
Blizzard is secretly watermarking WOW screenshots - mike_esspe
http://www.ownedcore.com/forums/world-of-warcraft/world-of-warcraft-general/375573-looking-inside-your-screenshots.html
======
citricsquid
Some speculation in the thread about whether or not it's JPG artifacts, but if
you make it to the 2nd page (post #21) someone included some information
proving it's intentional: [http://www.ownedcore.com/forums/world-of-
warcraft/world-of-w...](http://www.ownedcore.com/forums/world-of-
warcraft/world-of-warcraft-general/375573-looking-inside-your-
screenshots-2.html#post2489452)

Edit: Page 6 includes confirmation from a (supposed) Blizzard representative
that this is for NDA leak tracking: [http://www.ownedcore.com/forums/world-of-
warcraft/world-of-w...](http://www.ownedcore.com/forums/world-of-
warcraft/world-of-warcraft-general/375573-looking-inside-your-
screenshots-6.html#post2493282)

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sabalaba
One reason Blizzard would do this is to combat RMT + selling your account to a
third party. All they would need to do is set up a crawler on eBay or any
other website where somebody has posted a screenshot of their account for
sale, then dole out a warning / suspension / ban.

~~~
revenz
One reason nefarious people would use this is to gain verified account name
information. Get enough of those and there are bound to be some passwords that
are easily brute forced.

Furthermore as the article states blizzard could use this to track private
servers.

~~~
Contero
What I don't understand is why the screenshot would contain your literal realm
id, and not a hash that only Blizzard could understand.

As long as Blizzard is the only party that can glean meaningful information
from these watermarks I see no problem with it.

~~~
ef4
A hash isn't really the right construct for that purpose. If Blizzard just
produced a salted hash of user_id & realm, it would be pretty expensive for
them to reverse it, even given possession of a complete list of user ids and
realms. If they didn't salt it, they could keep one big "rainbow table", but
then again so could anyone else.

What you'd really want is encryption. If you chose symmetric encryption, the
key would be in every client (easy to steal). If you chose asymmetric
encryption, the message would suddenly get much, much bigger to the point
where it's harder to reliably encode in a screenshot.

~~~
shenberg
The data wouldn't get much bigger - a 2048-bit RSA key requires the output to
be at least a 256-byte block, roughly 3 times as much data as the current
watermark has, not some insane amount of data. The watermark is repeated many
many times in the image anyway, so it seems like the trade-off could be made
between less copies of the watermark and more data in it.

~~~
makomk
Current speculation is that most of the 88 bytes of data in the existing
watermark is an error-correcting code that hasn't been reverse-engineered yet,
so in practice it has less actual non-redundant data than that.

------
ChuckMcM
We'll add this one to copier watermarks, printer watermarks, and fax machine
watermarks.

So your account id and realm is available as a watermark in the screen shots,
what nefarious problem does that cause? (I can imagine it helps identify
griefers and people who cheat and brag)

~~~
RHSeeger
I'd be concerned for lots of random people that take screenshots and post them
online, making public their account ids. Probably not a huge deal, but it's
more information that they're giving out that they don't need to be.

The people under NDAs, hackers, and griefers are going to know about this now
and just turn them off. Which means the only people negatively impacted by it
are the innocents.

~~~
ChuckMcM
Well it will be interesting if they go the other way, and try to 'spoof' it
which is to say get someone banned by posting a screen shot of some bad
behavior that points back to them.

My understanding (and it may be incorrect) that the character name and realm
is embedded not the battlenet account id. so something Blizzard could turn
into an identity but 'regular' users could not.

------
zwdr
The only problem here is that Blizzard didnt encrypt the information in the
screenshots. I can understand why they would embed this info, and 9/10 of
those cases are ethically sound, but I wouldnt want some random skiddies get
this information.

So why wouldnt they encrypt it? Not enough space?

~~~
TazeTSchnitzel
Um, this is done client-side, no? How would they protect the encryption key?

~~~
judofyr
Public/private key-pair. It wouldn't stop people from faking values, but at
least only Blizzard can read them.

~~~
ef4
They don't really have enough bits here for asymmetric crypto.

How many bits are they able to reliably recover from the screenshot,
especially if they want to survive simple downsampling? I would guess not more
than 500, probably less than that given the patterns we're seeing.

You can't generate a ciphertext smaller than your key size. And 500 bits is
really not enough to do typical asymmetric crypto safely.

~~~
gsibble
"The pattern, which consists of approximately 88 bytes of data..."

Actually seems like more than enough room to be encrypted. They probably just
didn't think of it.

------
nitrogen
I'm growing increasingly tired of technology being used by the large to
monitor the small. I'd like to see an RFS from YC for companies that use data
mining, machine learning, etc. to the advantage of the individual.

~~~
stcredzero
I have a project for DRM for the masses. (will also use watermarking)

~~~
nitrogen
A tangentially related idea that might be interesting: adding a mechanism as
easy as Bump for transferring public keys between users, then automatically
encrypting all communication between them. It'd be great for business; meet
people at a conference, then easily communicate with them without worrying
about MITM industrial espionage.

~~~
tankbot
Love this idea. Surprising that it hasn't been done yet, has it?

~~~
mike-cardwell
Sounds like "STEED", which was announced about 11 months ago by the author of
GnuPG: <http://www.gossamer-threads.com/lists/gnupg/users/56053>

Although I'm not aware of any implementations yet.

~~~
tankbot
I've seen this pop up a few times on HN now, seems a good candidate for this
type of setup.

Tomorrow on HN: "Hi, we're Stump! It's like Bump for messaging but with the
encryption of STEED!"

------
kibwen
_'in order to avoid any further watermarking, type: /console SET
screenshotQuality "10" which will set the quality of your screenshots to the
maximum and create screenshots that do not include the watermark.'_

If this was nefarious, I doubt they would give you such an easy way to disable
it. Though I am curious what the default value of screenshotQuality is.

In any case, steganography remains awesome, as ever:

<http://en.wikipedia.org/wiki/Steganography>

~~~
chaud
The default setting is 3.

~~~
dexter313
Beat me to it...

Some links that confirm this

<http://www.wowhead.com/help=screenshots-tips-tricks>
<http://us.battle.net/wow/en/forum/topic/3759356695>

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cousin_it
So it looks like Glyph Lefkowitz's "extremist" opinion on software ethics
<http://glyf.livejournal.com/46589.html> was completely right. When a program
does something the user doesn't want, the programmer is in the wrong.
Programmer is to user as lawyer is to client. We need a recognized and binding
way for programmers to submit to this code of ethics.

~~~
phazmatis
Your premise is flawed. Programmer is to user as refrigerator manufacturer is
to user. If the fridge fails and your food goes bad, caveat emptor. If you
have a problem with that, nobody is stopping you from writing your own code.

~~~
yk
I assume you build your own refrigerator, just in case GE did include some
wiretapping device in theirs?

A programmer has much more possibilities to include malicious code than a
refrigerator engineer, simply because a program can have an almost arbitrary
complexity while a fridge can not. Furthermore we see in programs today a
spectra of shady behavior which ranges from user did not notice the obvious (
Facebook assumes private data is public) to outright fraud ( banking trojans).
So the due diligence for users can not be too completely reverse engineer any
program they use, but that programmers have a responsibility too create
reasonably surprise free software.

~~~
phazmatis
I don't think we can agree on philosophy. But how can we punish those who
misrepresent what their software does, when a large portion of the software
out there was released anonymously? At least, if software developers were held
responsible for malicious code in their products, software that could not be
traced back to a developer would be easierto create than software created by a
company, which would likely need more developers to review code, and insurance
to cover possible lawsuits.

~~~
cousin_it
Commercial software is copyrighted and sold by companies. Open source software
comes with copyrights and licenses. What anonymous software are you thinking
of? Viruses or something?

~~~
phazmatis
TOR maybe.

------
ericcholis
Being a former player, I can think of some _good_ uses for this technology.

1) Automatically attaching image galleries to the Armory* profile of
characters based on account id

2) Easy to give credit to players providing screenshots for Blizzard run
contests

3) Opens the Armory API a bit more

Obviously, these can all be exploited due to the "openness" of the screenshot
format.

*For the WoW illiterate: The Armory is a public database of player's characters, items, achievements, etc...

~~~
phazmatis
Yeah except they can be faked.

------
hcarvalhoalves
Clever, although I believe it's unethical.

It starts like this. How far from the day companies do this with the images
you take with your mobile, with the videos you stream, etc.? The world will
turn into a DRM fest.

~~~
fmax30
something like this can be used to track down someone who does bootleg
recordings. Say our bootlegger buys a camera from samsung, samsung uses a
water mark like this which gives out a unique device id. The bootlegger who
doesn't know about this tracking thing uploads his 1080p raw video. MPAA then
collaborates with samsung to find out was the bootlegger(although that would
involve tracking the sale from the reseller/distributer and
contacting/capturing the bootlegger).I just gave MPAA a really nice idea.

~~~
theevocater
Actually, imagine how much worse this could be: person on youtube posts
(bootlegged | police harassment) video under one account, family video under
another: bam they have you.

------
debacle
Very interesting technology. Would be cool to see this put to good use. It's a
lot easier to get someone to post a screenshot than it is to get them to email
a dump.

~~~
mattdeboard
Isn't this just steganography? I'm quite sure organizations of all flavors and
kinds are putting it to good use as we speak :)

~~~
pydave
Spore saved its creatures in their portrait pictures:
[http://nedbatchelder.com/blog/200806/spore_creature_creator_...](http://nedbatchelder.com/blog/200806/spore_creature_creator_and_steganography.html)

------
rtkwe
I don't see the huge issue here. There's no real private information given by
this, it's just character name and realm.

~~~
teamonkey
A minor point: the character name is not included, the account ID is. I don't
think the account ID is that helpful for any prospective hacker, but this
method might allow you to compare two screenshots and confirm that they were
taken by the same person.

------
yen223
Why would Blizzard want to watermark their own screenshots?

~~~
pavel_lishin
A couple of hypotheses, off the top of my head.

1\. NDAs - if someone's in a closed beta, and starts posting screenshots, they
can quickly identify the culprit.

2\. Hacks - if someone anonymously boasts about finding some exploit in the
game, and shows screenshots, they can be tracked down.

3\. Abuse prevention - if someone posts screenshots of themselves abusing
another player, or breaking the TOS in some other way - but with names blurred
out - it would still be possible to find out who it was.

~~~
cube13
Also:

If a user emails support, and their email address is not directly traceable to
their login(for example, if they use firstlast@gmail.com for battle.net
instead of first.last@gmail.com as the sending email), it allows support to
add that to the ticket.

~~~
chaud
There is no direct email address for support. You must log in with your
Battle.net account and file a support ticket.

------
markszcz
Curious question here: If you take the screenshot you get from WOW and open it
up with photoshop/gimp/paint and save it now as PNG or different format, would
it be possible to degrade the quality of the dots rendering it useless to be
tracked?

~~~
shawnz
PNG is a lossless format and will not cause the image data to change
whatsoever upon saving. JPEG, on the other hand, is a lossy format, but until
more is known, it's impossible to say whether or not this secret data (if
that's what it really is) happens to be muddled by the lossyness of JPEG's
algorithm.

~~~
markszcz
Thanks. You got me thinking in the right direction and I found a Wiki page
that talked about image formats and if they are lossy or lossless.

<http://en.wikipedia.org/wiki/Image_file_formats>

I found it interesting and wanted to share.

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andrewljohnson
Secretly seems a little strong... is there any sort of effort to cover this
up, or did they just not mention it in the patch?

I don't fault them for not mentioning it in release notes - if I make a change
to my apps that the user won't notice, I don't mention it in the release
notes.

To the extent that they introduced a security bug, they should admit it and
fix it. But that's a technical lapse, not a moral lapse.

------
makmanalp
I can see this being partially helpful when verifying that in-game screenshots
have not been tampered with (for example. for support, when you claim you had
an item and it disappeared etc), but I don't know if there are that many
copies of it duped across the image.

~~~
chaud
There are a significant amount of logs for things like that. Screenshots are
likely never accepted for that kind of request.

------
jc4p
Is it just on my machine or does every single part of that web page start off
a Amazon referral pop-up to Mists of Pandaria on click?

------
lostlogin
He give instructions on how to find the watermark. Am I missing what you mean?

------
talloaktrees
Not sure whether to be upset about this or proud of the technical achievement

------
mike-cardwell
Textbook example of why proprietary software is bad for users.

------
zdouglas
I find the title inflammatory and ignorant; I would downvote this if I could.

While I applaud the tenacity in prospecting and divulging the methods at which
Blizzard has employed to create such "tracking" "watermarks," I highly doubt
this is to discourage or indict anyone. Quite frequently, screenshots are used
during support requests.

As the author states, "we [...] verified that there is no pattern included in
high quality screenshots." I find this highly suggestive that Blizzard was
rather interested in an easier way to debug their program, and the mode
slipped out in production.

There's a work around, please remove your tinfoil hats.

~~~
pavel_lishin
I'm not sure if the title was changed, but it currently reads "Blizzard is
secretly watermarking WOW screenshots", which seems accurate enough to me.

~~~
zdouglas
I was mainly referring to the implication by omission that Blizzard had
nefarious intent with its watermarking. Though, my comment was itself
inflammatory; karma's a jerk.

~~~
ghshephard
The title, as currently, written, "Blizzard is secretly watermarking WOW
screenshots" is pretty generic (and entirely accurate - They are watermarking
WOW screenshots, and it is being done secretly).

I'm curious as to what your title would have been:

"Blizzard watermarking WOW screenshots?" - This is less informative, but
removes the word "secretly?"

------
p_sherman
All speculation, guess work, no external sources, no reproducible results.

Paranoid stoners is my guess.

