the system isn't robust and can't detect multiple sigs). This assumes the introduced signatures are indistinguishable from the source (quite reasonable).
- allemagne 11y agoEven if that worked (maybe it does, I don't know) you'd still have the very major obstacle of getting two potential leakers (from presumably separate publications) to find each other and collude without getting caught.
- contravariant 11y agoI think that could be avoided by making sure that large parts of the signatures overlap. There's probably some scheme to be able to recover which copies were used to make the leaked copy (up to some finite number of copies, but it quickly becomes impractical to get enough copies).
- MichaelGG 11y agoOver 4 separate files, depending on how they encode the IDs, you might still find out who the leakers are. They might share some bits and not others. The studio can take its time if it has a serious leaking issue.
- tbabb 11y agoI will say that steganography is definitely in use already, at least on feature films. (It's particularly easy in animation, where literally anything can be changed seamlessly). A film pirated from a theater (even by a camera pointing at a screen) can easily be traced to the exact theater and showing of the movie, and IR cameras in the theater permit authorities to identify the exact individual with the camera. In short, don't try to film a movie in a theater; they will find you.
- azakai 11y agoYes. The author of the article is barging through an open door: It's very likely that those Game of Thrones episodes had individual hidden watermarking, and that using those they can tell exactly who leaked it. The author jumped to the conclusion that those don't exist, apparently because they aren't visible (but that's the point!) and that there is a visible watermark which the author apparently assumed was the only one (but it almost certainly isn't).
- erikb 11y agoI guess we all agree that watermarking the viewable content instead of thinking about securing/signing the whole data file was not so smart in the first place. When I download a video from the Google Play Store I can only watch it for 24 hours or so. I thought there was already a highly protected digital signature/encryption system involved. Why is that not used for reporter previews?
- glazun 11y agoI'm surprised they just send out DVDs with content... HBO have a streaming service, creating a preview section shouldn't be hard. Up to reporters to get a decent connection to stream...
- shawabawa3 11y agoAnything that is viewable cannot be secured. The play store can stop you watching the content after 24 hours on the play store. It cannot possibly stop you recording your screen while it's playing and saving it forever Preventing leaks is basically impossible, but making them traceable is possible using watermarks
- erikb 11y agoSounds quite reasonable, actually. Haven't thought about that. Thanks!
- NoMoreNicksLeft 11y agoNot very clever. Get two leaked copies, and mix them up. Use the credits from copy A, or hell, even chop off 11 milliseconds from them. Then mix and match scenes... even chop off a few ms from some randomly selected scenes. I bet you wouldn't even need the two copies.
- slayed0 11y agoThis assumes you know the method they are using. As the post mentioned, a few milliseconds + or - at the end of a scene would not be noticeable and the overall timestamp would still be constant if "self-compensating offsets" were used.
- TheLoneWolfling 11y agoYou can figure out the method they are using by comparing two copies.
- bigiain 11y agoSo how many video frames do I lop off a scene to subtract "a few milliseconds" from it?
- NoMoreNicksLeft 11y agoIf it's 30fps, each frame is about 33ms. One or two is sufficient. Most films are 24fps, or 23.99 for some weird NTSC->film->NTSC reason.
- zapu 11y agoOnly if you knew that was already going on. Security by obscurity, but still, I don't believe this kind of watermarking was ever used. Maybe something like Cinavia[1] could be used instead? It's an analog watermarking system for detecting pirated copies and refusing to play them if player detects such copy is played on something else than bluray disc. Apparently this survives transcoding, and was/is major pain for people ripping their discs for various reasons and trying to play the files on certified players. [1] http://en.wikipedia.org/wiki/Cinavia http://en.wikipedia.org/wiki/Cinavia
- tempodox 11y agoThis must be one of those posts you only understand after you've been primed into some obscure context.
- strangecasts 11y agoIt helps to be familiar with steganography; the post is basically proposing to make a unique watermark in a video by changing the starting times of each scene, and the rest of the post is mostly math to figure out how much you'd need to alter it to let you identify a single leaker from a given number of people.
- acomjean 11y ago> and the only tracking set up HBO seemed to be a watermark in the bottom left corner of the screen. If they only had the one obvious watermark, I think HBO was hoping that maybe the people getting the screeners would think that there is more than one way they had the video tracked. Either the person who uploaded didn't care, or didn't think about it. Its worth noting HBO has been on a path to make content available on the internet even without Cable (HBO now). probably a good long term strategy. There are always people who want it sooner, and free! This is why we can't have nice things..
- tarpherder 11y agoHow can people so easily assume that the watermark was truly the only tracking present? HBO wouldn't immediately come out swinging even if they knew who or where the copy was leaked.
- droopyEyelids 11y agoThats an astute observation. Whenever you're tricking someone, you put something stupid easy in for the tricked person to defeat, so they assume they're tricking you. But it could be even easier. Why not put the watermark in a different location for every copy you distribute?
- tarpherder 11y agoThe silly thing is that nobody seems to realize that the public has only seen 1 leaked copy, probably from 1 source. HBO could be using any number of techniques and none of us would notice any of them because we have a sample size of 1. Even the odd techniques OP describes could be present in the copy, your described technique as well, any number really. We won't see them unless they are as in-your-face as the watermark.
- dmbass 11y agoHow do we know they're not using techniques like this?
- genericuser 11y agoWhile using the millisecond length of things would be clever and would catch which copy it originated from while it remained secret that was how you were doing it. As soon as it was known it is not much harder for the person ripping the copy to shorten all the scenes by a random number of milliseconds than it is for them to blur the watermark. I mean this could be a good addition to the current tech used in something like Cinavia, which is the most robust system I have seen and if not already doing it could easily identify individual sources. But the inaudible audio and steganography used in that system just seem much more of a pain to circumvent than using lengths of scenes as a serial number of sorts.
- deleted 11y ago[deleted]
- bigiain 11y agoIt's a bit hard to encode millisecond scale differences in scene or credit lengths - when the video is quantized to ~40ms frames...
- TazeTSchnitzel 11y agoEdit the frame length.
- Galactor963 11y agoWhile this is cool idea, how possible would it be to extend any particular scene by that short of a time? If the video is output at a typical 24 fps, the shortest any scene could be modified would be ~42 ms. Even with a lot of newer footage being filmed at 48 fps, it's still only able to clipped at a rate of 21 ms. Past that, I've seen a small amount of time shifting take place during a not-so-careful re-encode. At 1 ms precision, even this would be enough to throw off such a tracking system.
- gpmcadam 11y ago> Apart from that I think that binge-watching the first > 4 episodes is a stupid idea that will make you ache > for a month waiting for the 5th episode ☺. For me, I find more enjoyment in binging shows than being drip-fed, I watched all 4 in a row and don't regret not waiting (besides I've waited 12 months I can wait a few more weeks for more.) But more importantly, my online activity means I'll probably be spoiled before the 4th episode airs, not to mention people "predicting" events (read: passing off spoilers as theory) throughout the coming weeks. I'd rather not take that risk, personally, the cost of spoilers far outweighs the costs of waiting for me.
- asillystory 11y agoBinging makes the pacing of slow shows way more tolerable.
- nissimk 11y agoYes, I was wondering why they sent 4 episodes for review. Then I watched the first episode and I saw why...nothing is going to happen until the 4th episode. They've been teasing us with white walkers since season 1. And those dragons too...they were born in season 1 or 2 and they've hardly killed anyone yet. I guess I'm a sucker for the never-ending suspense...best show on tv.
- joshvm 11y agoThe 'problem' is that there are relatively few minor characters. Though there are clearly some overarching plot lines, pretty much all the arcs are very important to the story. As a result you've got to focus a little bit on each person and in a 55 minute show that means 5-10 minutes per story arc per episode. This only gets worse as more characters become important. It's somewhat balanced by other characters being killed off, mind!
- Redoubts 11y agoIt feels like there should be a lot more than 10 episodes per season.
- higherpurpose 11y agoWhile everyone is thinking how awful this is for HBO, I wonder how much it will boost the future viewership not just of the reason but for the whole game of thrones show. I imagine those who watched it early told all of their friends about the show, making them watch it too when it came out on TV.
- kayfox 11y agoI'm not sure you can vary video by anything other than full frames, so you would have to vary it in 33 ms chunks. Also, editors would cringe at "varying the length of scenes".
- dan00 11y agoWouldn't it be smart to add one easy recognizable and breakable tracking system and another more hidden one? ;)
- golergka 11y agoAll these methods meddle with films editor's jobs. And, the be frank, their job is much more important than considerations for piracy: they make the movie (or tv series) actually interesting. Making them do that (or changing their tools to support meta-data to do that) would be equal to bothering creative professionals who are essential to your product's success with mere details. And, if I remember correctly, GoT producers already said in some interview that they're not that concerned with piracy anyway.
- nothrabannosir 11y agoThere's a difference between post-release piracy and pre-release bootlegging. I would be surprised if this leak doesn't noticeably dampen their view count for the first four eps. Although that's hard to measure.
- imglorp 11y agoPiracy is actually in their interest up to a point. It generates free advertising through free samples, and might lure new subscribers who are on the fence about buying. The endgame is they really want people to sign up for the whole package.
- thefreeman 11y agoWhy does the attacker need a second leak? Can they not just randomly clip each scene by a few milliseconds? This would defeat the identification, and not be noticeable to a viewer.
- xenophonf 11y agoAnyone else here think HBO's missing out on a business opportunity? I wonder why they don't charge rabid fans (a _lot_) extra for early access to episodes. There appears to be a lot of demand for this.
- slayed0 11y agoThose episodes would immediately be leaked to everyone after becoming available and HBO would lose a ton of viewership on its own platform.
- Phlarp 11y agoThis is happened anyway, and they are capturing none of this possible revenue. Even if only one person purchased the early access and leaked it to everyone else they'd still be one sale better off than they currently are.
- slayed0 11y agoYes this has now happened one time. It doesn't happen every season. If you allowed early release of episodes to customers who were willing to pay more, you can pretty much guarantee that those will be leaked early every single time.
- xenophonf 11y agoI don't mean they should charge $10 or $20 for early access. I think they should be charging a couple hundred dollars - think VIP bottle service prices. Human nature being what it is, I suspect that people who are willing to pay for that level of access won't want to share it with the rest of us proles.
- zenojevski 11y agoIt works. Take, for example, $1,600 Photoshop Extended, which has never been pirated.
- Udo 11y ago
- peterkelly 11y ago"A few milliseconds" won't work - you must do it in units of frames.
- erroneousfunk 11y agoThat's what I was thinking, too. Given that each frame is about 42ms, that's not a trivial oversight. Much easier would be to use stenography to slightly manipulate the color of sets of pixels in the video. Far more information available to mess with, and extremely easy to hide (do it in various corners of various frames, keep the secret carefully guarded, or only let parts of the "secret" out to different groups, so that no one person knows all of the manipulation information, except, perhaps a head of security coordinating the entire thing)
- bisrael 11y agocame here to say the same thing. the same ideas apply to frames, if you drop one from a scene you'd have to add it back elsewhere. it just means comparing two copies would be easier to check for this technique than with a ms-based approach. i think it also reduces your problem space as cutting a scene by over a few frames would be extremely obvious in most shows with competent editors.
- intopieces 11y agoCan someone help me understand the negative impact of this leak? From what I can tell, the leak only benefits HBO. Viewership numbers in the age of time-shifting are worthless. Moreover, viewers now cost HBO money, in terms of server load during the peak viewership time. If even a small number of people avoided the broadcast during the premiere, HBO actually wins - and there's no telling how many people decided to subscribe to their new service after watching the leaked copy. Anyone who remembers the first GoT streaming premieres, they were largely catastrophic on the the servers. Last night appears to have gone well. I'm beginning to think HBO leaked it themselves.
- smitherfield 11y agoHBO most certainly did not leak it themselves; they could have their copyright on the material invalidated for that.
- smitherfield 11y agoTo elaborate, intellectual property law is essentially "use it or lose it" - a company that does not defend its IP against unauthorized use is likely to have it invalidated. One that actively promotes unauthorized use is almost certain to.
- bryanlarsen 11y ago"use it or lose it" is only a property of trademark laws, not copyright or other IP laws.
- smitherfield 11y agoIf HBO is not making a good-faith effort to secure for George R.R. Martin all the royalties that he is entitled to (which deliberately leaking GoT to torrent sites certainly would not be), then there isn't a court in the world that wouldn't consider HBO to be in breach of contract and return the TV rights to Martin.
- nelhage 11y agoWhy do we think the blur is sufficient? The blur loses information, but there are presumably a small number of watermarked versions, and a lot of frames. It's almost certainly possible for HBO to reverse-engineer the blur algorithm — I bet it's a stock option from a common tool — and then run it over all the originals and see which produces the best post-blur match.
- damon_c 11y agoHow about a scheme where some selection of 16 shots throughout either are or aren't missing a single frame? You could number 65k unique distributions that way and the overall length would rarely be affected by more than a frame or two. It could be implemented with a pretty easy python script.
- aamar 11y agoSpeaking as a former film/tv editor, one frame here or there can definitely affect the pacing and feel of a scene. Yes, sometimes external constraints—broadcast formats, licensing issues—can force compromises, but it's still an artistic decision where to cut a frame and where to keep one. Much better to adjust coloring slightly in central but low entropy parts of occasional, appropriate frames, sort of like Omron rings[1], but designed specifically to be visually inconspicuous while surviving encoding. The newish CineFence supposedly does something like this. In any case it wouldn't be hard to improve on the horrible Deluxe code.[2] [1] http://en.wikipedia.org/wiki/EURion_constellation http://en.wikipedia.org/wiki/EURion_constellation [2] http://en.wikipedia.org/wiki/Coded_Anti-Piracy http://en.wikipedia.org/wiki/Coded_Anti-Piracy
- zevyoura 11y agoNow I'm eagerly awaiting a colorist jumping into this conversation to tell us why that would be unacceptable. (Agreed that it's probably less of an issue to encode data in color than timing, but it just strikes me as funny how we've passed the buck from programmer > editor > colorist)
- Htsthbjig 11y agoOh man, this guy is a genius, just make each file different so it cost 10 times as much to make... It never ceases to amaze me how smart people consider their selves and how stupid consider the rest of the world are.
- salibhai 11y agoGenius!
- robertwalsh0 11y agoWas talking to my partner about this and she had a pretty clever take: "Seems like a simple idea would simply be to change just the spelling of one seemingly insignificant name near the end of each version of the credits and then by actually watching the credits you'd know the leaker straight away." "Of course, you'd leave the watermark on there so the leaker doesn't know how you caught them and thinks that the watermark is still the tracking mechanism."
- objclxt 11y agoThat's a mountweazel (better known as a fictitious entry) - reference books used to do it to trap people copying the text: http://en.wikipedia.org/wiki/Fictitious_entry http://en.wikipedia.org/wiki/Fictitious_entry
- ceejayoz 11y agoWith it changing to detect which person leaked, it's more a http://en.wikipedia.org/wiki/Canary_trap http://en.wikipedia.org/wiki/Canary_trap
- DanTheManPR 11y agoHilariously, that wikipedia page uses an example from Game of Thrones. Tyrion tells different versions of a rumor to the various members of the king's council and successfully identifies who is an informant for Cersei.
- alexsop2 11y agoOr a trap street, used to detect copying of maps. http://en.wikipedia.org/wiki/Trap_street http://en.wikipedia.org/wiki/Trap_street
- themoonbus 11y agoOr, just add an insignificant name (changing someone's name might run you afoul of contracts, even in a review copy).
- jawr 11y agoThere are audio watermarks on these leaked videos, and potentially other video watermarks that might not be visible at first sight. The watermark which has been blurred is a just a visual warning to the original receiver of the file to remind them that they have a special copy, it's not meant to act as a form of identification.
- krob 11y agoEveryone in her claims that there are mechanisms to add non-visual watermarks into both video & audio, anyone have any suggestions as to what products / systems to use so this can be implemented? Minus writing one yourself (like writing your own framework, you don't know all the gotcha's of an expert)
- TazeTSchnitzel 11y agoIt's not a very compression-resistant approach and more sophisticated methods are usually used, but a simple one is using the low bits of colour channels. In a red pixel you have bits like so: RED GREEN BLUE 11111111 00000000 00000000 A change in the most significant bit of any of these colours would be massive. 01111111 is half as bright as 11111111. But a change in the least significant bit(s) is barely noticeable. You probably wouldn't notice the difference between 11111111 and 11111110, especially as you don't experience individual colour channels, you see a blended colour. And when you're looking at something with thousands of pixels you simply won't spot it. So, stick your secret message in the low bits: RED GREEN BLUE 11111XXX 00000XXX 00000XXX You now get 9 bits of data per pixel. Or less (for a less noisy image) or more (for a more noisy image). For a 640x480 image, you now have 345.6KB of data. And if you use encrypted data, it won't even seem like data if someone looks (plausible deniability). Just noise. Techniques like this were used on 4chan to hide child porn in high-resolution photographs. This the "mods are asleep, post hi-res" meme.
- CHY872 11y agoYou don't get plausible deniability in any way. Turns out that the least significant bits of a pixel are not uniformly distributed. The obvious example of failure is that you expect more pixels with value 255 than 254, since any overexposure will be stuck at 255. The rest is obvious when you look at a histogram of pixel values; as the number of LSBs used increases you see the curve become stepped. LSB replacement steganography is easily detectable at about a ratio of about 0.01 bits per pixel. The smarter plan is to add or subtract 1 randomly (or do nothing) in order to match the LSB to what you want; this symmetry is harder to detect (but still very possible, the methods are just more complicated). The reason you encrypt the data is not just for data security, it is so that the embedder does not have to worry about the data that they are embedding screwing everything up. tl;dr LSB steganography does not give you any plausible deniability because it's really easy to detect in any type of image at very low embedding levels due to inherent limitations of the process. If you want to use it, you'd be safe with a single message at perhaps a level of 0.005 bits per pixel, but then in a ten megapixel image you'd get 150kB of data which hardly seems worth it when you have to transmit losslessly. Even then, you'd still be screwed at a theoretical level with Ker's square root law.
- exelius 11y agoOr there's another reason not to use a better tracking system: HBO is ok with leaks. The more the show gets leaked, the larger the audience. Some portion of that audience will pay for HBO, and hopefully stick around for the other HBO shows. HBO has been remarkably progressive on the piracy front. It's also only the first four episodes: enough to get you hooked enough to want to see the end. Of course, torrents are always an option, but at some point $15/mo is worth less than the hassle of downloading the show on a weekly basis.
- deleted 11y ago[deleted]
- dewitt 11y ago> HBO has been remarkably progressive on the piracy front. I'm not suggesting that's not accurate, but I'd love to better understand your sources for that, as my single point of anecdotal evidence suggests otherwise. About six or seven years ago we torrented a single episode of an HBO series (I forget which—we were cable-cutters and it wasn't available to rent online at the time) and while we knew it was wrong, it was convenient and it worked. However, we were surprised when, two days later, I received an email from Comcast saying HBO had reported that our IP address had pirated copyrighted material, and that if we did it again our service would be shut off and we'd possibly face civil charges. That actually shocked me into avoiding bittorrent altogether, which was undoubtedly their goal. Empty threats or not, I hardly walked away feeling that HBO was "remarkably progressive on the piracy front". Maybe things have changed? (Note, I'm not actually pro-piracy, since I do think that copyright holders deserve a right to monetize their work as they see fit, within bounds. I just wish more of them had a more sophisticated view on how to make their content more broadly and conveniently available.)
- exelius 11y agoThey're just empty threats to make you sign up for HBO service. I don't recall hearing of HBO ever going after anyone who just downloaded a torrent. They've said in the past that they accept some level of piracy as part of the business model; so long as people are watching their shows they will keep making money. It's not "sure, go ahead and pirate our shows!" but more of "People pirate our shows, so we look at piracy for trends to see what countries/audiences have a large, underserved viewer base for our shows." Some people pirate because shows are unavailable, so you can sell to them and make money. People who pirate because they're cheap and don't want to pay aren't HBO's target customers (and they probably don't have enough money to be worth suing anyway).
- NiekvdMaas 11y agoGoogle cache URL, since the GitHub page is down: http://webcache.googleusercontent.com/search?q=cache%3Ablog.frite-camembert.net%2Fgot-leak.html&oq=cache%3Ablog.frite-camembert.net%2Fgot-leak.html&aqs=chrome..69i57j69i58.3049j0j4&bmbp=0&sourceid=chrome-mobile&espv=2&ie=UTF-8 http://webcache.googleusercontent.com/search?q=cache%3Ablog....
- sxp 11y agoWhat happened to the site? http://blog.frite-camembert.net/got-leak.html http://blog.frite-camembert.net/got-leak.html Now shows a generic 404 and http://blog.frite-camembert.net/ http://blog.frite-camembert.net/ shows a github 404. Was the information DMCA'd?
- TazeTSchnitzel 11y agoStill works for me. Also, the author seems to know nothing of steganography so HBO haven't had anything of consequence discovered by them.
- bru 11y agoIt's hosted on github pages and I inadvertently deleted the CNAME file when updating the post: https://github.com/brunal/brunal.github.io/commit/89fd81f93dd80d8ba2cea7fee4d345ce3d103129 https://github.com/brunal/brunal.github.io/commit/89fd81f93d... It took me ~20 minutes to realize it was gone, you probably tried to hit the page during that time frame.
- JacobEdelman 11y agoAll of these systems are security by obscurity. Just suggesting them on a blog ruins them. Watermarking is not truly possible with current technology, which means you can't give someone something without given them control over it. Is that such a bad thing?
- bithush 11y agoI am surprised things such as Cinavia[1] isn't more widely used for tracking. It is designed to cut off the audio after 20 minutes which you see on a PS3 with many Bluray Disc rips released on torrents. For that to work obviously you need the player to implement the feature but this isn't about disabling playback but simply tracking a leak. Just tweak it audio on each early release copy and you are good to go. The really interesting thing about Cinavia is that it survives even an audio transcode/re-encode so even converting 5.1 DTS to MP3 or similar won't kill it. It is extremely robust in that sense. [1] http://en.wikipedia.org/wiki/Cinavia http://en.wikipedia.org/wiki/Cinavia
- felixgallo 11y agoFor at least the last 20 years, there are steganographic watermark systems in which inocuous parts of the images are used to hide coded data that stands up to even most lossy recompression. Either HBO is using these and nobody knows yet; or they had an internal leak prior to their application; or they leaked it themselves. Under no plausible circumstances did they visibly watermark a corner and hope for the best.
- cbhl 11y agoI wouldn't be surprised if they leaked it themselves so they'd have download numbers that they could use to evaluate the success of HBO Now (their over-the-top offering).
- minthd 11y agoIt seems that HBO gave copies of the four episodes screeners(?) to much more companies than previous years and this what's led to the leak. So since HBO is interested in leaking , i don't think it cares that much about protection. And in any case - this won't hurt their subscription numbers - if you've wanted to watch the show, you've already subscribed to the first month and it's too late to cancel.
- glomph 11y agoI think they watermark a corner to clue the person receiving it in on the fact that it is watermarked.
- jewel 11y agoI looked into stenography for a client who had a problem with audio being leaked by the users of his service. Even though there is a lot less signal in audio, it was trivial to encode a 32-bit pattern throughout the audio track in such a way that it was not discernible to his well-trained ears, and yet it would survive being encoded as a 64kbps MP3. We also checked pushing it through an analog loop, since that was most likely how his tracks were being pirated. The pattern would repeat throughout the song (I think once per minute) such that only a small sample was necessary to recover the pattern. It also had enough check bits that it was impossible to get the wrong code; either you'd get back the right code or nothing. This was all done with COTS software (a command-line executable) that could be licensed for a few hundred dollars. My client ultimately decided not to add stenography. He believed that his users would be upset with the possibility that there was some quality loss due to the process, as they were paying a lot of money to have high-definition tracks. He thought the losses from the discovery that he was applying stenography would exceed the ongoing loss from piracy.
- mattjjh 11y agoThe chances of this leak not being steganographically watermarked are close to zero. The visible watermark is added as well as the invisible watermark just for the purposes of deterring screenshots.
- wslh 11y agoThere are similar approaches for software. See "Advanced Security Now" [1]. [1] - http://arxiv.org/abs/1006.2356 http://arxiv.org/abs/1006.2356
- plorg 11y agoEven with a blurred watermark, the mark itself could be enough to pinpoint a source. At least if the watermark disappears and reappears several times in a video you could use the timestamps of its appearance and disappearance to indicate who was responsible for a leak.
- forrestthewoods 11y agoThis is a stupid blog post. There are two goals: 1) Prevent copies from being leaked 2) Trace leaks if they happen Watermarks are actually great for the first goal. They are big, ugly, and obvious. This discourages people from leaking. If they do leak it's crystal clear they're taking a huge risk. This is also why the DVD screener is low-res SD. HBO already tracked down where the leak came from. Whatever methods they have in place to do so were successful. Thus any complains about watermarks being ineffective at goal #2 are irrelevant.
- bru 11y agoThat you for that "typical HN comment". >This is a stupid blog post. Have you seen the topic discussed on the Internet? I looked for it and I haven't, so I simply started it. Given the score of the submission and the number of comments, that goal is reached. I learned a lot from other comments and I'm happy. > HBO already tracked down where the leak came from. Source?
- forrestthewoods 11y agoNormally I'm the one complaining about typical HN comments. However given the blog post was titled "Game of Thrones leak and watermark: a stupid tracking system" I felt that leading with "This is a stupid blog post" to be a fair and amusing twist. “Sadly, it seems the leaked four episodes of the upcoming season of Game of Thrones originated from within a group approved by HBO to receive them,” the spokesperson said. “We’re actively assessing how this breach occurred.” http://www.buzzfeed.com/jaimieetkin/game-of-thrones-season-5-leaked-online http://www.buzzfeed.com/jaimieetkin/game-of-thrones-season-5... They've at least narrowed the leak down to be from inside HBO. They may not have it down to an individual just yet. Their internal process may need some work.
- bru 11y agoAh, I feel dumb for not catching it. It is fair indeed. About the article: that's not what I understand... > a group approved by HBO to receive [the episodes] What I understand is that the leak did not come from HBO but from one of their service providers or journalists or anything like that. Am I missing something?
- alanh 11y agoDoes all the math littering this post add anything? "Add a few ms variation to each each scene" seems extremely self-explanatory, and so does the concept that only a few bits per scene are needed to produce a meaningful number of variations.
- deckar01 11y agoAs much as I enjoy using summations liberally, a simple visualization of the spacing between frames would have been more useful.
- bru 11y agoAuthor here. I can easily use summations, but I'm definitely incompetent when it comes to making a visualization! And as per your parent's remark, most math is there "for fun" as written in the article.
- AshleysBrain 11y agoA smart protection system would be: 1) use stenography or some other subtle process to watermark content 2) put a big obvious decoy watermark in the corner Leaker chuckles to themselves thinking what a dumb publisher this is, masks out #2 and releases it. Publisher immediately identifies them by #1.
- baddox 11y agoPeople seem to be ignoring one obvious solution: don't send out copies of the first four episodes of what is arguably the biggest and most-pirated show in the world. I get it, there are apparently still these "print publications" out there that need time to "print" their reviews. How important is that really, in 2015, for Game of Thrones? I doubt that a few reviews in pop culture magazines are worth more to HBO than preserving the desired experienced of weekly viewing. Or maybe it's a trial run for HBO to gauge what viewers think of binge watching.
- RobertoG 11y agoI am curious about if somebody with access to two copies can just compare them and blur the stenographic watermark.
- AlyssaRowan 11y ago>The case of a leaker getting her hands on 2 copies is however highly unlikely. I'm not so sure about that. Some groups used to have a general practice of always getting at least two distinct copies from a supplier to avoid burning sources. And I doubt they just averaged either, but detected discrepancies and manually eliminated potential areas of interest. A few releases of cracked software were even actually compiled afresh from source, or were object code before a wrapper protection was added. Some suppliers were developers themselves, who weren't always seeing eye-to-eye with their publishers. Of course, perhaps the 'race' to be first has all but eliminated this from modern practice. I couldn't say.
- deleted 11y ago[deleted]
- shmerl 11y agoInstead of wasting efforts on DRM and watermarking, they can avoid handing out copies until release time. But in practice they probably benefit from leaks, it keeps the buzz. About the futility of so called "social DRM", see also http://www.publishersweekly.com/pw/by-topic/columns-and-blogs/cory-doctorow/article/50413-with-a-little-help-digital-lysenkoism.html http://www.publishersweekly.com/pw/by-topic/columns-and-blog...
- waspleg 11y agoThe website says his method of randomly changing the length of the credits is a step in the right direction. I think that's completely wrong. https://www.techdirt.com/articles/20130808/02084524106/time-warner-ceo-says-having-game-thrones-as-most-pirated-is-better-than-emmy.shtml https://www.techdirt.com/articles/20130808/02084524106/time-... "Our experience is that it leads to more paying subs. I think you're right that Game of Thrones is the most pirated show in the world," he said. "That's better than an Emmy." - Time Warner CEO Jeff Bewkes THAT is a step in the right direction.
- pyvpx 11y agoas a child of the early oughts, having the CEO of Time Warner extol about having the most pirated show in the world -- not to mention explicitly stating it leads to more subscribers -- is almost jaw dropping.
- bradleyjg 11y agoEven if you decide that you are okay with some leaks, you still want to know which employees / partners / journalists you can't trust.
- allemagne 11y agoI think he meant it's a step in the right direction towards solving the technical problem of identifying who leaked the material. More generally he could have meant that tracking the leak is a step in the right direction towards HBO having control over when their material is released. Even in a fantasy world where all entertainment is free I think artists should have control over releasing their own work. In any case, I'm curious as to what the endgame is in the right direction you mentioned.
- towelguy 11y agoIt makes sense to add the watermark as a low-hanging-fruit tracking system so the leaker simply stops at blurring it and doesn't look further.
- fleitz 11y agoIt's easily defeated for the same reason that netflix's geolocation stuff is easy to bypass. The entire point of the scheme is more subs, not not pirating GoT.
- speakeron 11y agoThe only thing that needed to be done when distributing the review copies was to ensure that they were 1080p Blu-ray instead of SD DVD. This would have ensured even more global jonesing to see the 5th episode after after the cliff-hanger in the 4th. Apart from that, mission accomplished.
- nissehulth 11y agoHBO spins this into a marketing activity. Every news outlet seem to report about this leak. Remember some year ago, some HBO executive said that GoT was the most pirated show in the world and that it was better than getting an Emmy. Not saying that HBO did leak the episodes, but they do benefit from all the free marketing...
- ryanlol 11y agoAuthor is plain wrong here. The big visible watermark is there for the psychological effect, not to trace the leaks. There's always a plenty of hidden ones. (Missing frames etc) HBO will definitely know who they sent the episodes to, but that doesn't necessarily mean they know who leaked them.
- devindotcom 11y agoyeah I thought this was the case too. no one in the industry, let alone the people distributing one of the most popular and leak-sensitive shows of all time, is going to rely on just a logo in the corner.
- anigbrowl 11y agoNext iteration would be changing the length of each scene by a few milliseconds. One can count that the first episode holds s=18 scenes. Each scene lasts several minutes. Once again each copy can be made shorter or longer by a couple milliseconds, providing a unique fingerprint for each version sent. This sort of thing makes it hard for me to take any of the article seriously. The author doesn't seem to know the first thing about either video formats or the authorial role of editing. Things are cut on particular frames for a reason. Also, editors don't deal in milliseconds, they deal in frames. Sound editors work in frames and samples, and while I have no objection to steganography-type adjustments to the final output, the idea of monkeying around with the content of the film, even on the margins, for tracking purposes tells me that the writer shouldn't be allowed anywhere near a post-production facility, for the same reason that most programmers don't want an art director telling them how totheir code would look prettier in a fancy font and in a more earth-toned color scheme. Honestly, I think HBO is quite well aware of this srot fo thing already, and the 4 episodes were leaked to hook people on the rest of the series. There's already a lot of digital distribution technology involving rock-solid encryption, single-use keys, check ins and outs, and so on. Tweaking things like the length of the end credits (or rather the black frames at the end) are potentially viable but also trivially obvious to any editor. But monkeying with the program material is strictly out of bounds.
- iron_ball 11y agoAnyone who was going to get hooked on Game of Thrones is hooked, and anyone who is still on the fence isn't likely to torrent the leaked episodes. Incompetence is a better explanation, I think.
- InclinedPlane 11y agoI think that statement is really rather silly. It's a bit like saying "anyone who is going to drink coke is already drinking coke". There's a ring of truth to it, but it still falls flat. Edit: a few things: arguments based on the behavior of "the majority" and arguments founded on the principle that 100% of all people who have ever been Game of Thrones viewers are completely and utterly committed to viewing every single season are rather weak. Viewership of shows changes from season to season. More so, not every TV show viewer is the sort of person who must start a series from the beginning. Pulling in folks who are caught up on Game of Thrones but haven't been hooked on the current season and pulling in folks who will begin mid stream (and then maybe go back and watch from the beginning, or not) adds to their viewership. More viewers means more purchases, more purchases means more dollars. Not to mention the value of retaining their existing viewership base. These are all the same reasons why coke continues to dump massive amounts of dollars into advertising despite already being well known and having a huge chunk of the soft drink marketshare. In fact, the returns on investment for advertising already popular products tends to be higher than for products just entering the market, because the numbers are so big. There are millions of Game of Thrones fans. If even a few hundred thousand existing fans who might have held off on watching the new season are kept on the hook and if even a few hundred thousand non-watchers gain interest in the show via starting with the new season and if only a small fraction of those folks end up purchasing the discs, or HBO (in whatever form) then that's a considerable amount of money in HBO's pocket that would have been left on the table. Which isn't saying it wasn't an accident, but business wise this is still a win for HBO.
- ianstallings 11y agoYeah they forgot. Just like a crack dealer conveniently forgets to charge for the first hit.
- OSButler 11y agoThis is just a wild guess, but the visible watermark could be the result of a legal issue. Having hidden tracking elements in such videos could require disclosing them, whereas a visible watermark could be used to argue that the viewer is aware of the video being marked and therefore other included tracking elements do not need to be specifically named. It has the potential side-effect of the watermark getting blurred out by the leaker, but leaving other tracking pieces intact.
- greggarious 11y agoYou're confusing eavesdropping law with tracking in general. (You're probably thinking of the one party vs two party consent issue: https://en.wikipedia.org/wiki/Telephone_recording_laws https://en.wikipedia.org/wiki/Telephone_recording_laws) If I were to somehow create a Game of Thrones video file that "phones home", yes that would need to be disclosed. If I want to add an invisible watermark to a video file and note who got the video with that watermark, that is legal.
- jarxg 11y agoThis person has no idea of how video production and editing works.
- djyaz1200 11y agoDigimarc solved this.
- iamleppert 11y agoI despise people who use formal equations to explain otherwise simple concepts.
- whelden 11y agoNothing based on time is as simple as this article implies. When movies are ripped, they tend to have slight adjustments in playback speed as a side effect, and not necessarily at a constant rate; it can result in a total language change of a couple seconds. Any playback type analysis needs to be based on frames.
- whelden 11y agoNothing based on time is as simple as this article implies. When movies are ripped, they tend to have slight adjustments in playback speed as a side effect, and not necessarily at a constant rate; it can result in a total language change of a couple seconds. Any playback type analysis needs to be based on frames.
- sanp 11y agoIn the "Scenes Length" section - Should it not be n = k^s and not n = s^k?
- kahoon 11y agoI think the same! It is k choices per scene for s scenes.
- amelius 11y agoPerhaps the author should have a look here: [1] and note that transmitting a message over the air in an undetectable way, and embedding a watermark are roughly the same thing. [1] http://en.wikipedia.org/wiki/Spread_spectrum http://en.wikipedia.org/wiki/Spread_spectrum
- sln 11y agoWhat a terrible post. Every single example is simply security through obscurity. Once a leaker understands the ways in which a file may be watermarked, they will likely be able to circumvent it. An example of a watermarking method that does not fall apart when people know what to look for would make a very good article. This is not that article.
- sln 11y agoWhat a terrible post. Every single example is simply security through obscurity. Once a leaker understands the ways in which a file may be watermarked, they will likely be able to circumvent it. An example of a watermarking method that does not fall apart when people know what to look for would make a very good article. This is not that article.
- sln 11y agoWhat a terrible post. Every single example is simply security through obscurity. Once a leaker understands the ways in which a file may be watermarked, they will likely be able to circumvent it. An example of a watermarking method that does not fall apart when people know what to look for would make a very good article. This is not that article.
- monkeymolester 11y agoThe problem with least significat bit approaches mentioned by others is that they don't survive through re-encoding very well. A much better way of watermarking IMHO would be to add features (could be patterns, even images or text) in Fourier space- imperceptible if done correctly, and guaranteed to survive through encodings.
- warrenmiller 11y agoThreres a dash that flashes during playback for a while, they may have a different flashing/timing sequence for each reviewer...
- Lerc 11y agoIt's crazy to muck around with timing, When things are quantised to frames you have very little scope for change without it being very noticeable. There are a heap of image based ways to encode data. Kerning on the credits, Position of titling. Minor brightness colour tweaks. The thing that springs to mind the most. THERE'S A FULLSCREEN WHITE NOISE EFFECT AT THE START OF THE SHOW. You could stick whatever you want in there.
- smegel 11y agoWhat a load of blogspam. Its like it was written by a kid who didn't bother researching any of the effective copy tracking systems that already exist.
- circuitslave 11y agoI scanned these comments and didn't see any mention of it - I used to work for a company - http://www.teletrax.tv/ http://www.teletrax.tv/ - that used Philips made hardware to encode video watermarks that were not easily detectable. We would then use detector hardware in the top (n) markets of the US and "detect" whenever some channel broadcast a watermarked piece of video. This was usually used to enforce things like Sony licensing you to show a movie of theirs (n) times over a given period of time. There's competitors in that space as well like Nielsen, etc. I am sure HBO is using more than just a visible watermark to track their content.
- jheriko 11y agothere is a lot of assumption here... maybe they have tracked it down already? even so it could have been stolen from the original intended recipient.